Tinkerer toys (65cc bicycle)

Discussion in 'The Garage' started by Reista, May 8, 2012.

  1. Reista

    Reista Tech turned Mech

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    I've just about fixed my bike well enough to be very satisfied with it which leaves me with looking for another project, one that certainly grabs my attention is that of strapping a 50cc-100cc motor to a bicycle (with disk brakes of course, 3.4" downhill thorn proof tires) I understand the legality of these on the streets and won't be doing road riding- this is more to make my biking distances a bit further- or even act as a last ditch transport to school should, god forbid, my GS eat the dust. Anyways, I'll link the cheapest chinese kit available. Is this a horrendous idea or will I get to buy/play with my toys and enjoy them so long as I understand they aren't the most durable things around? Thanks for any input in advance ^^
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  2. assquatch20

    assquatch20 Hoss Cat

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    http://www.motoredbikes.com/

    I was really interested in doing this sorta thing with a Schwinn Stingray I came across, but I'm a bit large and whatnot. Heck, if you want the Stingray too you could have it. I'd like to see someone make it like the ones on that site. Best of luck and have fun.
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  3. OldPete

    OldPete Be aware

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    I'll be buying wheel building parts for my GT full suspension project this week.
    A 35cc Robin Subaru is on hand from these folks. http://www.bikeengines.com/

    If i were to do an in-frame project i'd seriously consider a Morini engine.
    Check out this more mature(IMO) board http://motorbicycling.com/

    If you go Chinese... be SURE the connecting rod small-end does NOT use a bronze bushing.
    The only units to consider have a proper needle roller wrist-pin bearing.
    With the bronze bush the oil to gas ratio has to be silly rich and they still fail.

    Rear wheel rims and spokes fail often.
    The best hubs with provision for left freewheel can be had here... http://www.staton-inc.com/home.shtml
    Staton is known for producing gas powered wheelbarrows. :lol3 One man can move 1,000#.

    If you go the quick 'n dirty cheap Chinese kit in-total... like most do, with the rear sprocket that clamps to the spokes,
    relace the rear wheel's failure prone/known Asian SS spokes with 14g DT or Wheel Smith spokes.

    EDIT: Look at the mix ratio on that ebay link... 16 to 1 for a 300 mile break-in, then 25 to 1 there after.
    Betcha with a 3.4" tire there will be no chain clearance.

    Research the above two boards and report back please.

    Now let the dog-pile begin... :evil :1drink
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  4. svejkovat

    svejkovat Been here awhile

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    http://motorbikenz.com/

    Highly recommend a look through that link. That's my idea of minimalist adv'ing.

    This is damn near the only respect-worthy hybrid I've ever come across. And I've looked plenty. I belonged to that motorized bicycle forum and also one called endless-sphere. If you're interested in a motorized bike you can use realistically as a pedal bicycle when desired you are not going to find much interest anywhere out there. Unless things have changed dramatically in the last two years.

    What's really unfortunate (if you're into gas engines) is that all the brains, imagination, and engineering skill collect at endless-sphere and the interest there is all but exclusively electric-bike. Motorbicycling.com is depressingly casual by comparison with interest mostly centered on tweaking the china two stroke kits grafted onto beach cruiser bicycles. Before anyone gets upset with that, of course there are wonderful exceptions to be found. But mostly it's just high-school level shop stuff.

    I pretty much wore out my welcome at both forums a couple of years ago... even weighed in here at advrider on the topic at the time... to exchange ideas related to a true pedal/motor bicycle. The photo above of the guy in N. Zealand is a RARE example of that true hybrid. Pretty much every other gas motorized bicycle in existence fails miserably as a pedal bike. With any of the chinese kits they lack a means to isolate the xmission to the motor while pedaling.... pretty much like pedalling with a flat tire. I got sick of trying to discuss this with others at motorbicycling. Its almost like "who wants to pedal anyway? I've got a motor".

    http://endless-sphere.com/forums/ has, almost inexplicably, just about zero interest in petrol power. Shame that since plenty of the emphasis is on true hybrid human/electric vehicles. Personally I see gas powered transport being around for sufficient time to make continued interest in it more than worthwhile.

