The Folding Society

The Brompton - Choosing the model specification

What is available?

Note: Since the demise of Sturmey-Archer, only the 3-speed models have been available. Of course, 5-speeds are still available second hand. A version with 6-speeds - a dual sprocket at the rear doubling the gears provided by a 3-speed, has recently been launched (April 2002), and we have a test report available (still being updated). The section below will be revised when we have more experience of the latest modles.

There are currently (since March 2000) five models of Brompton to choose from, which differ only in terms of the fittings. Prior to March 2000, there were four models, which were upgraded at that time with new, improved brakes, better tyres, mudflap, folding left-hand pedal as standard, a new range of colours, and other detail changes. The small price increase was in effect cancelled by the folding pedal no longer being an extra, and the additional Companion model was introduced at a price lower than any of the previous models.

All the models except the Companion come with mudguards as standard - the mudguards and stays form part of the locking mechanism at the front when folded, and carry some of the auxiliary wheels at the back which support the bike when folded (on T models these wheels are mounted on the rack).

All models can take the front luggage mounting bracket, although it is an extra on all models. Once this bracket is fitted, any of the Brompton front luggage racks and bags can be used.

The brakes on the L and T models are reportedly greatly improved over those on the earlier Bromptons, and the new Brompton tyres are reported to have much lower rolling resistance than the previous Raleigh Records, though not as good in this respect s the Primo tyres that many owners have fitted.. In addition to the standard Brompton tyre, these models can be specified (at extra cost) with a Kevlar reinforced Brompton tyre (for greater puncture resistance), or the Schwalbe Marathon tyre, similarly reinforced, and which has received very favourable reports since it was introduced late in 1999.

Choosing the model

There is a strong argument for keeping the Brompton as simple and light as possible. The Companion is rather minimal in specification, and if mudguards etc are fitted, then there is little if any saving over the L3. For these reasons there are many people who regard the L3 model as the best. However, different people have different requirements, and there are certainly many who find the extra gears of the 5 speed models useful (not only do they give a wider range of gears overall, but the gaps between the gears are slightly smaller, which means the change in pedalling speed is less after gear changes). The T models with the dynamo lighting and rear carrier may be useful to some, but they do have drawbacks. Firstly, they weigh around 2 pounds more. You may feel that does not matter when riding the bike, but remember that you intend to lift and carry the bike too, and it will be noticeable then. The rear carrier does make the bike slightly more stable when folded, and avoids possible damage to the rear mudguard and stays when folding, but if you put anything on the rear rack it interferes with even the first parking step of folding the Brompton, and will need to be removed. there is no quick release rear bag for the carrier of the type used at the front. Dynamo lights do save on batteries, but are prone to slip when it is wet (even if correctly adjusted) and can cause wear of the side wall of the tyres - a particular problem if the excellent Primo tyres are fitted, as they have no dynamo tread on the side wall. And you also end up carrying the lighting system even when it is not needed, adding to the weight. Clearly which model you choose depends on your own particular requirements (and budget) - I bought a T5, but would choose an L5 another time.

Since the specification differences only affect components, it is possible to modify one model to another specification, but it is much easier to get it right in the first place. A particular difficulty in converting from L to T models and vv is that the rear mudguard and stays differ (partly because on the T models the one set of auxiliary wheels are mounted on the carrier, while on the L model a singe wheel is fitted on the mudguard, requires multiple stays to support the weight of the bike when folded).

Gearing options

Apart from choosing between the 3 and 5 speed models, there is another factor to consider. The Brompton is available with standard gear ratios, or with one higher and one lower gear option, 12% higher and 14% lower. This is a change from the situation prior to March 2000 - the standard ratio is now what used to be a lower option, and the higher option is what used to be the standard. For most people this makes sense - the standard gearing as it used to be was on the high side. Even now,  the gear reduction option is well worth considering, as many people preferred the old extra low option which was close to the new low ratio. The reduction option only costs a few pounds more, and simply lowers all the gears by the same percentage. It is achieved by the use of a smaller chainwheel and a larger rear sprocket. As with other things, this is very much a personal choice which option you go for, but we will try to provide some general advice.

If you live in a fairly flat area, and do not carry particularly heavy loads, and you are reasonably fit, then the standard gears will probably suit you, or you might even prefer the high option.  If the area in which you live has some hills, not too steep, the new standard gears will probably suit you, though you might opt for the low set. If you have steeper hills to tackle, or plan to use the bike under many different conditions, it may be better to opt for the low gears.

Personally I would always rather be under geared than over geared (within reason) - I can put up with coasting down hill, but pushing up hill, or straining the knees and legs climbing hills, is much less acceptable.

Of course your choice is not absolutely irrevocable - you could have one of the other options fitted at a later date if you are unhappy with your original choice, but you will then have to pay for it, and it's very much easier and cheaper to get the right ratios in the first place.

You may wonder if it is feasible to lower or raise the gearing more, or to fit other gear systems, such as a seven speed hub or double chain ring. Well, anything is possible, and some people do manage to do remarkable things, but it is not easy, and I would suggest that messing about with the bike to that extent is rather defeating the object of the bike. One of it's great virtues is that although it is a superbly clever piece of design, the finished product is in many ways a very simple, straightforward, clean piece of engineering. In order to keep it small when folded, clearances are small, and this means that different chainwheels and sprockets, or other types of hub gear, cannot easily be accommodated. If you really feel you need something so different from the way the bike was designed, perhaps you should start with another type of bike, rather than spend a lot of time and money bodging a Brompton, and, in many people's eyes, spoiling it.

Many people find the extra gears of the 5 speed useful, and the majority of people prefer the lower gear option. I have a 5-speed with the 18% reduction, and although it is under geared for some situations, I much prefer that to being over geared - coasting downhill is preferable to having to push up hill, or risking knee damage. I believe that the ratios on the 5-speed are a bit closer than on the 3, which is also an advantage: I find the step from 3rd to 4th uncomfortably large even on the 5 speed - one moment your legs are spinning round and threatening to fly off, then you change up and the knees start creaking. The majority of people I have spoken to who have the OLD standard gears (ie what is now the high option) wish they had opted for something lower. But of course if you have strong legs like David Henshaw, or Dave Holladay, and/or live in a flat area, then the high gears would be fine, and probably 3 speeds will suffice, with the added advantage of simplicity and a small weight saving.


Until relatively recently, all Bromptons that one saw were very similar - just as they left the factory. However, in the last year or so a lot of accessories have become available from third parties to allow owners to modify their Bromptons to more perfectly match their own individual requirements For information on accessories and modifications, please see the page on this subject.

If you have any information suitable for inclusion on these pages, please contact us.

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Copyright (C)2002 Ferrets Anonymous
Last updated: 18 April 2002