# 7 speed crankset?



## Markleo (Feb 20, 2006)

Hi, my Kelly's Mtb is 7 speed. I want to change the crankset. Do I have to find one that is for 7 speeds? Or an 8 or 9 speed is ok since all are 3 chainring cranksets? Thanks.


----------



## Sickmak90 (May 27, 2012)

I think (key word is think) you should be able to run an 8 or 9 on your hub. You will need a new shifter and maybe a chain. Someone more knowledgeable than I will come along shortly.


----------



## marpilli (Feb 8, 2011)

You're only wanting to change the crankset? You should be fine switching to an 8 or 9 speed crankset, then. The main difference between those is going to to be the thickness of the chain rings. The higher the number of gears the narrower the chain. And, the narrower the chain rings must be to accommodate said chain.

Now the fun part... I'd be concerned about the bottom bracket on your bike being compatible with any modern bottom bracket bearings.

Every older 7 speed bike I've worked on had square taper non-cartridge bearing system like the 1st one in this photo.









Most modern cranksets will use a cartridge or external bearings like the 2nd, 3rd, and 4th examples.

Hopefully someone else will chime-in with any compatibility issues regarding the bottom bracket. If you don't get a response here, head over to the drivetrain forum and ask.


----------



## Sickmak90 (May 27, 2012)

You can still find square tapered bottom brackets and the tools for cheap. Jensonusa.com has shimano Alivio square taper cranksets for under $20. I got the bottom bracket tool and crank puller tool for under $20.


----------



## joeinchi (Jun 19, 2010)

Markleo said:


> Hi, my Kelly's Mtb is 7 speed. I want to change the crankset.


What sort of change are you looking to make? Different ratios? Fewer rings? Switching cassette down the road? Arm length? Weight savings? Are you having a problem with your current crank?

Niagra Cycles Works also has plenty of 6/7/8 speed crank set options. Amazing selection and prices but, sometimes, their service is a tad slow.

Here's an example of all the specs you should be familiar with before pulling the trigger:
Shimano FC-M361 Acera Crankset 170mm 42-32-22 Black


----------

