General Discussion Triathlon Talk » Cassette and crankset question Rss Feed  
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2010-07-02 8:21 AM

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Albion and Cadillac
Subject: Cassette and crankset question

Can anyone give me some insight as to what the numbers associated with the crankset (such as 53/39) and cassette (say 12-25t) mean? Also will all of the combinations (say from one company and all 10 speed) work together? What benefits/drawbacks does one have over the other (say a 11-23 vs. a 12-25)? And any other information that you think I might find useful on the subject. Thanks



2010-07-02 8:45 AM
in reply to: #2957561

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Subject: RE: Cassette and crankset question
The numbers (53/39, etc) refer to the number of gear teeth on each end. In the case of the crank, it means that your large chainring (the "gear" attached to the crank) has 53 teeth, and the smaller one has 39. In the back, it means that your smallest cog (the "gear" on the back wheel) has 12 teeth, and the largest has 25 (and there are standard steps between that will be fairly common).

Larger numbers in front means more wheel travel per pedal revolution (or "harder"). Smaller numbers in the back mean the same thing.

The spacing between the cogs on the back wheel has become standard between the various companies, however they can't just be switched, as the splines on the hub are different between the difference companies. So you could put a Campagnolo wheel onto a bike that otherwise runs Shimano shifters, and it'll work okay, but you can't put a Campagnolo cassette (the set of cogs on the back wheel) onto a Shimano hub, and vice versa.

If you're a strong rider, or train and race in fairly flat terrain, then the switch from a 12-25 to an 11-23 might be beneficial. I've ridden everything from a 54/42 with an 11-21 (when I was bike racing a LOT), to a 50/38 with 12-27 in back. Just depends on yourself and your riding.
2010-07-02 10:59 AM
in reply to: #2957561

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Subject: RE: Cassette and crankset question

The type of riding to plan to do should dictate the type of cassette and chain ring you run.  The 11-23 cassette will be better for moving fast on mostly flat terrain.  The 12-25 will be more advantageous if you have some hills.  Generally its better to have more gearing than you need so that you have a few bailout gears.  For example, if you run an 11-21 on the rear, you will have plenty of gears to run fast on the flats, but will run out of gears quickly when you point that bike uphill.  The 12-25 combo is a pretty good all around set up, and when combined with a 39T ring on the front will get you up most hills.  Watch the TDF this week and pay attention to the cycling news pages... they discuss the equipment setups for the various stages...  32 spokes for cobbles,  Triple chain rings for the mountains.. or a 11-28 with a 35T front chain ring for a mountain stage... etc. 

2010-07-02 11:46 AM
in reply to: #2958017

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Subject: RE: Cassette and crankset question
huerto - 2010-07-02 8:59 AM

Watch the TDF this week and pay attention to the cycling news pages... they discuss the equipment setups for the various stages...  32 spokes for cobbles,  Triple chain rings for the mountains.. or a 11-28 with a 35T front chain ring for a mountain stage... etc. 



I think you underestimate the stratospheric abilities of the pros... I seriously doubt you'll see ANY triple chainrings there, and many of them will run a 42 small chainring with an 11-21... The really strong climbers won't even shift off the big chainring until the REALLY steep stuff hits.
2010-07-02 12:32 PM
in reply to: #2957561

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Subject: RE: Cassette and crankset question
Thanks for the insight guys that's helps me out a lot.
2010-07-02 12:53 PM
in reply to: #2958144

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Subject: RE: Cassette and crankset question
briderdt - 2010-07-02 11:46 AM
huerto - 2010-07-02 8:59 AM

Watch the TDF this week and pay attention to the cycling news pages... they discuss the equipment setups for the various stages...  32 spokes for cobbles,  Triple chain rings for the mountains.. or a 11-28 with a 35T front chain ring for a mountain stage... etc. 



I think you underestimate the stratospheric abilities of the pros... I seriously doubt you'll see ANY triple chainrings there, and many of them will run a 42 small chainring with an 11-21... The really strong climbers won't even shift off the big chainring until the REALLY steep stuff hits.


No I am not mistaken... I am a big geek about what the pros ride.  Think about what it takes to ride those mountain stages day after day.  Lots ride 11-28 cassettes with a compact 35 on the front... but on the big mountain stages even the elites will run a triple on occasion.  Some of those climbs have a 22% grade... I guarentee they are not on the big ring.  Contador ran a triple last year on two stages.


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