Page last changed November 28, 2000

Spotlight on handlebars

Broken handlebars

Victim's accounts

• Clive Page, Aug 1997:
  My handlebars broke a couple of years ago, and I got them replaced free under the warranty by Messrs Brompton - and I noticed that the replacement tube has a strengthening piece around it in the centre. [...] Fortunately not hurt at all, just a little startled. It broke when I had almost come to rest at a junction, and one half just tore away near the centre as I came to rest. I wondered at the time what would have happenned if it had given way when I was going fast down a nearby hill, when I commonly brake from around 50 kph.
  The difference in the replacement tube is that there is an outer tube around the main tube exactly 50 mm long at the centre where it fits in the top of the steering post. The original just had a single aluminium tube expanded at that point to fit the hole in the steering post. I suspect that I'm not the only one to have had the same thing happen, since the design changed. But that's the trouble with aluminium - it does suffer from metal fatigue. I'm glad the main frame of the Brompton is made of sterner stuff. [...] No problems since, thought the bars still flex a bit in use.
• Phil Gough, Aug 1997:
  As I have mentioned before my T5 is about nine years old, so this correspondence has me anxiously exmamining the handlebars, clamps and brazings for anything that might be the beginnings of a crack. There was a dealer recall some years ago (over 6 probably) for a reinforcing bar to be clamped across the U of the handlebars to reduce flexing. My recollection is that there were in the early production period two types of handlebar material, one shiny and the other satin type of finish and it was the former that were suspected of failure. I didn,t fit the kit to my bike as it had the satin finish and there are no signs of cracks at the moment. I am pleased to be a 137lb weakling, keeps the stresses on the bike low.
• David Henshaw, Aug 97:
  A most interesting debate gentlemen. The early Brompton handlebars (satin with expanded centre) were relatively reliable, but as someone said, aluminium has a tendency to fatigue failure, so one or two broke - always near the centre.
  The next bars were the chunky 15/16-inch polished alloy items with a ferrule in the middle. These were better, but with a rare tendency to fail either side of the ferrule - having said that, mine have lasted in excess of 12,000 miles without problems and so have the vast majority.
  In Mid 1995 Brompton began to use the bars fitted to far-Eastern Bromptons produced under licence by Neobike. These more conventional 7/8-inch bars (satin finish once again, with a raised centre section), were found to have a better fatigue life than both the previous designs. They are not to everyone's tastes however, being rather higher than the earlier types, which leads people to fit quick-releases to give a lower sportier riding position.
  Two tips here - a quick-release is not recommended, because moving the bars leaves tiny scores in a very highly stressed area that can lead to failure. A quick-release will invalidate Brompton's warranty. Secondly, it really is important to treat these rather tall, fragile handlebars with respect - you simply cannot haul on them as you would MTB bars, because they will eventually fail if you do.
  If that all sounds rather daunting, Brompton have seen very very few failures of the earlier bars and none at all of the post-1995 pattern to my knowledge. If anyone is nervous about their elderly bars snapping, just order the new pattern - they're only 8 pounds or so plus VAT in the UK. If you want lower bars, there are plenty of examples right down to straight MTB bars that will fit and give a lower position and a more solid feel. But as Len 'Folding Bike' Rubin rightly says, the Brompton bars are designed to give a degree of suspension - clever stuff. You'll just have to order his titanium jobs.
• Andrew Brooks, Sep 1997:
  Talk of the devil... my handlebars have just failed.
  Pulling away from traffic lights the right hand bar suddenly felt rubbery. Disconcertingly I couldn't actually see anything wrong - no sign of cracks on or off the 'neutral axis' - but they were definitely about to go. After an extremely gentle, one handed ride home a good tug on the bar tore it nearly clean off. The failure started on the underside of the bar right where the knurling starts about 2mm inside the clamp, which is why I couldn't see anything.
  The bars have a satin finish with the tube widening out where it goes through the clamp. Is this the new type or the old, I lost track in the previous string? If they're the new type I don't fancy replacing the bars with the same thing, since they've failed after only about 2500 miles and I don't think I treat the bike particularly roughly. Nevertheless I guess I need something stronger that what I had.
• Andras Toth, Jun 1998:
  I bought my L3 Brompton in November 1997 and have been using it extensively ever since.
  I weigh 67 kg and I have always payed special attention to not exercising excessive power on the handlebar when starting out at green lights. I always switch back to second gear when I have to stop so that getting the bike move again is smoother and less forceful. The last time I had to stand up on the pedals because of the steepness of a slope was more than a month ago. I never have to do that on my daily trips here in Paris. What I have to admit doing is standing up on the pedals (when they are in horizontal position) in order to get my head higher so that I can see what is going on when my bicycle is at a stop in a traffic jam. I did it a lot at the monthly bicycle demonstration last Saturday, too. But on the whole I have the impression that I have not been too rude with the handlebar until now, especially after I read in the Brompton FAQ the messages of the Australian guy who got into trouble with his handlebar breaking.
  Just about an hour ago, when starting out at a green light the left half of my handlebar was detached at the stem and I almost fell under the cars accelerating beside me (in fact, if I had been standing on the pedals, I would have almost certainly fallen, but as always, I did not have to get up from the saddle to gain speed). The bar broke where it is fastened to the stem.
• Stein Somers, Jun 1998:
  My Brompton's handlebars broke, weeks after an accident that presumably caused the frame to break as well, so the accident seems a likely contributor. The situation in which they broke off, while starting out, wasn't scary. Still it sure didn't leave time to react, and could have been very scary, unlike frame, wheel and crank failures and whatever else I had.
  The handlebars are 2mm Alumimium. Every little reflector bracket I made in less than 3mm Aluminium, broke over a month of so under its own weight.
• Roland Elsenberg, Jun 1998:
