Riding issues

Problems covered elsewhere:

How can I go faster?

To improve transmission efficiency, from muscle to movement:

Rolling resistance tests

Stein Somers, May 1998:
With a fresh pair of primo's (mail-ordered from and then taken back to England...) I cycled around until I found paradise: a low traffic, wind shielded stretch of smooth tarmac descending steeply and then rising gently, with well spaced road markings starting at the perfect place. One problem was I didn't have a pressure gauge... Anyway I let myself roll down and up again without peddling and counted the road markings, for different bike configurations. The results are in the table below the load of text I will now produce.
While establishing the accuracy of the test, as well as a measure for the 90psi still left in my rear Raleigh Record, a puncture crossed my way... down to the 70psi my compact pump can deliver, at least given enough human power.
First test: the best coasting gear of my five speed. Corresponding to the sound (and feel, I used to wonder?), I found 2nd gear is best, 4th worst and the others lie somewhere in between. Sometimes 3th gear is as silent and as smooth as 2nd, sometimes it seems something inside sticks and 3rd makes more noise and the bike doesn't roll as far. All the same, I conclude that the circle around the 2 on the five speed gear controller means not only "adjust the rod in this gear" but also "0th gear" for peddleless cruising.
Second test: I exchanged the rear Raleigh for a Primo, and... my goodness, it clearly slowed me down! In retrospect the difference wasn't that great and I'm sure my arms didn't quite push up the psi in the Primo as they did in the punctured Raleigh.
I then set my hopes on the front tyre. This was still a Raleigh set a low pressure because lately I had been riding through the cobblestone infested centre of Ghent. What a relief when this proved to be the place where a Primo scored! Particularly if you inflate them at a moderate pressure.
Just in time the idea occurred to relate these results to other topics of riding efficiency. Here we go. The Gain/Loss numbers reflect the extra distance I could roll compared to the reference. This is definitely not a linear measure!
Reference = Standard T5 = Raleigh Records at (very roughly!) 60psi, coasting in 2nd gear, upright riding on the standard best folding handlebar position, pannier clipped in the front luggage block, 95kg total load, tall 1m96 rider. Anything else? I carried the same amount and shape of load on all tests and repeated every roll several times (I even postponed organic waist dumping for the sake of science! I did sweat under the midday sun though...).
Change Gain/Loss (accuracy: +/- 0.5)
Rear 40psi Primo -1
Rear 60psi Primo 0
Deflate front Raleigh to 40psi -2
Front 40psi Primo +1
Front 60psi Primo +2
Handlebars raised 15cm via curved bar ends (very upright and comfy) -1
Lie down on handlebars (very aero and uncomfy) +5
Lift legs and align on main tube (scooter like, still comfy) +1
Tie pannier to rack +1
Coast in 4th gear instead of 2nd -1
Engage Nordlight dynamo -1

Suspension versus efficieny (biopacing?)

How can I improve comfort?

Discussed elsewhere:

Changing the Brompton's gearing set-up

Three things you might desire: For opinions on what is a suitable range, see Which model is meant for me? - Reduced gearing.

What are gear inches?

Peter Amey, Jul 1998:
Gear inches are the diameter in inches of wheel that would roll as far in one revolution as the bike would travel for one turn of the pedals in a gear of the same number of inches. Imagine an "ordinary" (or penny-farthing) bike; a 90" gear is the same as riding one with a 90" front wheel.
Metric gears are usually in terms of the actual distance travelled for one turn of the pedals. i.e.
pi * GearInInches * ConversionFromInchesToMeters
Ruud van Tol, Jul 1998:
In other words: it's the (imaginary) size of the wheel when there wouldn't be any gear.

Is it normal for the hub gears to go "tick-tick-tick" when you pedal forward?

My heels hit those darn castors!

[The rear castors, at the front of the rear rack, are] odd shaped rollers that used to catch my heels (usually its women who have the problem as they cycle with feet closer in). You can experience the same problem with luggage: Transporting (more) luggage with a Brompton - Heal hindrance.

Waggly rear ends

Roland Elsenberg, Aug 1998:
[...] I found it less precise in steering. This is probably due to a worn hinge between the main frame and the rear triangle.

Adjusting suspension

If the suspension is too weak for your weight...

Rear mudguard too short (the mud striped back syndrom)

Loose frame clamp

Custfold, May 1998:
I've been experiencing a loose main frame clamp with annoying regularity lately. This ocures even when I'm positive that it was fully tight at the start of my ride.
It may be that the clamp plate has stretched - I'm checking with Brompton for a service gauge measurement to determine when a plate should be changed (e.g. the gap between clamp seat and frame plates). It may be movement in the frame fretting at the joint.
The indicator when riding is the distinctly unnerving floppiness in front end response when braking hard.

Loose chainguard

Undesirable sounds

This is not the most common complaint, but a frustrating one. It seems all sounds can be supressed, except those coming for the hub's internal gears. Some report they rattle, some hear no more then the normal ticking in high gears.

