Page last changed August 3, 2003

Maintenance at home

• Spotlight on tyres - Tyre pressure
• Spotlight on brakes - Replacing the brake cable (old models)
• Spotlight on brakes - Do the 'toe in'
• Spotlight on the (hub) gears - Adjusting Sturmey Archer hub gears
• Spotlight on wheels (rims, spokes and hubs) - Building a (small) wheel
• Transporting (more) luggage with a Brompton - Front bag jumping off: front carrier block maintenance
• Spotlight on the chain - When to replace the chain?
• Spotlight on the chain - Chain lubrificants

Removing a wheel

1. Undo the gear cable at the adjuster - if you do this by slackening the knurled lock nut by the very tiniest amount then you shouldn't lose track of the gear adjustment when you put it back together.
2. Pull off the black plastic bit with the pulley.
3. Undo the first wheelnut you find; this will allow you to remove the piece of bent metal which holds the thing referred to in (2) and also the chain tensioner.
4. Undo the wheelnut now exposed and the one on the other side - the wheel can now be removed. It is not necessary to unscrew or remove the bit of chain dangling from the hub as long as you are careful not to catch it on anything while mending the puncture.

1. That the support washers either side of wheel slide all the way into the fork slots and are flat against them.
2. The bit of bent metal that holds the plastic pulley thingy has its tab aligned with the direction the gear cable must go.

Rear wheel removal

• Willi Mindak, Mar 99:
  Rear wheel removal? In under one minute on my T5. It's a case of *not* reading the manual, because it will only frigthen you. Disconnect the gear selection cable, remove the wheelnuts and you're there. It's dead simple. The re- fitting of the wheel is a bit more involved due to gear selection cable adjustment. Here you should read the fine manual. A lot was made recently out of the necessity to adjust hub gears once in a blue moon. I have a puncture at least once a month, and the adjustment takes care of itself when re-fitting the wheel.
• Richard Lighton, Mar 1999:
  My first (only one so far) puncture was detected 300 yards from home, so I wheeled the Brompton back and went to work by car that day. I'm very glad it wasn't a couple of miles from home, as it took me rather a long time to sort out everything. MAKE SURE THAT LITTLE WASHER DOESN'T GET DISPLACED from the slot that holds the rear wheel.
  When I put Primos on the bike, everything went MUCH faster.
  In short, the practice would be a worth-while investment. There's a piece in the FAQ about how to do it that lives in my wallet, but I don't think I would need it.
• Stein Somers, Mar 1999:
  I too was (made) nervous about removing the wheel but is was easy. I did it on the roadside too. All rings and parts have an obvious function, at least for the mechanically inclined.
  Only problem was fitting a wrench on the first nut on the right side, the one covered by the 5-speed's gear roller assembly (GRA in the manual, IIRC). The "finger" that orients the GRA sits in the way of some ordinary wrenches (English wrenches, we call them over here).

Removing the rear triangle

• Custfold:
  An experiment with the OEM chainring is to drill a 3/16" hole through a spider arm - not opposite the crank (one of the other 4) [otherwise, the left crank would cover the left bolt], so that an allen key can get to the rear pivot bolt to tighten it should this work loose (it does for heavy users)
• Channell Wasson, Apr 1999:
  A procedure to remove rear triangle. (If you are lucky this will work)
  1. Obtain a high quality 4mm allen wrench mounted in a socket.
  2. Use long handled socket wrench or breaker bar with the allen 4mm socket.
  3. Heat the area around the allen head bolt with an electric hair dryer.(As hot as you can get with dryer)
  4. When bolt area is hot, insert the socket and apply pressure with pulsing action. While torque is applied tap the end of socket with a sharp tap from hammer. The idea is to free the bolt from the thread locking compound used in factory assembly.
  5. If you get one bolt out then try the other side. The first bolt must be reinstalled and tightened before starting on the second bolt to prevent the bearing from turning while tourqing the 2nd bolt. Good luck!
  Note: If this procedure fails then the bolt must be drilled out to remove the bolt head.