  On my old Brompton the diameter of the handlebars seems to be constant over the whole length. They are fitted into a small aluminium tube which is mounted into the stem. On my new one the middle part of the handlebars has a bigger diameter than the rest. Which is better? I always wonder how the aluminium survives being brought into the shape of the Brompton's handlebar. The problem of suddenly breaking handlebars is an issue every now and then in German papers and it is certainly not more common with Bromptons than with other bikes. I also would prefer handlebars made from steel, as the seatpost (or the longer part of the telescopic seatpost) luckily is.
• David Henshaw - A2B magazine, Jun 98:
  For all it's worth, and I've probably said this before more than once: I bought my Brompton in late 1992 and it's still going strong. I've ridden 13,000 miles and replaced only chains, tyres, tubes and sprockets. My bike has been off-road many times. It has climbed mountains, been thrown across ravines, been hammered across London and many other big cities... I've also raced several times at CycleFest and elsewhere, and Richard Grigsby holds the unofficial Brompton speed record on my bike, naturally.
  I weigh 80kg and I ride the bike hard at times. I stand on the pedals, do wheelies at city traffic lights, and generally abuse it. Yet my early Brompton still has it's original rear triangle and handlebars... both supposedly frail.
  Now, I might just be a very lucky individual, but knowing the folk at the factory pretty well, I know that they get very few returned broken parts, except for a few rims, but that's another story.
  To read this list, you'd get the impression Bromptons are incapable of wobbling more than a few miles between major rebuilds. It's not a toy, it's a bloody sturdy little machine.
• David Hansen, Aug 1998:
  I've just been added to the list of those with a broken handlebar.
  Fortunately I was just starting off from traffic lights when the left hand bit came adrift just where it joins the steering tube. Studying the fracture it happened suddenly.
  The bike is now being fixed, under the warranty. The shop said they had not seen one recently, following a spate before the design was changed to the sort I have. The bits will be going back to Brompton.
• Andrew Brooks, Sep 1998:
  It's happened again, just a year and a half since I broke the last set of bars. Exactly the same place - the break started at the knurling which is just under the clamp, so it's impossible to see it before it happens catastrophically. I'm 175 lb so not unusually heavy, and since the first incident I've gone easy with the bike. Admittedly the bars have lasted 6 months longer than the first set but I still don't reckon it's acceptable - it isn't safe, for me anyway. Brompton should supply at least an option of some steel bars.
• David Henshaw - A to B, Sep 98:
  I'm one of the satisfied customers. My 1991 Brompton has now passed 15,000 miles with the original bars intact and looking like new. I too weigh 175lbs and I have never deliberately been kind to the bars, although I am probably sympathetic. I find two failures quite inexplicable.
• Willi Mindak, Jan 99:
  My name can finally be added to the list of people with broken handlebars. It happened without warning while I was doing about 20 mph on a cyclepath. My riding became a bit wobbly (more than usual) as a result of that, but nothing spectacular happened apart from me being thoroughly annoyed.
  I post this as a warning to fellow Bromptoneers who like me thought that the problem with weak handlebars was all but solved. Apart from a few freak occurrences, the new style handlebar with the thick middle piece was thought to quite safe. And these few occurrences were limited to handlebars which were used beyond the 5000 mile limit, when the handbook recommends replacement anyway.
  My bike is from August 97. I don't know the exact mileage, because I fitted a cycle computer only in October 97. It is safe to state, however, that it has done under 3000 miles. I was quite aware that there could be a problem, and examined the handlebar frequently. I concentrated on the area around the central clamp, but could find nothing remotely suspicious. Even though I follow this list, it appears that I didn't know what I was looking for.
  When it did break it did so on the left hand side about 5 cm from the clamp, at the point where the upward bend just starts. The break followed a hairline 'scratch' I had discovered during my examinations, but had dismissed as a normal wear and tear. It was less than 1 cm long, thin as a human hair, and looked just like a minor scratch. Ignore these at your peril ! Lessons to be learnt:
  a) The new style handlebar can break on Bromptons with less than 5000 miles 'on the clock'.
  b) It doesn't always happen when pulling away from standstill.
  c) The bar can break anywhere on its entire length, and not only around the central clamp.
  d) A telltale sign is a very thin black line appearing on the bar, easily confused with a scratch. Whatever you do: do NOT ignore !
• Custfold, Jan 1999:
  As posted many many months ago and reported in The Folder - my bars snapped in 1992 IIRC after I'd observed a possible crack along the face of the curve which eventually reached the end and migrated across - the process took around 6 months of observation during which I pondered on when and how it would fail.
• Richard Partridge, May 1999:
  A cautionary tale: the problem persits. The bars on my [barely] four month old T5 have just been replaced under warranty after bending/breaking away in my hands while commuting to work. Fortunately it was a quiet street and I was able to keep control.
  Bars broke just left of the steering column clamp in a way that suggests a pulling stress. Close inspection showed some kind of machining or manufacture line on the bar either side of the fatter clamp section and the break followed this.
  Brompton replaced bar within a week with no quibble - new bar seems to be of a slightly heavier guage aluminium and there are no manufacture marks. Feedback via dealer [Freewheel in Nottingham - helpful people :-) ] was that Brompton have changed supplier.
  Bike has barely done 600 miles. Though I'm 6' 2", 12 stone and a brisk rider, I'm no out-of-the-seat pumper - I don't consider my riding style in any way extreme. The only contributing factor I can think of are the profusion of traffic humps in my area. Even so, extremely disappointing performance for a machine of this age and mileage.
• John Carss, Feb 2000:
  My handlebars broke last month after 4 years of use. I mentioned the fact to the mechanic who fixed it, that I'd heard that it was a common fault. He told me that the handle bar spec has now changed and there is a different number printed into the new spec bars (the number I've forgotten I think it was 9) and that they have been asked to contact Brompton if any of the new spec handlebars fail. So far he has not seen any.
• Jeff Dauvin, Jun 2000:
  My handlebars failed a couple of weeks ago. Via my dealer the part was replaced free. The discusssion they had with Brompton indicated a problem with a batch which they thought they had withdrawn - but mine slipped through.
  They knew exactly where the fracture occured & what I was doing at the time when they snapped (ie pulling a way). The new ones look(!) a better product.
• Stein Somers, Jun 2000:
  I replaced mine as a precaution after a good year of use and to my surprise the new one was even thinner, 1.8mm against 2mm. But I bought it a year ago.

