Comet CVT Modification

C

culvercityclassic

Well-Known Member
This is my second CVT that I have purchased and will be using on my newest build "Custom Frame for Board Track Thumper". The drawback of the CVT is you have to off-set the motor to get the drive chain to line up, if you don't mount your motor just right the alignment will be off with no adjustment.

The modification moves the drive gear to the opposite side of the plate which allows you to center the motor and have adjustment for the correct alignment. The gear can slide back and forth with ease. I have had this idea for awhile and decided this build would be the perfect time to try it. Plus ya gota love the way a CVT works...
 

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2 pieces of 1/4" do the trick? Or should I just buy a mill? That's a great answer to the problem of CVT offset, was going the same direction with this. Nice work as usual!

I've got just the gearing on my 212cc now using a 12t on the CVT.

dnut
 
Very interesting. Is there only one bearing supporting the CVT shaft? Or is there another on the inside of the plate?

You said that this mod was to move the sprocket to the opposite side of the plate. Does this mean that the sprocket was on the same side of the plate as the CvT pully?
If I understand the pics correctly, it looks like this mod just moves the drive sprocket a couple inches closer to the plate.
I'm just trying to understand the configuration of the stock CVT before I invest in one.
I have two scooters and Heald Bronco, with CVT's and I realy like the way they work.
Thanks, Wayne
 
wayne z said:
Very interesting. Is there only one bearing supporting the CVT shaft? Or is there another on the inside of the plate?

You said that this mod was to move the sprocket to the opposite side of the plate. Does this mean that the sprocket was on the same side of the plate as the CvT pully?
If I understand the pics correctly, it looks like this mod just moves the drive sprocket a couple inches closer to the plate.
I'm just trying to understand the configuration of the stock CVT before I invest in one.
I have two scooters and Heald Bronco, with CVT's and I realy like the way they work.
Thanks, Wayne
Click to expand...

The sprocket was on the same side as the CVT pulley, sandwiched between the plate. It is now on the other side and can be moved back and forth. I have two bearings on the plate; if you look close you can see another spacer plate on the back side holding the other bearing.
 
I have decided to add a 3rd bearing for added support to the CVT. Now comes the fun part of making a bracket for the bearing and the caliper.
 

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That really is nice work. I wished I had the tools and money. I had my eyes on the comet since mid nineties when it was the rage on Jr dragsters
 
culvercityclassic said:
Hey Wayne I like that bearing, just wish they showed the dimensions.
Click to expand...

You can go to the sellers store, and click on the bearing size you want. There is a descripton there.

Edit: The descripton is on the auction page , down a bit. Not sure exactly where they're measuring the shaft height
I have a 5/8" set at home, I can check those later today if you like.
 
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At the risk of sounding stupid can someone explain something for me .
I know how a cvt works by expanding and contracting to change the drive ratio , but here's where I get confused .

the torqueAverter ... i,m pretty sure is a cvt .

KEEP IN MIND ...i,m talking about little torque converters that they sell for go-carts
I know how a fluid filled automotive torque converter works .

But , what they are calling torque Converters ( look to me like nothing more than a centrifical clutch .... yet i see some advertiseing 10-1 overdrive ? How are they getting the overdrive ? Planetary gearing ?

OK ... my stupid question .
whats the difference between ( go-cart type ) centrifical clutchs and a torque converter ? or is the torque converter nothing more than a drive pulley off a cvt ?
Sound stupid but i,m a bit confused .

And with Comet going out of buisness , what other brands are there that i can search .
 
OK, I measured my pillow block, it is exactly like the one in the link. It measures 2.75" from the base to the center of the shaft.
 
well , i,m still confused ... that link shows a clutch ... and a cvt .
they are calling the cvt a torque converter .

now i see where i was getting confused ... some of the sites i was looking at were showing ONLY the driver and refering to it as a torque converter .
In the same add they were claiming 10-1 overdrive ( which personally i think is impossible ) ... it wouldn't have thrown me off if they had shown the driven with the driver .

thanks
 
Very nice CCC. I like how you have a longer shaft and mounted the rotor to it :eek: Where's my brother I need to show him this......
 
I made the 3rd bearing bracket, which I feel is necessary with this modification. This bike has turned into a project.

Now comes all the measuring and bolting down.
 

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