Localising the nosiy culprit


Nico van Beek, Aug 2000:
I bought, some one and a half year ago a T3. Great fun. Everybody wanted folding demo's. However, after some time a vague clanking started in the neighbourhood of the back-wheel. Couldn't find exactly where. I performed greasing and tightening of screws and nuts. Didn't solve the problem. So: back to the dealer, who checked the bike. "Did you solve my problem"? No, that appeared to be not really possible. Had to do with something within the nave of the back-wheel. A common Brompton problem. Dismantling the nave would not give any solution. Not very satisfactory! The rattling became worse (and in Holland we do not have tarmac everywhere as in California). So I wrote to the factory. Answer came from the main distributor in Holland by telephone. A nice chat about grease, oil, tirepressure etc. However it may be: a well known problem! Had to do with the general construction: only one hinge between back and front parts and therefor no possibility to spread the rumour over the total frame. Again, not satisfactory. I'm now in the stage to advise others not to buy Brompton, unless they can cope with a lot of, now very noisy rattling. I took the nave completely apart, greased, oiled, well did everything, but the problem still exists.
Freewheeling on, let's say, rough surfaces, is the main problem. Has nothing to do with little wheels but with the inside of the SA nave.


Stein Somers:
My new T5's has been taken over by a mouse. It hides inside the suspension block and produces noises that make the Brompton sound like a rusty old bike.



The other day I noted that the paint at the n/s (left) joint between the chainstay and pivot hinge plate had lifted. My concern was justified, when the 'crack' noises which had been up to then untraceable revealed their source when the chainstay split neatly around the circumference at the high stress point where the thin walled tube is brazed to the thicker pivot plate - modern Bromptons do try to spread this load by having a slightly different design to the first machines produced, which had the benefit and weight of the substantial integrated carrier and reaer frame. With the tie between the rear triangle and the main frame, the bike remained rideable with care to limp back to base, albeit with the key clue to any incident like this, the unnerving crab wise travel of the main frame when compared to the road, as one looks down - fi your bike starts doing this look carefully at the frame for any damage..
Note that with the rear frame securely lashed to the main frame seat tube, I have 'ridden' a bike with both chain stays fractured after a particularly severe bout of damage. The n/s stay rarely goes in normal use, as the o/s is the one subjected to cyclic compression & tension loads, but the attachment of a trailer will obviously affect this - especially if the load is all going through the n/s of the triangle to the rest of the frame.


Don't be alarmed by the normal ticking of hub gears (Riding issues - Is it normal for the hub gears to go "tick-tick-tick" when you pedal forward?).


David Goldfarb, Jun 1999:
My Brompton seems to have developed a click that occurs when pedaling with some resistance (i.e., no click when coasting, so it's not from the wheels), at a rate of one click per crank in any gear (so it's probably not the gears). Anyone else have this? The bike is pretty new (maybe 3 months, 400 mi. or so) for bearings to start wearing out.

Screaming or scraping

Richard Lighton, Jun 1999:
At the moment my problem is a scream (not a squeal or squeak, a full blooded traffic stopping scream) from the front brakes. I've cleaned the (fairly new) brake pads, adjusted them, aligned them, cursed them. They still scream, mostly in low-speed braking. The back brake with the same pads is as silent as one would expect. Any ideas anyone?

Rattles from the rear

Norman Tulloch, Nov 1997:
On road surfaces which are less than perfect (e.g. on country roads which are tarred but not exactly silky smooth), I get an annoying and persistent rattle from somewhere at the back of my Brompton T5. I cannot reproduce the problem when the bike is stationary,

I have tried tightening all the screws and so on at the rear but this has made no difference. (I have not tampered with the rear hinge screws since the Brompton owner's manual emphasises that these should be left alone.) At one time I suspected that the mudguard might be vibrating against the luggage rack. I therefore put some pieces of foam rubber between mudguard and rack but still the rattle remained. I have wondered whether the source of the problem might be the castors on the rear rack, but if I try riding with my feet on the castors on the front of the reack (don't try this at home, children), the blasted rattle is still there.

Has anyone else had a similar problem? I so, how did you cure it, or did you just hurl the bike over a cliff, driven into an irrational rage by the rattle?

Noise from the front

Willi Mindak, Jun 99:
For a couple of weeks now my T5 has developed an irritating noise that repeats itself with every turn of the front wheel. I suspected the wheel bearings or the cones, but when I examined them they looked o.k. to me. The bearings showed no wear at all (at least I could see none), and the cones had just a small, uniform line of wear were the bearings are running. This 'line of wear' is visible, but you don't feel anything when you run you finger over it. Regreasing the front hub brought no improvement, neither did turning the wheel back to front. The noise only appears when the bike is ridden. When the front wheel is spun without load all is quiet. Can the noise be caused by uneven spoke tension? Any ideas?

Silencing a whiny generator

Channell Wasson, Jan 1998:
Try this
  1. A little oil around rotor
  2. Check alignment of rotor to side wall
  3. Super glue two o rings on rotor. ( Be sure not to get "s/glue" on rotor shaft area) [or get a regular dynamo cap from any (European?) bike shop]

Why is the Brompton's steering sensitive?

Riddell, Toby, Jun 2000:
Is this anything to do with the frame geometry, in particular the trail?
I have noticed that when pushing my Brompton along, holding it just by the saddle and steering it by leaning it one way or the other, it is less responsive than other bikes, that is say the amount of turn is small for a given amount of lean. I think this reflects a shorter trail. And this in turn is reflected in the fact that it's harder to balance the bike when riding it hands free, there is less self-centering.
Does this make sense?
When researching folding bicycles I came across a report concerning a particular model of Dahon. It had a geometry which meant that there was no self-centering effect. A case came to court because someone was riding one when he looked over his shoulder and took one hand off the handlebar - because of the lack of self-centering he could not tell with one hand which way the front wheel was pointing and it turned to 90 deg. and he was deposited on the deck. So presumably this Dahon had no trail at all?

Riding on the sidewalk - is a Brompton a children's bike?

Wobbles and top speed