Theories

• David Edge, Jun 1998:
  I'm surprised that you managed to break a bar so quickly; I'm a 100kg gorilla and it took me two years, pulling on the handles to get up hills.
  I agree that cycle components are in general insufficiently reliable and durable; it is the penalty of reducing the weight for human power. Suggest you inspect the bars at six monthly intervals until your confidence returns; at least the penalty of Brompton bars breaking is less than on a drop-bar machine. I don't think that Brompton equipment is any more or less fit for purpose than the great mass of stuff out there - but it is very alarming when critical components fail.
• Leonard Rubin, Jun 1998:
  Those who are familiar with my work realize that I just have to weigh in (wince) on this issue. For those unfamiliar with my background: I worked as a professional bike mechanic for nearly twenty years, including long stints at some prestigious racing shops, and a few of my own. I then served as technical editor (and major contributor) as well as tech. support person for Sutherland's Handbook For Bicycle Mechanics for many years. I now design, manufacture and sell custom, high-end folding bicycles and upgrade kits for the Brompton.
  A few years ago I was offered the U.S. West Coast distribution for Birdy. I declined. It wasn't because I didn't like the Birdy's ride (I did), nor was it because I didn't like the Birdy's clever suspension (I did), nor was it that I didn't think they'd sell well (I thought they might indeed). It wasn't even the fact that, compared with the Brompton, they seemed large and awkward when folded -- better suited to car trunks (boots) or long range travel than the rushed, crowded and space-constrained world of gritty urban public transit.
  It was that they were made of aluminum! I don't like aluminum very much. While it's true that, when massively over-engineered, aluminum frames and components can last their "intended lifetimes", many fail prematurely at the highest- stressed points, especially if compromised by surface scrapes or gouges, which often arise on a soft material daily subjected to the variety of hostile micro-environments (luggage racks, other bikes, etc.) encountered during inter-modal transit commuting.
  While it's also true that aluminum is relatively inexpensive, compared to other lightweight materials, such as carbon fiber or Titanium, the true "cost" is often much, much higher. Its fatigue memory and propensity for catastrophic failure, (owing, in part, to aluminum's extreme sensitivity to stress-risers, such as surface scratches and common grain imperfections) makes it very unreliable in applications where regular inspection and replacement are not routine. We have seen that even in such applications (civil aviation) the risks are still not unsubstantial!
  In a highly stressed, highly leveraged application such as the long, curvy Brompton handlebar, it would be natural to expect some failures in a large population. The problem is that a catastrophic failure of a handlebar can be extremely dangerous. The only solutions are to:
  1. Make the bar using much more costly alloys and production techniques, or
  2. Make it considerably thicker and heavier, or
  3. Make it out of a different material, like one of the high-strength-alloy steels or Titanium
  Those of you who know me already know which one I favor.
  I have, in fact, designed a nice replacement bar in Ti, with a lower rise, more hand room on the grips (to accomodate our twist-grip shifters) and slightly different angles, and will soon get around to actually making some. While the most cynical amongst you might think that, therefore, this missive is entirely self-serving, I am merely proceeding because I don't trust aluminum in the long run (despite positive anecdotes) and steel is too heavy for my taste. Of course if some of you will be interested in purchasing one of these lovely items, (once I have completed testing and certification) I will, as usual, not have any fundamental objection.
• Willi Mindak, Feb 99:
  I now believe that this fairly common failure is due to a design flaw. I scanned a German catalogue recently, and under handlebars it says: ".....aluminium handlebars should not be combined with steel stems because of the increased risk of breakage." Anyway, examine your handlebar carefully. The early signs are easy to miss.
• Peter Hubbard, Feb 1999:
  Excuse me chipping in - I'm much more familiar with Land Rovers than Bromptons. A well-known cause of corrosion in LRs is uninsulated contact between steel and aluminium. Somebody please correct me but I believe that with moisture present galvanic(?) corrosion of the aluminium is quite fast.

