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Old 09-16-19, 04:15 AM
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To me, 35" is still too big when touring in mountains with a loaded Brompton.

An 18T sprocket required adding a spacer because the chain was rubbing slightly against the chainstay, and a 19T rubbed even more.

Even with an 18T cog and a 30T chainring, we're still at 2.20m/27.6", much higher than the 1.58m/19.8" I now have with a 46/30T crankset on a stock six-speeder.

>he adivices smaller than 33t the chain will rub on metal square cabble holder on chainstay.

I don't see what part it could be on my six-speeder: Is it specific to the single speed Brompton?


Originally Posted by WeeBike View Post
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.
A couple more questions about a SA drum brake+dynamo:
1. The OLD is 100mm: How did you fit it on a Brompton whose OLD is 74mm?
2. What about fitting the reaction arm on the fork?
3. Are you confident the Brompton fork can withstand the force from the reaction arm?

And about using a SA X-RF8(W) gear hub:
1. Is "X-RFR8" = "X-RF8(W)"?
2. Can a six-speed Brompton fit a X-RD8(W?) gear hub and enjoy its drum brake?
3. The web page says that the X-RF8/X-RD8 gear hubs can only take 20-23,25T sprockets: Aren't those too big to fit on a six-speed Brompton? Is a single speed Brompton required?

Finally, in case I wanted a wider gear range, are there subcompact double cranksets 30/20T with square taper?

Thank you.

Last edited by Winfried; 09-16-19 at 06:01 AM.
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