Brompton gearing qu...
 

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[Closed] Brompton gearing question(s)

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Tried out some Bromptons today to figure out whether I should get a standard model or go B spoke. Settled on M bars, firm suspension and extended seat post. However, I was amazed at how high the standard 3 speed gearing felt. I went home to do some maths and worked out that the 3 gears I use most on my main 27 speed commuter/touring bike are 38, 60 and 78 inches. This leads me to ask the following:

a) am I a big jess? (Yes!)
b) can you really compare gear inches calculated for Bromptons and big wheeled bikes?
c) looks like the -18% 3 speed might meet my needs (39-69 inches). Is this a popular option for other Brompton riders?

Thanks all in advance for your help. Let the jesting begin.


 
Posted : 08/02/2014 8:22 pm
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It depends where you live. I use mine (firm sus and flat bars) mostly around London when I'm in there and I find the gearing fine. I guess if you are somewhere hillier then the first gear might be a bit too high?

and yes gear inches (the distance for one crank revolution) are gear inches irrespective of wheel size so you can compare them.


 
Posted : 08/02/2014 8:46 pm
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Cheers for the reply. And thanks for not confirming question a 😉


 
Posted : 08/02/2014 9:19 pm
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I think mine is an 18% reduction and I fit category a).

Rich.


 
Posted : 08/02/2014 9:44 pm
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When I ordered mine I asked the shop if I should reduce the gears. They told me not to be a jessy. I live in saddleworth and it's fine. I'd miss the top speed around Manchester if I reduced the gearing.


 
Posted : 09/02/2014 12:23 am
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Rear cogs are really easy to change , I rode mine for a while then reduced the gearing slightly by swapping the cog for one with an extra tooth. And yes I'm a big jessy but I did tour Holland on mine and needed it for the hills 😀


 
Posted : 09/02/2014 7:43 am
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Three speed here. Hilly in the morning en route to the south station, then across London. Perfect.


 
Posted : 09/02/2014 7:51 am
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I previously worked in Edinburgh's biggest Brompton dealer.

We all found the std gearing a little high, and almost all the bikes we sold were reduced. Mine is also.

Bear in mind its a slower bike than a regular one, and its a nightmare out of the saddle - making lower gears even more sensible.

Changing sprockets may be less flexible.


 
Posted : 09/02/2014 8:19 am
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Where are you going to be using it? FWIW, around London I found the 2-speed gearing to be far more suitable. (..and it's lighter too.)


 
Posted : 09/02/2014 8:25 am

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