Torque confusion

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MartDude · #1 Post by **MartDude** » Sat Apr 16, 2011 8:36 pm

Re caliper bolts:

I've just been replacing some of my fasteners with Pro Bolt SS ones.

The Pro Bolt leaflet says 'when fitting flanged hex head . . . bolts use torque values specified by your equipment manufacturer'

It goes on to suggest, in a little table, a setting of 37.6 nm for M10 bolts.

Aprilia give a setting of 50 nm for the caliper bolts (M10) - a significant difference, to my mind

Any comment on which to go with?

Ta

#2 Post by **Kwackerz** » Sat Apr 16, 2011 9:21 pm

Aprilia know the stresses and strains placed on their components better than Pro Bolt do. I'd go with the Aprilia settings.

If the bolts are decent quality and grade suitable for the task, they'll be fine

D-Rider · #3 Post by **D-Rider** » Sat Apr 16, 2011 9:54 pm

Yes as Tim says.

Pro Bolt will specify a nominal torque without knowing anything about what the bolt is being screwed in to or its precise function.
In the absence of other guidance, it's a good place to start.

Aprilia know the function and they know what the bolt is being screwed in to. Normally their data for things like this is the best advice.

MartDude · #4 Post by **MartDude** » Sun Apr 17, 2011 9:10 pm

Well, they got tightened to 50 nm. After today's ride, nothing's cracked or fallen off, so I guess that's about right.

Thanks for the reassurance & advice.

Nooj · #5 Post by **Nooj** » Mon Apr 18, 2011 10:25 am

I'd go with Pro-Bolts settings and a dab of loctite, in case the heads are a different design to the OE bolts eg. a smaller hex driver may round off at 50nm. Can't remember what the stock bolts look like though.

MartDude · #6 Post by **MartDude** » Mon Apr 18, 2011 4:07 pm

Stock have a reduced hex head, similar to the Pro Bolt; stock is 13 mm, Pro Bolt is 12mm