If you decide to go with the jack shaft, talk with Pat, the set up he dropped into his 200 is pretty darn slick. That it doubles with the bicycle crank is just the coolest way I've seen it run. It's so compact, and the chains are just perfect. It really is a killer way to run.
Custom Frame for Board Track Thumper
- Thread starter culvercityclassic
- Start date
Two inches should be OK. You don't want to go down too low because you don't want too much air between the top of the valve cover and the tank tube. The old bikes had an unusually long stroke engine that necessitated the drop loop frame. What would be neat is if someone made a valve cover that was finned like the cylinder that made the engine appear to be 3 or 4" taller than it actually was. That would be cool. You don't need to run the Comet mounting plate to run the Comet CVT. Mount the Jackshaft where you want it separately from the engine. That way you get the best of both worlds. It really is an awesome piece of machinery, that CVT. If you could ride my bike to see what it's like with the Comet on it you would be a total believer.
Update: I made a new motor mount and did not like the way it looked and the effort to change it all. So back to the orignal look.
I have decided to run jack shaft now...the CVT on my race bike has a love hate relationship with me...lol so it going to sit or be sold for a very good price...
I have decided to run jack shaft now...the CVT on my race bike has a love hate relationship with me...lol so it going to sit or be sold for a very good price...
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wow, looks great CCC. I thought the frame looked pretty large at first, but the engine fills it well. The extra large rear tyre looks pretty cool. Whats wrong with the GTC CVT? mine just arrived and now I'm a bit worried
Cobra is right...I wanted to mount the motor centered and with the CVT would require an extra jack-shaft to get proper alignment. I will try the jack shaft and see if I like it and if not I will adapt the CVT.
Whitey: you made the right choice as far as purchasing a CVT, you will love the low end and the way it runs with top end. Its smooth and the motor does not over RPM. Your purchase from AGK was a very wise choice...good people and in this day and time its hard to find...
Whitey: you made the right choice as far as purchasing a CVT, you will love the low end and the way it runs with top end. Its smooth and the motor does not over RPM. Your purchase from AGK was a very wise choice...good people and in this day and time its hard to find...
I agree with Rich, definitely check with (Pat), sportsmanflyer aka sportscarpat!
Pat, has designed and or re-designed his own version of an amazing reduction drive system which is a design well proven nearly 100 years ago on original BTR's!
Hopefully he'll make these available to his customers, maybe Rich knows something about this.
Pat's, reduction drive system is very similar to these originals below!
C.H.
I agree with you CH, it's the best system going right now. It sure would look and perform well on this bike.
Too bad all we have are automatic clutches. If we had manuel clutches then the bearing on Pat's reduction could be a one way bearing and allow the engine to be started by pedaling rather than a rope. Pat needs to develop a manuel clutch and then all will be well in the world of retro biking 
Oh, I've been thinking about it. One little piece of the puzzle at a time. I racked my brain on the pedal/drive reduction system for months, then one day the light bulb turned on and I sat down and drew it up. The new system works great and I couldn't be happier with it.Pat needs to develop a manuel clutch and then all will be well in the world of retro biking
Pat and I have had lengthy discussions about one way bearings and such, but I have to say his current setup is pretty slick as it is.
I have figured out a clever way to make it work by moving the clutch to the jackshaft. But no time for a new build right now, and besides, I have a cool little kickstart 3 spd gearbox to fool around with when time allows.
I have figured out a clever way to make it work by moving the clutch to the jackshaft. But no time for a new build right now, and besides, I have a cool little kickstart 3 spd gearbox to fool around with when time allows.
To bad you couldn't find a old Monark clutch for a patern. My old Monark Twin back in the 60'S had a real simple clutch. It set up under the seat like Wizzer bikes,but had a single lever like the china girls. I could draw a scetch of how it worked. It had about a 6" pully up front and about a 21/2 or 3" in behind. The large pully moved out when you pulled the lever,and was hallow with diskes inside. Sliding shaft that had a single ball at the end between the lever and the shaft that would be the bearing when spining.
If I remember right that was the part that failed and had to have redone but with modern thrust bearings it might be better...........Curt
If I remember right that was the part that failed and had to have redone but with modern thrust bearings it might be better...........Curt
Update: the more I ride my four strokes the more I like the way the CVT performs. With the jack-shaft setup the motor is always above 4000rpm when cruzing...and this gets old real fast.
So I am back to the CVT with some modifications so I don't have to run a jack-shaft. I made a new plate and moved the sprocket to the other side which gives me perfect alignment to the rear sprocket...
This new design is how it should be made so we don't have to off-set the engines. Wolf CVT...lol
So I am back to the CVT with some modifications so I don't have to run a jack-shaft. I made a new plate and moved the sprocket to the other side which gives me perfect alignment to the rear sprocket...
This new design is how it should be made so we don't have to off-set the engines. Wolf CVT...lol
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Ok, I see what you did. You installed your own repositioned bearings and moved the sprocket inboard. Good idea. This will give you the two inches you need for a centered engine. Once you ride with CVT there is nothing like it Are you still going to use the forced air shroud for the engine or was that just for testing purposes?
Are you still going to use the forced air shroud for the engine or was that just for testing purposes?Wow I love how you used different bearings to center the engine. Do you mind if I copy that idea? I test fit my engine today and it was way too far towards the right for me to bear. What is the name of that type of bearing?
This new design is how it should be made so we don't have to off-set the engines. Wolf CVT...lol
^ perfectly said.
This new design is how it should be made so we don't have to off-set the engines. Wolf CVT...lol
^ perfectly said.
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The bearing is a 2 hole flange type: McMaster-Carr
You will need some Alum plate to make a new backing plate or you could use the one you have.
You will need a 5/8 keyed shaft to use since the old shaft will not work without having it machined down.
http://motorbicycling.com/f48/comet-cvt-modification-35248.html
You will need some Alum plate to make a new backing plate or you could use the one you have.
You will need a 5/8 keyed shaft to use since the old shaft will not work without having it machined down.
http://motorbicycling.com/f48/comet-cvt-modification-35248.html
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Three thick at the bearing...1/4 6061, this is to run that type of bearing. I wanted to keep that space as narrow as possible. If this becomes a problem I may have to run a 3rd bearing at the end of the shaft, which would mount to the motor mount plate.
Update: I made the adapter for the disk brake to attach to the rear wheel drive shaft off the CVT, I am going to mount the caliper at the bottom since it will look cleaner in that location.
I am itch-n to get this bike done but need to order some small items and some larger ones too, Felt rims...with brick tires... are da chit
I am itch-n to get this bike done but need to order some small items and some larger ones too, Felt rims...with brick tires... are da chit
