NEW! 4-Sprocket Kits for Sturmey Archer Gear Hubs - for non-P/T Line bikes
This kit is for: Brompton Wide Ratio (BWR) hub
(We also have 3-sprocket kits for Brompton BWR)
This conversion kit involves replacing the existing freehub body or the driver on the Sturmey Archer gear hub with our custom piece that can accommodate multiple sprockets, as well as modifying the Brompton post-2017 2 speed derailleur shifter from 2 to 4 speed. The new freehub is compatible with individual sprockets, down to 11T, and will make use of the cassette lockring instead of the cir-clip. The 4 speed indexed shifter has reduced stroke that is very easy to get used to. The shifter is also capable of shifting multiple gears in one stroke, similar to many mountain bike shifters.
Pre-requisit / Required existing equipment
- Post 2017 integrated derailleur shifter (left hand)
- Brompton chain pusher
- Brompton spring mechanism
- Derailleur type chain tensioner.
Any Brompton made between 2004/5 and 2016, (excluding the new P/L line), can be retrofitted with the above parts, if required.
This kit is essentially plug and play. The sprockets have been made/tested to shift properly, and there are no parts compatibility issue.
- Freehub body kit (Freehub ASSY, cone nut, cone wrench, axle nuts, extension guide nut, tensioner nut)
- 2 to 4 speed shifter conversion parts, (Alloy internal parts, gear cable, stronger spring, display window, logo button)
- Chain pusher modification parts
- Sprocket set (Including lockring. Some combintations include longer tensoiner pulley axles)
- Chain tensioner longer axles and bolts
- 12 speed YBN chain 110L
- Installation instruction & tuning guide
Please note that the conversion will require re-dishing the rear wheel. Please ensure that you are comfortable with this task or your local bike shops offer this service.
Please also note that for sprocket combination invovling 11T, the chain guide (protrusion) on the back side of the stock tensioner base plate may need to be removed. For more information please see here
. Most aftermarket chain tensioners do not have such feature.