Well, almost! This Brompton has a Sturmey Archer Duomatic rear hub which gives two gears and a brake with no cables – you backpedal a little bit to change gear, backpedal more to brake.
The front brake cable spoiled the look of the bike, so I ran it internally down through the stem.
Hi I always fancy a cableless coaster brake brompton for its simplicity looking, I would like to ask a few questions: 1 Can the modification apply to the Sram automatix hub with coaster brake? 2 Do the modification need changing on the frame or other significant part of the original bike? 3, when braking, how the chain tensioner reacts and how is the braking performance overall? 4 Will the coaster brake cause a lot of trouble in folding (pedal position, namely) or its a minor issue once get accustomed? Thanks!
1. I haven’t tried, but I don’t see why not.
2. No frame modification, no.
3. The tensioner is reinforced, and it moves up to hit a stop when back-pedalling.
4. You just put the left pedal forwards before folding, then it ends up in the right place.
Hi,
excellent work…
If I’m not wrong, the cable seems to pass through the stem screw hole… how did you lock the stem with the fork?
Thank you!
It’s a hollow stem bolt, so the upper brake cable stops at the bolt, and the inner wire continues through the bolt to a lower brake cable that carries on to the calliper.
Do you know if bike shops (whether or not they sell Bromptons) are likely to make these specific modifications (or modify it so that it’s just a single speed with the coaster brake)? I love the frame of Bromptons, but the draping cables are a visual distraction. Thanks so much!
The coaster brake modification needs a special tensioner to work, because of the backwards pedalling forces. The front hidden cable is tricky because it needs a specially machined stem bolt and some other parts.
Would you be able to explain how you fitted a 135mm hub into the Brompton 112mm rear triangle without modification to the frame? Is there a way to reduce the ‘Over Locknut Distance’ of the hub?
This 2-speed hub isn’t 135mm, it’s 115mm.