Bike repair stand for Bromptons

• Channell Wasson, Jan 2000:
  Park Tool makes an excellent unit for consumers. Their products are quality.
• Len Rubin, Dec 1999:
  The best all around stand for home use is made by Ultimate (no relation) and now distributed by Trek under the Wrench Force (a Snap-On Tools division that caters to the bike industry) name. It is versatile, sturdy, adjustable, light, attractive and --best of all-- folds very compactly into a nylon storage bag! It's quite distinctive with its all black, oversize aluminum tube construction.
  Although I used Park's professional shop stands for years in my bike shops, I think the aforementioned stand is much nicer than the consumer stands that Park makes.
• Robert Payne, Jan 2000:
  I bought the Wrench Force stand and am very happy with it. I've already used it many times. It makes maintenance very easy (and comfortable).
  The folding feature is nice too if you have limited space as I do.
  More information can be found at: http://www.wrenchforce.com/
• Velovot, Jan 2000:
  Park sells each level of its clamp (I think there are three basic grades) as a separate unit that can be mounted to a wall or work bench. I use Park's "Race Day" collapsible work stand. It's light weight and easily stored. However, it's not all that rigid and it definately is a compromise from the heavy-as-a-ship stationary workstands for which Park is so well known. I'd give it a qualified thumbs up is space and mobility are important attributes for you.

How to apply the right torque?

• Jane Thomas, Jul 1998:
  Sykes-Pickavant do a beautiful little red tin box with a selection of allen bits and a 1/2 inch drive adapter, which then fit onto a standard torque wrench. Be careful when purchasing the torque wrench to get one with an appropriate range for bicycles. Available from Halfords.
• David Henshaw - A to B Magazine, Jul 98:
  Just to bung a spanner in the works (ho, ho, ho), US-side folk might prefer to use a 31/31" AF socket, which works perfectly well on the pedal. Or have you been metricated now too?

Adjusting the stearing bearing

• Andrew Mackay:
  My problem is that I developed a loose steering bearing with a slight wobble of the steering when I braked. { you can feel the handlebars move a little forward and the wheel backwards a little} So I bought a 36 mm flat spanner that fits the two nuts. I loosened the top one as you look down and then tightened the lower one c. an1/8th of a turn and retightened the upper one which I presume is a locking nut (?). Try as I might I have found that either I have the wobble when I brake or the steering is too stiff to cycle with hands off the handlebars.
• Steven D. Hanel:
  The secret to proper bearing adjustments (missed by MANY bike shop mechanics) is to sneak up on the proper ajustment. Yes it is very possible and easy to overtighten and ruin your headset. Start with the wrench on the lower wrench surface, known as the screw race or upper cup, while holding it tighten the upper lock nut. Squeeze the brakes and try to rock the bike forward and back. If it is loose you will feel the loosness. You want to start with the adjustment with the 'too loose' feeling. If it does not rock you will need to loosen it. Tighten the lock nut as-if you are done, don't try to adjust the lower screw race to what you think is right then tighten the lock nut, I guarantee it will be too tight. I have found that moving the wrench in as little as 1/8 inch increments (not 1/8 of the turn), tightening the lock nut and testing you will be able to get it JUST RIGHT. When you are making adjustments keep the screw race or upper cup from moving much and even thogh you are making lots of adjustments you can use its position as a reference point. This takes a few minutes because you will be making multiple adjustments but it is your headset and you might as well do it right. The LBS mechanics usually just try to get it to spin freely. I have loosened this type of adjustment as much as 1 full turn to get it correct. Headsets get replaced frequently due to there use and design.

Disassembly of the steering column

I've taken out the allen bolt to remove the stem - now what? It's as solid

• David Henshaw - A to B magazine, Oct 98:
  The Brompton is just like a conventional bike. Whack the loosened bolt and the wedge (should) drop down allowing removal of the stem. The only thing to watch is on reassembly. Firstly, the stem should not be pushed right down against the headset - there should be about one millimeter of clearance to allow the headset locknut to be adjusted. It's also more difficult to get the bars straight than on a cumbersome - remember, they have to line up properly when folded as well. Do this by partially tightening the allen bolt and testing the bars in the folded and unfolded positions before fully tightening the bolt to 20NM. Or quite tight plus a bit more, if that means nothing. If in doubt refer to your Brompton manual. If you haven't got one, order it from Brompton. Remember they're now on: +44 (0)181 232 8484.
• Tom Vogt, Oct 1998:
  I JUST did this myself last night. I had the exact same experience. I loosened the stem bolt and tapped it rather heartily with a metal bar--no result. I then called Mr. Bike Guru (a.k.a. Len Rubin) and he informed me that a healthy whack with a proper hammer was indeed required. After apologizing to my Brompton, I swung away and "chunk" the cone let go.
• David Cox, Apr 2000:
  It is the same as any other stem. But you have to wack the bolt quite hard and you need to do it with a straight drift or punch very directly. It is more difficult than on most conventional stems. I know this because when I bought mine the headset was loose because of a missing washer (very unusual they are usually well prepared), Roger Page the shopowner phoned Brompton directly (open on a Saturday afternoon because of a factory move) to check that he was doing the right thing. Using a straight allen key as a punch solved the problem.

