Custom Frame For Thumper Motor

Thanks guys. I have plenty of hubs available. I burned through the sprocket kits pretty quick but more are coming. As for tooth count I can supply as small as a 40t with this design and as large as a 26" wheel can swing before the sprocket hits the ground!
 
You discussed a 56 teeth rear spocket before, I’m curious how many teeth are on the CVT side?

And with those big gears do you even ever need to pedal...?

-Kirk
 
It's a 10T coming off the CVT.....and no, the pedals are pretty much just for looks....you don't pedal these giants.

dnut

Mr.B. said:
You discussed a 56 teeth rear spocket before, I’m curious how many teeth are on the CVT side?

And with those big gears do you even ever need to pedal...?

-Kirk
Click to expand...
 
Hope to not go to far OT here, but I’ve been picking up components for my own Thumper built- I have the Greyhound 6.5hp and Comet Torq-o-verter with a 10t gear.

I’m not building a racer and plan to pretty much use the engine stock with a Mikuni carb. If fact I’m more interested in being able to climb the hills in my neighborhood, but still have a reasonable top end for the flats.

For this what would the experienced recommend for the rear sprocket?

Thanks!,

-Kirk
 
jeff, you and pat should incorporate your chain tensioner and his split sprockets, and you guys would have a winning combo for quick gear changes.

thats an awesome product. i just wish they were somehow available with smaller sprockets. anything over a 32 and i'm winding out.

i could always put a 40 on with one of my motors and build a bike that'll do donuts and burnouts...(:
 
bairdco said:
jeff, you and pat should incorporate your chain tensioner and his split sprockets, and you guys would have a winning combo for quick gear changes.

thats an awesome product. i just wish they were somehow available with smaller sprockets. anything over a 32 and i'm winding out.

i could always put a 40 on with one of my motors and build a bike that'll do donuts and burnouts...(:
Click to expand...
With your 24 inch tires I say it sure would..boogy1a
 
Hey Baird,
If you can't get the right sprocket for the engine, then get the right engine for the sprocket. I see a clone in your future.
 
Was gonna go with 24" wheels on my current race bike but I felt like it may be like cheating :D


Goat Herder said:
With your 24 inch tires I say it sure would..boogy1a
Click to expand...

Mr.B. said:
Hope to not go to far OT here, but I’ve been picking up components for my own Thumper built- I have the Greyhound 6.5hp and Comet Torq-o-verter with a 10t gear.

I’m not building a racer and plan to pretty much use the engine stock with a Mikuni carb. If fact I’m more interested in being able to climb the hills in my neighborhood, but still have a reasonable top end for the flats.

For this what would the experienced recommend for the rear sprocket?

Thanks!,

-Kirk
Click to expand...

Hey MB, I've been running a 52T on mine and it's been perfect with my CVT and j-shaft set-up......front end comes up reeeal ez .wee.

I may run a 56T at Grange, it will be like riding a unicycle laff

dnut
 
i have a goal with these two strokes. i've got a 50cc on the way, which i plan on beating on it to the point where i can challenge the land speed record at bonneville. i've studied it, mapped it out, and set my mind to it, and next year, if everything falls into place, it's me, a crappy chinese stump puller engine on a 1940's bicycle, beating the current class record of 80 something miles an hour.

confidence-wise, i think i can pull it off. reality-wise, i can get close enough that there's nothing else i coulda done to beat it.

while you guys are making fragile bicycles to hold giant paint sprayers, i'm trying to make a lawn edger into a rocket booster.
 
And we old guys are just trying not to fall off our bikes as we watch you go by.

Pat, that's a great design with the sprocket. Why not a smaller sprocket? My Sachs engine calls for a 28T. It would be nice to be able to change the gearing depending on where I am... mountains or flatland. What is the hub you're using? Nice to have the combination available. Also would be nice to have an easy source for 12 and 11 gauge spokes in lengths for either a 24 or 26 rim. Just wishing...
SB
 
silverbear said:
And we old guys are just trying not to fall off our bikes as we watch you go by.

Pat, that's a great design with the sprocket. Why not a smaller sprocket? Also would be nice to have an easy source for 12 and 11 gauge spokes in lengths for either a 24 or 26 rim. Just wishing...
SB
Click to expand...

Hey SB,
On my drum hub I used the adapter plate thickness to establish the correct offset with a flat sprocket. From there we needed to come up with a sprocket bolt pattern. This pattern was chosen based on available sprocket blanks, which are common and therefore cheaper in current standard sizes. The sprocket bolt pattern has a specific call out number so you can easily order from various suppliers. Give them the tooth count and pattern number with chain size and you can get the sprocket made. Same split pattern as Jr. dragsters and Karts. I can go smaller than 40t, and may, but it will not be a split design.
Spokes? There are spoke companies that can easily make any spoke diameter and length you need including 11ga for 24" wheels.
 
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hey CCC a ''snuff or not'' from the 60's honda 305 scrambler would be nice on the end of that exhaust pipe and you could set it on quiet to sneek around like i used to back then.
 
I have been riding this bike around a lot lately and felt the pull starter pulley needed a new design. This is the prototype till I get the billet machined one made. It is really not bad with rope starting it.
 

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ccc

Looks good, the stock hub could be cut off and notched, for poor people like me! lol

That hub is a lot smaller that the oringinal rope spool that turns it . Do you think a 5" dia. or so would be better, easer to pull (for us senior`s) ?

Recently bought a Honda 160cc with belt driven OHC and plan on stripping the tin off it.
The "Bullet Line" cvt looks like the unit that will be used in my Chrome Stretch Cruiser.

Have enjoyed your`s and Cobra Freak`s threads, thanks much.

Ron
 
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