"kindalikeawhizzer"

How about that? A few hours ago this looked like a pretty difficult problem. With possible solutions, yes. But no guarantee that these solutions wouldn't have problems of their own.

I've been working on my own bike this afternoon and checking in here during cigarette breaks. And during that time I've watched the ideas gel to the point that there's very little doubt that our pal silverbear will have a good, solid driveline without too much trouble.

That's really cool.

The know-how and good thinking from msrfan and curtisfox sure didn't hurt, either.

Nice job, guys!
 
Thanks BlueGoat. Been at it for few years. When I was a kid did mini bikes go kart,then bought a Monark twin ( sure wish I had it now ) after I broke a rod I just built a motor bike. I think the most exspencive part was a V-plex clutch $7 (kind of wshed they still made them, they were like the front half of a CVT,pinch the belt and go. About 56 years ago,back then and after just not of a lot of money so and learned to make do and make it myself......Curt
 
Is this a great forum or what?

A couple of days ago I had concluded that the torque converter I bought was not going to work. Then a couple of wrong ideas came to me which seemed to make it possible, but pretty difficult. And now I'm in a different frame of mind altogether.

After some tightening down of the bolts holding the transmission mounting plate to the engine and assembling the drive pulley correctly I see there is no problem at all with the keyway being too short on the engine drive shaft. All I need to do is drill and tap the hole at the end of the shaft for the bolt and washer to lock the pulley in place.

And the only modification I need to make at the rear pulleys and 5/8" shaft is to buy a longer shaft which has a long keyway and is threaded at one end for a nut. If that isn't available then I need to purchase a keyed shaft and make my own threads with a die. And then I need to purchase the right stepped pulley for the final drive. Don't know if that will require any modification at all.

What has made the progression from impossible to possible to not all that hard or expensive is the willingness of knowledgeable and considerate forum members to share their thoughts. I can't thank you all enough. Stay tuned as there will no doubt be other questions later on.
SB
 
Loud cheering from the old guy in the back room on the West Coast. That's about all I have to offer at the moment.

Steve.
 
They are solid. Most common pulleys have a "hollow" side. How much offset do you need?
Also do you want a multi sheave pulley?
 
I don't know yet how much offset I need, but in general it needs to go over where the bearing is... something like the drawing msrfan did on post 432. I think the stepped business is so it can be hollowed out. Once I have the right gearing I don't foresee changing it. I had figured the diameter of the final drive pulley would be about the same as the diameter of the sprocket now on the transmission. But what do I know? That's why I ask a lot of questions. So with a stepped cone shaped pulley the interior would need to be opened up with a lathe, is that right?
SB
 
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I don't think it matters Curt, I generally use aluminum pulleys as they are cheaper.

SB figure the final drive by dividing the dia., of the front pulley into the dia. of the rear. I seem to remember the Whizzer sheave is 15+" in dia. Ideally no less than a 3" pulley is good to get enough belt wrap for a good positive drive (I have used 2.5" when dictated by space). That's basically a 5:1 reduction. Should be fine with the CVT.
 
Thanks. Aluminum can be had just about anywere,ACE, Farm supply. Just about everything I work on has been steel,or cast.......Curt
 
I see the McMaster Carr step pulley is "zinc", so that would be okay? The biggest pulley size on that one is 2 3/4" which would probably be alright, do you think? Solid steel would be difficult to open up inside I would think. Even with aluminum I would guess a lathe is what would be needed or is there another way?

This is working out great! I'm so looking forward to the day I ride this pony off into the sunset. 200cc's of vintage thumper, a CVT transmission and smooth belt drive to the sheave... woohoo!
SB
 
Yeah sb, cannonball is right about the pulleys. A stepped pulley would not be my first choice, I just used it as an example. Hopefully there's a stamped steel cupped pulley out there somewhere that only requires a little welding and no lathe work. But you got a real nice offer from curt to make one and I would be able to help also. I have a pretty good selection of used pulleys and I'll take a look this weekend and let you know if I have something promising. You need to make a little drawing like a blueprint of the dimensions you require when you figure it out. Great job so far.
 
msrfan said:
Yeah sb, cannonball is right about the pulleys. A stepped pulley would not be my first choice, I just used it as an example. Hopefully there's a stamped steel cupped pulley out there somewhere that only requires a little welding and no lathe work. But you got a real nice offer from curt to make one and I would be able to help also. I have a pretty good selection of used pulleys and I'll take a look this weekend and let you know if I have something promising. You need to make a little drawing like a blueprint of the dimensions you require when you figure it out. Great job so far.
Click to expand...

Thanks for your comments and offer of help. I have some pulleys, too, and Curtis is a worse packrat than me. First thing is to know what I'm looking for. What diameter pulley, do you think? 3"? Good to know that I could use a stepped pulley in case I can't figure something else out. With it being either stepped or a hollowed cup, it would seem to me that steel would be better than aluminum or does it really matter? If it weren't hollowed out I would think aluminum would be okay, but for this situation is it strong enough?
SB
 
Your variable drive setup offers a high and low ratio which are known (or easy to calculate). And your rear sheave is known. So you know you're engine has at least a 1hp advantage over a stock Whizzer, which has an overall ratio of around 8.5:1 depending on which final drive pulley is used. So with that info you can calculate a starting ratio for a strong takeoff and a final ratio for good top speed. I think you're going to like the results. Keep in mind that the only pulley size that's not known is the one you're trying to fab. So a little off on the calculated ratios should still give good range. What I'm trying to say is that if the pulley you make has to be a little large to fit over the bearing housing, I think it will be fine. I would tend to go with a lower range if possible considering things like the extra horsepower the trans requires and overall weight. So don't stress over an exact size and fit the smallest one possible to the extended shaft. Having a low range is much more rideable than a high range. Keep the photos coming. This is fun.
 
Msrfan what is the size of the Whizzer pulley that drives the wheel? Have always wondered that,as don't see any around here to measure. For that matter don't see any motor bikes around,but that's going to change soon.LOL........Curt
 
Hi curt. The rear sheave is close to 15'', while the most common double pulley is 5''X3.5'', and the flywheel is 2.5''. Once sb knows the offset he needs and the I.D. of the cup, then we'll know what to come up with.
 
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