I now make belt-drive systems for any Brompton – Gates belt drives need no lubrication and are very durable, so there’s no oil or mess, and no regular maintenance needed. This system folds just like the chain drive system.
Any of my conversions, with Rohloff, Alfine or Enviolo hub gears, can have a belt drive instead of a chain – if you order the belt upgrade, then I build the rear triangle with a split for the belt, and removable sliding dropouts. The kit includes front and rear cogs, the belt, and a special belt tensioner. I’ve standardised on these gear combinations:
- 22/60 for Alfine, a bit lower geared than usual, giving gearing of 23.5″ to 95.5″* with the 11-speed.
- 19/70 for Rohloff, this is lower geared than usual, giving gearing of 17″ to 89″*.
Belt Drive Kinetics Upgrade: £395 – Add To Cart
Important: this is not a stand-alone kit, it is only an upgrade when you order a Rohloff, Alfine or Nuvinci kit.
*on standard 16″ wheels, 18″ or 20″ wheels will gear this up proportionately.
For standard Bromptons, I now make an upgrade kit to convert to belt drive – this kit works with 1-speed and 3-speed bikes (no derailleurs, obviously), and uses 19t rear and 70t front cogs, to give gear ratios of 46″ to 82″ with the 3-speed BSR hub.
This kit requites you to cut through the right dropout of your frame. It’s not hard to do, but if you don’t want to do it yourself then you can send me your rear triangle for modification, or I usually have a few spare rear triangles in the shop.
Belt Drive Standard Upgrade: £395 – Add To Cart
I also now make a similar kit for the new Brompton G Line bikes, to convert the 8-speed chain drive to 8-speed belt drive. This can also be combined with an upgrade to 11-speed gearing or Rohloff 14-speed gearing – see the G Line Upgrades page for details.