Switched to shorter cranks....many benefits but worse at climbing

So I’m looking for some advice here. I’ve been dealing with back pain, leg fatigue and hip pain for a while. I got a fresh bike fit done which raised my seat a bit. I decided to move from 172.5 cranks to 165mm (I’m 6’1", btw) and raised my saddle about 4-5mm. I’ve only got one long ride aside from a few, short, hour long rides on them.
So far, the benefits have been great:

  • leg fatigue is reduced quite a bit and my legs don’t hurt when climbing anymore
  • zero back pain
  • reduced hip pain (I’m working through this in PT)
  • I’m just way more comfortable on the bike and actually feel pretty good afterwards.
  • Left/Right power balance is improved (used to average Left 53%/Right 47% now averaging (Left 49%/Right 51%)

Here are the challenges that I’m trying to sort out:

  • I was already a weak climber, now, the two people that I normally ride with are dropping me so bad on climbs that they’re having to wait on me. In all previous rides I maybe finish a bike length behind them.
  • I did start to cramp in my calf muscle a bit. I’m curious if I should move my seat back 4-5mm to compensate for the shorter crank.

So here are my questions:

  • TR doesn’t really offer any training plans (aside from Climbing Road Race “Race” block). I know the trope about just having improved overall fitness will help is true but I feel that I need some focus on improving climbing specifically. What can I do to improve climbing?
  • On the calf cramp - will moving my seat back help?

Any ideas of what you are doing differently to get dropped? Too fast a cadence? Too short a gear? The shorter crank should be capable of equivalent power but one or both of those other two must change.

Hi Russell

Thank you for the response. I can’t think of anything that I was doing differently. I mean on one of several climbs I was pulling (and a hard effort) going into the bottom of the hill and got passed by the rider I was pulling - but that’s to be expected. And, that was one of 15+ climbs today where they dropped me even when I was being more careful about the lead into the hill.


@spessx, I know your post is specifically about climbing performance but I’m curious about your hip pain. I also have pain in my right hip, on the back side above the glute. The muscles there feel tight and overworked. After getting off of the bike my lower back is slightly misaligned. I also got a bike fit and will likely reduce my crank arms from 175 mm (too big for me since I’m 5’ 11") to 170 mm. Wondering what your symptoms were and how the shorter cranks have helped. Thanks!

Hi RK,

My hip was closing up too much and causing an impingement which was tweaking my back over the thousands of revolutions that occur during a ride. The hip pain may be caused by something else but is aggravated by the impinging. I gotta say, my back pain is worlds better, and I can use the drops! My hip pain is in the side/top of the socket and my PT has identified a misalignment and muscle weakness issue that we’re working on. If you’re curious, unfortunately, the only way you’ll know for sure is to try it. I personally am not going to switch back even if it impacts my climbing as I’m so much more comfortable and pain free on the bike.


Thanks for the quick reply. I’m also working with a PT and will (hopefully) see a Sports Medicine specialist soon. My low back does feel better overall after my bike fit, but the specific hip discomfort is still there.

Good luck! I hope that you get it sorted.

I’m 5’11 and switched from 172.5 to 167.5 mm cranks this year and I run an 11-30T cassette. I’m an average climber at best I did notice a couple things:

  1. I slightly improved my speed
  2. My power out of the saddle decreased slightly (torque?). This was surprising as the difference in crank length is very small - based on pedal power meters.
  3. I increased my cadence and have no problem staying in saddle at 9 to 11% grades

I takes a few climbs to get used to the new cranks but after a while you won’t notice it. My TT bike has 172.5 and I switch back and forth with no issues.

I switched to 165’s from 172.5’s many years ago on the TT bike and last summer on the road bike. For me the most noticeable advantage is a shorter crank effectively moves my cleats rearward which does have a small but, real change in biomechanics of the pedal stroke. Best way to describe it is being over the pedal or I feel like I have more leverage over the pedal. I left my saddle position the same with regard to the BB…I don’t know if I have short legs compared to torso or shorter torso compared to legs but, I make better power up, down and flat this way.

For a taller guy your torso to leg dimensions might be very different so moving the seat back for you may help. I’d definitely try it. No one seems to talk about how crank length affects foot position on pedaling when the crank is at 3 and 9 o’clock. Only hip angle and seat hight at 12 and 6 0’clock…

Yeah, I just rode my old road bike with 172.5’s and my current bike with 165’s back to back. I felt fatigued instantly (because of my ride earlier today) when pedaling up a hill on the 172.5. I swapped over to the 165’s and felt instantly not fatigued and more comfortable.

I don’t think I’m going back to 172.5 I just need to figure out how to be a better climber on the 165’s.

I switched from 175s to 170s. I’ve found that I needed an extra easier gear and a little faster cadence to go the same on climbs. I guess the explanation is that a longer crank will provide more leverage and give you more torque at a certain cadence. You just raise the cadence with shorter cranks to put out the same power. With one extra easier gear I could just spin up climbs rather than slog up them at a slower cadence.

I think something else is at play.

I have 165mm cranks on all my road bikes, including the one permanently mounted to the trainer. The shorter cranks help a lot with my knees during sustained efforts. I’m 6’0, so close to your height.

My XC MTB race bike (Epic) came with 175mm cranks and I didn’t bother changing them out. I don’t have knee issues on the MTB because of the more dynamic nature of the riding.

My climbing power numbers are about the same across all bikes.

1 Like

Switched from 172.5 to 165 also, and I have found it beneficial. On your issues:

Climbing performance: I’ve noticed no problems here, except less torque capability (not sure how to word it) as you mentioned. Answer is a lower gear to cater to the naturally high cadence a shorter crank provides.

Calf cramps: I also experienced this, I moved my cleats further back on my shoe (another bike fit recommendation) and adjusted saddle height accordingly, but did not alter fore/aft on saddle. I’ve since not had issues. Not sure if this really answers your problem, or just indicates my cleats were too far forward to begin with!

Generally I take the shorter cranks as a net positive, accepting the higher cadence, and also that studies show almost zero difference in overall performance across a much larger range of crank lengths.

Shorter cranks are better… until they aren’t.

That inflection point is different for everyone, but generally speaking I reckon most people could benefit from going shorter (to a point). There will be a point that’s too short and in my experience it is blatantly obvious where that point is within 5 minutes of riding.


The studies I’ve seen indicate that there is no difference in performance down to around 140mm.

I think the biggest difference for me was the opening of the hip angle. This allowed me to have a lower saddle to bar drop which resulted in a more aerodynamic position. I wouldn’t mind trying 165mm cranks next.

At what cadence do you normally climb those hills? The shorter cranks will reduce the amount of torque, so if you relied on stamping a largish gear up the climbs, you’ll have reduced torque now. So you need to up your cadence, and maybe spin up the hills more.

Regarding moving the saddle back - when you raised your seat, you also moved the saddle back a bit, because of the angle of the seat tube. So moving it back will increase the changes you have made.

I’m guessing I’m averaging about 5 more rpms with the shoerter cranks.

Cadence concerns always seem to come up with short crank threads. Unless we are talking fixed, just shift. Ride the cadence and torque necessary to give you the power you want to meet the speed required at that moment. No thinking required. Am I missing something?


calf cramp, could be a one time thing, otherwise, i suggest moving the cleats all the way back. Regarding saddle height, err on the side of lower rather than higher.
Shorter cranks means you can ride with a higher cadence for the same leg speed.

For me it feels more natural to spin higher cadences with shorter cranks, I don’t want to replicate rpm across different crank lengths and I don’t think you generally should.