EVR Progressive Engagement Pressure Plate

[Howie]

Just for the sake of clarity the idea behind the 4 spring idea my thought was in stead of the fancy pressure plate.  My thought was lighter pull would make the clutch easier to modulate.  And yes, it will slip before minimum stack height, but hopefully at that point the young lady would have enough experience and two more springs would then cure the slipping.  Good idea?  Dunno.

But then again, Yogi has the formula.

[koko64]

Thanks Yogi and Howie.

Since the bike is an M900 with less plates I'll have to measure my results without hard reference to stack heights. That info is great for anyone with an 1100, and can be applied in principle to 900s. The big thing I got from Yogi's info was the removal of the innermost steel driven plate. Something you shouldn't have to do, but there's no where else to do it on the stack besides the front you are instructed to move.

The 4 post idea is one I have tried and works well for lever effort. I'm running that at present at Howie's suggestion. I had a drum aside to do it and it's giving a better result than the fancy pressure plate. I may try the EVR plate with the 4 post hub/drum in conjunction with the inner driven plate removed.

Howie, do you have any reservations about only having one steel driven plate at the base of the stack? It's the only way I've got any chance of getting the stack to a workable height, even when only using 1.5mm plates.

[Howie]

I don't see it as a problem, no guarantee though.

[koko64]

I spent some time experimenting today. Trying to get the plate to work without marking it. It has small rub marks. I am leaning towards seeking a credit on the EVR plate.

I was able to achieve a really nice progressive clutch engagement by just swapping over the dished plate in the stack with the first plate on the outside of the stack. The EVR plate basically has a dished plate stuck to it, so I guess I'm a copycat. Works better than the EVR plate with no side effects and no mucking around.
Just adding a dished (or curved plate) in place of the last outermost plate without removing the one in the stack can cause clutch drag and grabbing as Brad pointed out.
Unfortunately the EVR plates instructions don't cover any of that except to mind your stack height maximums and minimums and remove one outer plate.
As Yogi said you need a bunch of 1.5mm plates to have half a chance of getting the clutch to behave. You also have to remove a plate from each end of the stack. You need to be comfortable with running one driven plate at the base of the stack which supports the whole clutch pack.
Don't go too heavy on the springs with this plate unless you have succeeded in avoiding clutch drag to the point its starting to slip. The pressure plates thickness may be preloading the springs too.
I decided to run my four poster Vee Two drum with strong springs to give a light clutch action for the newbie while avoiding slip. Howie's suggestion is working really well.
The tolerances of the EVR plate are nice and tight on the OEM drum but can be too close for aftermarket drums, so keep that in mind. Probably depends on the make. As the stack height got lower and lower when using a couple of Vee Two drums the tolerances got tighter and tighter. The pressure plate could jam on the drum.

EVR appear to make some really good stuff like their 48 tooth clutches, but this item, as beautiful as it is, isn't worth the money imo. If you want a beautiful pressure plate, EVR have their regular vented version.

Our good sponsors Moto Wheels were happy for me to return it. I gave them all my observations and what I learned trying to make the part operate as intended.
Cheers.