Nytro primary in a sidewinder

[1nc 2000]

Don't be fooled. The cats are blowing belts also.

 

[KnappAttack]

Just asking, why does the team primary clutch on AC not break belts? Same motor ,same stub shaft, how could it be all these thing said above?

They still do when geared up. The most successful are the ones geared down, which the Cats come from factory with 24/50 gearing.

The only way I see to keep belts on is to stay at that actual 240-250 HP level or below, run less traction, ride like a beginner, less lug on the track, stay out of any hard pulling. I don't think were going to have success running big power levels and riding them hard no matter what the clutch setup, we'll see.

I've got lots of things to try and keeps belts intact at the high HP levels. 8" fan blowing on the belt and clutches to install into the clutch panel, Team primary, lower gears, belt alignment tools, PB80 Drive clutch and the ability to turn down the power levels. Hope we get a decent winter to try all these parts, because what good is 290 HP if you can't run faster and actually use it properly.

 

[shagman]

The reason the Winder clutch takes less weight for same RPM, is the pivot point center being moved further out from the old Yamaha clutch. With the weights further out like that, they generate more shift force using less actual weight.

I've never seen or heard of a Winder clutch actually exploding or going boom on the Winder. I have seen however a HH or HH style of weight breaking at the threads on the weight and blowing pieces of the clutch away after it slams past the roller from being too short or actually breaking, no fault of the clutch in an instance like that.

I would like to clear a couple things up here. 1st. HH or Heavy Hitter weights have never had a weight failure. It’s also been proven that the HH weight can’t go past the roller. That is directly from the owner/patent holder. 2nd. We know of over 60 blown sidewinder primary clutches so there is a problem which Yamaha is well aware of. Here are a couple that the clutch failed. The weight pocket cracks thru the pin and set screw and back of pocket breaks out. Also attached is a clutch that is cracked and caught before it blew. We found the cracks and then did die penetrant to confirm.

 

[1nc 2000]

Get your clutches real hot one time and it raises hell with the bushings. Roller bushings sieze up and leads to failure in a hurry. Some weights will go past the roller with worn bushing and blow the clutch apart...

 

[Tarzan]

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I would like to clear a couple things up here. 1st. HH or Heavy Hitter weights have never had a weight failure. It’s also been proven that the HH weight can’t go past the roller. That is directly from the owner/patent holder. 2nd. We know of over 60 blown sidewinder primary clutches so there is a problem which Yamaha is well aware of. Here are a couple that the clutch failed. The weight pocket cracks thru the pin and set screw and back of pocket breaks out. Also attached is a clutch that is cracked and caught before it blew. We found the cracks and then did die penetrant to confirm.

They crack no matter what weights are in them,stock,aftermarket. Just a matter of time before someone gets hurt of flying clutch pieces. I dont know what causing this,maybe the new design around the set screw ore more pulses from the engine to the clutch becouse of the new lighter stubshaft or the set screws are tighten to much?

 

[shagman]

They crack no matter what weights are in them,stock,aftermarket. Just a matter of time before someone gets hurt of flying clutch pieces. I dont know what causing this,maybe the new design around the set screw ore more pulses from the engine to the clutch becouse of the new lighter stubshaft or the set screws are tighten to much?

There is no radial bracing on the back of the pocket to support the forces that are being generated. Look at the previous Yamaha clutch and you’ll see the support webbing. Tarzan you are correct. We have seen completely stock machines break. Stock weights and tune.

 

[1nc 2000]

Nytro clutch. I had two of them come apart on my nytro. At least the plastic held up at wot.

 

[Tarzan]

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Nytro clutch. I had two of them come apart on my nytro. At least the plastic held up at wot.

Yes with that profile on the weights i gess you loaded them over 90gr pr weight? 95gr pr weight and you are gambeling with clutch breaking there.

 

[1nc 2000]

Yes with that profile on the weights i gess you loaded them over 90gr pr weight? 95gr pr weight and you are gambeling with clutch breaking there.

That's a stock nytro with a Ulmer clutch kit in it.

 

[Tarzan]

That's a stock nytro with a Ulmer clutch kit in it.

Ok .

 

[Crossfire12]

Just saying team primary has steel spider , wider weights, wider rollers, stronger!

 

[Byam]

Just saying team primary has steel spider , wider weights, wider rollers, stronger!

And cheap sheaves.... Even after the 2018 recall they're still cracking

 

[Byam]

The reason the Winder clutch takes less weight for same RPM, is the pivot point center being moved further out from the old Yamaha clutch. With the weights further out like that, they generate more shift force using less actual weight.

Realy interesting to know! That explain why the primary moveable sheave is bigger than the fix one..? I just mesure it and its ~~~3mm further out on the SW clutch

 

[Crossfire12]

And cheap sheaves.... Even after the recall they're still cracking

I don't know I didn't have recall and I have no cracks nor belt breaking, I use heavy weights with 270.

 

[TT]

I have now mounted the Viper secundary and Apex primary clutches in my Sidewinder. I dont trust the Sidewinder clutches,so many primary that have exploded and that with stock weights and aftermarked weights. I have run for years 380-390 hp on my Nytro with Thunder produkts weights and with no isues.

Now that that you have had some time with your setup. How are clutches holding up (primary rollers) & beltlife Tarzan? What offset did you end up with with the apex primary & viper secondary?