The different faces of Aluminium (scientific)

• Andrew Henry, Feb 100:
  Its because Aluminium doesn't like to flex back and forth. Frame designers get around this by using large diameter aluminium tubes. These are stiffer, and so reduce the flexing, which makes the aluminium last longer. Large diameter tubes would be heavy, but if you make the walls of the tubing thinner, then you can keep the weight low enough. The problem is then that the tubes dent easily, like a coke can.
  In contrast if you bend steel back and forth, then so long as you don't bend it too far, then it will bend elastically (so it goes back to its original shape). You can bend steel like this for an infinite number of times. If you have a steel tube, of the same dimensions as an aluminium one, then it will have exactly the same stiffness, but will be quite a bit heavier.
  To come to Bromptons:
  The handlebars are made from aluminium for the light weight. If you made them from steel, then they either would be much heavier, or you would need to use narrower tubes. These would be more flexible. Having aluminium handlebars does mean that they _will_ break eventually. Hopefully, Andrew Ritchie has done his sums right, and this won't happen in the lifetime of a typical Brompton for many years.
  Aluminium rims are much better than steel ones. Spoked wheels are wonderfully designed so that the rim is evenly stressed, so it doesn't flex much. The wear from the brake blocks means that most aluminium rims die when the sidewalls wear through before they fail from fatigue. The other advantage of aluminium rims is that they are a better surface for the brake blocks to work on.
• Custfold, Feb 2000:
  To which I would add that steel has a much better grain structure with carbon interstices - which make excellet crack stoppers.
  Pure aluminium is rarely used for any components most is aluminium alloy - largely with copper in an eutectic mix which can be influenced by heat treatment to segregate the copper to harden the alloy. Howver the material is very fluid (in theoretical terms solids are just very dense gases which we find it difficult to pass through - but electrons being smaller have no difficulty at all and larger discontinuities move through at Gaia's pace.
  Thus aluminim alloy components have a major flaw in the brutal world of bike riding. If there is a notch on a highly stressed piece of material the end of the crack will seek to find a way of relieving its stress. This is commonly done by the crack propogating through the material until it reaches a point where it is either releived or it is stopped by the effort of growing being greater than the effort to stay put. Drilling a round hole at the end of a visible crack does this in many instances. Sadly it is all to easy for the crack to move through the alloy - hence the cracks in alloy 'bars regularly start where the bars have been scratched or scribed at the clamp
  Wheel rims of course are generally polished free of cracks, although I did suffer soem differential stress corrosion of a sakae eyletted rim which had radial cracks from each spoke hole eventually reaching over 60% of section and the wheel exploded into many pieces when the bike dropped off a step.
• Mark Maier, Feb 2000:
  

  To which I would add that steel has a much better grain structure with carbon interstices - which make excellet crack stoppers.

  Depends VERY much on the type of steel you are looking at. Carbon content in steels can vary over a wide range. And cracks definitely do not stop at interstitial atoms in the crystal lattice. You need something larger than an atom in order to stop a crack.
  

  Pure aluminium is rarely used for any components most is aluminium alloy - largely with copper in an eutectic mix

  
  And Mg. However, the Cu contents in those alloys are far below the eutectic concentration. In fact, they usually are even below the minimum Cu content to form any eutectic microstructure. We are in the range of the Al-rich solid solution, which, cooled below a certain temperature (between approx. 520 and 200 deg C, depending on Cu- content), will become metastable and eventually form precipitates of other, more stable phases.
  

  which can be influenced by heat treatment to segregate the copper to harden the alloy.

  
  What you get is the precipitation of metastable delta particles (three types, at three different temperatures, and depending on the cooling rate), the grain boundaries of which are either incoherent (delta), semicoherent (delta') or incoherent (delta") to the host (Al) lattice. Because of this coherency mismatch, those particles can slow down the movement of dislocations (responsible for the plastic deformation of an alloy) and thereby harden the material. A specialty of Al-alloys is that certain precipitation hardening 'treatments' do not involve annealing at elevated temperatures but can be carried out at room temperature (in fact, you just wait a while).
  

  Thus aluminim alloy components have a major flaw in the brutal world of bike riding. If there is a notch on a highly stressed piece of material the end of the crack will seek to find a way of relieving its stress.

  
  This is true for any material, even for ceramics. Cracks always start at a point of locally increased stress. A notch is such a point, as is a scratch.
  Andrew almost gets to the point:
  

  It's because Aluminium doesn't like to flex back and forth.

  
  The key word is FATIGUE. Here, steels are by far better than Al and its alloys. Secondly, crack propagation in steel is much slower than in Al. You can ride a cracked steel frame for many miles until it finally breaks. A cracked Al frame can be dead within seconds.
  Reason is that Al-alloys usually are precipitation hardened, as I described above. Fatigue will eventually destroy those hardening particles (cut into pieces by moving dislocations), until the hardening effect is gone. At a certain point the weakened material cannot withstand the applied stress anymore, a crack will form at a point of locally increase stress, and it will propagate very fast. The alloy breaks.
  

  In contrast if you bend steel back and forth, then so long as you don't bend it too far, then it will bend elastically (so it goes back to its original shape).

  
  Al-alloys can also be bent elastically. Every material can. I have seen ceramic tapes that could be coiled up around a pencil.
  

  You can bend steel like this for an infinite number of times.

  
  As long as you stay below the characteristic stress amplitude. Materials with the crystal structure of Al do not have such a threshold so they will always break, eventually.
  Sorry folks, for the digression, but this is part of my job...

