Mountain Bike Reviews Forum banner
1 - 8 of 8 Posts

·
huffing and puffing
Joined
·
92 Posts
Discussion Starter · #1 ·
I just installed my SLX double cranks and they seem to spin slow. My test is pretty rudimentary but it seems to illustrate my suspicion, what I did was spin the pedals with my hand to see how many rotations it would make. I tested it against my old bike that has a recently installed square taper bottom bracket and here are the results:

SLX outboard (installed today): 2-3 rotations

Square taper BB (a couple weeks old): too many to count and much faster too.

I do not own a torque wrench so I'm not sure if they are too tight or not.

As always thanks in advance for any and all insight.
 

·
meh....
Joined
·
3,589 Posts
Probably nothing wrong. Try this, undo the left crank arm, re-install it by sliding it on without using the crank arm fixing bolt. Tighten the pinch bolts and give it a spin. Probably do the same as before. New bearings.
 

·
...idios...
Joined
·
5,662 Posts
Shimano external bearings won't give you more than a couple of spins, but it's not something to worry about, just a result of the different bearings/seals. Unless you're extremely sensitive, you won't feel it when you're riding. They'll loosen a little after a short while, but wil lalways feel slightly heavy to the hand.
 

·
Registered
Joined
·
1,498 Posts
The spin test isn't a reliable way to gauge if bearings aren't properly adjusted. The reduced number of turns might be from seal drag, or the viscous drag of the lubricant.

If you want to use your spin test as a comparisson, first establish how many turns you get
when you know the bearings ale slightly loose. Afterwards a slight decrease would be normal, but a big difference would possibly indicate a problem.
 

·
Registered
Joined
·
802 Posts
Make sure too that you have the right amount of spacers installed. When I built my Vagrant, Transition had the BB shell width listed as 68mm, so I used the spacers needed for a 68mm shell. BB didn't turn very well and decided to measure my BB shell. 73mm exactly. Oops!

If you have that correct, don't worry about it too much. It should break in and become a bit easier.
 

·
local trails rider
Joined
·
12,300 Posts
How did you tension the cranks?
I use the Shimano "plastic button", just with my fingers, and all seems well.
 

·
huffing and puffing
Joined
·
92 Posts
Discussion Starter · #7 ·
great thanks everyone, shell is 68mm measured with calipers and the plastic button or cap was tightened with my hands. I'm going to keep it as is cause it seems this is normal. thanks again for all the help.
 
1 - 8 of 8 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top