Top Speed

Discussion in 'Motorized Bicycle General Discussion' started by kevinkrg6, Aug 9, 2011.

  1. rustycase

    rustycase Gutter Rider

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    Decoherence, it actually sounds good except for the four stroking, then it falls on it's face.
    Nothing there... will not build revs...
    Someone said in another post, it's like it hit the rev limiter my 00 ford has at 93mph... just will NOT go past that!

    I dropped the needle to the top groove and tried it again this morn. nada...

    Now I'm gonna take the stock pipe off and see what's goin on in there.

    Oh, I didn't mention... my mab sounds quiet... quieter than I think it should sound.
    Seems like there is more exhaust noise coming from the front than where the pipe dumps on the ground.

    I do NOT want a loud MAB!
    (I'll be in hot water with the tax collector soon enough. Don't want to give them additional reasons.)

    It's all good. These lil thangs are ez, and fun to work on.
    rc


    btw msrfan had posted instructions to balance a motor crank... but I don't think he ever posted the final results... balancing quality components is the key to hi-rpm without vibration.
     
  2. Dave31

    Dave31 Moderator
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    I will be hooking up a tach here soon, been curious myself what rpm I am turning.
     
  3. biknut

    biknut Active Member

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    It's funny the similarity a China Girl motor has to a Harley. They both blow about the same speed.
     
  4. biknut

    biknut Active Member

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    It's easier to do it on paper, so to speak. All you need to do is measure the tire circumference. I use this website to do the calculation. The first link will give you the ratio, and the second link, the mph to rpm

    Gear Ratios

    Calculate MPH from RPMs
     
  5. Dave31

    Dave31 Moderator
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    Yes, but it has a hour meter and I would like to know how many hours I ride a week.
     
  6. rustycase

    rustycase Gutter Rider

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    ...how many r's do their V-rods turn???
    I haven't a clue...
    rc
     
  7. biknut

    biknut Active Member

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    Humm, my speedo has about 45 functions of which I know how to use about 4. One of the ones I don't know much about is a timer of some sort.
     
  8. Dave31

    Dave31 Moderator
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    It counts hours and minutes, when I took the pic had 1 minute on motor. My speedo also has a timer but I would rather know how many hours I have on the motor. I also ride my bike a lot without motor running so the speedo would not help there.

    http://motorbicycling.com/f42/2010-hardrock-27538-2.html#post315626
     

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  9. Greg58

    Greg58 Well-Known Member

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    I have a 48cc grubee angle fire with cns2 carb. main jet drilled to a #66, sbp air filter port matched intake and exhaust. Dual end cap pipes. I got 30.5 sunday with a 44 tooth sprocket and 2.125 tires, I have got 32 on a cool day and 35 down hill. I let off because I started thinking what if it blows at that speed.
     
  10. Hacksawdecap

    Hacksawdecap New Member

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    I was at a stop sign a few nights ago just chilling smoking a cig (with my bike off so I don't die in a terrible fire) and this dog comes rushing up at me. bit my pants and I finally got my bike started..in the middle of a intersection and cars were flying by me...ended up opening my throttle beyond the point of any break in period and got away...and this morning in a ally way where I ride to get to my guest house I got attacked by a gang of dogs coming in my direction luckly I just yelled at them and they all ran away.


    I dislike dogs.
     
  11. Hacksawdecap

    Hacksawdecap New Member

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    Oh. I can go about 27-35 on my 48cc skyhawk.
     
  12. ddesens

    ddesens New Member

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    43.2mph on a genesis onyx cruiser 29" wheels. flat ground. takes a minute to get there. 66cc 200 miles on motor with opti 2 oil. Upgraded intake and exhaust. Love it.
     
    #32 ddesens, Aug 12, 2011
    Last edited: Aug 13, 2011
  13. rustycase

    rustycase Gutter Rider

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    Dem dags r dangerus, hack ! evn werse if yah HIT 1 !!
    after a quicker stop, bambi will bite AND kick!
    Ders no nice way to fix em.
    rc
     
  14. etownbuy

    etownbuy New Member

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    skyhawk 66cc gutted stock muffler, manic intake, cns v2 carb, 44t rear on a trek MTB with 26x1.95 tires. today while tucked in it hit 36.1mph my speed is fairly accurate I rode beside my wife in her car and we both showed 30mph so I would say my 36 isn't too far off. but then it overheated and started blowing passed the headgasket. I am still on the "break in" mix for fuel I am thinking once this is gone I am going to start running aviation 100LL fuel for no more than I use $7 every couple of weeks or so is not bad and would rule out all detonation
     
  15. Texhun

    Texhun New Member

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    Stock 66cc running at 30:1, with Dax RT carb and SBP Xchamber, 32MPH 110MPG.It's not bad I ordered smaller jets for the carb so I might hit 33-34 and I also ordered a 36T sprocket so we'll see what that does.
     
  16. kevinkrg6

    kevinkrg6 New Member

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    O.O Woot! May the lords of aluminum be with you. I wanted that bike but went with steel instead.
     
  17. 5-7HEAVEN

    5-7HEAVEN Well-Known Member

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    One great thing about a shift kit is that you can get up to speed quickly. When you ride in traffic and claim the lane, it's a must. I can get up to cruising speed in about 10 seconds.xct2
     
  18. 5-7HEAVEN

    5-7HEAVEN Well-Known Member

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    How's this?

    http://motoredbikes.com/showthread.php?t=27897&page=2

    Stuff have changed; this was my bike's maiden voyage. Motor mount holes are drilled thru frame, carb now faces downward, ADA pipe switched out to Tanaka pipe, no boost bottle, larger brakes, Armadillo tires w/double-walled aluminum rims, no reserve fuel carried, OEM tank replaced by 4-liter Happy Time tank.

    xct2
     
    #38 5-7HEAVEN, Aug 14, 2011
    Last edited: Aug 14, 2011
  19. nightcruiser

    nightcruiser New Member

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    Checked my spedo today and it says my top speed was 36.9MPH, that's a little bump from 34.8MPH where it had been sitting. Really, I find it hard to find places to go that fast safely...
    I have a stock Grubee SkyHawk GT5 66cc kit with CNS carb on a late '80's Specialized 26" wheel Mountain Bike, only motor upgrades are the NGK plug and a quality plug wire. I did a lot of carb tuning, including opening the main jet up from the size of a #72 drill bit to a #69. The rest is stock, exhaust, rag joint sprocket etc. I have about 250 miles on her now and am running a 32:1 mix with standard 2-stoke oil.
     
    #39 nightcruiser, Aug 14, 2011
    Last edited: Aug 14, 2011
  20. SlowBalt

    SlowBalt Member

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    Boy go fast x-80 (68cc) home made exhaust 36 tooth pitate sprocket. Carb tuned. clocked at 40 mph at Jb's rally. [​IMG]
    Boy go fast z-80 (68cc) home made exhaust 36 tooth pitate sprocket. Carb tuned
    ran out of revs at 45 mph This engine has more top end than my x-80. Next step is to talk to Pirates about a posable 30 tooth for this monster. [​IMG]
     

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