Compact cranks

[Roy E. Munson]

I had a discussion with a buddy of mine today regarding switching to a 50 tooth big ring from a 53. He's kind of overweight and not overly fast, actually races with the 45+ group and he's under 35, but he wonders will he lose much top end in dropping the 53. Any experience, advice, insights?

[Kurt]

he will lose tons off the top, there will be nothing left to sprint with, even though it does not sound like he is in the sprint in the end. All the nice fat gears in the bottom end will also be different, if its a crit he will never find the right gear, meaning the ones everyone else are using, either too much spin or push. Wide Q if that matters. Have to drop you front del to make it work, marks the frame sometimes, if that matters. If he likes going down hill he will just spin out and the low you get, close to a 39x29 is really not that low.

[Brian]

Roy,

Let's assume your buddy's smallest cassette cog is a 12. A 50-12 falls in between a 53-12 and a 53-13. It is, however, much closer to the 53-13. When it's all said and done, your buddy loses only the 53-12 combo.

Based on his riding style, he doesn't sound like he's hammering along in brutally fast pacelines or sprinting all-out for county lines. So I'm guessing he'll only miss the 53-12 combo on 35-40 mph downhills - assuming, that is, he actually wants to pedal and not enjoy the descent.

[Kurt]

There is about a 6% diff between a 53 and a 50 about 3". He said his friend races 45+, which is what I do. The speeds in socal average close to 28 most time in a crit - I am always in a 53/16 or higher, sprints always in the 12/13 dep on the grade. Look around, nobody that races locally uses these cranks - they are a fad, imo.

[Roy E. Munson]

So it ends up about $200 for the cranks, $50 for the rings, and $50 for a cassette for a minute difference at the top and bottom end if you went with say a 50/39. Is this correct?

Wouldn't a 12/27 cassette be a much cheaper investment? Would this help him work on spinning a little more as opposed to the 50/39 setup?

[Kurt]

most of the compacts are 50/34, does he want to spin up hills, is that the idea? If he is overweight then a 29 will prob not be enough. Spin on the flats and you can use a 25/6/7. Power to weight, again.

[flydhest]

I'm not sure I see a reason to go with a 50/39. If you want a compact crankset, get a 50/36.

Kurt says that most sprints end up in a 53 and 12 or 13. A 50-12 is close enough to a 53-13, so . . . you're not giving much of anything up. But why give anything at all up if you're not going to change the small ring?

Where do you all live? I know that there are big variations across localities in terms of racing speeds. Somehow, SoCal strikes me as one of the faster places, since you can train all year round.

If the guy isn't really all that fit, it will do him some good to spin anyway.

[bostondrunk]

I prefer to use a 54 x 42 with a 11x21 cassette. I've never been in a sprint where I wasn't spinning/sprinting out in my 54x11. But I also use topolinos for wheels, which probably gains me a gear in speed.