Hello. Just fitting front and rear Vernier isolastic upgrade to my 73 model 750. I purchased the kits from RGM, the kits utilise your existing centre bolts My question is should the central bolt through the centre be a snug fit? It is on the rear but the front feels a little slack. I've contacted RGM who said it won't make any difference once the nut is nipped up. Always had very good service and parts from RGM but this just doesn't sound right. No obvious signs of wear to the bolt which is/was a snug fit in the old isolastic assembly. Is this something I should be concerned about? Are RGM correct. Any thoughts or experiences welcome. Many thanks Paul.
what you mean by "snug". The bolt / stud should be able to slide through with hand pressure but not flap about (yes I know it's subjective). It could be that your front bolt is slightly worn. Have you passed a micrometer over it?
Likewise I've found RGM ok.
As Ian says some measuring is called for.
Andover Norton and RGM list the nut (06.0438) for this bolt as 1/2" UNF so it would be worth checking that the bolt is to spec, i.e. exactly 1/2" major diameter and something very close to this for the internal diameter of the isolastic centres.
It is difficult/impossible to know what has been fitted previously and you may need a new long bolt (06.0423) and nut.
I agree it should be an easy push fit but not be loose - vague I know.
Thank you for your replies. I have to admit I haven't checked the bolt with a micrometer, needs a new battery! I've ordered a new bolt from RGM to be on the safe side. The current one is slack/baggy and can be rattled in situ through the mechanism. I suspect at some stage it's been replaced by a previous owner with a slightly wrong gauge one. Still don't understand the advice from RGM but hopefully the new bolt will be a nice fit. Thanks again. Paul.
Somebody's probably replaced it with a metric "equivalent" - ie 12mm. If I had a quid for every metric fastener I've found on old British bikes....
The worst was an Ariel Arrow whose bodywork was held together with guttering bolts and square nuts!