{Susan Mathis, Apr 1999} I'm in the process of installing Channell's new front fork with the V-Brake and I'm having a heck of a time tapping out what I assume is the "expansion bolt" that keeps the steering column attached to the bike. I've loosed the 6 mm bolt in the unfolded steering column. It doesn't clear the frame so the bolt can't be hit directly. I cut a block of wood to fit and really gave it a good hit or two (or 10!) and the bolt hasn't budged.

• Len Rubin, Apr 1999:
  Wood is far too soft to transmit enough force to loosen a truly "frozen" stem bolt! The next step is to use lots of penetrating solvent (even WD-40 often works well), then let it sit for a while, and finally use a long, narrow steel punch (or an old, long stem bolt obtained from a bike junk pile), a punch holder (an arcane tool found in professional punch kits) and a heavy steel hammer. It can be a real bear of a job sometimes! Any decent local bike shop should have plenty of experience in this department. Once the wedge has moved a little bit, you can often use a side-to-side twisting motion to work the stem & handlebar assembly loose, or in the worst cases, a soft mallet or wood block to "encourage" the stem upwards, out of the steer tube. If all the above fails, you will need to visit a framebuilder or other craftsman skilled in the delicate application of heat from a small torch.
  Make sure to employ all safety measures, regardless of your level of experience. Solvents should only be used in a very well-ventilated area, and safety goggles must always be worn when using punches. Most important-- failure to use a punch holder when generating enough force (via hammer blows) to move a seized metal item often results in serious injury!
  Also, while the bike should be supported/secured during the operation, it is possible to inadvertently disfigure or bend/crush a frame tube through the direct or indirect transmission of force, if you aren't careful and vigilant about how and where you clamp or support the frame while delivering these punishing hammer blows to that wedge.
• Alasdair Baxter, Apr 1999:
  While I agree that wood may be too soft unless it is a very hard wood, I'd use a 6 inch length of copper rod of, say, 3/4 inch diameter as a punch.
• Susan Mathis, Apr 1999:
  Update on my problem removing expander bolt to remove front fork. I took the bike to a little hole in the wall bike shop and the very nice man there substituted the Bromton long bolt with and even longer bolt from and old bike (the treads are the same!). Two wacks with the hammer and the wedge popped right out. I had applied a generous dose of WD-40 overnight which I would guess helped this process. So Len, your advice to use and long stem bolt was excellent.

Headset lubrification (or not)

• Tom Vogt, Oct 1998:
  After cracking the headset, I was amazed to find it well-greased and little worn. I've abused by Brompton over many a mile in the last three years including driving Irish rain storms, blowing California dessert sands, and French cobblestone streets (with a fully loaded front pannier). Also, the head tube seems perfect (there's been a few posts to this group in the past that suggest the Bromptons head tube is weak). I got out my blindingly-bright halogen work lamp and shown its light on the head tube--absolutely no sign of fatigue.
• David Edge, Oct 1998:
  The headset is built like the proverbial brick-built latrine block and was therefore in perfect condition - unlike some rather fancier ones I have used. Somebody was unkind here the other day about the quality of Brompton components. I'd be happy if the bike weighed 35lb if they were all as robust and economical as this. Despite three years of portly abuse it was in perfect nick. It won't be coming apart again.

Spare parts you may need one day

• Graham A. Patterson:
  It's worth obtaining a couple of spares of [ support washers either side of rear wheel ] - they can break from time to time.

The Brompton spare packs

The Brompton Folding Bicycle FAQ