I’m riding a Cervelo P1 (51) and I’m having some clearance issues. The top of my quad is contacting my ribs just enough to bother me a little after I’ve been riding for an hour or so…
I’m 5’4" and my legs are big for a little guy. My inseam is at 29.5 or so.
I’m running a 165 mm red crank. No spacers under my stem. I’m thinking of picking up a 160 mm or maybe even a 155 mm crank for testing.
I’ve read some of the previous posts about shorter cranks but most people are running the 165’s. The other thing I noticed was most people riding them are way taller than I am.
Slowman or Mr. Rapp, any idea if the shorter cranks can help out a little guy?
I’m a short guy too…5’5" with a 28" inseam. I’m running 165mm Red cranks as well. I’ve considered getting shorter cranks so I can raise my seat and get a bit more aero. For you, I do think it would help with comfort in the position. You’ll have to spin a little faster…and you’ll lose a little bit of arm leverage so turning the cranks will be a little harder. But “they” say the trade off is minimal and the gain is worth it.
I’m still hesitating on going shorter. On my roadbike, I lost speed with I went from 170mm to 165mm because I’m just not good and spinning fast. And I swear I could feel the tiny bit of lost leverage on long hill efforts (granted, you probably won’t see long tough climbs in most tri’s).
Wicky, if you don’t mind telling - about how tall are you?
When I went from the 172.5 to the 165 I felt it. It took a few rides up the local bridges to get the hang of it.
But since I’m in Florida it’s no big issue.
gear selection has nothing to do with it. it’s clearance - the distance from knee to torso at tdc. john cobb has a lot of luck converting bmx cranks to road cranks, and he “makes” his 155mm or 160mm cranks that way. he happens to be at the compound at the moment, i’ll alert him to this thread.
I understand shorter crank arms opens the hip angle allowing for improved breathing in aero position. I am saying that gear selection should mitigate any perceived concerns about increased cadence or decreased leverage associated with moving to shorter arms.
If cadence IS constant, then length doesn’t matter, as long as you don’t change gears. I’m not sold on shorter always being better. I think it really depend on the rider, and is more complex than just leg length.
Take a look at the Kent Bostick photo that is on a few of the threads. I don’t think he needs to get lower and I doubt he is on 160 cranks. For someone who can’t get lower without hitting there abs and can’t go much more forward then shorter may be better.
For my self this year my main race is on a very hilly course. I could always gear down, but when climbing I think the best choice is to have the leverage of a bit longer crank.
I’ve gone from 175 to 165’s. I’m 6’1" with a 34-34.5 inch inseam. I’ve been able to improve my aero position quite a bit, and the more and more I ride them the stronger and more comfortable I’m getting on them (which I guess you can prettty much expect to happen anytime you start consistently spending time doing something new). I try to do alot of my riding on the computrainer or on flats right now to adjust to the shorter cranks without getting frustrated with the different feeling on the hills. After about 2 months now of mostly riding on the 165’s I’ve started doing some hillier rides again and it feels really good so far. I’ve been able to go out and do some of my rides I’ve done in the past on the 175’s a little bit quicker than I was before. I’m still not certain I’ll be better on 165’s, but I do think it’s something that takes a bit of time to get used to and you need to get strong on flatter rides before you can go out and feel good on hillier rides.
Instead of a pm, please post on how to convert the bmx cranks. I’ve been trying to figure out how to do this. I’ve got Shimano compact crank with the integrated spindle. As best I can tell, it will take moving over to a square taper BB, but I don’t understand the mechanics of how to make that happen.
I’ve been thinking of moving to a shorter crank too. I’m 5’8 (there’s a extra half in there, but I don’t like to mention it) w/ a 32" inseam. Reading on slowtwitch has me convinced i’m on the wrong bike (51 p2c), with the wrong crank length (172.5), probably training completely wrong too.
My thighs do kind of bump up on my stomach quite a bit, so I was thinking of moving to something a little shorter – like a 167.5 when I upgrade my cranks this spring.
I saw a thread yesterday where I saw the much taller rappstar was riding shorter cranks than me.
We’re about the same height (I’m 5’9"-ish) w/ a 33" inseam, and I ride a 51 P2 w/ 172.5s w/o issues. I am wondering why are you convinced you’re on the wrong size bike.
I saw another thread where they were talking about the P2 being not-so-great for a longer leg, shorter torso rider. Really, that part was more my (weak) attempt to be funny – if you read these forums long enough you’ll end up pretty much questioning everything. I actually love my bike.
But, I really am considering a shorter crank. The whole open the hip angle to allow you to get lower with better power kind of makes sense to me.