    There is, of course, the bone simple, but eventually problematic, idler drive against the rear tire. Poor compromise, but simple. A more sophisticated drive that emulated rim brakes, with a drive wheel on one side, an idler wheel on the other might be interesting.

    I'm still going to pick this up again when time permits. It just got shelved for a while. One more example perhaps of my perfection paralysis.
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  5. P B G

    P B G Long timer

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    I got started on one of these awhile back, at the time the hold up was that I had a mountain bike with rear suspension that I wanted to use this on.

    Issue is that the pivot of the suspension is not around the countershaft of these little motors. So what I planned on doing was making a jackshaft to feed the engine in to the chain ring on the bike. And then having the drive go through the factory chain/gears. I figured this would make a much nicer set of drive speeds, but requires not sourcing the usual pedal start bike components. Since I would then also be replacing the factory "cranks" with fixed pegs and making it not a bicycle.
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  6. OldPete

    OldPete Be aware

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    Good post.
    Both those boards are filled with fighting high schoolers. :lol3

    Easy pedal power is why i offered the Staton link for a left side freewheel mount.
    Those hubs come with 4 bearings but use screw on cassettes.
    The goldeneagle kit has no freewheel but the belt can be tied to a stay in 30 seconds.

    For a first attempt the OP needs to know of spokes and wrist pin bearing.
    #6
  7. OldPete

    OldPete Be aware

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    I have no idea of the quality but free wheeling chain ring set-ups are on offer.
    However I doubt bicycle chains like 2+ HP running through them very long but one does get gear selection.
    #7
  8. P B G

    P B G Long timer

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    I think bike chains are pretty stout.

    Maybe 2+ horsepower, but with smoother power delivery, and less torque. Figure a strong bicyclist cranking up hill standing and bouncing on the pedals is generating way more instantaneous torque than any 65cc engine ever will.

    One thing I assume to be true about power delivery is that smoother power delivery is easier on components. Bicyclists are about the least smooth power delivery I can think of.
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  9. DRPhoenix

    DRPhoenix Viking

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    To the OP, if you like tinkering the cheap kit will provide good entertainment. I have two bicycles using the cheap two smoke engines. Each install presented various challenges overcome with beers and laughs at a friends place. They vibrate like crazy and if you beat the crap out of them it creates more fun fixing them as crap breaks and falls off. If rode at a moderate pace they are more reliable than I expected for the price. You cannot make them as tough and reliable or safe as an actual motorcycle, remember this if riding around cars, nobody thinks a bicycle is doing 30 mph as they pull out in front of you. The motorized bicycle forums seem to be good for gleaning info, but not much else. Overall it has provided some cheap entertainment for my friend and I and continues to do so when time permits.

    Cheers
    #9
  10. hugemoth

    hugemoth Long timer

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    I've built a few bikes with the Chinese engines. Very crude but they do work. Still have a couple of those engines in a box in the garage. IMO bicycles aren't made to go nearly as fast as the engines will push them so be very careful and take it easy if you want to stay alive.
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  11. svejkovat

    svejkovat Been here awhile

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    Full suspension might seem the ideal, but it's often an extravagance on bicycles. Handy for extreme downhill, but maybe overkill for anything else. The unsprung weight of a modern mountainbike frame, rear wheel, drivetrain, especially with the front already equipped with shocks, is so miniscule when compared to the rider's weight that for 95 percent of riding, even street use, a well suspended saddle is a better alternative. It eliminates a raft of concomitant technical problems as well.
    #11
  12. CallMeBoog

    CallMeBoog hi functioning idiom

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    did anyone notice the specs on the ebay ad? 80cc, 2.5hp?? My Husqvarna chainsaw is 59cc and 3.5 hp... what's going on there?
    #12
  13. lockyv7

    lockyv7 Long timer

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    Here's mine, one of them.

    [​IMG]
    #13
  14. OldPete

    OldPete Be aware

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    Kewl... now give the OP some build info with close-up pictars. :wink:
    #14
  15. lockyv7

    lockyv7 Long timer

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    Bit better pic, fount the bike cheap and had a kit motor laying around so just build a few brackets to fit it, had to make up a chain roller to get the bike chain to clear part of the motor because it was so long. And i had to offset the rear rim about half an inch, did that with the spokes. The others are a purple beach bike for the daughter and a cheap alloy framed mountain bike with a motor kit.

