What is the difference between an 8 speed crank and a 9 sped crank?

Yes, I know there is no such thing as an 8/9 speed crank, but I am talking about the ones that say they are specifically for an 8 or 9 speed drivetrain.

Is the spacing between chainwheels different? Are the chainwheels thinner ? Or are they exactly the same.

I guess what I am asking is…… Will a triple crankset with the shimano “mega 9” sticker knot, work ok with a 9 speed drivetrain? Or is it somehow specifically designed for 9 speed??

Thanks.

IIRC the chain rings are ever so slightly thinner, but go and have a read of the late Sheldon Brown’s website, he covers it there.

I guess what I am asking is…… Will a triple crankset with the shimano “mega 9” sticker knot, work ok with a 9 speed drivetrain?

I guess that’s not what your are asking! I think you want to know whether a 9-speed crankset will work with an 8-speed drivetrain. Yes.

Thanks tucker. I read the info on Sheldon Browns site earlier today. But then I read on a Shimano tech doc that I need to use a 9 speed crankset when using their 9 speed rear derailleur or it wont shift properly. Probably must the manufacturers way of getting u to buy more gear??

PSA Shimano LX HT2 triple 9-spd chainset + BB for £50 on Merlin at the mo.

No brainer for me as I’ve just trashed my XTR crankset and whipped the XT one off my sons bike – he’ll be getting the LX 🙂

Thanks. lready got my eye on that one. But will it work with 8 speed drivetrain?

You might want to note the number of people having issues with HT2, against the number that use Octalink. True, only Octalink Deore are still available new (although a couple of new XT on Ebay).

pembo6 – Member

Thanks tucker. I read the info on Sheldon Browns site earlier today. But then I read on a Shimano tech doc that I need to use a 9 speed crankset when using their 9 speed rear derailleur or it wont shift properly.

Shimano say things like this quite a lot- pretty sure they say the same about 9 and 10 speed. They also said 9-speed mechs couldn’t possibly do 36T, until they wanted to sell a 36T cassette at which point it became fine 😉 Shimano tech docs are sometimes an extension of their marketing.