[billybigbrains]

Happy New Year to you all.

I have a question about the mounting of a 748 rear shock (Ohlins or Showa; doesn't really make any difference).

At the top of the shock is the outer mounting "eye" which contains a rubber bush and an inner metal bush. The top mounting bolt passes though the rocker and through the inner metal bush.

When I tighten the top bolt to anything much more than finger-tight, the top joint becomes very stiff. The bolt tension has tightened the rocker arm onto the inner metal bush. The joint now only moves because the inner metal bush and rubber bush together move (reluctantly) inside the eye.

Is this how it's supposed to work? It seems very stiff to me.

When I took off the original Showa shock, the top mounting bush had been destroyed. I now have a new shock, a new set of mounting bolts and a new rocker, but the same stiffness is there in this top joint.

 

[billybigbrains]

Seized bearings

Well, I found the problem. Each shock eye contains a spherical bearing (pictured). The bearing is sandwiched between a collar and a felt washer on each side. This whole assembly is pushed into the shock eye.

In my case, both top and bottom spherical bearings were completely seized and the entire bearing assembly was rotating in the shock eye. Hence the shock mount was much too stiff.

New bits are on the way from Ohlins via K-Tech. I could probably have got the bearings a bit cheaper elsewhere, but I'm replacing the collars and felt washers too, so I went with Ohlins. Two sets of bits (top and bottom bearings) cost £56.00.

Cheers.

 

[Ducati 748 Delaware]

Good Info

I'll check mine. Thanks for the pic's and happy new year.

 

[billybigbrains]

New bits - photos

In case it helps, here are some pics of the new bits received today from K-Tech. You can see the spherical bearing, the spacers/collars and the foam inserts, and they are all sandwiched together in the shock eye.

The bearings and spacers are in the freezer now, ready for fitting tomorrow.

Cheers