Anyone running yoyodine or sigma slipper clutches?

[yorkie_chris]

Specifically newer ones?

You may have a problem;
http://forums.13x.com/showthread.php?t=223518&page=8

Originally Posted by evil dave(WERA forum)

Well, the plot thickens...

Mr. Sunshine brought over two plates. One green. One black.

We calibrated the measuring device on raw aluminum.

We checked the thickness on the black part. It read over 1 mil.

We checked the green part, fully expecting to read 2 to 3 mils.

The green part read slightly over 1.5 mils of coating.

I had one of our most experienced guys in the shop look at the part. The plating shop manager. He has been at this for over 30 years. He looked at the two parts and I informed him of the strange readings, not at all what we expected.

This is what he said:
He believes the black part is regular sulfuric acid anodized. What you would find on any aluminum part that is for decoration purposes only. The green part appears to have hard anodoze. He disagreed with me on the seal, in his opinion (which is better than mine) is that it is probably dyed that color and getting a different seal. (There are several different seals for different purposes.)
If the green part is in fact hard anodized than it would explain why there is less wear on the contact surfaces. (we checked film thicknesses on different surfaces on the part and found it was slightly thinner on the surface that gets wear).
He continued to say that certainly if the black part was regular anodized it would not offer any protection beyond corrosion protection. Hard ano goes "half in and half out" or better "penetrates" the surface of the aluminum.

Remember, the duc parts get ceramic coating (due to dry clutch). So I still stand behind my belief that the black parts are standard anodize and the green ones are hard anodize, but maybe a different seal (which would make no difference as far as the wear surface is concerned).


So, the bottom line is this....

We can strip and reanodize the plates for whoever wants to be test lab mice and report back the results to this board.

I have no real gain or loss here. Personally I am only:

1. Trying to help out a close friend (Mr Sunshine)
2. Am personally intersted only because my hobby (racing motorcycles) and my job (powder coating/ plating) are intersecting.

Hope this additional information helps.
__________________
evil_dave
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Sigma are building a new race version of their slipper in conjunction with Steve Jordan. Steve has run one in his SV700 all season and has had back plate wear which is due to springs and the power his bike is putting out being more than the clutch was originally designed to work with.

Sarah

[yorkie_chris]

Why would there be a need for a race version?
Have you read that thread? Is the one he's got an older model which has been anodised properly?

Because alot of people race tuned SV's now. The problem is with the extra torque on the tuned motors the clutch is slipping too soon and for too long which wears the plate out.

Steve has spoken with Neil about this a fair bit and we may have one to test very soon.

Nothing at all to do with the anodising.

[yorkie_chris]

Originally Posted by SV650Racer

Nothing at all to do with the anodising.

The problem described on WERA? Or your problem with the back plate?

TBH I havent read the whole thread yet. The problem we have had with the back plate wear on the Sigma which looks the same as what is posted in that thread in one of the pics with the Yodo clutch and is down to the clutch slipping too long and too soon.

TBH it was hard to pick up. When I rode Steve's bike i couldnt notice it. Hence why Sigma are now doing a new race version.

[squirrel_hunter]

Ok so I read that entire thread and am left confused.

Are we saying that there is a problem with Sigma Slipper Clutches, but only the newer ones?

If someone would for example have one in their garage that they bought second hand, how would they know if their clutch is effected by this problem other than running it to destruction?

[yorkie_chris]

The way I read it;
Old ones were green anodised pressure plate, these were fine. Then maker of yoyo and sigma changed to either different ano process or subcontractor who did a different process, black in colour. Cheese like in its wear quality.

My personal view, if I had old one I would use it, I would not buy new. If I was desperate I would skim it or get it stripped and redone.

[yorkie_chris]

Originally Posted by squirrel_hunter

Are we saying that there is a problem with Sigma Slipper Clutches, but only the newer ones?

If someone would for example have one in their garage that they bought second hand, how would they know if their clutch is effected by this problem other than running it to destruction?

We? I'm saying little, the arguement is between some very pee'd off customers of yoyo and yoyo. I am just messenger.

It seems colour of anodising is key to look at, you can see in thread. To test for real you could fit it, use it a while then see what state it's in.

[squirrel_hunter]

I was inferring the royal we. As in we are off to the garage to see what color clutch we have...