[RyanCanfield]

i want to buy a new crankset for my gary fisher tassajara. however, i need to kno what mesurements i need to get to make sure that it fits, and i need to know if i need any special tools to install it. PLEASE HELP ME OUT!!!!!!!THANKS!

 

[Speedub.Nate]

Shimano LX M572, ES51 73x126mm BB, Park BBT-2 & Park CCP-4for extracting it down the road.

Hands down best deal going in a stiff, affordable and reasonably light crankset.

 

[RyanCanfield]

well what do i need to mesure so i know it works?? i see these numbers like 45/44/43 or sumthin. thanks

 

[Speedub.Nate]

well what do i need to mesure so i know it works?? i see these numbers like 45/44/43 or sumthin. thanks

The numbers you're probably referring to are the chainring sizes. 44/34/22T rings are typical, although you may see some OE models with 42T big rings or 24T granny rings. Whatever they are, they'll work with your bike.

Crank arm length is typically 175mm, personal preference again. LX only comes in 175 or 170.

BB dimensions are 73mm (shell width) x 126mm (spindle length).

The shell is measured directly off your frame, as in the photo I've attached. Fishers are one of the few big manufacturers using the 73mm width in favor of the more popular 68mm width.

There are two spindle lengths that will work with the LX 572: 121mm and 126mm. These determine your chainline, or the distance of the middle chainring from the center of your frame. Because Fishers use fat bottom brackets, fat seat tubes and relatively short chainstays, the 126mm (50.0mm chainline) is the size I would choose. You might get away with using the 121mm for a narrower 47.5mm chainline, but be prepared with some bottom bracket spacers/shims just incase you get crank to bottom bracket interference, shifting problems, or chain interference problems with adjecent chainrings.

 

[RyanCanfield]

does the cranksets usually come with a bottom bracket? or are those seperate. and also, i could buy a standard crankset and it should work if i just leave my BB the way it is. how do u remove a bb? thanks for all your help

 

[Speedub.Nate]

does the cranksets usually come with a bottom bracket? or are those seperate. and also, i could buy a standard crankset and it should work if i just leave my BB the way it is. how do u remove a bb? thanks for all your help

The new XT and XTR with the external bearings have come with everything you need. Otherwise, you'll need to purchase the crank and bottom bracket separately.

If you buy a square taper crankset to fit on an existing square taper spindle, there's a good chance it'll bolt right up and work with minimum adjustment, but the square taper interface has a bit of imprecision in it, so there is strong chance that a different brand or model of a crank will seat differently on the tapers. Often it'll be "close enough", or adjustable with spacers (this is all assuming you have a cartridge bottom bracket).

You remove and install the bottom bracket with the BBT-2 tool and a 3/8" ratchet or breaker bar.

 

[RyanCanfield]

The new XT and XTR with the external bearings have come with everything you need. Otherwise, you'll need to purchase the crank and bottom bracket separately.

If you buy a square taper crankset to fit on an existing square taper spindle, there's a good chance it'll bolt right up and work with minimum adjustment, but the square taper interface has a bit of imprecision in it, so there is strong chance that a different brand or model of a crank will seat differently on the tapers. Often it'll be "close enough", or adjustable with spacers (this is all assuming you have a cartridge bottom bracket).

You remove and install the bottom bracket with the BBT-2 tool and a 3/8" ratchet or breaker bar.

thanks for your help!