RS rear wheel cush drive donuts

[Henk]

Bugger
I was hoping to get this sorted without ending up buying stuff overseas as a bulk buy using a PayPal account that I don't have. Will leave it a week or two for now.
Wonder if there is enough interest to get another local production run done.

[Bert]

PM Scott. He has stayed out of this given others were doing it; but if there is no one then I'm sure he will be interested in stepping up. He made all of ours...


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[F5 Dave]

Yeah they were ok but didn't last as long as they could have cause of the lack of inner. Cost to add them would be same as standard

[Grumph]

Henk
I also asked Dave the same question, answer was no.
Try these guys - TSR world, approx $9 each http://www.tsrworldwide.com/
There's a couple of us wanting sets so let me know and we can combine shipping

Sad to say Dave's right - steel inner would bring them close to this price from me.

What about scott ?

[Rick 52]

Sad to say Dave's right - steel inner would bring them close to this price from me.

What about scott ?

when the red ones started to wear i inserted copper tube around the bolt head, Its refrigeration pipe 1/2 inch i think, any refrigeration guy would have a off cut... thinking about it i might of expanded the pipe to fit, anyway they are still working well now .

[F5 Dave]

Part of the problem is the NF4 spacer wobbles so much that it kils the cush donuts. I'm going to try talk Sketchy to make some HHybrid NX4 type

[Gigglebutton]

I can make a mouldand get LEP to knock them out if enough people want them.

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[Grumph]

Part of the problem is the NF4 spacer wobbles so much that it kils the cush donuts. I'm going to try talk Sketchy to make some HHybrid NX4 type

That would have to be a large part of the problem....that sort of thing will kill the donuts regardless of whether they're rubber or urethane.

If that can be fixed - at reasonable cost - donut life shouldn't be a problem.

[richban]

That would have to be a large part of the problem....that sort of thing will kill the donuts regardless of whether they're rubber or urethane.

If that can be fixed - at reasonable cost - donut life shouldn't be a problem.

I run a Vortex sprocket carrier and had the same problem. They need inserts like the rubber ones.

[Grumph]

I run a Vortex sprocket carrier and had the same problem. They need inserts like the rubber ones.

OK - the problem with the OE rubbers on the NX4 125's was very short life. Probably due to wobbly sprocket carrier...So stronger urethane donuts with steel inserts solved that problem - roughly tripling donut life...BUT the feedback from among others, Steve Ward was that they were too stiff and may even have been a reason for some gearbox probs he had...

SO - when i was aked to do some for buckets, I told Dave - and others too - about this and suggested no steel insert as this made them much more compliant.

Speculation....the harsher torque of 4 strokes like yours Rich, may indeed require steel inserts. The more violent speed changes of Kart tracks Vs big circuits may add to this too.
What i will point out is that among my previous experience with urethane donuts in this application was a GSXR1100 with all the fruit and on Alky - using Marvics - and with some guy called Holden pulling the string....5 donuts in the rear and in two seasons, no wear. No steel inserts either....I will admit that the Marvic sprocket carrier was a high precision piece with zero wobble.

So - whoever does them should probably put in inserts - and ask for feedback.....

[richban]

OK - the problem with the OE rubbers on the NX4 125's was very short life. Probably due to wobbly sprocket carrier...So stronger urethane donuts with steel inserts solved that problem - roughly tripling donut life...BUT the feedback from among others, Steve Ward was that they were too stiff and may even have been a reason for some gearbox probs he had...

SO - when i was aked to do some for buckets, I told Dave - and others too - about this and suggested no steel insert as this made them much more compliant.

Speculation....the harsher torque of 4 strokes like yours Rich, may indeed require steel inserts. The more violent speed changes of Kart tracks Vs big circuits may add to this too.
What i will point out is that among my previous experience with urethane donuts in this application was a GSXR1100 with all the fruit and on Alky - using Marvics - and with some guy called Holden pulling the string....5 donuts in the rear and in two seasons, no wear. No steel inserts either....I will admit that the Marvic sprocket carrier was a high precision piece with zero wobble.

So - whoever does them should probably put in inserts - and ask for feedback.....

Another thing that adds to the wear is flogged out wheels. Oval hole that the rubber goes in. Mine are not to flash so would have helped shorted the life. I did prefer the feel of the bike with the urethane over the rubber. I would run them again. It would be interesting to try with inserts.

[quallman1234]

Using a Taloon Style Sprocket carrier versus the standard HRC sprocket carrier. Doubles the life of the donuts.

We have a few of these left as we did a run of them. If anyone wants to buy one. However, we never got around to doing the middle spacer, as it varies by application. I.e if RS wheels are on a different frame.
PM me if your after one.

[husaberg]

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