Cures

• Be prepared: Preventing problems - taking care of your Brompton - Check the handlebars
• Get a new handlebar from Brompton or elsewhere (Spotlight on handlebars - Alternative handlebars)
• Add a crossbar or bracing bar:
  • Custfold, Aug 1997:
    Additional to Dave Horne's piece, IIRC the B did for a while have a brace across the handlebars (a la BMX) when an early version proved weak and snapped, after a relatively short fatigue cycle, under heavy use. Useful check point - if a thin dark line appears on your 'bars along the neutral axis then ditch the bars - this is a crack, which will fail catastrophically when it reaches the lower bend, and will leave you with tiller steering and a hand held brake lever. The current bars are about the 3rd style I've noted, and now omit the shim, with a full diameter centre section in the clamp. Anyone else offer historical notes?
    Other steering related change was the increased diameter of head tube, and steerer tube from 1" to 1.25" which means that early bikes need a different luggage block, and headset bearings. Similarly, around 1991 the rear triangle design was changed to reflect the weakness of the joint between the r/h chainstay, and pivot plate, which can fail through heavy cycling between compressive and tensile loading under severe use, and later main frames have a neater design of joint between the brace and main tube, to deal with high stresses at the joint, and I would guess these changes also make production simpler.
  • Doug Faunt, Jun 1998:
    All this talk about collapsing handle bars brings to mind my thought that an add-on reinforcement/accessory bar to go across the "gap" in the bars might be a good idea. It would greatly reduce the stress on the standard bars, and give a place to mount a reasonable battery-operated headlight and a computer. My bars are pretty full now, with a bell, and bar ends.
  • Stein Somers, Aug 1998:
    I've recently purchased something I think is called crossbar. It clamps onto and firmly links both upper curbs of the handle bar. It boosted the feel of the brompton tremendously: no more squishy handling but the solid steering of "grown-up" bikes.
    This should also stretch the life of the handle bar. At the risk of getting either physics or English or both wrong, here I go. The forces on either end of the handle bar are originally independently countered by straight forces and a force momentum at both sides of the root. The force momentum manifests itself as a scale of large push and pull forces accross the small diameter of the handlebar tube, causing a noticable flex. The crossbar spreads the force momentum as straight forces over both sides, much further apart than the width of the tube, thereby greatly reducing the forces induced by the momentum. It moves the weak spot towards the stem which is not aluminium but stronger (I sure hope PML isn't reading this...)
    However it occupies valuable real estate on the handlebars and requires an open mind towards the position of gear and sound controllers. On the other hand it creates space for mounting lights or panniers, although the tube is much thinner than the handle bar itself so creativity is stimulated even more. I made my own bracket to fit the front light.
  • Roland Elsenberg, Aug 1998:
    I believe in your theory as long as the forces on both sides of the handlebars go into the same direction, as should be the case when hitting a pothole. The effect of the crossbar should be much less when the force on the left side is upward while that on the right side is downward or vice versa. A similar movement on the handlebars comes from exercising great forces on the cranks, especially when the rider lifts from the saddle.
    Perhaps a combination of using the crossbar, reduced gearing and a sensitive way of riding is the best we can do until we get handlebars from steel, carbon or glassfiber. I too distrust aluminium on parts having alternating loads. This is one of the major points in favour of Brompton: We have to worry only about the handlebars. Breaking handlebars are not only a problem with Brompton. Gazelle recommend in their leaflets to replace handlebars from aluminium when a bike has fallen and prohibit to put seats for children on them. A professor at a German University tested bicycles and handlebars (not Brompton) with desastrous results.
  • Thorsten Rentel, Aug 1998:
    The crossbar is manufactured by Humpert in Germany for their downhill bars. It's not adjustable. We ordered it because it looked as if it would fit and luckily it did. It should be widely available in Germany.
    Robert, if your LBS can't find it, the wholesaler who stocks them is Hartje. They also took over distribution of Sachs parts in Germany now, so every LBS should know them. I case yours doesn't, contact me and I provide you with the details.
    Anyone else interested in such a device should ask for downhill-crossbars at their LBS. They come in all shapes and sizes. Even if you can't get the Humpert one, there's a big chance that another manufacturers product fits the Brompton.
  • Rob Cope, Sep 1998:
    Handlebars: I worry that putting a brace across just transfers the stresses and breakpoints elsewhere, probably either end of the brace. I presume it would invalidate the guarantee? The slight springing effect of the bar shape is crucial, given the lack of front suspension. The bars are very strong, but they are there for steering, not (as in most cumbersomes) to bear any appreciable proportion of the rider's weight. Honking up hills while pulling hard at the bars is not recommended.
    • Stein Somers, Sep 1998:
      I agree that stiffer doesn't mean stronger, but I think the next weak spot is the stem, and I hope that if that fails it won't fail so abruptly as the handlebar did.
      The "braced" Brompton still flexes forward-backward as much as before.
      But the handlebars must cope with all the push while braking! On the other hand, the broken handlebars reported here always occurred while starting off so indeed it's the pulling that kills them.
  • Thorsten Rentel, Sep 1998:
    The X-tasy crossbar [...] is now available via mail-order.
    It is made of 'AL6061' aluminium, weighs in at just under 100g and comes in silver. To install it, grips, brake levers and shift lever have to be removed. Do NOT try to bend the clamps open! They are aluminium and you might damage them.
    You can order by e-mail or phone quoting your credit card number (we accept Visa, Diners Club and Master Card) and expiry date. You can also send cash (sorry, no change given ;) or a eurocheque together with your address (don't forget to put your cheque card number on the back and sign again). The cheques can be written in US dollars or British pounds but we would prefer Belgian francs. Cash will be accepted in any European currency and US dollars. Credit card owners will always be charged in Belgian francs (sorry about that, but this is required by the credit card companies).
    Prices for the crossbar and p&p are as follows:
    

