Aftermarket shock

bob duke · Mar 7, 2020

Just got a used wilbers shock. The oem shock has a bigger bottom hole on one side and the bolt fits perfect.. With wilbers I can't use the yamaha bolt. Is it OK to use just a longer bolt with threads inside the rear linkage?

infrared · Mar 7, 2020

bob duke said:
Just got a used wilbers shock. The oem shock has a bigger bottom hole on one side and the bolt fits perfect.. With wilbers I can't use the yamaha bolt. Is it OK to use just a longer bolt with threads inside the rear linkage?

Bob,

Common bolts have cut threads. Aircraft bolt threads are "rolled" in, as may be done with a rod of modeling clay (to illustrate). Cut threads may cause the metal to crack. All that to say, you want a solid shaft (shank) at work, not threads, inside any loaded usage.

Ask to see if the Wilbers people have a way to use the stock Yamaha bolts (different shock bushings, maybe). I would not be in a rush to use a bolt smaller than stock there, even with bushings (adapters) to make the smaller bolt "fit" better, in that location. Any failure there could be uglyyy . . .

user 213 · Mar 7, 2020

To add to what infrared offered, you might find a shoulder bolt that will work. Apply a light coat of grease to the portion that goes thru the shock. A good hardware store should be able to help you find what you need. Most of these are hardened and should hold up well. I can't recall if my Wilbers shock came with a bolt to use or if I re-used the stock shock on the '04. Regardless, you want the bolt to fit the hole, not be loose. If it's loose, it will deform or worse quite quickly.

bob duke · Mar 7, 2020

I bought the shock used. Maybe a machine shop is the answer. To cut the spacer at the bolt head. . One other solution is to open the wilbers hole to oem shock size hole https://www.cmsnl.com/products/bolt_9010910007/#.XmQIYregdkw

infrared · Mar 7, 2020

bob duke said:
I bought the shock used. Maybe a machine shop is the answer. To cut the spacer at the bolt head. . One other solution is to open the wilbers hole to oem shock size hole https://www.cmsnl.com/products/bolt_9010910007/#.XmQIYregdkw

Bob,

That trick shoulder-bolt only fixes one side of the problem. I believe that Wilbers will want to help you, either for free or cheaper than a machine shop. Where you got the shock is not important; I would only tell them if they asked. Be ready to tell them what size bolt Yamaha uses, there.
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