sheered disk bolt

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Spike16
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sheered disk bolt

Post by Spike16 »

I got a set of used honda disk bolts from a well known 400 parts seller off here and iv just come to torque them up and one of them has sheered off leaving half the bolt in the wheel thread.

apart from having it drilled out and heli coiled theirs nothing I can do with it now but the question is is it safe to run with 5 out of the 6 disk bolts? baring in mind il be racing on this so lots of hard braking, will it get through scruit?
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royster81
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Re: sheered disk bolt

Post by royster81 »

i think it's simon ed that runs 3 outta the 6 disc bolts so 5 outta6 is fine but GET IT SORTED
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CMSMJ1
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Re: sheered disk bolt

Post by CMSMJ1 »

royster81 wrote:i think it's simon ed that runs 3 outta the 6 disc bolts so 5 outta6 is fine but GET IT SORTED

What he said..

Re-using disc bolts is always a sketchy one as they seem to get very friendy in the wheels unless copaslipped to the max.

Were you using a big torque wrench?

Stick the 5 bolt wheel on your road bike and use the 6 bolts for racing...imagine the mess if something happened due to this!

Also, as it is fresh in and I guess you used anti seize then drill the middle out and use an extractor, it should come out easy
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fastdruid
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Re: sheered disk bolt

Post by fastdruid »

Best way to remove if you can is to weld another bolt onto the stub, failing that once the head has gone the bolt should unscrew fairly easily, a drill down the centre and an easyout should work without requiring helicoiling.

As regards the original problem though a couple of things:

1) It is not best to re-use disc and caliper bolts
2) Do *not* use copperslip on them.

Reasons:

1a) Caliper bolts are 'stretch' bolts, meaning that as you tighten them up they stretch, if you re-use them then they can over stretch and fail, failure could be when tightening or later. I'm not sure about the disc bolts but it wouldn't surprise me.
1b) Brakes are going to be the only thing keeping you out from the bales/gravel/barrier, is it worth the risk for something like 25 quid?

2a) Torque settings are there to give a precise clamping force, copperslip reduces the friction and can result in overtightened stretched bolts that can subsequently fail, snapped bolts or stripped threads. If you use copperslip you should reduce the tightening torque.
2b) Disc and caliper bolts if re-used should have the appropriate locktight applied and the torque values reduced, this is because the Honda torque values for disc bolts are with the factory applied locktite already applied, this requires more torque to tighten than a 'clean' bolt or one with liquid locktite applied.

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Re: sheered disk bolt

Post by Neosophist »

fastdruid wrote:Best way to remove if you can is to weld another bolt onto the stub, failing that once the head has gone the bolt should unscrew fairly easily, a drill down the centre and an easyout should work without requiring helicoiling.

As regards the original problem though a couple of things:

1) It is not best to re-use disc and caliper bolts
2) Do *not* use copperslip on them.

Reasons:

1a) Caliper bolts are 'stretch' bolts, meaning that as you tighten them up they stretch, if you re-use them then they can over stretch and fail, failure could be when tightening or later. I'm not sure about the disc bolts but it wouldn't surprise me.
1b) Brakes are going to be the only thing keeping you out from the bales/gravel/barrier, is it worth the risk for something like 25 quid?

2a) Torque settings are there to give a precise clamping force, copperslip reduces the friction and can result in overtightened stretched bolts that can subsequently fail, snapped bolts or stripped threads. If you use copperslip you should reduce the tightening torque.
2b) Disc and caliper bolts if re-used should have the appropriate locktight applied and the torque values reduced, this is because the Honda torque values for disc bolts are with the factory applied locktite already applied, this requires more torque to tighten than a 'clean' bolt or one with liquid locktite applied.

Druid
:up:

Couldn't phrase it any better :D

Locktight is recommended. A small bottle keeps for ages if stored properly. What were you torquing them upto? 30/40nm?

Try cutting a slot into the bolt so you can use a flat head screwdriver to undo it if you can't weld to it.
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Spike16
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Re: sheered disk bolt

Post by Spike16 »

20nm

im gona drill it and easy out I recon. it sheared too far in to cut or weld onto im afraid

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