Crank arm bolt torque?

[Trevski]

Hi Folks,

I am chasing the torque specs for the crank arm bolts. I have removed the arms and repacked the bottom bracket bearings, but couldn't find any branding on the bottom bracket components, so I can't do a web search for manufacturer specs. I have done the bolts up about 25% tighter than they were when I removed them after reading this http://www.sheldonbrown.com/brandt/installing-cranks.html. I also found this http://bicycletutor.com/replace-cotterless-cranks/ which suggests around 40nm. One says use grease on the shaft, one says not to. After doing a little more web trawling on the grease v no-grease subject, it seems like the chain lube debate, revisited.

Any help appreciated.

Cheers,
Trev

 

[Doug Burton]

Hi Trev,

See here:

http://www.cncexpo.com/MetricBoltTorque.aspx

Use specs for 8.8 - 8mm bolt; you can lube it or not as you like (I like a bit of light oil on a properly-torqued bolt).

Note these numbers are in inch-lbs.

Cheers,

Doug

 

[Trevski]

Thanks Doug, that's a useful table! They even have a conversion calculator to whatever measurement you like - I make it 169 inch pounds / 19 Nm. Glad I asked and didn't go straight for the 40Nm I found previously...could have been nasty...
Cheers,
Trev