    X-tasy crossbar	BP7.95	USD13.50	BEF450
    p&p (Europe, normal carriage)	BP2.50	USD 4.50	BEF145
    p&p (Europe, express carriage)	BP6.50	USD11.00	BEF370
    p&p (Overseas, normal carriage only)	BP3.00	USD 5.50	BEF170

    
    Please note that normal carriage within Europe can take up to 7 days, express up to 3. Oversea shipping times can vary depending on the destination. We always try to send on the day of your order (exception: weekends ;).

    Velodroom rue Van Artevelde straat 41 B-1000 Brussels Tel/Fax (32)2/5138199 velodroom@hotmail.com

  • Ian R. Platt, Sep 1998:
    I also fitted a handlebar brace. There were several slightly different lengths available in different colours. I got the shortest one (also the lightest and near aluminum looking) by eyeing up the length (quite a whizz that you can take your bike up in the lift to 2F and into the shop to try this, eh?). Model MT152, designed by 'club ROOST (Calif), but made in Taiwan, 'Impact control Gofast brace for GOFAST bars only - not for resale'(!), it features 'an impact elastomer bumper' (plastic liners between the cross brace member and the clamps through wich the fastening bolt goes 'to permit...the bumper to function properly'. The label says it must be fitte on Hardcore XL/XT models of their bars. The black labelling sands off reasonably well.
    Forgetting the hype, it proved to be just doable without removing the brake levers (fortunately). A slight repositioning of the gear changer was needed, but less than I feared - just tilted it a bit more over the front. If you _do_ fit a cross bar, you need to be very careful it doesn't foul the wheel axle locking nut when the things folded or the tittie on the stearing tube won't go in the clamp to hold the bars folded. I _did_ have to turn the nut 20 degrees so the bar cleared it! A close thing.
    An extra bonus is that it makes folding and expecially _unfolding_ the bike even easier as there is something to grab at waist-height, over the longitudinal centre line, and you don't have to even bend over or try to balance the thing from one end of the h/bar. A _good_ thing, I suspect. Cost: £12.50, equivalent
  • David Dodson, Sep 1998:
    Perhaps a burr on the inside of the edge of the steel(?) clamp can press a stress-raising grove into the alloy handlebar, even on replacing the bars?

Alternative handlebars

• Simon Shearn, Aug 1997:
  I replaced the standard Brompton bars with some aluminium mountain bike handlebars (an old Italmanubri model) shortly after getting my T3. My main aim was to improve aerodynamics - I'm about 1.7 metres tall so the shape of the standard bars resulted in an execessively upright riding position.
  Apart from the improved riding position, the new bars are a lot stiffer than the standard ones, but slightly heavier. There is now much less flex in the combined handlebar/stem assembly, which makes the bike nicer to ride. I'm not sure if fitting stiffer bars is likely to place greater stresses on the handlebar clamp of the stem, but I haven't had any problems so far.
• Custfold, Aug 1997:
  I have fitted 2 alternative replacement steel handlebars to the Brompton
  One is currently in production, and the other is a high rise Chopper type. Raleigh Chopper steel bas, slightly cut down, which give around 4" extra rise. Both have suffered from being too stiff, and trasferring the forces absorbed by flex in the OEM [original Brompton] bars to the clamp which is only mild steel, and thin for weight reduction. This results in making it very difficult to keep the bars tight, and I have had one set brazed in place. Once we have sorted out how to ensure that
  1) the bars don't move (many heavy/tall riders can move the existing alloy bar a bit too easily when pulling hard, or braking.
  2) stopping this belling out of the clamp and consequent impossible to tighten situation.
  Ideally with no need to modify the steering tube unit.
  [...] [Despite the extra rise, folding is] not too much of a problem, and it adds a new method of parking the bike by putting the bars down and making a support point from the bar end. You can then sit on the main frame at a slight angle, and use the seatpost as a back-rest, it looks very casual and laid back. (The bend of the bars, fits into the wheel inside the rim, so the sticking out is reduced slightly, a bit like the AVC stubbie specials, which fit over the outside of the front tyre when folded.)
• Leonard Rubin, Aug 97:
  I am working on a Titanium replacement handlebar. It will be very light and absurdly strong, though not any stiffer probably, as I rather like some shock absorbtion on unsuspended front ends (especially with a 16" wheel! One of my goals is to achieve a better riding posture, which in my case means rotating the bars forward quite a bit. I have designed the first model with angles to assure that the "flats" are properly oriented at that bar rotation. If others would be interested in a high-end (not cheap, as I do not like aluminum in this application, and steel is too heavy for my taste) bar, let me know what you want and I will contemplate making more than one model, depending on interest.
• Mike Hessey, Jul 1999:
  [...] description of the bars on the SP [...] in Folding Society News and the web pages. Since they use a seat pillar for the sprung mounting, the height can be adjusted by quite a bit. [...] at the LOWEST position they are about an inch lower than standard Brompton bars. I have not investigated the highest position, as it is not of interest to someone who is unashamed of being short, but I would GUESS that they would go at least an inch higher than the standard bars.
• Custfold, Jul 1999:
  I have used what I am told are Raleigh Chopper bars on the 2-speed hydraulic braked trailer towing Brompton, these give about 60-70mm extra height to the bars and as a bonus will just touch the ground when folded flat to the front wheel and steering turned slightly, this allows me to sit on the main frame tube and rest my back against the seatpost in a resonably comfortable manner. The front bag also stays on as (when not too heavily loaded) the trailer does also.
  I'd love to source a regular supply, BUT as a caveat on fitting a steel bar (and there is a design which will substitute at about the same height as B originals) the Brompton clamp is weak and uses a central bolt - with my weighjt and leverage I have frequently had the alloy bars rotate on severe braking or impact with a road defect - potentially very dangerous. The stiffness of the steel will 'bell out' the clamp and my solution is to cut off the 1 bolt and get 2 seat pillar clamp sets brazed at either end, making the clamp stiffer and the grip much stronger.
  There is actually yet another, but brutal option - chop off the brompton clamp and cut just enough off the steerer tube to fit a BMX/MTB oversize clamp unit - the offset (c.10cm) are 'fairly cheap' but the ideal would be the close fitting (<5cm). Then you have a huge choice and perhaps even a suspension stem option, although the offset on these tends to be too excessive to allow folding neatly Stein has pics of the 7 speed (which has this arrangement). Two things happen - the stem can allow higher setting of clamp position, and you can choose appropriate bars.
• Custfold, Feb 2000:
  Options
  1. fit steel bars (some almost direct swaps) As steel is stiffer it will then bell out the thin section which is used to make the clamp and leave all held by the ridge of the central bolt. Not Clever - it rocks and rotates (as the Brompton bars do with heavier riders under severe braking even when assumed to be tight)
  2. fit 2 bolt clamp (seatpost bolt lugs) to handlebar clamp
  3. cut off existing clamp and fit short reach/0mm reach 4 bolt clamp for BMX bars into steerer tube.
• Mike Hessey, Apr 2000:
  It's not really front suspension, but Steve Parry has fitted a suspension seatpost into the stem to carry the handlebars. It gives much improved insulation from the road, makes the handlebar assembly stiffer (ie it does not bend when you pull on the bars) and also gives some adjustement to handlebar height. Details are in the SP section of the Folding Society web pages (http://www.foldsoc.co.uk ). Steve produces this modification as part of his SP bicycles (which are built from Bromptons). Kinetics do something similar as a kit which can be retrofitted to an existing Brompton (http://www.kinetics.org.uk )

