Latest Lunacy--Honda CT70 Clone Build

[cannonball2]

With a strange turn of events I find now myself building a bike with the small Honda Cub type clone engine instead of thinking about it. A friend I hadnt seen in a long time called me yesterday and asked me if I wanted two Honda clones. Sure! I got a 49cc and a 70cc. Both 3spd auto clutch. One is electric start even. I am sure there are issues with them but it will allow me to build the bike atleast and either get one running or hang a new one when the bike is done. I had posted just yesterday in another thread I thought a 5" stretch would be good. I didnt have a suitable frame though. Well my cheap-n-easy trailer was made from the right kind of frame and believe it or not was stretched 5"! Bye bye trailer at least for now. On hand were a set of 24" wheels and tires. The front even has a brake. So its in the rough/mock up stage in just a few minutes. The engine will be about 2" higher than in the pics. It is no wider than a Grubee G4 unit so the wide crank will clear. But I dont think pedals are probably possible with a kick start engine. Not necessary in my state any way. I may or may not use the tank in the pics but it was laying around so I hung it on. Just what I need another MB!

 

[cannonball2]

Wanted to add Im not crazy enough to run a single tube! The frame will be substainally trianglulated above the engine once the mount is established.

 

[wheelbender6]

That looks like it will take some effort finish. Keep us posted.

 

[cannonball2]

Was fooling around with it some have worked out most of the details. Am really trying to keep the pedals and think I have a way. Getting the engines sprocket to line up with out offsetting the engine may be tricky, trying to avoid the offset. May take a jackshaft. All in all doesnt seem any worse that some of my other builds.

 

[wayne z]

Hey, I like this project! Now ya gettin serious, havin gears and juice to work with.

Maybe you could work out one of those hollow jackshafts with an internal shaft for the pedal crank, that could fit in a std bottom bracket.

 

[cannonball2]

Have the frame well along the way, fabbing the mounts now. Went ahead and became an outlaw with a 125cc semi auto/4speed Lifan. Figure the lack of a clutch handle might help with disguising the larger engine(no manual clutches allowed). The specs. list the engine at nearly 8hp-wow! The pedals havee been dropped. not that it was totally impossible but required raising the engine a good bit to clear even a small chain ring. I want to keep the 45lb engine as low as possible. These engines have bolt holes on the bottom for foot pegs. May build a set from pedal cranks set in the normal configuration for effect. This thing would be no fun to pedal even in a break down situation. Id rather push it, so dont see pedals a a great loss, except I have come to believe a true MB should have them. My major problem is figuring gearing only because I dont know the drive sprockets final ratio/rpm. It will run a jack shaft. So the ratios can be adjusted. Also having trouble finding 420 sprockets fot the jackshaft(5/8 bore). Any insights?

 

[moonerdizzle]

Tractor Supply Company might have them

 

[cannonball2]

Checked all the usual suppliers, Grainger, MM Carr, etc. no luck on the 420 sprockets. Will just mod a stock one. Found the primary reduction ratio so have worked out the basic gearing. This engine has two HP ratings one at 8+ hp continious @7500, one at 11+ at 9500 limited. If it really would do the upper limit it would top 55mph. Not what I am wanting to do, but should cruise easily in the 40-45 mph range, and still climb any thing out there. Now just sitting waiting on stuff to arrive.

 

[happyvalley]

The pedals have been dropped.
I want to keep the 45lb engine as low as possible. These engines have bolt holes on the bottom for foot pegs. May build a set from pedal cranks set in the normal configuration for effect. This thing would be no fun to pedal even in a break down situation. Id rather push it, so dont see pedals a a great loss, except I have come to believe a true MB should have them.

I'd have to agree, no big loss with the pedals, you've stepped beyond MAB into the world of scooter/small motorcycle.

 

[cannonball2]

For anyone considering a build using a clone engine like this, I found these and thought they were pretty neat.engine stand motor mount crf50 Lifan ct70 z50 sl70 xr70 | eBay

 

[cannonball2]

Installed a jackshaft in place of the pedal crank. Will drive off the left side. There is no reduction in the primary, it simply aligns the engines chain, Gearing changes will be made at the secondary small sprocket, I have three 9.10,11. The 11 gives a theroetical top speed around 60-way to fast! Ordered a sprocket adapter and 40t sprocket from Sportsman, so I now have almost all of the puzzle pieces on the way. Still toying with pedals, have a way to install them but dont know if I can shift with out a fixed foot rest. Could make a hand shift but that a sure give away its an outlaw bike. Dont think one of my 49cc decals will cover that.

 

[cannonball2]

Update on the whatever it is. Hung the mock up engine, and fabbed the foot peg mounts. The Lifan 125 just got here along with the exhaust. The exhaust fits well, will just require a simple mount. Picked a muffler to keep a low profile versus a straight pipe that would certainly advertise this thing is being shifted- illegal in my state. Am still waiting on some key parts so thats about all to do until they arrive. The bike sits well and the foot peg placement is comfortable. If its not too vibe prone should be a great ride.

 

[MEASURE TWICE]

I rode the 70 in the 70's. Wooo flash back!

Nice...really nice!

MT

 

[cannonball2]

Thanks MT! Fabbed the muffler mount last night, is mounted with a rubber isolator to the frame, also got the coil and CDI unit mounted, Fortunately the manifold sent with the engine is offset to the left avoiding the lower frame tube. Will have the ability to run some decent lighting with out a battery, but requires a voltage reg to keep the voltage from spiking and blowing the lights. So should be pretty cool. Am trying to keep as much of the bicycle look as I can so it doesnt look like a M/C. The muffler doesnt help visually though..

 

[happyvalley]

Am trying to keep as much of the bicycle look as I can so it doesnt look like a M/C. The muffler doesnt help visually though..

We know you do good work CB but I'm afraid that's a losing battle. I'd be tempted to accept the fact it is a MC and just put knobby tires and a big rear sprocket on it and have it be a lightweight and zippy trail bike for strictly off-road use beyond the purview of any LEOs.

 

[cannonball2]

Probably truth of the matter its neither Too light to be an M/C and by definition not an MB either, must be a cross over, yeah thats it a cross over. Have parts made to change out the foot pegs to pedals maybe that will do it. Have already conditioned myelf to say the shifter is the disengagement lever for pushing. Maybe a front basket, a bell and some streamers for the handle bars.

 

[moonerdizzle]

Don't forget the playing cards in the spokes. lol

 

[cannonball2]

Don't forget the playing cards in the spokes. lol

Great idea, that will explain the noise. Maybe I can convince the LLE that the Lifan is a vintage Matel Varoom Bike motor.

 

[MEASURE TWICE]

Yes get a different motor like the 2 D cell powered. If you get pulled over, then pay the fine. But tell em you'll take one D cell out to get in under the wire and you don't have to walk home.

See Vroom

VINTAGE "V-RROOM II MOTOR BIKE ROAR". by MATTEL [RARE] in ORAGANAL BOX | eBay



Should that not work, get the siren and you do the pulling over. Cound not find on for sale like this though. We had them in the 60's and no one I ever knew was told it was illegal to use the siren.

Vintage Bike Siren | Collectors Weekly


Fun with the way back machine

MT

 

[cannonball2]

Hmm, maybe get some V-rroom decals made, and JB weld a couple of D cells to the top of engine case. Just to be safe I think my daughter still has a set of Strawberry Shortcake saddle bags, those would convince even the most hardend officer Im on the level( if not a bubble off).