Aggressive trail riding – crank length?

I’m up to the drivetrain part of my Ellsworth Specialist build and now have the decisions of what cranks to go for.
Make and model wise I’ve decided on Shimano Saints and will be going for a 34t front ring.
I’ve now got to decide on the length.
I currently have a Pashley trials bike which utilises a 175mm set of Middleburns. However this is a different discipline of MTB’ing so i’m open to trying a different length on the Ellsworth.

I’ve read that longer cranks will give more torque (which is ideal for the trials bike when doing power moves), so maybe a shorter set will suit trail riding.
I’m 5’6″ with an inside leg measurement of 31-32″.

Sheldon as always has a good article about why crank length really doesn’t matter, especially on any bike with gears. Just stick to 175 or thereabouts.

aggressive trail riding, 172.5mm is best.

I’ve always used 175s, but I’m psychotic or just antisocial depending on my meds.
If I wanted to be aggressive I’d use 172.5s as Al has suggested.

Sheldon as always has a good article about why crank length really doesn’t matter

Too long cranks cause excessive knee flex, and can cause pain/injury if it causes your knee to flex more than it is used to.

I learned this the hard way when I bought a used mountain bike that came with 180 mm cranks. I found that it made my knees hurt every time I rode it.

You didn’t really read it properly did you. 🙂

Utter tosh, every fool knows that for agressive trail you need 170mm cranks. If you go 165 or, heaven forbid, 175, your bike will handle like a pile of poo and you’ll be 3% less rad.

I use pacifist 175.382 length myself.

Aggressive but only 5′ 6″ ?

You are Gimli son of Gloin and I claim my 5 Minas Tirith dollars.

Passive aggressive is 170 L / 180 R. You don’t have an issue with that do you?

cynic-al – Member

aggressive trail riding, 172.5mm is best.

i think cynic-al is confusing “aggressive trail” with “contentious singletrack” riding.

if he were to check his noted i’m sure he meant to say 172.35mm. easy mistake to make, but it could be the difference between “grr” and a child’s face.

be careful out there, folks!

Alpin, you win teh interwebz! 🙂 Brilliant!

It doesn’t matter how long they are it’s how sharp a point you file the ends to.

Shorter you can get away with the better. less ground strikes and more freedom to cranks in over rough ground and out of corners. Technical climbing benefits too. And unless you’re planning a seasons DH racing ro the bike is 83mm bb Saints are pretty pointless.

If you cant tell the difference between 2 ro 3 mm height adjustment to the saddle then it doesn’t matter.
Otherwise if the bike has a high BB then I’d go for 175mm just to keep your saddle height lower though 170mm would probably suit your height/leg length better.
I use 170 and 175mm. The 170 is better suited to my Commencal as it has a rather low BB.

5 foot 6 with inside leg of 31/32? You must have a very short body.

Anyway, this lot don’t know what they’re talking about as “aggressive trail” always needs 170.666mm to succeed. Just ask any grom downhiller/dirt jumper. Innit.