Rotating the handlebars

• Leonard Rubin:
  I successfully fitted a high-quality, special quick-release to the stem, which allows the bars to be rotated to any position for riding, while simultaneously allowing them to be rotated back again for folding. I customarily ride with them rotated forward at a 45-degree angle, and sometimes at nearly 180-degrees! I leave the brake levers just a tad loose, so I can rotate them to match (I use Kooka hydraulic levers, but this would work with many others). In months (and many hundreds of miles) of riding, I haven't had any problems. I haven't tried other quick releases, but it would be essential to use only the highest quality, well-matched design. This would have a cam action (lever travel and tightening/clamping force) that is optimal for that application, as well as robust, properly-sized and surface-mated washers. Besides sufficient strength, appropriate geometry and good fit, it would need to not stick out too far, as that would increase the chance (albeit quite slight) of something catching on it and opening it inadvertantly, or interfering with the folding of the bike (also unlikely). We have found and sell just such an item. It is custom made for us, and is, like all the other upgrades we sell, well-designed, beautiful and light.

Bar ends

• Winton Evans:
  For me the fitting of bar-ends transformed the bike's comfort on journeys above 100 metres. We used 'Trans X', a sort of turquoise blue at about £12 per pair, and cut a different length off each. They are now about 4 inches and 4.5 inches to the centre of the bars. The left-hand one does sit on the ground when folded and gets a little scratched but so what, and the right hand one is positioned so that it just has to be pushed past the tyre to complete the folding process and thus assists the catch that prevents the folded bike opening up.
• Channell Wasson, Jan 1998:
  I use Newk clamp on drop bar ends. Several styles available. One gets many riding positions from this accessory. I remove them quickly when folding. Good for longer rides. See their one inch ad in "Bicycling" magazine, or contact Newk Bike Products 17452 Revello Dr. Pacific Palisades CA 90272 tel. 310 230 2725 Fax 310 230 2625
• Rob Cope, Aug 1998:
  Avon Valley Cycles Stubbies/ Super Stubbies: reviewed last in A2B 5: mentioned in Avon Valley ads in most issues. These wedge neatly either side of front wheel when folded. £19.95-£23.95 in UK.
• Ka Lun Tam, Feb 2000:
  I attached barends to my Brompton too, although I simply purchased regular bar ends. It took a little while to figure out how to angle the handlebars and bar ends so that it would still fold properly, but I did manage to do it. I had to move the brake levers in a little, and cut short the grips, but I got a satisfactory ride out of it after the fact.
  I should probably mention I'd replaced the handlebars with a set which didn't have quite as much rise as the originals, but they were shaped pretty much the same otherwise so I don't think it played a factor.
• Stein Somers, Feb 2000:
  I have had long bar ends which inserted into the handlebars, rather than clamp around as some do, but still needed to move the accesories inwards.

