Anyone managed to break a footpeg mount - 12'+

[barossi73]

Nice one.you were riding so fast you rearended some innocent bug with your eyeball!

[Jakobi]

No idea man. Unlikely for me to move anywhere fast.. must have been a quick bug!

Few pictures for those interested (if any).

4.5mm pilot drilled through. Commenced 6mm.


Swarf bucket. What was left of the bolt came out very nicely.


Cleaned up and ready for refit.


The mount/bracket from the damaged failed side. Fortunately it didn't let go entirely.




And the other side too. Bolts were all tight, but still shows stress marks and some cracks forming both sides of the upper hole.

[barossi73]

Iv noticed those tapered head bolts tend to do that to their brackets/plates(diff application,early jap car door hinges).nice and tidy but they are effectively a wedge trying to force sides apart.add enough stress/vibration/excess torque and you can get cracks

[Neil E.]

That's just poor design. There isn't enough meat outboard of the holes to have any real strength. It cracks easily to the hole, then cracks further since all the load transfers to the middle of the bracket.

[n_green]

Here's my effort. Good tip re the carbide drill bits Jake. I'll grab some today and tackle the bolts this afternoon.

[Jakobi]

The lower one appears to go into the frame, so you may find the threads drop through the far side and end up inside. Could be a pain. You could have success using an easy-out or other extractor, but if they snap off they typically make the job even more challenging.

[GGRider01]

I've snapped many many bolts and have had great success with reverse drill bits. Even if they fail to remove the bolt, you have a neat hole all the same for easy outs. Most of the time they alone are enough to back the bolt out though.

[shang]

Originally Posted by GGRider01

I've snapped many many bolts and have had great success with reverse drill bits. Even if they fail to remove the bolt, you have a neat hole all the same for easy outs. Most of the time they alone are enough to back the bolt out though.

I have had the same experience. I also try to soak the bolts with a penetrating oil for a day or so and hit it with some heat as well.

[CombatYoga]

I've done it twice - fairly recently both times, and only on the right hand side.

Used an easy out once. Also used my dremel to cut a slot and then used a hammer drill with a flat blade bit to back it out.

Once it happened during practice before a race - I zip tied it on with metal zip ties and it held up!

After the second time, I began to think my rear shock is bottoming - I can't think of any other reason that much force would transfer to the footpeg bolts.

[Jakobi]

Originally Posted by CombatYoga

I've done it twice - fairly recently both times, and only on the right hand side.

Used an easy out once. Also used my dremel to cut a slot and then used a hammer drill with a flat blade bit to back it out.

Once it happened during practice before a race - I zip tied it on with metal zip ties and it held up!

After the second time, I began to think my rear shock is bottoming - I can't think of any other reason that much force would transfer to the footpeg bolts.

Does the kickstarter contact the footpeg on this side? I think it does. That would be transferring a fair whack of force into the peg. Couple that with the design limitations highlighted by Neil and Barossi and you have some cuplrets.

I had considered also if it could be related to the rear suspension, however I think unlikely. I'm sprung quite firmly for my weight and most jolting I get is hitting large square edges - fallen trees etc - of significant size.

In saying that, my left hand peg mount was showing some distortion (had to lever the peg out where the mount had clamped down on it). Also has cracks forming too. My bike has 5600kms/160hrs on it now. Replacing all hardware and brackets. If they go again I'll look at other options.