I have a 74 850 Commando that I'm restoring. When I bought the bike it had a Dunstall fairing and a set of clip ons. The Smith gauges where bolted to a home made bracket that was connected to the upper tree where the handbar clamps would normally be.
I've recently removed the entire front end to remove the clip ons and replace the leaking fork seals. I'm installing the original roadster bars and have purchased new instrument cases to mount the gauges. When I reassemblied the front end, I followed the instuctions in the shop manual so that the fork tubes were properly installed into the upper tree and the tappered end of the fork tubes are flush with the upper tree. The problem that I'm having is that the top fork bolt does not seem long enough to properly thread into the fork tube.
The top fork bolt itself is a litlle more than 9/16 from the bottom of the bolts head to the very end of the bolt. The instument cases I have are 7/16 thick where the top fork bolt goes through on it's way to the fork tube and the washer that goes on top of the instument case is also 1/16 thick. This leaves only a little more than 1/16 of the top bolt left to thread into the tube. Obviously it is not long enough and would certainly not keep the springs contained if one was to hit a sharpe bump.
I'm starting to think that either the instrument cases are too thick or that the previous owner had replaced the original top fork bolt with a shorter version when the original instument cases were removed.
Does any one know if there are two different lengths of fork top bolts or if anyone has heard of someone shortening this bolt when the instument case is removed. I'm presuming the only reason for someone shorting the bolt would be to correct the damping of the fork springs.
Any ideas or help would be appreciated.