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Solve belt deflection on CVT belt clutches

donbrown

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Okay we all hear about the hit and miss of belt alignment.

One modification Ive seen in the past is to allow the secondary clutch to move along the jackshaft to compensate for some misalignment. (float the secondary)

But this only solves one axis of deflection. Hopefully it is enough to lower the heat and prolong belt life.

Other solutions are stiffening the rubber on the mounts to keep alignment but adding vibration to the sled and possibly to the rider.


Is the following solution viable OR will it add TOO MUCH WEIGHT?

Align the ENGINE , BOTH primary and SECONDARY clutches all mounted to the same RIGID frame and bolt to the frame via traditional rubber to sleds frame. Maybe float the secondary to compensate for belt deflection from the clutches opening and closing. But I think a rigid identical frame should do it.

This should minimize belt heat issues.


This will shift the flex / out of alignment issues to the jackshaft , shaft from the secondary to the gears.


Split the shaft and add a Constant velocity JOINT like ones used on drive axles of a car , utv etc ? Misalgnment solved !!!


Constant-velocity joints (also known as homokinetic or CV joints) allow a drive shaft to transmit power through a variable angle, at constant rotational speed, without an appreciable increase in friction or play. They are mainly used in front wheel drive vehicles. Many modern rear wheel drive cars with independent rear suspension typically use CV joints at the ends of the rear axle halfshafts and increasingly use them on the drive shafts.


Or make the secondary a clutched point with a EASILY replaceable CV joint attached to the shaft?


Well ? Well ?
 

Teth-Air

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The theory is valid but isn't it much easier to just run a belt drive instead of chain that can handle the twist without the extra constant velocity joint? Don't forget if the shaft moves much it will also need a sliding yoke with splines to deal with the lengthening of the shaft while out of alignment.
 
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donbrown

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The theory is valid but isn't it much easier to just run a belt drive instead of chain that can handle the twist without the extra constant velocity joint? Don't forget if the shaft moves much it will also need a sliding yoke with splines to deal with the lengthening of the shaft while out of alignment.

If built close to secondary clutch I think you could have a yoke in the cv joint
 

Mafesto

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Why do we seem to start having issues. (with 2strokes) at the 150 hp range?
Yet very few turbo 4 strokes north of 200 hp are having issues?
 

sledfvr

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My opinion is that the hp, track size, and riding style has surpassed the abilities of cvt clutches.
My 300+hp yamaha turbos didn't blow a belt ever with 162x2.5 tracks. I could run the same belt all year and not let off the throttle all day. Once I put on 174x3 tracks I can blow a couple belts per day if I don't let them cool down.

Maybe wider thicker belts with larger clutches would help solve the issue?

It seems that it is time for someone to address this issue. I have seen it on all turbo sleds, 2 stroke or 4 stroke with 174x3 tracks on them. It does make sense that the little belts can't handle those big tracks.
If someone comes up with an alternative clutch system, I would be first in line...
 
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