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2005-02-22 6:00 PM

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Subject: Bike gearing question
My Cervelo can't climb like I need it to. Friend of mine suggested a FSA Energy compact crank. Current cassette is a 12-25t

Gear ratio would go from 3.0 to 2.7. My old road bike that I could comfortable spin up hills on was 2.4.

I guess the question is: will it help? Cervelo v. Old Bike would be 3.0 v. 2.4 and that was a world of difference. I guess I'm worried that 2.7 will still be too much in the middle.

It might not seem like a big deal, but getting 230+ pounds up a hill is hard enough

edit: this is using the 'gain calc' on sheldonbrown.com

Edited by zakk 2005-02-22 6:13 PM


2005-02-22 6:55 PM
in reply to: #121167

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Expert
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Subject: RE: Bike gearing question
Wish I had a good answer for you, but I don't. If your front rings are 53/39 and rear cassette is 12-25, I would find smaller hills! ;-) I can't imagine changing your crank arms is going to make that much of a difference. If you haven't, make sure the bike shop gets you fitted good. If you seat height is off, or to far forward/back that can significantly impact power generation. Sorry I couldn't help more. Hopefully someone here has some good advice.
2005-02-22 11:26 PM
in reply to: #121167

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Master
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Subject: RE: Bike gearing question
have you thought about going to a tripple chainring? then you could keep your top end ratio but still gain some climbing ability.
2005-02-23 12:12 AM
in reply to: #121167

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Subject: RE: Bike gearing question
I have the same hill problem but I came from a triple. I was having problems with the front triple shifting so I went with the double FSA Compact Gossamer (same chain rings as all FSA's but aluminum cranks). I also installed a SRAM 12-26 in back which gives a 2.54 gain using Sheldon's calculations. I backed out from the calculations the fact that you are using 175mm crank arms. This gives me almost the same range as my triple and is easier to maintain and ride. I used the SRAM because Shimano 12-27's are in short supply. I found the SRAM to be an excellent replacement and believe it is better quality than the Shimano
2005-02-23 3:55 AM
in reply to: #121167

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Subject: RE: Bike gearing question
Why not just get a higher casette. Much cheaper. I have a 23, a 25 and a 27 with 39 front I can work it out. Worst case get a Shimano Deore LX Cassette 9 Speed in 32 or 34. You could climb walls with that bad boy.
2005-02-23 2:19 PM
in reply to: #121167

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Subject: RE: Bike gearing question

I am not certain, but I think that a triple is going to be problematic (and ugly) on a Cervelo, with the short chainstays being a major limiter. Likewise, going to a cassette bigger than a 27 is probably going to cause you to need another rear deraileur. The compact crank is a pretty good solution. A 34 tooth inner ring will significantly lower your low gears with the cassette you have now, and the crank (and maybe a botom bracket) is all you will have to purchase

The only downside will be a loss of top-end. a 50/12 is a bit lower than a 53/12. There may be some 11-28 mtb cassettes out there that would work though.If you can score one of those, the difference between a 50/11 and a 53/12 are not as great, and your short-cage deraileur will probably still wrap it correctly.



2005-02-23 2:25 PM
in reply to: #121167

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Subject: RE: Bike gearing question

I would suggest (only half in jest) that you reduce the size of the engine while increasing the horsepower generated by said engine.

I believe both can be accomplished simultaneously if you follow the advice of the great Belgian cyclist Eddy Merckx and "Ride lots."

;-)

2005-02-23 2:48 PM
in reply to: #121167

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Subject: RE: Bike gearing question

Like Bear said, Best advice ever:  "Ride lots."

12-25t is a little bigger than "normal" cassettes, I use a 12-23 and a lot of friends use it also, and 12-21 for racing.  So, if you can't climb with 12-25t, you have three options:

1- "Ride lots" more hills.
2- Find smaller climbs
3- Loose some weight

Don't know which Cervelo you have but tri-bikes aren't friends of hills.

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