HIGH PERFORMANCE CLUTCH MUSHROOM

As we are all finding that this part is the achilies heal of the bike I am looking at having a stronger part made. My local engineering shop has some trick steel called 555 or similar that is extremely strong. if the mushroom was made of this and the stem of the mushroom increased in diameter (the activating rod would need machining out a little as well) I think it would resolve the problem we are seeing. I think the cost would be about £80 a unit but I can confirm this when I see him. I know it will be expensive as i have had them made before to get over a similar problem with a Z1000 inj. bike that had a lock up clutch similar to Nevs.
If I can get a group buy together I will go ahead. I will come back with a firmer price.

mushroom , no wonder its weak ,,,got any pics so i know what part your talkin about specifically ,cheers :wink: :wink:

Mushroom

I could be wrong but I think the stem is breaking because the activation
rod is over rotating and contacting the stem. This is probably caused by
a combination clutch plate wear and the activation rod wearing at the
point it contacts the lifter "mushroom". I think the lifter piece is not
supposed to rotate when the clutch is activated, but without the proper
clearance it will wear when the engine is running.

I might be in on the new beefier lifter piece but I had just put my clutch back together twice last month and honestly hope I don't have to go back in there again for a long long while. Still, I'd want the better stuff on hand for next time.

I think the biggest problem with the lifter parts isn't so much that the lifter shaft (activation stem/rod) is contacting the lifter piece (mushroom) stem when not pulled but that the lifter piece is rotating too much when the clutch is pulled.

The original thrust needle bearing in the pressure plate didn't allow enough rotation of the bearings when the load was on it, especially with the much stiffer heavy duty clutch springs, because there was too much force on the bearings but the newer pressure plate bearing I upgraded to does allow for easier spin so the lifter piece stays stationary while the bearing spins with the clutch.

I think it more important to upgrade to the post-2005 pressure plate bearing than to harden the mushroom. A harder mushroom could actually hurt more if it don't stay stationary when pulled. Eat up the lifter shaft faster.