[Closed] 170mm cranks

It's happening because it makes more sense for those with shorter legs and because wheels have got bigger.

Rode my new bike for 2 months before I realised they were shorter so I could not tell any difference

I have 175 on my HT, 170 on my FS, helps with pedal strikes on my old school 26er

Changed all my bikes to 170mm cranks to help avoid pedal strikes. Can't tell the difference otherwise.

I usually ride with 170's but have just bought some 165 XT's!!

I'm just shy of 6'2" and still run 170 cranks. I like to spin and it helps, I also ride fixed gear commuting who h is also 170 mm so it is nice to have e a consistent feel.

I thought the crank arms were all the same length, just with holes further in - thus making the comments about clearance null and void ?

Or was this just in the good ol days.

i have 170mm cranks on one bike - i think i prefer them being as i have shortish 30" legs. but i cant really tell so much when im riding. then again, i test rode a couple of bird aeris's the other day with a taller mate and he didnt mind the 170s on those either. my next bike will have 170mm cranks for sure

After a recent thread about crank sizes I changed from 175 to 170 cranks. I'm 6ft3 so it took a bit of convincing.

To be honest I've not noticed much difference. I've raised the saddle a tiny bit too.

Less rock strikes, faster cadence etc.

I think it's worth having a try.

I thought the crank arms were all the same length, just with holes further in - thus making the comments about clearance null and void ?

Certainly not true for Shimano SLX, XT etc.

I thought the crank arms were all the same length, just with holes further in - thus making the comments about clearance null and void ?

Even if this were true why would it make a difference? It's usually the pedal that hits obstacles on the trail not the crank arm.

love the eureka moment above,

tis true the hole is closer to the centre of the axle thus so is the pedal and as it's usually the wider platform of the pedal that strikes the chances of a strike are thus reduced. Science

I get the strike thing but gasp a whole 5mm....got a good deal on some unfashionable sized hopes thou so carry on 🙂

Haha. Not a eureka moment at all. I can count the number of times I've hit a pedal on a trail obstacle on one hand, but I have hit the bottom of the crank arm more.

Probably about once every five years though, so not exactly a good test subject.

I have got some 170's to try as I too only have 30" legs and do feel the strain in my knees on a really grinding climb, hoping that 5mm will make that little bit of difference but also trying an oval ring so might have to try one then the other. If I don't like them I got XTR so suspect a swap to some XT 175's will be easy!