Author Topic: Brompton gearing and chain length  (Read 578 times)

Gattopardo

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Brompton gearing and chain length
« on: October 04, 2017, 03:36:51 pm »
My brompton has a 3 speed Sturmey archer hub and was geared to 50 13.  The replacement crank is a 54. 

What rear cog would I need to keep the gearing similar and then the chain length.  Currently I have a 13, 14 and 15 toothed rear cog.

Re: Brompton gearing and chain length
« Reply #1 on: October 04, 2017, 04:12:49 pm »
54 - 14 is almost exactly the same gearing as 50 - 13
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PaulF

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Re: Brompton gearing and chain length
« Reply #2 on: October 04, 2017, 04:12:55 pm »
Unfortunately you can't have both the same gearing and the same chain length.

14.04T but they're pretty rare :-D to keep the same gearing so obviously the 14T or a 9T to keep the same chain length but they're even rarer.

Gattopardo

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Re: Brompton gearing and chain length
« Reply #3 on: October 04, 2017, 04:30:51 pm »


This just confused me more will 102 be too long and 100 too short?

Also am running a 1/8th chain with a connector.

Re: Brompton gearing and chain length
« Reply #4 on: October 04, 2017, 05:59:35 pm »
102L will be absolutely fine with 54x14 (if that's what you're asking) since the table shows it will accommodate a two speed 54x12 - 54x16
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