Crank length question

[trener1]

I am in the process of building up a gravel bike and am thinking about crank lengths.
I have always ridden a 172.5 but the trend now seems to be going to shorter cranks, how would going to a 170 or maybe even a 167.5 feel?.
Anyone do this?.
I am more of a spinner then a masher even on my road bike.

[zmalwo]

shorter cranks = less stress injury. shorter the better until you runs our of gears... *If you don't race. Shimano gave us 160mm option on 105 cranks this generation might as well try it.

[trener1]

Thanks for responding.
Can you expound on your last 2 points?
Until you run out of gears.
If you don't race.

[Hilltopperny]

I have a bunch of bikes with 172.5 and 170mm. I like the 170 for my gravel/allroad bikes and am currently using it on three of my builds right now. Two are gravel bikes set up 1x and the other is my winter roadie.

I like the 170mm set up with compact or sub compact gearing. It seems a bit easier on the knees.

Sent from my XT1650 using Tapatalk

[cribbit]

shorter cranks = less stress injury. shorter the better until you runs our of gears... *If you don't race. Shimano gave us 160mm option on 105 cranks this generation might as well try it.

Shouldn't it be the opposite since you have better leverage with longer?

[Joe Remi]

I've always ridden 170 on road and dirt and recently switched to 165. It's better.

[Ken Robb]

We have quite a few threads on crank length in the archives.

[charliedid]

I am in the process of building up a gravel bike and am thinking about crank lengths.
I have always ridden a 172.5 but the trend now seems to be going to shorter cranks, how would going to a 170 or maybe even a 167.5 feel?.
Anyone do this?.
I am more of a spinner then a masher even on my road bike.

Nobody can answer this question but you. All you can do is try it. You might like it.

[charliedid]

We have quite a few threads on crank length in the archives.

LOL

So all the threads in the archives hold all knowledge, facts and wisdom?

We should just close this place.

Sigh

[Ken Robb]

LOL

So all the threads in the archives hold all knowledge, facts and wisdom?

We should just close this place.

Sigh
I didn't say that but it's a good place to start looking for info on this topic.

[R3awak3n]

I have to say, I feel no difference whatsoever btw 170, 172.5 and 175s. They all work great for me.

[pasadena]

Track sprinters like Hoy ran 165's
2500w sprints at 75kph.
Yes, track needs to prevent pedal strike, but if longer cranks were faster, they would certainly use them.

Try shorter cranks, they may help you get more aero and improve your fit.
If you don't have those concerns, you might not notice much difference

Going between my track bike (165) and road (used to use 172.5) I felt a huge difference.
I now use 170s and love them, though am thinking of going 165 and getting more aero.

[vincenz]

Some people can tell the difference and some can’t. I could tell going from 172.5 to 170, but only slightly. I don’t have long legs. May be different for you. Only way to know would be to try.

[charliedid]

I didn't say that but it's a good place to start looking for info on this topic.

Nothing personal Ken.

The whole "search the archives thing" just always strikes me as a bit of a non-answer. I guess a link would be more useful...

Imagine walking into a restaurant and asking the server "what's good today?" and they tell you to read the menu.

:-)

[oldpotatoe]

I've always ridden 170 on road and dirt and recently switched to 165. It's better.

I've always ridden on 170 and got 175...it's better'...:eek:

Put 3 people in a room and ask about crank length and 4 or 5 'opinions'..Unless there is a physiological reason to have one or another..there is no answer, no formula, no equation that means this one or that one is 'better'...
Nobody can answer this question but you. All you can do is try it. You might like it.


What he said..

[fmradio516]

I usually do 175, but did 180mm on a bike that had a slightly too short seat tube for me. Instead of raising the seat more and causing hard neck pain for me, I lengthened the crank instead. Doesnt make much of a difference otherwise.

[mattsurf]

Some people can tell the difference and some can’t. I could tell going from 172.5 to 170, but only slightly. I don’t have long legs. May be different for you. Only way to know would be to try.

I can't tell going from 165 to 170, however, I notice a 172.5 straight away.

[Mark McM]

Some people can tell the difference and some can’t. I could tell going from 172.5 to 170, but only slightly. I don’t have long legs. May be different for you. Only way to know would be to try.

In some cases, I think sensitivity to crank length can depend on rider position. I ride my MTB in a more upright position, and I find that I don't notice much difference between crank lengths However, on my road bike, I sometimes hunker down into a low position, torso nearly horizontal, knees rising up close to my chest. A few extra millimeters in crank length means my knees have to come up higher, limiting how low I can bend my torso. Here, I strongly prefer shorter cranks. I think this is part of the reason that triathletes (who ride in low, aero TT positions) are now favoring shorter cranks.

[Jef58]

Track sprinters like Hoy ran 165's
2500w sprints at 75kph.
Yes, track needs to prevent pedal strike, but if longer cranks were faster, they would certainly use them.

Try shorter cranks, they may help you get more aero and improve your fit.
If you don't have those concerns, you might not notice much difference

Going between my track bike (165) and road (used to use 172.5) I felt a huge difference.
I now use 170s and love them, though am thinking of going 165 and getting more aero.

I split time between a single speed/fixed with 165 and road with 170. I recently switched to 165's for both and it feels better and more natural for me. I ride a small bike for comparison sake.

[Sjambok]

I recently had a retul bike fit done. The fitter started me with 170s since that’s what I’ve ridden for the last year or so (from 172.5s). Once we dialed my road style setup, the fitter adjusted down to 165s. I immediately could tell the difference. He said I probably prefer shorter cranks due to my tight hips/hip flexors.

[CNY rider]

Also a short guy here,and I generally ride 170 mm.
I don’t notice anything different on 172.5.
If I spend time on 175s my knees get achy.
What does all of that mean for anyone else? I’m not sure.