Belt Angles - do they matter?

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Belt Angles - do they matter?

Post by sideshow » Mon Apr 27, 2015 7:04 pm

So - quick question that I haven't figured out yet (and haven't figured out if it actually matters either) -

Different cvt belts have different side angles. For my application (94c+90d Comet), the angles seemed to be in the 25-30 degree range.

From some shoddy quick research, it seems like at least one application of the 94c (honda odyssey atv) uses a 26 degree belt, so I just looked for a belt of the right width/length with a 26 degree V, but there seemed to be a lot of other belts with 28, 30 degree belts.

Anyone know the issues in using different angled belts?

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Re: Belt Angles - do they matter?

Post by coachgeo » Tue Apr 28, 2015 2:51 am

would assume wrong angle of belt would increase slip potential and faster wear. Assume the pitch of the belt is based on the angle of the sheaves the manufacture uses

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Re: Belt Angles - do they matter?

Post by BertTrack » Tue Apr 28, 2015 8:59 am

The angle the belt has, changes as the circumference that it's rolling on changes. I have looked extensively into the belt options for my Track and have resorted to just forgetting about angle, it's a c.v.t. belt of the right length. And that's more important.

All belts need to be worn in before they get full grip, which i've taken to mean that the more used angle's found in your configuration will wear into the belt. Wearing them in my opinion means low power and giving it time to wear down to the right general angle.

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Re: Belt Angles - do they matter?

Post by Eddy Wane » Tue Apr 28, 2015 10:26 am

Hi All.

This is a link to some information about V belts. ... rives.html

The basic concept of how a belt works is explained but a CVT configuration is not. It seems to me that if the belt angle matches the pulley angles exactly then there would be problems. Looking at some CVT set ups the pulleys are not inline but offset by a small amount. So by default the belt twists its way around the pulleys driving slightly harder on one side of a sheave than the other. It may be necessary for the belt to do this driving on one side under acceleration and on the opposite side when slowing down. Looking at the wear on my Aixam belt, it is rubbing the belt at the top where the strengthening fibres are, which seems logical, whilst the inner part where the blocks are, seem OK. Apparently the grooves in the belt are to make it more flexible and not for driving.
Reading the article it appears that the working part of a belt is where the fibres are (near the outer edge) and the rest of the belt is just for support and is dependent on the application of the belt.
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