Big Guy

Discussion in 'Motorized Bicycle General Discussion' started by bellcorps, Aug 13, 2014.

  1. bellcorps

    bellcorps New Member

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    Looking for a bike motor kit recommendation for a guy that weighs 270.
     
  2. maniac57

    maniac57 Old, Fat, and still faster than you

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    Any standard engine kit. I wiegh 250+ and run a 36 tooth gear on My Pig. Stock engine internals with a tuned pipe, a FredHead, and Lightning CDI.
    Totes my big behind around every day just fine.
    If you are REALLY heavy, run the stock gearing (44 tooth)
     
  3. bellcorps

    bellcorps New Member

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    Thanks, that is encouraging.
     
  4. Kioshk

    Kioshk Active Member

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    I'm 280# and carry about 30# extra on my back on average. 66cc with NT carb and Voodoo pipe. I found that I needed a 56T sprocket on my 29" wheel until I got the knack of tuning the engine properly; the biggest concern was adequate torque for the moderate hills around me, and the desire to avoid over-stressing the engine. I now run a 44T, and average about 27MPH on the flats and can top-out @ 32MPH which is PLENTY fast IMHO. I should note that this is my daily-driver...I literally ride it every day about 20-30 miles.
     
  5. Davezilla

    Davezilla New Member

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    I'm about 225# and the 66cc kits are doing just fine for me, I'm running a 44 tooth on mine right now but it's begging for a smaller rear sprocket since it accelerates very quickly to top speed of about 32mph and runs out of rpm. I'm sure that setup would push a 300+ pound rider just fine with the 40 or 44 tooth rear sprocket and a fairly close to stock engine.
     
  6. mkatt4x4

    mkatt4x4 New Member

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    Ya bro, welcome to the club, I have never been over 300 lbs. in my life, being at 6'6"
    Probably all the beer and chocolate milk I been drinking, tho lately the vodka gets it done quicker and cheaper. From what I gather, a 66cc engine, like the Grubee one I be gettin, is sufficient, then its all about the gearing and the 44T is the way to go from my research. I just popped back on, cuz I always price out electric kits first for a DIY its a cool $600+, I know gassers the way to go at $180 shipped!!!!!!, but just a little extra power would be nice I think, you know what I mean. Ive beeen eyeing that Grubee for a loooooong time, but a 120cc would be better right, double the cc's must mean double the HP, then I say to myself what about frabrication. I can do it, just a matter of price and time and tools. Final Opinion is Just have fun with a simple kit for $180, see where it goes.
     
  7. BarelyAWake

    BarelyAWake New Member

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    This is a common assumption, but no less untrue for it's frequency - as a popular example the 50cc two strokes can be as low as 2hp or a mighty 9hp, even more... but this is based on quality & design, not brand or retailer. "There's no replacement for displacement" a misunderstood misnomer to say the least.

    Research carefully before you buy, dismiss all advertising with a very large grain of salt - if the specifications are unavailable and/or cannot be confirmed by another, unaffiliated source... it's likely untrue ;)
     
  8. ajoh

    ajoh Member

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    i beg to differ but my example would be kinda extreme since this is about
    small motors (lawn mower/ edger motors in basic terms)
     
  9. BarelyAWake

    BarelyAWake New Member

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    If you're comparing two of the exact same design types, differing only by displacement - then in this very specific instance displacement might help dictate which one is more powerful, but it's quite unlikely to be double the HP for twice the size even then.

    The 50cc I believe qualifies as a small motor, the above two stroke examples could be the commonplace motorized bicycle two stroke kit motors (2hp) vs the 50cc Morini, KTM50 & their clones (9hp), of which are 4x the HP at a minimum vs their exact same displacement comparison.

    A common small displacement four stroke example relevant to this application would be the 99cc Harbor Freight Predator vs the 49cc Honda CRF50 & clones, both of which are just about 3hp... despite doubling the displacement.

    Displacement alone means very little in generality, pretty much limited to knowing which parts ya need to order, there's so many flavors even with common engine types - piston ported, case inducted, reeded or the flathead & OHV conundrum, the bore vs stroke ratio, compression ratio, the quality of manufacture... there's too many variables, just to many exceptions to list lol, let alone to trust a catchphrase ;)


    ...as for landscaping equipment, give weedwackers & model airplane engines a google - similar in displacement, it's amazing what 14,000rpm+ can do :D
     
    #9 BarelyAWake, Aug 19, 2014
    Last edited: Aug 19, 2014
  10. ajoh

    ajoh Member

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    i agree with you barely the example i was pointing at, at being a little extreme for this topic here was car motors specifically racing engines

    but for these types of motors yes you are right 2strokes make more hp for the same cc........

    i been looking for 99cc hf motor but it seems HF don't list them only 79cc
    ahh well i'll look else where

     

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