Frankenbike function over form

Discussion in 'General Questions' started by mickal1025, Jul 4, 2007.

  1. mickal1025

    mickal1025 Guest

    I loved the idea of riding my motored bike to work but hated the heavy vibration and constantly streaching chain so I built a alternative motor mount and tested it a little while ago. it worked just the way I had hoped it would so I'll start with a discripion and post pics after Tammy shows with her spare camera (mine craped out after 3 pics).

    I started with a 1 1/8 OD pipe and cut and welded it in a V shape to match my bike frame. then I welded a 1 in long by 1 in OD by 3/4 ID bushing to the V tube. next I cut and drilled 2 mounting plates, each mounting plate has bolt holes for mounting and a 3/4 in hole centered in the plate. I then assembled all this on the bike using a large washer on either side of the bushing with a 3/4 in bolt going through the plates, washers and bushing. then I bolted it to my bike frame. when I was confident it would work I gambled and tack welded the plates to the frame then put a longer chain back on my bike. I next put 2 utility springs between the frame and new mount. these proved to be too weak so I added a car brake spring to each side. this worked out just right. the mount lets the motor move forward and back while the springs keep tention on the chain. the 3\4 in bolt is tight enough that it works like a brake so it dampens vibrations. if it continues to work and proves dependable I'll look forward to my daily commutes. now for the pics
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  2. mickal1025

    mickal1025 Guest

    I was having trouble uploading pics.
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    I'll try again.

    I also had to lengthen all my wires. when I did this I twisted about 6 in of wire tightly around a small screwdriver shank so my splices will stretch without breaking.
     
  3. azbill

    azbill Active Member

    does it give any chain tension probs?
    that is the only thing that I would worry about
     
  4. Wouldnt a spring loaded chain tensioner do the same thing?

    I wonder what the constant added stress on the chain will do to the drive sprocket bearings.

    Do you have a stop anywhere to stop the motor from rocking backward (for whatever reason) and slacking up the chain and maybe cause it to bind up in the engine case.
     
  5. mickal1025

    mickal1025 Guest

    I dont know about a spring loaded chain tensioner. I've never used one. but this cut down on the vibration alot and I can still push the center of the chain down 1/2 in or so with firm finger pressure. I havent had any problems with the mount hitting the frame and right now there is only about 1/2 in of clearace between the mount and the frame. time will tell. I just got it all together this morning and went for 1 short ride so I dont know if its going to be durable. I'll know alot more tomarrow after I ride it to work, the 18 mile round trip should tell me alot.
     
  6. I cant hardly wait to read the ride report.

    It is a very interesting mod.
     
  7. srdavo

    srdavo Active Member

    cool idea.....I've seen a couple old, OLD, homebuilt scooters, with spring loaded engine mounting plates, to keep tension on the belt-drive.
    I really hope this works out for you. (for us too :) )

    Now I must say...... if you can no longer feel all the vibration, good. But it did not go away. It is just concentrated somewhere else.
    keep an eye on all your add-ons. and all the nuts & bolts on your engine/bike. (I've had bolts vibrate out of the clutch cover :???: )

    just be safe & keep us posted. 8)
     
  8. Ingenious mod you got there, can't wait to see how it performs for you. :D
     
  9. Wow. That's what I call thinking out of the box.
    That's seriously brilliant. BRAVO!
     
  10. mickal1025

    mickal1025 Guest

    thanks. I think the vibration is being mostly absorbed where the bushing contacts the big washers at the pivot point. I dont know, i'm just guessing.
    I'll get some miles on it andpost an up date. thanks again for all the great comments.
     
  11. mickal1025

    mickal1025 Guest

    I rode it in to work today and lost a bolt out of the back sprocket side original motor mount. I had replaced the stud with a shorter bolt that I thought would work. it didnt and I put the old bent stud back in. the strange thing is the bike still had less vibration (then stock instaul) even though only held tight by the front mount. the bigger problem I had was that I lost another intake gasket but at least I found out why. the intake manifold and the mating surface on the jug don't match. I had hit both surfaces with a file to even them out as Augie suggested to someone else then made a new gasket that matched the jug surface but when I compared it to the intake it did'nt look right so I put the intake on the jug without a gasket to compare them and found out that there is an air gap from the studs being drilled 1/4 in to low. I guess I'll have to make an adaptor plate or I'll never be able to keep a gasket in this thing. I'm going canoeing tomarrow so it might be a couple of days before I get it put back together. later
     
  12. mickal1025

    mickal1025 Guest

    so I could'nt wait till after the canoe trip. so last night I made the adapter plate for my intake from an old aluminum trailer fender I had laying around with a new gasket on both sides and this morning after loading canoes I took it for a test drive. the motor ran fine but the drive chain derailed. glad that didnt happen on the way to work yesterday. found that the pivot was sticking a little but moved freely after moving it by hand a couple of times, so to avoid this happening again I added a rubber bump stop between the top-back of the mount and the frame of the bike. after a quick test ride it all seems to be working well but I'm leaving in less than an hour so I dont have time for a long ride. gotta finsh getting ready. I'll add pics later.
     
  13. Yeah I was wondering if you had a stop in there to keep the chain from slacking up to much.

    I really like this project or yours.
    Keep up the good work.
     
  14. mickal1025

    mickal1025 Guest

    didnt need one until the pivot got sticky. live and learn.
     
  15. srdavo

    srdavo Active Member

    good report.....have a fun day.
     
  16. iRide Customs

    iRide Customs Member

    Very ingenious design ya got there.
     
  17. quay1962

    quay1962 Guest

    hi Mickal1025,
    nice ride, good luck, the guy who got his install the same day as as me had the same problem, if he would read the forum he would see how to fix his right! people here flock together to help a guy or gal in need. it's too cool! i am waiting myself for dax to call...lol. :grin: :smile: :shock: :cool: :p
     
  18. mickal1025

    mickal1025 Guest

    well it was really drunken out on the river today. I did not drive home. I wish I had read all the posts here before my build but it was still fun. I'll post again when I'm sober.
     
  19. mickal1025

    mickal1025 Guest

    I rode 19 miles today no problems. 6-8 miles in town at under 20mph and 11-13 miles on county roads at 24-28 mph. the odo says top speed was 31mph but the motor seems to like running 24-26mph so I think thats where I'll run her outside of town.
     
  20. mickal1025

    mickal1025 Guest

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