Replacing crankset and bottom bracket
 

I have a 2013 specialized sirrus elite and need to replace the crankset (it is trashed and i might as well replace the bottom bracket anyway). Here are the specs off the website:

CRANKSETShimano FC-M391 triple, 9-speed, w/chainguard
CHAINRINGS48/36/26, w/ chainguard
BOTTOM BRACKET Cartridge bearing, square spindle w/ crank stop right side, capless bolts

It is also a 9 speed drivetrain. I am looking to replace it with a crankset with the relatively same gear ratio on the front with a chainguard and a bottom bracket that will work with my bike. I am fairly new to repairing bikes so I am not sure what components to get.

I already have an octalink crank puller and a shimano bottom bracket remover in my wishlist and also have found a cheap crankset on amazon http://www.amazon.com/dp/B003ZMDJW6/...=IFCGRVVD8N1ZQ
I am not sure if this would work with my bike or what bottom bracket would be compatible. Thanks.

You need the Shimano FC-M391 as a direct replacement, least problematic. I just went through that with a 8 sp, Octalink.

That's the problem. I need the absolute cheapest replacement possible and that is out of my budget currently.

You can see the responses I had on a very recent thread:

http://www.bikeforums.net/bicycle-me...-crankset.html

By the time I got done, I bet I didn't save over $10 after shipping charges, compared to buying one or two chainrings, and not being confident they would shift properly.

Check Shimano TechDocs if you can find them to see if the crankset you picked out is compatible with the FD you have - there might be a difference, even being a 9 sp crankset.

Looks like you have square taper already? Then you need a square taper crank puller, not Octalink. How did the crankset get trashed on such a new bike? Is it the chainrings or cranks too?


See, I did this once, makes me a BF Expert. Not....

I'm curious about "trashed"?
You do realize the teeth appear to be missing/worn out on a NEW crank set, don't you?

If you are confident the one you want (M131) will work, xtremebikeandsport has it a cheap as you are likely to find. And if this is the same xtgreambikeandsport that is on ebay, they shipped my really fast.

http://www.amazon.com/Shimano-M131-C...981806&sr=1-47

What happened to the old crankset? Does it have replaceable chain rings? It would take a lot of miles to wear out a crankset in 2 years.

The local Bike Co-op may also have miscellaneous cranks and chainrings that would work for you. It doesn't hurt to swing by.

One of the problems with the M131 is that it doesn't have replaceable rings. Perhaps the whole crankset is as cheap as new rings, but it does limit you somewhat if you're wearing heavily on your equipment.

+1 This comes up frequently.

It says you need a 122mm square taper bottom bracket.

Isn't the absolute cheapest BB the one you already have?

I'm beginning to turn blue on this, holding my breath, waiting for more info. Trashed crankset means bent and damaged. Unless worn, then that also means a new chain and cassette.