Isolastic friction washer preference

Hello,

I'm thinking it may soon be time to replace my front isolastic's friction washers. The last time I did this I believe I used the bronze impregnated PTFE type. I believe these are supposed to be superior to sintered bronze. I also see plain nylon ones around. Does anyone have any preference. What is the thickness of a brand new friction washer?

-Eric

I am not aware of bronze sintered friction washers. I think there is a fair amount of info in earlier posts on the pros and cons of different material, including nylon, delrin, etc, and references to thickness.

Stephen HIll

Straight Nylon, Delrin or PTFE will wear quickly. I have tried all of these.
Mine don't wear, & I have not got adjustable Mk3's either.

Flo said:

Straight Nylon, Delrin or PTFE will wear quickly. I have tried all of these.
Mine don't wear, & I have not got adjustable Mk3's either.

Click to expand...

Are they sintered bronze then? Do they put more wear on the collars and endcaps?

-Eric

I have solid bronze ones, they were made to order in a toolroom from Bronze sheet, have not had to fit them as the bronze impregnated PTFE ones I put in 20 years ago to replace the badly worn plain nylon ones are unworn :shock: .

Eric, The washers are 1/16". I made a set out of PTFE impregnated acetal 1/8" sheet. They've held up for around 20,000mi with no sign of wear. I don't think I would bother again because about the time the stock washers are shot would probably time to go at the iso rubbers too anyway.

They aren't relly "friction" washers. Their purpose is to allow vertical movement of the isos without allowing any lateral movement. The original ones were a high-density polyurethane, and I think they had a coating of Teflon on the rubbing surfaces.

They onl;y work as designed if there's no friction at all. If perfectly adjusted (which lasts just a few minutes of riding!) there's complete freedom of movement of the engine/transmission cradle in the vetical plane of the frame and zero side-to-side motion. In practice, you have to work out a compromise.

We spent hours trying to get it repeatable for a production bike, but we were fighting the distortion in the transverse spacer tubes, which took a few months to diagnose. The problem was shunted over to Plumstead once serial production had started, and I don't know how it ended up. It might be that the production guys didn't undertsnad how those spacers were supposed to work. Communication between the Devlopment Department in Wolverhampton and Production in Plumstead was tenuous at best. There was a sizeable "NIH" factor, and a lot of "real motorcycles" vs "those clowns that make those little two-stroke engines".

Another of the myriad reaons the company went down the toilet.