Having to replace rear rotor bolts?

[Guest]

I have a 1980 GS550E and when I replaced the rear rotor with an EBC aftermarket rotor, the oem bolts would not tighten all the way. The rotor is dimensionally identical to the oem except for the flange thickness. So now the oem bolts are not threaded high enough to be tightened. Do I need to replace the bolts now and if so what spec. bolt should I be looking for?

[fastbysuzuki]

I So now the oem bolts are not threaded high enough to be tightened. Do I need to replace the bolts now and if so what spec. bolt should I be looking for?

Can you confirm or not, are you tightening the bolts down and they are hitting the bottom of the holes before tightening up or have I got it wrong?
Or are you saying that the new rota flange is a lot thicker and the bolts are not long enough?
i would be very worried if they where not long enough.
if the bolts are bottoming out in the holes this would indicate that the new flange is slightly thinner than the one you have replaced in that case you need to shorten the bolts a little not forgetting to use the locking tabs to secure the bolts.

[jchavez]

Yes, the bolt appears to be bottoming out before it tightens. The new rotor flange appears to be thinner than the original. The oem bolts are not threaded all the way to the top of the bolt so when you run them in, you run out of threads. Just wondered if anyone else was having this issue with the EBC replacement.

[Nessism]

Do the bolts have a shoulder that fit down into a matching hole in the rotor? Can you use a washer of some sort?

[Cipher]

if you are using OEM bolts and locking tabs just measure the difference in thickness of the OEM vs aftermarket rotor and shim that thing up.

[fastbysuzuki]

Can you not get a die nut of the same thread and run it down the bolts to lengthen the thread?

[jchavez]

Can you not get a die nut of the same thread and run it down the bolts to lengthen the thread?

This OEM bolt measures 30mm long and only 15mm is actually threaded. I really not sure one can cut new threads. Sounds easier just to go get new bolts. If I shim it, would it be with washers under the bolt?

[Cipher]

Far cheaper and easiDo you have access to a pair of calipers to measure things?

[hillsy]

This OEM bolt measures 30mm long and only 15mm is actually threaded. I really not sure one can cut new threads. Sounds easier just to go get new bolts. If I shim it, would it be with washers under the bolt?

Washers under the head of the bolts - the disc carrier MUST be flush against the wheel hub.

I had this problem on another bike and ended up drilling a couple of MM of the threads out of the hub to accommodate the "longer" shoulder of the bolt because washers underneath the bolts heads made the bolts foul the caliper carrier.