Home | The Bike | Transmission | Non-Standard

Over the years almost every possible gear system has been tried with a Brompton, usually to get a wider range for touring but sometimes with the idea of simplifying the controls. Costs vary from affordable to extremely luxurious. Here are some of the ones that are most widely used. The gear ranges quoted are mainly from the XLDev Brompton Gear Calculator, thanks as ever to the guys at XLDev for a great tool. The ranges indicate what is possible rather than an absolute limit in every case and of course range is only one of the questions you have to ask. Reliability, weight, efficiency, ease of installation and compatibility with the Brompton fold all play a part.

Sturmey Archer 5 Speed (range 225%-256%)

Modern Sturmey Archer 5-speed hub gears are included in the 5-Speed Page of the Transmission section as they can be considered as successors to the hub gears fitted by Brompton in the past.

Sturmey Archer 5x2 (5 speed hub and rear derailleur) (range 295%)

It is possible to combine the Brompton 2-speed rear derailleur with a Sturmey Archer 5-speed hub to obtain a wider gear range and/or closer steps between the gears.

Sturmey Archer 8-Speed (Range 325%)

Requires adaptation of the Brompton frame (This needs confirmation)

Wide range 2-speed (range 161%)

The standard 2-speed can be modified to give a wider range (but still only 2 gears).

Shimano Nexus 8-speed (range 306%)

Requires adaptation of the Brompton frame, may offer no advantage over Brompton's standard BWR 6-speed which has a range of 302%

Shimano Alfine 11-speed (range 409%)

Requires adaptation of the Brompton frame

Rohloff 14-Speed (range 526%)

Rohloff hub gears are renowned for quality and reliability and increasingly chosen by touring cyclists and others who like their simplicity and ease of use.
Requires adaptation of the Brompton frame

Schlumpf Drives - Double your range (range up to 776%)

Florian Schlumpf is a Swiss engineer who has designed a variety of high quality bicycle transmission products including the 2-speed drives that replace the normal chainset and cranks to provide a very wide range setup, for example converting the Brompton 6-speed to a wide range 12-speed. He also makes gears for unicycles. Schlumpf Drives can be fitted to Bromptons quite easily and Schlumpf make versions for the Brompton.

Twin Chainwheels (range up to 540%)

It is quite difficult to fit a front derailleur to a Brompton, but it's cheap, lightweight and simple to fit a second chainwheel and use manual changing for an occasional "granny gear", a number of Brompton owners have done this to extend their range for touring.

3 Speed Cassette (range up to 327%)

It is possible to fit three cogs in the space taken by the standard two on a two-speed or BWR hub. This won't (normally) increase the range, but does allow nicer narrower steps between gears.