2 stroke motorized bicycle top speed

Discussion in 'Motorized Bicycle General Discussion' started by paul, Aug 18, 2012.

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motorized bicycle top speed. 2 stroke out of box

Poll closed Dec 16, 2012.
  1. less then 20 mph

    0 vote(s)
    0.0%
  2. 21 to 22 mph

    1 vote(s)
    2.0%
  3. 23 to 24 mph

    0 vote(s)
    0.0%
  4. 25 to 26 mph

    7 vote(s)
    14.0%
  5. 27 to 28 mph

    11 vote(s)
    22.0%
  6. 29 to 30 mph

    13 vote(s)
    26.0%
  7. above 30 mph

    18 vote(s)
    36.0%
  1. paul

    paul Active Member

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    i figure i would start this thread for people looking to get a china motorized 2 stroke bicycle engine kit. what i would like is for everyone to put their top speed on level ground before you make made any modifications. out of the box speed
     
  2. bairdco

    bairdco a guy who makes cool bikes

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    the only stock bike i ever built did a whopping 34mph in a full tuck. it wasn't straight out of the box, though. i match ported the intake manifold and the exhaust flange.

    the first bike i built i had a 35t sprocket and a stock motor. speed on that was 38mph.

    sea level, flat ground. 66cc Grubee GT4
     
  3. 2door

    2door Moderator
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    75 MPH. Confirmed by GPS and my Ford Ranger's speedometer on I-70.

    Tom
     

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  4. Mike B

    Mike B New Member

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    I don't know. Never held it wide open to check.

    The vibration was so bad I thought it unsafe.

    I can tell you it would go faster than 25.

    But I wouldn't - :)
     
  5. xenodius

    xenodius New Member

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    I have to know... what tires/wheels do you have? That's really impressive speed without a shift-kit or chamber or any other mods. Bet it pulls out from the stops really nicely =) I don't recognize the carb either. Did you just port it and that's it?

    My top speed out of the box was 24/25, after a proper jet it was 28. Switching to a 36t from a 44t only got me up to 29-- but removing my muffler cap got me up to 34. Going down a 30 grade hill at WOT only gets me up to 35. I know I have some significant drag somewhere I just don't know where. I'm guessing it's my wheel hubs/40psi tubes.

    The stock exhaust I had was really, really, really restrictive. Nothing I did made a more significant improvement than removing that cap. Of course it's too loud without it, that's why I'm putting an SBP chamber on it. But with the cap on, it takes a full 30 seconds (timed!) to get up to top speed. Without it I accelerate faster than most cars.
     
    #5 xenodius, Aug 18, 2012
    Last edited: Aug 18, 2012
  6. bigbutterbean

    bigbutterbean New Member

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    Xeno, his Ford Ranger was going 75, and his bike was strapped to the back of it. It was a joke, lol. The bike itself didnt actually go 75. Tom (2door) was being funny.
     
  7. Venice Motor Bikes

    Venice Motor Bikes Custom Builder / Dealer/Los Angeles

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    'Fresh out of the box' in stock condition should go between 25-30 MPH if you have experience with building the bike properly. (every engine runs a little different though).
     
  8. xenodius

    xenodius New Member

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    Hahahaah! Oh, I am gullible... >.>
     
  9. Arnold Layne

    Arnold Layne New Member

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    My bone-stock BGF kit with a couple hundred miles on it went 32 on level gravel road and tucked in, REALLY vibrating. Have had ZERO problems with it, about 800 miles on it now, have not had the spark plug out of this engine since I installed it! usflg I rarely run over 25mph now, more concerned with making it last than setting records.
     
    #9 Arnold Layne, Aug 18, 2012
    Last edited: Aug 18, 2012
  10. Nashville Kat

    Nashville Kat Active Member

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    "out of the box" is hard, because kits and bikes vary-

    But a little faster than several yerars ago- even comparing 66 kits, which now have either usually a 66 Speed carb or CNS- for more power

    and often a smaller than 44 sprocket-

    I voted 25-26 which in hindsight is maybe what my cruiser did with beach tires, a 44 sprock and old 50 cc NT standard carb and intake

    I get a good 30 cruise with narrow wheels, billet intake, Speed carb and 34 sprock. It will exceed 35 but I haven't pushed it there- and that's with 8 inch rise BMX bars, sitting normally. That's confirmed on the analog speedo which might be reading low for 26" tires and not the 27 wheels I have on.

    But I've drafted a semi truck at 60mph on 250 gram seta sew-up tires, so it is niente....
     
    #10 Nashville Kat, Aug 18, 2012
    Last edited: Aug 18, 2012
  11. ckangaroo70

    ckangaroo70 Active Member

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    My newest 66cc Z80 HT with a 41 tooth sprocket and my 230lb heaping pile of a$$ onboard will do a blazing fast 32mph on the flat according to Garmin. However.... it really cruises nice and comfortable at a not so blistering pace of 20-24mph.
     
  12. Moto

    Moto New Member

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    My bike has a puch head and dellorto SHA carb. Its has a MEAN load of torque and acceleraties well. As soon as I Hit 27 mph it hits a wall though, because I have to work out my jetting. It also feels like Im running out of gear. Im gonna get a 71 jet + 39 tooth sprocket and she'll rip! I wouldn't be surprised if she hits 32-33. Ps my intake and exhaust are part matched too. xct2
     
  13. 2door

    2door Moderator
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    Thanks, BBBean.
    I didn't mean to mislead anyone. It was all in fun.
    Tom
     
  14. BarelyAWake

    BarelyAWake New Member

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  15. Longshot270

    Longshot270 New Member

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    I squeaked out a 31 mph with a GPS before I swapped to a 36T.

    I LOL'ed. I almost made a bumper sticker with [picture of bike] + [picture of truck] = Averaging 67 MPG, take that Prius!
     
    #15 Longshot270, Aug 20, 2012
    Last edited: Aug 20, 2012
  16. maurtis

    maurtis New Member

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    Before swapping out my head and exhaust, my RB80 with only and SBP HD air filter and 36T sprocket could squeak out 38.2 MPH, but was pretty happy around 32 MPH. I never ran the original air filter or 44T sprocket, but figure they probably would have been good for a max of ~30.
     
  17. The_Aleman

    The_Aleman New Member

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    I blew up my first one back in 2006 trying to hit 30. After that I never went over 28MPH with a 44T.

    I voted 27 to 28.
     
  18. maurtis

    maurtis New Member

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    I tried for months now to hit 40 MPH, the best I got was 39.7. BUT, over about 35 - 36 MPH she sounded/felt very unhealthy. Recently I have been sticking to cruising in her sweet spot around 32 MPH and she seems much happier. 30 - 32 is where my girl sings, it is funny how her vibes smooth out right there, so I figure that is where she wants to cruise.
     
  19. thegnu

    thegnu New Member

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    had 40 in 8th gear loved it but 30 t0 35 perfect
    GARY
     
  20. Allen_Wrench

    Allen_Wrench Resident Mad Scientist

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    I have a port-matched, tuned up HT with an NGK plug and performance air cleaner, and 38T sprocket. While I have no speedometer mounted as yet, I have left a 49cc Ruckus behind me, chokin' on my dust and failin' to catch up. (Dude made some kind of comment related to "old man".)
     

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