How tight should crank bolts be?

Registered. Most square taper crank arms should be 29 ft-lbs. That is pretty darn tight. As has been mentioned, if it came loose, the crank arm is likely damaged beyond repair already and needs to be replaced.

Can you over tighten crank bolt?

Yes, it is possible

The bigger problem with over tightening a square taper is that crank arm can be deformed to the point where it will not stay tight. I always use a torque wrench when tigtening crank bolts to avoid over tightening.

How do you tighten crankset bolts?

How to Tighten the Crank on a Bike

  1. Pry the plastic protector cap from the crank arm with a wide-bladed slotted screwdriver. …
  2. Insert a hex key into the hex-head bolt. …
  3. Replace the plastic protector cap onto the crank arm.
  4. Tighten the other side of the crank by repeating the steps on the opposite crank arm.

Do I need a torque wrench for crankset?

Not full force, just enough to see if the bolts moved some, which they did–and that was the end. You really don’t need a torque wrench for this task, but there is nothing wrong with getting one either.

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What happens if you over tighten crankset?

if you overtighten a bolt, you will damage the thread. all bolts have a strength limit – depending primarily on the thread diameter. overtightening is a common mistake by amateur spanner twirlers (i.e. most of us). crank arm mounting threads are pretty meaty, you can apply some muscle, but there is a limit.

Why is my crank wobbling?

The “bottom bracket” assembly is loose. It may just be that it’s a one-piece “cartridge” and is rattling around in the frame, or it may be that the unit is “loose bearings” and the bearing caps need to be adjusted. Or there may have been some sort of failure of the bearings.

Why does my crank slip?

As the chainring teeth wear out, and you apply a certain level of torque on the cranks, it becomes possible to exceed the tension applied by the derailleur and the chain will simply ‘roll’ up and over the teeth on the chainring, effectively skipping a tooth. This usually happens very suddenly.

Why does my crank arm keep coming loose?

If you’ve been repeatedly riding with a loose crank arm it could be that it’s now damaged. You could try tightening with lots of torque, grease on the square taper and threadlocker (e.g. blue Loctite, but in a pinch any kind of glue works) on the threads.

How much torque should a crank?

Crankset – Another torque sensitive component on your mountain bike is the crankset. Both threaded bottom brackets and crank arms recommend a much higher toque than most other components on your bike. With Sram’s new DUB crankset, Sram recommends that the cranks be tightened to 54 Nm.

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Do you torque bottom bracket?

A torque wrench is not essential at all as long as you have a good feel for doing things up tight enough. The BB cups need to be as tight as you can do them with the correct tool by hand. The crank bolts need to be tight but not massively over tight, and rechecked frequently.

How many nm crank arms?


Component Brand Newton meters
Crank bolts Shimano® 34~44 Nm
Shimano® Octalink XTR crank arm bolt 40.3~49 Nm
Shimano® Hollowtech II crank bolt pinch screws 9.9~14.9 Nm
Syncros® 27 Nm

Should you grease square taper?

The logic behind not greasing a square taper spindle comes from the fact that it is an interference fit. Grease would make is easier for the crank to slide down the taper, and there is risk of it sliding down too far and widening the square hole in the crank arm.