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  16. DRPhoenix

    DRPhoenix Viking

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    More fuel for the fire,
    [​IMG]

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  17. OldPete

    OldPete Be aware

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    The OP has fled this thread. :huh
    #17
  18. DRPhoenix

    DRPhoenix Viking

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    Yup, cheap kits like these not for the faint of heart or those with lack of patience. Usually I'm all about dualsport and thrashing the DR650, but alas my wife was diagnosed with ALS last summer so these fit my limited opportunities to screw around with motorized two wheels for a few hours every couple of weeks or so as a break from caregiving and maintaining my sanity. Feels good to break them and then fix 'em , cause there ain't no tools in my arsenal to fix the other.
    #18
  19. btcn

    btcn Long timer

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    If youse still reading this I'll give ya my take on them there motor bikes.

    So, I had a 4 stroke verson. Its a chinese one but it was overall decent.

    You don't want the 2 strokes. There pretty shitty quality, and they won't last long at all. They ain't good for long rides. THAT IS, CHINESE 2 strokes at least. Other brand name 2 stroke bike motors can be very good.

    The 2 strokes have much worse gas milage than a 4 stroke, and gas ain't cheap cause youse gotta add like $2 for a bottle of oil per gallon for premix, so that means you'll be paying about $6.50 per gallon!:eek1 Maybe you can get oil cheaper, don't know, but remember oil is the only thing that stops it from siezing. It's so important.

    If you must have 2 stroke, go for a higher end one.


    I had a 4 stroke chinese kit. It was one of them Grubee ones. It had the 49 cc 4 stroke copy of a Honda GXH 50 [BTW the actual Hona motor can be used with this kit you can just buy the kit and motor seperatly]. The motor wasn't bad at all. It went for a while, ran good until I had modded it with a straight pipe and no air filter and didn't rejet! It blew an exhaust valve, zero compression now. Then fucked up the flywheel trying to pull it without a fly wheel puller. While the valve can be bought for only $7, with the flywheel and needing a pull starter and any other damage it's probably worth it to just buy a new motor they's only like $130 shipped for just the motor.

    However, if you take good care of it, and install it good, it'll last a good amount of time.:deal Not the best designed unit, but for about $350 its not bad at all.

    Stock, I'd get the claimed 35 MPH no problem. Later with mods and a smaller rear sproket I could run 47 MPH in the right conditions.

    What is the bad? Well, some things is a little cheap [like the motor's muffler mount bolts, they has cheap bolts in it and with that exhaust that hang off without support they'll brake eventually, had to have mine has heli coils in it, but they sell good screws that will prevent this from happening]. Also, mine never come with no air filter. Another thing y'all is I found many of the threads for screws they's cheap and shitty like the motor mount ones would strip easily.

    Also, only 1 gear! Makes for SHITTY off the line acceleration! I could pedal faster from about 0-8 MPH, shitty hill climbing, and lower top speed. I would love if these had either a CVT or like a 4 speed gearbox! If you can fabricate a little, there is a CVT that could be fitted to this you can buy. But gears would be funner and more top speed generally. Also, these motors are VERY low on torque. Torque is in like 2 ft/lbs range or something. But its more likely because of no gearing it feels more gutless.

    But, all in all, I'd say its good. Mine was fitted to a Schwinn Jaguar for $99 from target. Looked neat. I added a 1 gallon gas tank [motorcycle style] that had long range. The 4 stroke kits do get at least 150 MPG as claimed. I got more like 150-200 MPG, and that was 99% riding WFO! Cain't complain about that!

    But overall, its a good engine! It was very quiet stock, had a neat little sound.
    #19
  20. miked826

    miked826 n00b

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    My Gas/Electric Hybrid does all 3 equally well and flattens hills like a pancake without having to touch the pedals if you so choose. My 48V, 12AH, 9 pound, battery range is about 80 miles (no pedaling) with the gas engine running and electric brake battery regen. Can I get a amen? :lol3


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