CVT questions

[DAMIEN1307]

I hate geometry

Me too, glad I'm not there!

I guess you guys don't play pool then...a game of pool is all geometry...lol.

 

[DieselTech]

I guess you guys don't play pool then...a game of pool is all geometry...lol.

I'm a killer pool shot!!! I'm still glad I'm not there!!!

 

[Chainlube]

Good to know and it doesn't surprise me one bit. Thanks. I thought this was going to be easy until I found one seller with a picture I have never seen. It shows the chain coming out between the pully and the INSIDE of the aluminum plate. I had assumed the shaft and final drive sprocket would go through the plate and be on the outside like with our conventional chain drive transmissions. Does the chain on a Bravex also exit on the inside ?? I think I saw a video where this kid said he had to have a special shaft made. I'm going back to find it. I have never seen a CVT in real life, only pictures.

Yep you'll need to buy a 10" long 5/8" shaft, if you want to run the sprocket on the outboard side of the torque convertor. But yes all the torque convertors run the sprocket on the inboard side.
Actually you might get away with a 8" long shaft.

Years ago they made a torque convertor where the sprocket could be configured on the inboard or outboard sides. It was mainly used on mini-bikes.

You can place the sprocket in any position you want, not the shipped position. There is a snap ring on the shaft and once you take it off the whole shaft comes out. Then just put it back the way you like it. You may or may not need a washer or two between the parts.

 

[michael whiteman]

Thank you guys for all the great information on the CVT. With all your help, I know I can make something work just fine. BTW Diesel, if I buy a 10" slotted shaft, will it require any further maching to make the driven pulley fit ? Chainlube says there a groove for a snap ring. Anything else ?

 

[Chainlube]

Thank you guys for all the great information on the CVT. With all your help, I know I can make something work just fine. BTW Diesel, if I buy a 10" slotted shaft, will it require any further maching to make the driven pully fit ?

You might have to whack an inch off. Get yourself a hand full of locking collars.

 

[GW's Motorized]

I guess you guys don't play pool then...a game of pool is all geometry...lol.

Nah, I like pool. Pool is simple geometry. Geometry is easy for me, I just don't like it

 

[michael whiteman]

I measured my fat tire diameter at 22.5 in. today. Ran it through the speed calculatour with a 10/ 52T sprocket and to my surprise I'll be going 46 mph. OMG....I don't think so! Not on this little toy bike. Mid 20's would scare me. It seems to me that a CVT will not work with a 1to1 ratio at 3600 max (governor) RPM. It probably would have no pulling power up a hill either. The engagement point on the CVT is 2600 RPM, which would need to be reduced with lighter springs I suspect.

It's looking like a centrifugal clutch and a jackshaft is going to be the only way to make it into the 20 mph range.
Going to look at some more videos. What are you thoughts now ?

 

[Sidewinder Jerry]

I measured my fat tire diameter at 22.5 in. today. Ran it through the speed calculatour with a 10/ 52T sprocket and to my surprise I'll be going 46 mph. OMG....I don't think so! Not on this little toy bike. Mid 20's would scare me. It seems to me that a CVT will not work with a 1to1 ratio at 3600 max (governor) RPM. It probably would have no pulling power up a hill either. The engagement point on the CVT is 2600 RPM, which would need to be reduced with lighter springs I suspect.

It's looking like a centrifugal clutch and a jackshaft is going to be the only way to make it into the 20 mph range.
Going to look at some more videos. What are you thoughts now ?

Run the CVT to a double sprocket jackshaft, then to the rear wheel. This'll add another reduction point. Then your bike will have a reduction range of 36.4\1 to 10.4\1 which it'll adjust reduction range automatically.

CVT 10t > JS [20t | 10t] > Rear Sprocket 52t.

This set would be better than a centrifugal clutch setup.

 

[Chainlube]

I measured my fat tire diameter at 22.5 in. today. Ran it through the speed calculatour with a 10/ 52T sprocket and to my surprise I'll be going 46 mph. OMG....I don't think so! Not on this little toy bike. Mid 20's would scare me. It seems to me that a CVT will not work with a 1to1 ratio at 3600 max (governor) RPM. It probably would have no pulling power up a hill either. The engagement point on the CVT is 2600 RPM, which would need to be reduced with lighter springs I suspect.

It's looking like a centrifugal clutch and a jackshaft is going to be the only way to make it into the 20 mph range.
Going to look at some more videos. What are you thoughts now ?

It will pull you up any hill, the engine makes it torque differently. I have one on a mini chopper ("Used to be go cart" thread) it only has 10" wheels and motors around pretty good. Of course I put a PZ19 on it.

 

[michael whiteman]

Run the CVT to a double sprocket jackshaft, then to the rear wheel. This'll add another reduction point. Then your bike will have a reduction range of 36.4\1 to 10.4\1 which it'll adjust reduction range automatically.

CVT 10t > JS [20t | 10t] > Rear Sprocket 52t.

This set would be better than a centrifugal clutch setup.

Great idea but I do not think there is enough space to do this on the OCC frame. I was thinking about the jackshaft plate that bolts onto the engine. A compact unit. I could swap out the gears to create a custom ratio, I think. Thanks for the idea Jerry.