CVT Rack Mounted 33cc CVT Full Suspension Mountain Bike

Discussion in 'Transmission / Drivetrain' started by psychedelicode, May 20, 2012.

  1. psychedelicode

    psychedelicode New Member

    Hello all. I have been lurking around the forums for a couple of years.
    So I decided to share (show off) my latest project..
    Which would not exist without TREEWK's double right hand drive setup, Loquin's gearrat and bikepower apps, and numerous other users threads about CVT's (and some goped threads too). THANKS!!!
    Well it started out as a friction drive mongoose full suspension 46cc echo weed whacker with a homemade mount and a tank off an old dirt bike. Did 35mph got like 60mpg. Rode like (edit: heck.) Rear triangle was waaaaay to flimsy for the stresses of a friction drive (as the suspension flexed the roller changed position on the rear wheel , forwards and backwards. Upper and lower link rear suspension like on a atv's front kinda.) and after I mounted one of the Amazon $89 special Tanaka PF-3300 it cracked after about 200 miles.
    So what do I do with this great little motor that's not even broken in and mount that I made? I spent a lot of time searching for a tuff enough suspension frame with a solid mount point to the frame and heavy tubing for mounting the engine bracket. Amazingly enough none of the nice bike company bikes fit the bill.they care too much about weight nowadays.
    But, I found this Schwinn S-25 wrecked all to heck in my buddy's garage. Great thing about it is there are no funny links on the rear triangle so my drive angles won't change when the rear suspension flexes. The frame has HUGE BEEFY bearings instead of bushings where the rear triangle mounts to the frame and all the frame angles are trussed except the bottom bracket.
    He said I could have it and I said OK!
    So I slapped on the wheels, disc brakes, levers, friction drive mount, seat and rode it for a day. Then took it all apart again and ordered a CVT after reading the numerous TREEWK threads. I wanted to use a cvt from day one but the whole jackshaft thing would not have fit.
    So, It's not all together yet. I have yet to mount the motor and CVT and measure chain length.
    But on with the PICS!!!!
    More to come. Stay tuned...
     

    Attached Files:

    Last edited by a moderator: Dec 16, 2015

  2. psychedelicode

    psychedelicode New Member

    Update 1

    I mounted the Tanaka today. I still have to make a bracket to support the rear of the CVT (although the CVT is mounted to the motor for measurement purposes). It looks like I need a 46" 8mm chain. I do not yet have a tensioner (and am not sure if i need one). And, I have a bit of wallering holes so that I can straighten out the chainline (although it is pretty darn good right now. But, I am a perfectionist IF possible. But, when your dealing with chinese parts...NOTHING MEASURES OUT RIGHT!). The motor has rubber isolators at all 3 mount points and vibrates ALOT less than the friction drive that preceded it.
    BTW, Mike St deserves a bit of credit as I have implemented his balanced setup in this build.
    Speaking of which MIKE did you ever get your chain issues straightened out? I would like to know how you made your tensioner too.
    In the intro thread a member mentioned that I should not throw away my mount as it is an old friction drive part. You are correct. It is a home built (myself) part that is kinda a cross between the stability of the BMP friction drive and the thatsdax one. It was made in a belt drive shop drill press and I dont remember the dimensions but ITS TOO DANG SHORT NOW FOR WHAT I WANT TO DO. I'm using it anyway but in retrospect I wish I had made it longer to facilitate the addition of a CVT.
    Does anyone know where to get custom length 8mm chain? I need a 46" chain and all I can find is 44 and less.


    On with the pictures.......
     

    Attached Files:

    Last edited: May 22, 2012
  3. psychedelicode

    psychedelicode New Member

    IT'S DONE!!!!!!!!!!!! I rode it around for a day and threw the chain more times than I would prefer (Bumpy grand rapids streets kept bending my trans mount)......Then i beefed it up and rode 52 miles in just under two hours. Ran flawless. It is still a bit jumpy when you first get on the gas as it takes up loose chain, but im not bending anything now. I am in the process of designing a tensioner but after making it 52 miles on loose chain and not throwing it once, It is not on the high priority list. Its behind rear brakes for sure. Ill post pics and a fly-by l8r tonight.
     
  4. psychedelicode

    psychedelicode New Member

    And BTW. average speed was 28.2mph according to the GPS and max (going down a BIG hill in full aero tuck. to the point the bike was just freewheeling) was 42.2. going up hills was around 10mph (70lb bike including motor and all plus 150lb rider). it was a cross country ride through the country so every hill has newtons law applied to it. I have been averaging 27.8 around town today. I put a gallon in it yestrday before i left on the great journey and have logged over 80 miles and have yet to use half the fuel I put in. I did have to stop a few times on the long ride for cool down but thats expected, its not a motorcycle. i raced my buddys kymco yup50 across town and smoked him ( I literally finished a cig before he pulled up.) the next one will be alot closer to a motorcycle......


    Speaking of which. Beta 2 Is now becoming a reality. I picked up a 93 cannondale super v 700 for $25. No its not full suspension and that worries me a bit because of the speeds that it is going to be pulling with a 9hp motor......But it is ALOT more sturdy than the frame i was considering(a wally world micargi-mongoose). it is actually THE EXACT SAME BIKE as the first bike I ever purchased when I was 14 pushing newspapers. same frame size, colors, shock ect. I love nostalgia. The plan involves the dax gp50r and a shift kit. no holds barred regarding brakes (getting Hydraulic Disc shimano saint with the ICE rotors) Hubs (hope, chris king, or phil wood). and rims (48spoke velocity psychos with 12G spokes). This "beta 2" will be built around RELIABILITY and hopefully dont end up costing more than a new quality scoot (kymco, roketa, piaggio/vespa, honda ect).
    Its actually funny that I almost never ride my kawasaki klr650 anymore (it was my favorite vehicle) (just the gas bikes and roadie. much more fun even though the kawi is pretty much point-and-shoot-and shift).
    which brings me up to my next question:

    Can a SBP shift kit handle 9HP? and i think motors should have specs for TORQUE as well as that is what really counts when you are pulling a load. there are some r/c aeroplane engines that pull AMAZING amounts of power from a 50cc diesel twin. But, could not pull a model railroad down the track.......
     
    Last edited: Jun 14, 2012
  5. psychedelicode

    psychedelicode New Member

    So I have broken my freewheel three times now in the last few days. Is there a heavy duty freewheel available? The power coming out of the tanaka after rounding a corner at 15 or so keeps breaking them when I get on the throttle.
     
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