How short is too short (I´m talking about cranks) ?

[ggx]

So we are shortening our cranks to crazy lenghts to avoid rock hits . Wondering how our stability /good position on the bike is affected?

 

[Zimmerframe]

I thought we shortened them so we didn't catch our massive clown shoes in the front wheel ?

As someone with with very limited experience and ability, who by default, only has bad position and stability is something I can only relate to when either my feet or body is on the ground, I can say with 100% certainty that I've felt no negative effects from shorter cranks on the last two bikes.

I should add that on my first emtb, I only had 1 pedal strike. On the second one I had dozens because of the stupidly low bb and even with looking/planning and being convinced I'd missed things, I still had strikes so dropped to 150 Mirandas.

On the Kenevo, I ordered 140's because I'd read it had a low BB, but didn't have any strikes on the original cranks, but changed them anyway .. just because ..

I'm thinking of dropping to 50's - much more stable, legs and feet won't be flapping all over the place.

 

[drjarvis2003]

I never felt the need to go below 165mm. As Gary has said here before, its all about you timing and if you go too short your front to rear platform may affect your bikes handling.

 

[ggx]

So don´t be to short with your cranks , ride smarter

 

[Kiwi in Wales]

I run 140mm cranks and they work just fine for me in the very challenging steep, rutted terrain I ride in.
However, your bike may have a higher bottom bracket so you may not need to go as short as I have.
Ride smarter? I already know how to time my pedal strokes to avoid crank strikes. However, now I have a ebike I am riding very different terrain which I would never have looked at on a non bike. I am now riding a lot of very steep rutted chutes and switchbacks ‘at speed’ and to ride this type of terrain you need to constantly pedal otherwise you are going to stall (or if you have longer cranks, pedal strike) and end up rolling back down the hill you are attempting to conquer for the first time. Timing my pedal strokes in the above situation ends in the same result. This is the reason I gave shorter cranks a go and in ‘this’ environment they work.
We all ride different terrain so your terrain may not require short cranks. Mine does and short cranks work in my environment for my style of riding. Call me ‘lazy’ or ‘unskilled’ if you wish. The reality is I have very few pedal strikes and very few offs whilst riding steep ascents these days.

Stability of your bike on a reduced pedal platform?
I haven’t noticed any difference but I run flats and move my feet all around my pedals which may be why. Someone clipped in may notice it more?

Do they affect how my bike handles downhill or around technical switchbacks or when I have to lower and weight the outside crank?
Nope.

We are all different, they may not work for you but for under £20 delivered at least there is a very easy, cheap way to find out.

 

[ggx]

I run 140mm cranks and they work just fine for me in the very challenging steep, rutted terrain I ride in.
However, your bike may have a higher bottom bracket so you may not need to go as short as I have.
Ride smarter? I already know how to time my pedal strokes to avoid crank strikes. However, now I have a ebike I am riding very different terrain which I would never have looked at on a non bike. I am now riding a lot of very steep rutted chutes and switchbacks ‘at speed’ and to ride this type of terrain you need to constantly pedal otherwise you are going to stall (or if you have longer cranks, pedal strike) and end up rolling back down the hill you are attempting to conquer for the first time. Timing my pedal strokes in the above situation ends in the same result. This is the reason I gave shorter cranks a go and in ‘this’ environment they work.
We all ride different terrain so your terrain may not require short cranks. Mine does and short cranks work in my environment for my style of riding. Call me ‘lazy’ or ‘unskilled’ if you wish. The reality is I have very few pedal strikes and very few offs whilst riding steep ascents these days.

Stability of your bike on a reduced pedal platform?
I haven’t noticed any difference but I run flats and move my feet all around my pedals which may be why. Someone clipped in may notice it more?

Do they affect how my bike handles downhill or around technical switchbacks or when I have to lower and weight the outside crank?
Nope.

We are all different, they may not work for you but for under £20 delivered at least there is a very easy, cheap way to find out.

Perfect. Ride smart according to your preferences, terrain, skills, bike, etc. Tks for sharing.

 

[Zimmerframe]

It's an old thread but it seemed like a good place to put some experiences in.

I think @Kiwi in Wales has covered the positives, but as with anything, I think there are compromises .. Hail lord Gary ...

So for me, I've run the 140's for over a year . They certainly give you a lot more flexibility climbing rutty or rocky terrain where timing becomes an irrelevance.

The negatives :

Running a shorter crank means your foot is higher at it's lowest point - so you need to run your saddle the corresponding amount higher.

It also means that in those moments you raise a pedal to it's highest point to just miss a rock/object - those same few CM's which help mean you miss the rocks when pedalling at the bottom, can mean you end up hitting an object with the pedal at it's top stroke - upper pedal strike !

Having swapped back to 165, it's interesting that I now notice things which I didn't notice when I switched down.

It's harder to engage your quadriceps with the shorter cranks. It's far easier to spin with the shorter cranks and achieve higher cadences very easily - but in turn harder to apply power from the upper leg. This is running 140's - so probably the extreme of what most people will run. One advantage of this is for people with knee problems, the shorter crank could possibly reduces some pressure through the knee from the quads.

This translates to another problem though. If you have any issues with Achilles tendons, as I do, the higher cadence and both the way you apply power and the "smaller" relative stability platform means you place a lot more stress on these.

I suspect there is no "perfect" crank length as we're all different heights, with different length legs, different muscular builds, different injuries.

Hopefully this just helps a bit more when making those choices.

 

[Gary]

I'm just home from riding a 170mm Travel enduro bike with a 322mm BB height and 170mm cranks on technical rutted enduro tracks.

I honestly find it laughable when you guys cry about your 30mm higher "too low" BB heights.

Learn to look where you're going and co-ordinate your feet FFS

 

[Zimmerframe]

I'm just home from riding a 170mm Travel enduro bike with a 322mm BB height and 170mm cranks on technical rutted enduro tracks.

I honestly find it laughable when you guys cry about your 30mm higher "too low" BB heights.

Learn to look where you're going and co-ordinate your feet FFS

You forget .. most of us can't do that when we walk ! never mind ride !

 

[Gyre]

In fairness, learning to ratchet competently is a skill that needs to be developed. I understood the idea but putting it into practice wasn't natural.

We have a local trail with a lot of concrete drainage curbs, so I've been using that for practice for a fair chunk of the pandemic. Anyone looking to avoid pedal strikes should try to find something equivalent.