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Old 09-07-19, 11:23 AM
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Brompton Gearing and Brake Modifications

The Sturmey 8 speed

I have been running an 8 speed on a Brompton (16 inch 349) for 6 years and recently changed it up for another 8 speed but now with the drum brake. Works like a charm and I avoid the poor Brommie gears and worse brakes. The gears are a bit noisy but I always know what gear I am in by the unique sound from each gear. I use a J-Tek thumb gear changer (no space for a twist grip changer on a Brommie) which makes me think I have a Rohloff(what a dreamer) given how smooth it all works together. I use a Shimano Alfine 501 39 tooth crank set with the Sturmey 20T cog. This gives a range of 31 to 101 gear inches which works well in an environment without large hills (see Sheldon Brown's gear calculator if you wish to fine tune yours differently). On the Brommie you have to widen the rear triangle to 138mm (165mm initially to allow for spring back).

The Sturmey 8 speed gets a bad rap on the net, however, I have had great success with mine. I use Jagwire cable adjusters at the hub(for adjusting on the work stand)and at the gear selector(for adjusting on the fly) in case I need to fine tune the adjustment which really only is needed for the fist week of setup and riding.

I also installed a Sturmey front dynamo/ drum brake combo. The drum brakes are weather proof, dirt proof, stop on a dime and are nice and smooth. The dynamo has you lit up at all times for safety.

Next posting - Nuvinci hub with Shimano roller brakes on a Brompton (AKA - the heaviest non electric B ever)
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