I’ve always ridden on 175’s and loved them. Tried 172.5’s on the road bike for a few weeks but didn’t like the feel.
Now that I have a true tri bike and have it set up fairly aggressively, I’ve decided to try 172.5’s on it BUT I still have 175’s on my MTB. So far, I really like the 172.5’s on the tri bike because of the range of motion and comfort I get out of the position.
Now I’m building up a training bike and am wondering about what crank length to put on it. Training bike will be a cross bike and the races I am doing next year are a mix of on and off road tri’s so I’ll be racing on two different lengths (175 on the MTB and 172.5 on the road)
I guess my question(s) is(are): what the hell do I put on the bike I’m going to spend the most time on? What’s the training difference between the 172.5 and 175? if I go 175, will it hinder my performance on the 172.5’s? if I go 172.5, will I lose out on the MTB? What about moving down to 172.5’s on the MTB?
Little help with the crank length please!
BTW, I’m 183cm, use a 47 shoe, and a saddle height of around 78cm, but that has alway been with 175 cranks. No problems to speak of. I’m flexable, and have always been comfortable and fast on my setups.
I’ve always ridden on 175’s and loved them. Tried 172.5’s on the road bike for a few weeks but didn’t like the feel.
seriously? there was that much difference for you?
the bottom line answer to your questions: 2.5mm length difference for cranks is tiny. so your crank selection doesn’t really matter. go with whatever “feels” good to you, because any performance difference is so small, it might not even be measurable.
but if your questions were about selecting between 160mm cranks and 180mm cranks, then it would be a different story.
I definitely can feel the difference and I don’t like the cramped feel of 172.5 outside of the aero position. I think it has to do with my foot length. Having a 47, borderline 48, shoe size creates some problems at the top of the stroke. I usually have my saddle further back than most to feel more opened up.
So there really is no performance difference between the two lengths? I wouldn’t matter at all the length I put on my cross bike? What length would you build it up with?
I usually have my saddle further back than most to feel more opened up.
this is strange, because you actually have to move your saddle forward to open up your hip angle.
i can’t really give you a crank recommendation without knowing a lot more about you and your bike set ups. then, you should also know there is so little science behind crank selection, that nearly everything said on the topic is purely someone’s opinion. but i can say this, i have a road, a tri, and a mountain bike. i’ve found that i have had the most success by putting exactly the same length cranks on all my bikes.
I usually have my saddle further back than most to feel more opened up.
this is strange, because you actually have to move your saddle forward to open up your hip angle.
i can’t really give you a crank recommendation without knowing a lot more about you and your bike set ups. then, you should also know there is so little science behind crank selection, that nearly everything said on the topic is purely someone’s opinion. but i can say this, i have a road, a tri, and a mountain bike. i’ve found that i have had the most success by putting exactly the same length cranks on all my bikes.
Is it right that people tend to put longer cranks on TT bikes? If so, why? I would also tend to put the same length cranks on all bikes.
I don’t know about you, but I ride my cross bike WAY differently than my TT bike! MOST people use a slightly longer crank on MTB bikes, shorter for TT bikes. I keep my cross and road bike cranks the same. Not in the drops much (like in a crit where you are almost always in the drops) during a cross so you could go longer for the increased leverage (like a MTB bike) and not worry about your hip angle, but also nice to be spinning quickly out of corners/sand, etc.
I doubt I’ll even race cyclocross, I just like the tire size and ability to take on some nice dirt roads and paths here in BOCO. It’s really just a road bike setup for training this winter and getting around town.
Do you run the same length cranks on your road bike and TT bike?
I doubt I’ll even race cyclocross, I just like the tire size and ability to take on some nice dirt roads and paths here in BOCO. It’s really just a road bike setup for training this winter and getting around town.
Do you run the same length cranks on your road bike and TT bike?
I see. No, shorter cranks on the TT bike (but I did this years ago - ahead of the “current” curve)
“Is it right that people tend to put longer cranks on TT bikes? If so, why?”
in the old days riders wanted to put the big meat on their TT bikes. but, really, it was a silly then and remains silly today (tho it may have been slightly less silly before the era of aerobars). most riders nowadays who study this have gone the other way: they’re putting shorter cranks on their TT bikes.
Over the past five years I’ve used 175, 180, 190 and 170 on both road and tri bike applications. Having put a lot of money into the search I would like to believe that proportional cranks make one faster, but I never found that to be the case. I now use 190s on my road bike because I love to climb really steep hills and the length combined with the right gearing and lower cadences work of me. However, I wanted to climb those same hills I could probably put 170s on and spin really fast.
My tri bike has 170s and the more I ride those in the aero position, the more I like them. I’m thinking about trying 165s at some point, but don’t really want to spend the money right now. The smaller circle helps with a very tight hip angle I use riding a superman position on the aerobars.
Frankly, in a blind test, I would be surprised if most folks could tell the difference between 175s and 172.5s.
@Slowman: what is the current recommendation on crank lengths for really tall people (6’6") and long legs (almost 40" inseam)?
Thanks
Jever
I’m not Slowman…but IMHO the “recommendation” is to use whatever crank length “feels good” (within a fairly wide range) and doesn’t result in other fitting issues as a result.
I’ve ridden 180’s for many many years. This is on both my TT bike and my road bike. My mtnb was setup with the 175 and I never got around to changing them.
My 596 of course comes with the proprietary ZED cranks and can only get to 175. I don’t “feel” much difference in the length of the cranks but I’ve been able to get much lower with the 175’s. The 180’s made me stay higher in the front end to avoid feeling cramped. I like the 175’s in the aero position and I still ride 180’s on my road bike.
