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yep..

mikey_mike said:
Just wondering if anyone tried racing on a compact geared bike?
I ride a DA 20spd. compact (50/34) for local crits and road races...haven't really noticed a difference and my sprints are still upwards of 35-38mph with a gear or three left so I have no complaints. If I were a stronger sprinter and running out of gears, I might whine...but that's just not my case.
 

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Many years ago I raced many flat crits on a 50 front, 13-19 seven-speed rear.

I remember taking the 53 off my Shimano 600 (Ultegra now) crankset and just putting my 50 "crit ring" on. I did better with that setup than with the 53, but I have to say that I was good at holding high cadences then, and that amateur racing speeds were slower than they are today.
 

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Hamilton didn't ride a true compact.

ericm979 said:
Lots of people have. Tyler Hamilton won a Tour stage on compact gearing in 2003.
Except that Hamilton didn't ride a true compact when he won that tour stage. He used cranks with a 110mm BCD (like most compacts), but he used a combination of 52/36 chainrings. The 52 outer ring was roughly equivalant to the standard 53 used by most racers, and the 36 inner ring was only 2 teeth smaller than the 38 tooth minimum allowed by a standard 130mm BCD.

At best, you could call Hamilton's crank a "semi-compact."
 

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classiquesklassieker
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Gear calculator

mikey_mike said:
Keep it coming guys, thanks for all the input. So what gear do I need for my cassette to match a (50/34) crank?
This depends on your strength, stamina, and the terrain. Say hi to the gear calculator:

http://www.sheldonbrown.com/gears/

Note that using a 50/34 means greater jump from the bigger ring to the smaller ring, so you'll tend to cross-ring more than with a 53/39 or 50/36. I use a 50/36 mated to a 11-23 cassette and that's good enough for almost any climb around where I am now. In case of emergency, I have a spare 34 chainring that I can slap on.

So before you jump into the bandwagon, first make sure that you are getting the right gearing combination.
 

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Mark McM said:
Except that Hamilton didn't ride a true compact when he won that tour stage. He used cranks with a 110mm BCD (like most compacts), but he used a combination of 52/36 chainrings. The 52 outer ring was roughly equivalant to the standard 53 used by most racers, and the 36 inner ring was only 2 teeth smaller than the 38 tooth minimum allowed by a standard 130mm BCD.

At best, you could call Hamilton's crank a "semi-compact."
Or you could call it "Compact for the Pro Peleton". It probably gave him the same climbing boost that regular compact gives a mid to strong rider, and a triple gives to a new rider.

Gordon
 

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classiquesklassieker
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Only you can answer that

mikey_mike said:
Just planning to change my cranks but have a 12-27 casette would this be ok with general riding in mind or would this sacrifice my top speed a lot? Thanks
Whether or not you sacrifice your top speed depends on what your top speed is, without gear restrictions. Only you can answer it. Do you use your 53x12 regularly these days? Do you use your 53x15 every once in a while? Figure our which gear combinations you often use, and say hello to Mr. Gear Calculator. That way you can tell for sure whether 50x12 is a tall enough gear for you.

Sorry to sound harsh, but you haven't given any indication of your riding needs, so how do you expect people to answer your question?
 

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Sea change.

I have to agree with Orange Julius, and take it one step further. Gear ratios, number of teeth in the front, number of teeth in the rear and such are fun to play with and provide great entertainment on a rainy day. But if you're interested in your top speed, you should make a fundamantal change in your thinking away from the hardware and towards your legs. Ride your bike, do a series of sprints on a lonely stretch of road, time-trial against yourself, take notes about your performance. The gear thing will fade into the background, where it belongs.
 

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ultimobici said:
11-21 unless you have a hilly course, then 11-23. You might want to get a 36T to get a closer spread for flatter courses.
Not necessarily. It depends on how much you spin. As a junior racer I have to be a spinner, as my biggest gear is a 53/15. I rarely get up to 53/15. When I do time trials I'm often in 53/17 at 26mph for a loooong time. 50/11=4.5454 34/23=1.47... 53/12=4.41 39/25=1.56
a 11-23 gives a tiny bit higher upper and tiny bit lower lower (by .09). I would think a 12-25 would be best. Slightly lower upper, however it utilizes the Compact, by giving a lower low gear, which an 11-23 would not do very well as shown (in that it's basically the same as a 53/39 with 12-25)
-estone2
 

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I have 50-34 with 12-25 and I find that 50:12 is too short for anything over 25 mph. Perhaps my cranks are too long (172.5mm) or I am not much of a spinner, but I often wish I had 11T cog in the back. Mind you, I am a mountain biker and I ride/race single speed, so I may be too comfortable pushing bigger gear.
 

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classiquesklassieker
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Speed workouts

serious said:
I have 50-34 with 12-25 and I find that 50:12 is too short for anything over 25 mph. Perhaps my cranks are too long (172.5mm) or I am not much of a spinner, but I often wish I had 11T cog in the back. Mind you, I am a mountain biker and I ride/race single speed, so I may be too comfortable pushing bigger gear.
With a 700c wheelset, a 50x12 translates to ~25mph if you were pedaling at 75rpms. This is not a very high cadence. Speed workouts may be the key, to get used to smooth spinning while powering. On a flat with no wind and no drafting, how long can you sustain 50x12 for?
 
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