Lower mounting point, rear shock

[fracture]

Bike is a monolever R100RT. I replaced the rear shock yesterday. This was the first time I have ever removed the shock. The factory shock started leaking shortly after I got the bike and a shop in the town where I was living at that time installed an aftermarket shock. I did not buy the bike from the shop that replaced the factory shock.

The stud that protrudes from the final drive housing is gouged, as if someone tried to remove it with pliers. The gouges are, in my opinion, pretty bad. Apparently, I have been riding with this condition for many years. It is hard for me to believe that anyone would want to remove this part. And I would think that anyone working in a bike shop would be smart enough to never try something like this.

Another possibility is that the previous owner/another shop caused this damage, but I would have expected the folks at the shop that installed the new shock to notify me of this damage. But, you never know.

I suspect this lower mount is a stud that is threaded into the final drive housing. The Clymer manual appears to confirm this. The issue is what to do about it. Since I have been riding it with this condition for many years I see no immediate problem. If it is recommended to replace this stud, what must be done? I suppose there is a method to remove it without causing further damage to something else.

Your opinions, comments, previous experiences in something like this will be helpful.

[mymindsok]

No offence but: No photo = No answer

We're all :type

[fracture]

My error. Here are some pics.

After looking at this again, I am of the opinion that what I am seeing is galling, or fretting. There may be some type of plating on that stud, and over time, it wears off. Or, if no plating, the stud has galled.

The cause could be incompatible materials. That is, the spherical bearing of the shock is of a material that is not compatible with the stud. Thus, galling. I am not aware of any lubrication requirement at this connection.

There is no such wear on the upper mounting pin. However, the two pins may be of different materials.

I would prefer to replace that stud since if I ever sold the bike I would want things to be right.

I will most likely take it in to have shop mechanics look at it and go from there.

Your opinions and suggestions are welcomed.

[Rpbump]

You can smooth the gouged portion of the stud with a 6" long x 1/2" wide strip of material from a power belt sander. Use progressively finer belt material to remove sharp edges from the gouged area leaving the relatively smooth portions of the stud as close to original diameter as possible. The gouging in the photo should not affect the strength of the stud. I have done this to repair damage to car shock mounts that were damaged by shade tree "mechanics".
Ride Safe :usa :usa

[barryg]

I'm with bump, it looks repairable. Very carefull filing and the use of sandpaper should make the shock stud useable. That is a replaceable part if repairing it goes awry.

[mymindsok]

I'm with everyone else. That stud'll be ok with a little polishing. When youput the shock back on make sure that the steel spacer in in ok condition.

I allways install the shocks with a tiny dab of grease on these pins. It just seems like a good idea to me!

[fracture]

I used some fine emery paper and shoeshine motion to knock down the high spots. Cleaned it up and sprayed some moly lube on the stud and the upper pin. This is the stuff that dries and leaves behind a dark gray, dry film lube. Not sure just how good this stuff is but it is supposed to have a high load bearing capacity.

I measured the stud diameter at several places and it pretty well matched the upper pin diameter. I was surprised to see quite a bit of tolerance between the pins and the bores of the spherical bearings on the ends of the shock. The clearance averaged about 0.015 inch. Maybe this is a bit too loose and contributed to the problem. However, it that is true, then the top pin should also show the same condition as the lower stud.

Since I have been riding it like this for many years it should keep going. Thanks for the recommendations.

[sumran]

I agree that the various repair strategies should solve the problem.

That looks like the type of damage caused by the careless use of channel locks or vise grips. A mechanic that got there before you may have replaced the stud or tightened it with the wrong tool.