I doubt that change will make much difference. But never know till you try.

Might want to try and move your cleats further back and drop your saddle 3-5mm.

I run 145mm, but that's to try and get me into a better position on the bike. Meant I could raise my saddle 20mm

I have been running 160 for years after going as short as 150 and have just gone back to 165 to trial. I found the 160 felt amazing and beyond that seemed a tipping point that felt too short where it felt I had to put a lot more pressure through the pedal stroke and on my knees but it helped with my hip impingement issues and position. I think shorter cranks are great and sustainable over shorter races but I think I can get more over IM distance with longer cranks at least I want to try the next season. You are 6" shorter than me so it may well suit you and for your height definitely worth a try.

I am your size and didn't notice any benefit from going to 160 from 165, probably better things to do with your time/energy/money.

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Dimond Bikes Superfan

Can't say if the shorter crank would address your knee issue. I would start with adjusting my saddle fore or aft first.

The best advise for me has been through these youtube videos from the Bike Fit Adviser. https://www.youtube.com/...3Lgwqryq_QM00L1xJb4A


I'm 6' and use 170. I would go to 165 or 160 with no hesitation. PM me if you end up selling your 165 and they are Ultegra.

I love how even a 170 places the pedal a little higher while cornering so one is less likely to clip a pedal while pedalling through corners.

Shorter cranks are also a little easier on my hip flexors as the range of motion is smaller. The older I get the more I adjust the bike.

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Indoor Triathlete - I thought I was right, until I realized I was wrong.

Why dont you go and get a proper fit first? Just make sure it is a good fitter, and they have a fit bike with adjustable cranks. Then you can try out the 160's, and I would say, even 155/150's too. I'm taller and have just a bit longer leg than you, and I like the 155's. If all you want is a stab in the dark, and are going to just go buy before try, then I would say 155's would be your safest bet. Then adjust your fit around that change.

But really, your knee problem could be something non related, although those cranks you are using are on the long side for your size. Spend a couple hundred on the fit first, that way it will lessen the odds that your throw away the other $500+, or whatever you spend for new cranks..

You needed 145 to get into a better position?
Are you quite fat?

I think a good bike fit and cleat positioning are in order, in addition to the shorter cranks. I wouldn't try 160mm, I'd go to 155 to 145. A good bike fitter will have a dynamic fit bike with adjustable cranks and a good triathlon bike fitter will know where to put your cleats.

Eric

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Eric Reid AeroFit | Instagram Portfolio
Aerodynamic Retul Bike Fitting

“You are experiencing the criminal coverup of a foreign backed fascist hostile takeover of a mafia shakedown of an authoritarian religious slow motion coup. Persuade people to vote for Democracy.”

Yes

I’ve gone up and down the range of cranks. Started on 172.5. Gradually went down to 135. I’m now heading back up. I am presently readjusting to 165. I’ve got a square taper bb on my bike and I can get cranksets super cheap on eBay for it. I’ve now got 135, 145, 150, 165, and 172.5.

I have noticed you can pretty much get used to anything if you ride it long enough. It will start to feel normal. I suspect if you’ve got other issues causing your knee problem it will seem to go away with shorter cranks, but will probably come back once the novelty of shorter cranks wears out and you adjust to the new normal.

As already noted...this knee issue might need a saddle adjustment. But it might be hard for you to see it yourself, and a good fitter can help.

I’m 5’9” and the 135s were probably too short. (Ok for long efforts but not great for hills/sprints). In moving up to 150s it felt nice to get more leg movement. And now on 165s I feel pretty good. I think I’ll stay with 165s...but only out of convenience.

I don’t think you’ll notice much of a difference between 160 and 165. Why not go down to 155 or 150? The small change seems like it won’t matter much if you’re just doing it yourself. A fitter might be able to see what a small difference makes. But just on feel it’s hard to imagine you’ll be sensitive enough to know if anything is better...

Thanks for all the feedback!

I am going back to my fitter in 2 weeks. I will bring to him the comments from this forum

I adjusted my cleats back and this seems to have helped already

thanks again!

I'm 5'9 with a 32" inseam and I'm on 165, down from 172.5.

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Ed O'Malley
www.VeloVetta.com
Founder of VeloVetta Cycling Shoes
Instagram • Facebook

Keep your cleats *all* the way back. If your fitter does not understand why this should be, or why this should be for a triathlete, or why this should be for a time trialist, then beware.

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Eric Reid AeroFit | Instagram Portfolio
Aerodynamic Retul Bike Fitting

“You are experiencing the criminal coverup of a foreign backed fascist hostile takeover of a mafia shakedown of an authoritarian religious slow motion coup. Persuade people to vote for Democracy.”

You're welcome. 👍👌

Your knee issues might not be due to the crank length. I've found that any knee issues I've had related more to cleat position (as someone mentioned, further back - ie, more toward the middle of the foot than the ball of the foot) helped, and seat height. As I've aged I've found my hips getting weaker and the knee isn't tracking as straight as it used to. Since you've already changed the cleat position, you might want to experiment with lowering the seat a few millimeters.

I did go to shorter cranks a few years ago. The biggest difference was a) general comfort on the bike, although I can't say what exactly was different, and b) running improvement. The longer cranks were a bit better on flat courses when you really want to hammer, while shorter cranks have helped me in hills.