Help - Front Caliper Mounting Bolts

Originally Posted by yorkie_chris

Use threadlock on both, or copperslip and lockwire

Cheers..... New stainless Steel bolts & threadlock for me.

[yorkie_chris]

P.s bolts are not normal bolts they are ones meant to be strong in shear not tension.

Try BSR aerotek or hyperbolt or someone like that. Or just use stock ones.

Hooorahh!....... After lots of pulling with pliers and wedging of screw drivers I managed to unscrew the bolts and the threads on the calipers seem ok. I ordered stainless replacements from ProBolt for front & rear for just under £19. ( Chris, I tried BSR aerotek and found out they closed down before Xmas).

I also contacted Norbar who just baffled me with science and stated other 'dark forces' were at work between the alloy and steel metals causing chemicals/resistance in the thread effecting the torque. I thought I bought a torque wrench not a light sabre!

[yorkie_chris]

More drag on the threads = same torque stretches the bolt less
Less drag on the threads (coppaslip) = more stretch with same torque

With coppaslip, I reduce the torque by 10%.

[timwilky]

careful with your new bolts.

From memory some of them are metric fine, not off the shelf m10 etc.

Originally Posted by yorkie_chris

With coppaslip, I reduce the torque by 10%.

And I was just about to ask you what adjustmeent to the torque you make when using copper slip.

[yorkie_chris]

It's a bodge, you don't know what the actual tension will end up as (unless you want to make a test rig and put some strain gauges on?), but it seems to work alright.

Anything on the threads will affect tension, e.g cylinder head nuts ... you have to oil those before putting on, if you don't, and you do the nuts up to book tension then it will not put enough pressure on.

[skeetly]

Is copper slip a good idea on the caliper bolts...or not.

[yorkie_chris]

I use it. But the safest bet is to use threadlock.

Originally Posted by skeetly

Is copper slip a good idea on the caliper bolts...or not.

In a recent poll - linky - coppaslip came out 12-8 on top versus thread lock. Those in favour included Northy, Big Ape and YC...