170mm cranks what's the deal?

[medved]

On my search for a bike to get me rolling round the streets most of he completes seem to have 170mm cranks.

I understand the 25:9 gearing, but why the shorter cranks? Are they easier to jump/ boost with or just for a smaller rider?

Btw I ride 175s on my race bike and always have done so.  Does it make any noticeable difference  or not?

[Betty]

Makes spinning tricks easier.... allegedly 

[Peter J]

I've got 160's on mine 

Feel fine as I rarely pedal

Come to the I hardly ride 

[punkdSICO]

Feel fine as I rarely pedal

Come to the I hardly ride 

  I know the feeling..

Paul

[kev-s]

i run 170's but used to always run 180's only took 10 mins to get used to the difference

reason why alot of people run 170's is because it saves abit of weight, most new school bikes have shorter rear ends so makes sense to have shorter crank arms as when i ran 180's on a 13.75 rear end the heel of my foot used to clip the peg, now it dosent

if racing/dirt jumping then i can see the appeal of longer cranks but on a park bike they just aren't needed

also most completes are aimed at kids, who obviously have shorter legs

[Betty]

Good point on the short rear end Kev

I'm running a frame with 13" rear with 175mm cranks and haven't had any peg/heel clearance issues, must be down to my size 7 feet   

 

[hunterdubber]

On a race track is the only place it would matter 

If you are just rolling around streets or riding parks ,

where you just drop in and pump or do the the odd rev on your crank ,it doesn'r matter 

[kev-s]

Good point on the short rear end Kev

I'm running a frame with 13" rear with 175mm cranks and haven't had any peg/heel clearance issues, must be down to my size 7 feet   

 

lol my size 10's used to clip the dirtbike's peg when i ran 180's on the dirtbikes 14" rear end

[fugazi]

All the above & some people say You get more 'pop' with shorter cranks, as well as stiffer & less liable to bend.

[Dark Diggler]

short cranks and massive bars combined with seat/post combos make you look special

[SaMAlex]

Another reason for shorter cranks is  is its easier to "pinch" your feet (for bar spins) if they are closer together. And it makes crank arm/pedal slide tricks easier.

Or so I have read ....

[fugazi]

And to add to the mix, a lot of flat riders have cranks as short as 140mm!

[ED209]

I need some 170mms for exactly the reason Kev says about heel clippage.

[garran]

on my morales i had straight forks with 180 flights, kept hitting my feet on the tires and i'm only a size 7

[HARODAVE]

had some 170 prolines on my OS bike and they felt great to ride , wouldnt mind giving them a go on my NS to see if i can tell the difference between them and 175's 

[medved]

Well in the end the bike I bought turned up with 175mm cranks instead! That's that then