Crank length

[fatbikephil]

I had a read of this linked from that bikepacking.....
https://www.applemanbicycles.com/resour ... nk-length/

Quite interesting, a mate was telling me that shorter cranks are becoming quite the thing of late. Not sure about reducing the knee angle as a sure fire way of reducing knee pain though - when mine were giving me gyp in 2019 dropping the seat by 10mm eased things considerably which will increase the knee angle. I suspect it's more down to reducing the overall range of movement. Although going singlespeed caused me the most benefit, knee pain wise, in fact it disappeared completely until post BB300....

So I'm interested as my knees have again been a bit nippy of late but the thought of swapping all my 170's for 160's doesn't fill me with much joy...

[Lazarus]

I use time pedals and have no real knee issues

Due to pedal strikes, i would be interested to try some 5 and 10mm shorter- given the expense I wont be trying this anytime soon.

(PS: riding doesn’t need to hurt or ache, even after a long ride)

You were not trying hard enough, if it does not hurt, after every ride.

[Bearbonesnorm]

I fitted everything (pretty much) with 165 and I'm fairly sure it improved things in the knee department.

[voodoo_simon]

Briefly but a shorter crank helps with two things, it helps the knee to flex a little therefore taking the strain away but it also helps with the top of the stroke. We riders always setup the cranks for the 6 o’clock position for pedalling but it’s the 12 o’clock position at the top that stresses the knee

[Mart]

This made a lot of sense to me (see link below)
Used to ride 175 but went down to 170’s and had a good bike fit which confirmed this was my ideal length

https://ridefar.info/2017/02/crank-leng ... -cyclists/

[fatbikephil]

Interesting that - the graph suggests 170 is at the lower end of what I should use, which my wallet will be thankful for. Cleat position plays a part too as the further back the cleats are the less your knee angle is. Interesting comment about ultra riders generally using lower seat heights for more relative bar height so they should use shorter cranks.

[jameso]

https://meatengines.com/f/shorter-cranks-us

Interesting read on the pros + cons for MTB

[Pirahna]

175 on everything except track/fixed when I use 165.

My knees don't notice the difference.

[fatbikephil]

Defo interesting that - heading for "best crank length is the one you like best"
I'd agree with Pirahna too - losing 10mm crank length should not make much difference if your knees are borked - it may change the bit you are wearing so giving an easement of pain (much like me dropping my seat 10mm a few years ago) but knee pain is more likely a combination of factors - riding position, gluteus medius strength, lower limb flexibility, muscle balance not least, age and wear...

[Al]

Always used 175s until the new bike came with 165s. Felt odd but kept them on until the first proper long ride which crucified my knees.

Have now replaced with 175s and put the child cranks on the classifieds

[jay91]

I watched this a while back could be a interest to some.
Joe Barnes testing 155mm https://youtu.be/6X3zkMK8ZDM

[rudedog]

https://meatengines.com/f/shorter-cranks-us

Interesting read on the pros + cons for MTB

Hmm, not sure that guy has ever ridden a full suss with a low BB if he doesn’t get the benefits a shorter crank brings in terms of pedal clearance.

My Scott Genius was pretty bad on natural/rutted trails with 175 cranks.

[fatbikephil]

Hmm, not sure that guy has ever ridden a full suss with a low BB if he doesn’t get the benefits a shorter crank brings in terms of pedal clearance.

My Scott Genius was pretty bad on natural/rutted trails with 175 cranks.

And his kind of riding is somewhat different to mine (I mean I can do all that stuff, I just choose not to ) If all you are doing pedal-wise is short bursts of power to get you through a steep noodly descent, your pedaling requirements will be wildly different to those for grinding across mid Wales for 24 hours. I can see that super short cranks would be useful on such terrain given that most bouncers seem to be dragging their BB's on full compression these days. Having to put the seat up by 25mm would concern me as this would then cause me back and wrist grief.

Conclusion - gonna stick to what I have for now!

[jameso]

https://meatengines.com/f/shorter-cranks-us

Interesting read on the pros + cons for MTB

Hmm, not sure that guy has ever ridden a full suss with a low BB if he doesn’t get the benefits a shorter crank brings in terms of pedal clearance.

My Scott Genius was pretty bad on natural/rutted trails with 175 cranks.

He probably has, he's based in Vancouver and test + writes for NSMB. He's just covering some of the factors that aren't so widely discussed rather than saying shorter isn't all-round better.

[Lazarus]

Was thinking about this commuting in today and wondered if anyone had ever made a crank with a number of pedal holes so you could try different lengths...presumably not easy given pedal thread size.
Agreed I would not want to be taller on the road bike

[jameso]

Was thinking about this commuting in today and wondered if anyone had ever made a crank with a number of pedal holes so you could try different lengths...presumably not easy given pedal thread size.
Agreed I would not want to be taller on the road bike

They are available, mainly in very short lengths for kids. But you're right, the thread size means the gaps are much bigger than the variations of +/-5mm or so that we'd want to try.

On saddle height vs crank length, I went 5mm shorter on my road + gravel bikes and ended up with the same saddle to BB height after trying it higher. It felt best for me to have my knee bend feeling about right at the level crank position which is in the power phase. I wasn't so concerned about where my pedals were at the top/bottom of the stroke, the dead spot. It did feel different in a way that was a bit odd when starting out for a few rides, I did notice the full extension leg position was lower but I got used to it. I'd say climbing felt better with the level crank to saddle position being right.

[redefined_cycles]

Was thinking about this commuting in today and wondered if anyone had ever made a crank with a number of pedal holes so you could try different lengths...presumably not easy given pedal thread size.
Agreed I would not want to be taller on the road bike

You and me both Jon. I've been thinking about it and wondering (just wondering yet as I couldn't afford the costs of experimentation) if it might help my sciatica. Also been thinking about giving up long distance road riding but this might be something to explore.

Last year (December 2021) I did the 240 mile road ride to London for human rights and hopefully ending of torture God Willing. Came back with a wobbly knee which took about 6 months of foam rolling and knee stregthening exercises to recover. Since then I've done the same ride but in summer/autumn and the knees coped well!

This Dec 2023, for human rights again I'd planned to ride that same thing but a chest infection left me crippled. Much worse than my usual regular chest problems (ex smoker then vaper idiot) probably due to the couple of Covid years. The coughing affected my hips and once they (the hips and chest) were better I was ready for another thing.

Did the human rights ride locally over a week. Mtb of 100 miles, which maybe didn't cause it but certainly might have contriibuted. On my final 30 miler I recall having to raise (or lower) the saddle height due to using different boots. I'm left nursing a severe form of sciatica - I think piriformis syndrome... 3 weeks and counting.

Not done much biking yet with it but maybe saddle height/crank length (and possibly giving up trying to cover 200 miles in a ride) is the answer I've been looking for. Yes to see a physio (obviously ) but I keep moving/stretching/strengthening...