Alloy clutch centers

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madass140

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discussed before but I'd like to revisit this.
I had thought about producing these but research shows that their life expectancy may not be very long and
I'm wondering if the reason is because of the suppliers that sell them dont seem to have them Type 3 hard anodized , if
anodized at all.
One Ebay seller sells one and its not anodized at all, of course it will wear very fast.
Roger RGM sells one and it appears his is either not anodized or not properly hard anodized
My opinion but not proven (tested) is that if the clutch center is anodized Type 3 hardness then it should get good mileage
especially with fiber plates.
Today I was machining a Harley rear wheel drive pulley. The pulley teeth were hard anodized, obviously Type 3 hardness, it took
a bit of doing to get the Tungsten Carbide tool (insert) to get under the hardness.
Unless I can be convinced otherwise, I think with proper Type 3 anodizing this would make a nice lightweight, long wearing part
especially with fiber plates.
Don
 
Is there an actual, quantifiable advantage to an alloy clutch center other than a few ounces of weight reduction?
 
sorry for the confusion, I was thinking that it would be used with the alloy clutch basket of the belt drives, obviously not much advantage with the steel chainwheel, may as well stay with the complete heavy bundle.
 
Hi Madass

Have one in my NEB clutch. Didnt look hardened but lasted well with fibre plates.

Chris
 
Hi Madass,

If the original was a problem then I am sure someone would have done it by now and it seems they have. From what I can gather, in the motocross world, many junk the factory supplied clutch alloy parts and go over to a steel parts for hard use.

Life with fibre plates may be ok, but with sintered plates not a chance.
 
I tried an alloy clutch years ago on a 750 Commando with stock triplex chain primary drive. It had both center and outer (sprocket) in alloy. If it was anodized, it was only a clear anodize, not the darker finish I usually associate with the harder processes. The chain sprockets wore out almost immediately, and the center was already showing serious wear. After all this time, I'm not sure where I bought it, but I think it was from Les at Fair Spares. At that time I was still using the original fiber clutch plates. It would seem worth experimenting with the Type 3 finish to see how durable it really is. Aside from a little weight saving, I think the real benefit would be reduced impact on the gear teeth from abrupt speed changes. Anything that reduces the weight hanging off the end of that long mainshaft would be an improvement. Probably of more interest to racers than casual street riders, but also to those of us who just can't resist playing with the trick stuff. Price might also be a selling point. New steel ones are not real cheap.

And if you are thinking of making the complete belt drive package, you might think about modifying the design to take another pair of plates. That would give more torque capacity without increasing pressure at the lever. I looked at doing that last year, and it seemed feasible. I talked to Matt from CNW about a deeper clutch basket to take the extra plates, and he said it should be pretty simple, and referred me to John, his CNC guy. But then I realized that I would still have a problem with the center splines not being long enough. Unless I could find someone already making steel centers, who would be willing to make a few in a longer spline length, the cost would be more than I could manage. The quote I got from my friend with a local CNC shop to make a small batch of them was way out of my budget, so I scrapped that idea. But if you are going to be tooling up to make them anyhow, going to a higher torque capacity might be a good selling point. Or maybe it's just another bad idea. I seem to have plenty of those.

Ken
 
Would it not be easier to modify a clutch off a big Jap bike, they generally run in engine oil, transmit loads of power and it may be an option to fit one inside the original Norton item.
 
Hi
I have rebuilt a Kawasaki ZX10 (1990), a GT750 (1974) and a TR250 (1967?) and all have had aluminium clutch housings and centres, all these shown very little signs of wear.
All these bikes had cast/forged/diecast clutch parts, this would allow them to use a suitable grade with the good tensile/bearing stress as well as being an alloy that would allow it to be anodised to increases surface hardness, but not sure on this part as my experience is the surface hardness is very thin anyway
I am sure most Japanese bikes would follow suit, so couldn't you make one to suit a Norton out of 7075 bar stock, would be expensive but it is sure has plenty of strength, can't remember if it can be anodised though to increase surface hardness?
Best regards
Burgs
 
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