Handgrips

• Rob Cope, Aug 1998:
  Yup, [Biogrips] are handgrips. Made by Alfred Hartmann in Germany (got from 1994-5 Encycleopedia: sorry no contact details). They're rubber so v durable: mine are 4 years old & have outlasted 2 sets of handlebars. I used to go through a set of Grab ons (real ones, not copies) a season. The design supposedly forces your wrist into the optimum position relative to the bars, reducing stress & improving bloodflow. All I know is I don't get numb palms anymore. The chunky design absorbs some of the front end clatter, but down side is your brakes levers feel spongier.
  Only supplier I know of in UK is Cyclecare Olympia (0171 602 9757 tel/fax): mentioned in latest A to B advert, also short review in A2B 5. Last price quoted £19.95.
• john blackburn, Feb 1999:
  I can't claim to be disabled but I seem to be developing a muscle problem in my hands; they are very painful after a long ride. I sat and looked at the handle bars, and the position of my hands when riding normally, and I noticed that, when I reached for the brake levers, I gripped them very near the pivot, giving very poor leverage.
  I moved the levers to a new position on the bars, inwards towards the centre of the bar. When using the brakes, I now get better leverage. The improvement is very noticeable.
• O'Reilly, Peter, Feb 1999:
  It may be worth considering trying out a pair of bicycling gloves. (They contain padding on the palm side of the hand).

Twist-grip or other gear changer for the 5 speed hub

• VELODROOM, May 1999:
  The twist-grip shifter is very good but doesn't fit the Brompton handlebar if you have medium-sized or bigger hands :( The Orion is a product we sometimes install if customers explicitly demand it. I personally do not like it very much because it is a rather cheapo plastic part. Especially the installation of the outer cable needs attention. Make shure you place one of those metal caps (right size is of the essence) on the end. Shifters always have been a problem with Sturmey Archer, apart from the old three gear metal one.
• Chris Newport, Feb 2000:
  Perhaps worth making the point that, as delivered from the factory, the shifter is not necessarily optimally positioned.
  The first thing I did was to change the angle the shifter sits at on the handlebar so I can now operate it with a flick of my thumb. This improved operating comfort significantly.
  I hope Mr.Ritchie never falls for those nasty gripshifts. IMO the rapidfire is the peak of shifting technology. The gripshift is a fashion accessory originally designed to make small boys think they're riding a motorbike.
• VELODROOM -- urban mobility concepts, Feb 2000:
  Never liked the original 5-speed shifter myself and changed it on many occassions (we mostly sell 5-speed Bromptons) for a Sturmey-Archer made gripshift called HSJ-875 (see under http://www.sturmey-archer.com/p29.htm) with great success. Ease of use and ergonomy are greatly improved. Recoommended for the conversion is a change of brake levers. We recommend the rather cheap (495BEF or 12,27EURO) yet cherful Tektro RBP-366A (Stein uses them and is quite satisfied IIRC) as they give you enough space on the handlebar to use the gripshift even with the biggest of hands.
  BTW: The rapidfire enthuiasm of some people might come to an end when it comes to a repair. Ever tried to repair your wristwatch? Well, then look forward to it. I personally prefer the concept of simple, maintenance-friendly and robust gripshifts (whatever the brand).

Stem (steering column) failure

• Channell Wasson:
  As there has been recent discussion of use of aluminium on the Brompton with reference to safety precautions in the owner's manual, the following quote from Section J in the current owner's manual may be useful in thinking about recent postings: Brompton Owners Manual (current a/o 9/96) Section J Paragraph 5. "Aluminium frame components: as on other lightweight machines, aluminim alloy is used in the construction of the Brompton, and this material has a finite life before failure. In normal use, the risk of aluminium fatigue failure on the Brompton is extremely remote, even after many tens of thousands of miles. However, with a combination of high mileage, hard riding or other severe loading, the possibility of failure during the lifetime of the machine, whilst still small, increases. As such failure could cause injury, we recommend, as a minimum, regular checks of the hinge clamp plates and the handlebar, or better, replacement of these items every 10,000 miles."
• Stein Somers:
  In my manual (october 1996) it's down to section K and 5,000 miles. Note there's no mention of the stem, which is said to be made of Reynolds 531 alloyed steel.
• Custfold:
  [...] Back to the broken 'stem' which I take to actually mean broken handlebar. I experienced this with my 1989 bike, on early production units (frame c.2500) and there is an indication of failure well before any disaster. The bars had a mysterious line appear along the neutral axis of the bends at the bottom. This I observed with interest until one day the left hand half of the bars came off with a fracture across from this line to the outer diameter at the stress point where the bars are clamped up, and the alloy was slightly notched. New bars are bothe more substantial and treated differently in the design of clamp and bending I observe. Meantime the caveat is aluminium alloy has little resistance to crack propogation, which is easily encouraged by creating scores and notches in hicghly stressed areas. Beware I did MatSci for my degree (20 years ago).

  I knew my handlebars were cracking well before they went (a case of the cobbler's weans!), and wondered if the evidence revealed the tell tale shiny fracture faces of a long term progressive cracking, and perhaps a notch/stress raiser. I believe my experience in pushing the loading of the handlebar clamp by fitting higher handlebars has not lead to the predicted fracture risk - in discussing the overload with Brompton - of the weld at the connection with the steering stem, but instead worked the mild steel into a larger diameter and looser fit, showing some interesting aspects of the design capacity for abuse.

The Brompton Folding Bicycle FAQ