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



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
WMRRA #29
Team Motoplex Yamaha

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[SV650Racer]

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?

[SV650Racer]

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]

Nothing at all to do with the anodising.

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

[SV650Racer]

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]

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...

[squirrel_hunter]

Arsebiscuits.

It appears we have a green hub and a black pressure plate.

I await the outcome...

[yorkie_chris]

Bump. Read the thread on WERA forum (yes I know it's 700 posts...). It looks like zoran from TWF has managed to get one to work without breaking in 20 minutes. Different washers on the hub needed by the look of it.

[yorkie_chris]

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.

This is what guy from yoyo was saying to guys on WERA, basically blaming riders when clutches were set up as stock on stock motor. Not good PR when it seems solution is so simple.

If you've had problem with backplate wear it is something different. Main problem is pressure plates wearing out stupidly fast.

[SV650Racer]

Thats why I will always and only ever used a Sigma. The application we were using the SV clutch in was way beyond using it in a 72bhp minitwin.

Neil has been superb and Steve now has a new version of the clutch to work with the increased bhp and torque which is almost 18bhp over stock!

[yorkie_chris]

The sigma and yoyo look strikingly similar, and they both changed the colour of ano at same time. Almost like they are made in same place...

[SV650Racer]

Possibly, probaly i dont know. All I know is the problems we have had were caused by us using the clutch in a bike that makes considerably more than stock being ridden very hard also. You sometimes get this with products. Neil has been spot on and now we have one that will work inside the parameters we require it to.

Ive had one also in my 600 supersport bike now for 2 seasons..spot on!.

[yorkie_chris]

It appears that the problem was there in slipper mode by the hub raising up and contacting the wrong part. (a ring around the pressure plate rather than the bottom of the spring pockets).

As you well know a slipper clutch acts exactly the same as a normal clutch under power and using insufficient spring pressure on a tuned engine would cause slippage under power and rapid wear.

This does not explain the rapid wear experienced by new clutches on stock motors, set up with stock parts and in some cases stronger springs. Both suppliers have downplayed the wear as hamfistedness despite the clutches being set up as recommended.

Here's a bolloxsed yoyodine:
http://i281.photobucket.com/albums/kk217/steadyeddie21/yoyodineinner.jpg


Heres a sigma that's on its way to being bolloxsed:
http://i281.photobucket.com/albums/kk217/steadyeddie21/100_0333.jpg



Sarah as much as I know you have to stand by your sponsors this is not isolated wear caused by one nutter with 90bhp on standard springs. Some of bikes that have knackered the pressure plates have then been swapped back onto stock bits with same pack and springs and not broken anything.

Now it seems it is sorted by putting correct thickness washers in there so hub rises up to touch spring wells instead of edge of plate. Seems it was just an f-up from factory.

what stinks for me is both resellers were happier to supply the odd spare part and then blame the riders and mechanics than actually find out what the problem is.



Another note of importance is that there is no problem with sigma/yoyo for other bikes. This bolock with the washer thickness was only dropped with the SV clutch. Have heard of no problem with the rest.

[SV650Racer]

Sigma dont sponsor me or Steve, we purchase our clutches. I havent seen any wear issues on any of the clutches we have fitted other than on Steve's tuned bike and one other tuned bike.

So i can only comment on the personal experience I have had with using the Sigma and the service Neil has given us which has been 10/10. Nothing wrong with that.

[yorkie_chris]

My mistake, I assumed you would not put a companies stickers on your bike for fun

[SV650Racer]

No i put the Sigma sticker onto my bike to advertise that we use and sell them. So we do get a benefit from advertising the fact. Plus it does match the colour scheme quite well!!

I also sell other makes of Slipper but prefer the Sigma item and the back up we have had in terms of setup.

[yorkie_chris]

Who else makes a clutch for SV?

[SV650Racer]

Sigma do obviously, also a company called TSS who i think make the Sigma and brand them as TSS in Germany and other European markets. We have supplied and fit STM before but I know they dont.

[yorkie_chris]

TSS are a company in Czech Republic who supply sigma and yoyo. They also sell direct-ish on the continent.
http://www.slipperclutchs.com/

[SV650Racer]

Yup correct.

[lukemillar]

TSS are a company in Czech Republic who supply sigma and yoyo. They also sell direct-ish on the continent.
http://www.slipperclutchs.com/

clutchs? :lol:

[yorkie_chris]

Obviously English isn't their strong point, neither are tolerances or QC by the look of it.

[steadyeddie]

New to this site, but I thought I would chime in as I'm the one who started all this stateside.

Zoran from TWF might have a solution to this wear problem. The differences between the old hubs and the new ones is actually quite minimal. The old slippers work by lifting the pressure plate from under the spring wells. The newer ones lift from the top of the hub. The new ones have smaller washers under the post springs and that is what he replaced in order to lift from the spring wells. Washers are id. 10.5mm, od.18mm, thickness 1.6mm; much larger than what is there right now. He also used a newly re-anodized pressure plate, an 'new' one that had worn through. A combination of the 2 items seems to be working and will have more info after this weekends races. He is trying a few other things as well and will let me know the results.

Zoran has not seen any problems with the older 'green' slippers, just the newer ones with the black plates. My Sigma ( both pics in earlier post are mine, 1st is Yoyo, 2nd is Sigma ) has 7 races on it and you can see a slight wear line starting to form near the outside edge of the working surface, the inner wear line is from the hub lifting the plate.

I will be contacting Neil shortly as I am interested in what he has come up with.

[yorkie_chris]

So looks like sigma have new clutch out officially.

[steadyeddie]

A link to my post on the WERA site...

http://forums.13x.com/showthread.php?t=253484

[yorkie_chris]

Overall, I have to say I am very happy with the decision to go with Sigma Performance. Neil has been more than helpful, and his desire to fix the issue is to be commended. Anyone with a SV, stock or otherwise, that would like more info is encouraged to contact Neil Spalding at Sigma Performance.

Funny, my experience of his conduct was that he was rather defensive with little admission a problem exists.

These heavier springs and different ramps are IMO solution for different problem to what you had. Zoran-fix with shims working is proof there was an issue before.

SV650racer above says they had issues with slipping under power wearing the back plate out, I believe this is solution to their issue and original issue has been fixed by coincidence.