Top Speed

Discussion in 'Performance Mods' started by Snarfu, Jul 8, 2012.

  1. Snarfu

    Snarfu Member

    Can't believe I haven't seen one of these threads on here yet.... what are you guys getting??

    On my old road bike with no shift kit, my tops was about 24mph.

  2. Fabian

    Fabian Well-Known Member

    Ahh, another thread that's perfectly suited to this pic:

  3. MikeJ

    MikeJ Member

    Fabian -

    I like the graphical speedometer. My crutches would start around 24 mph / 40 kmph, maybe wheelchair at 60 kmph.

    My max speed? Don't know and don't have a need to find out. I limit myself to 30 mph / 48 kmph. Per calculation on a spreadsheet, I could do twice that speed.

    But I enjoy staying in one piece. . . .

  4. Fabian

    Fabian Well-Known Member

    Have to agree with you Mike.

    Because i'm always towing a lot of weight, my general medium speed is around 18 mph and maybe another 5 or 6 mph downhill. I need to give myself room to brake with the extra weight.

    Staying in one piece is the key to staying alive!
  5. The_Aleman

    The_Aleman Active Member

    My Huasheng and 5:1 4G on SBP kit tops out about 35-38MPH, depending on wind and what I'm wearing. My top gear ratio is about 15.3:1. HP peak is at 35MPH, redline is 40.

    I usually cruise 20-29, but when I get a nice tailwind I find myself cruising about 32 or 33MPH.

    Edit: I just noticed this is in the 2-stroke section. Oops!

    I managed 42MPH on 2 different bikes with 2 different chinagirls using the same 34T sprocket.
    My 4-stroke bike had a 2-stroke in it once, just a 44T sprocket tho. I never pushed it over 28.
    Last edited: Jul 9, 2012
  6. Happy Valley

    Happy Valley Active Member

    A little search in the archives will this covered many, many times.
  7. tooljunkie

    tooljunkie Member

    my 66 managed 46 kph a couple weeks ago,after 1/2 hour ride (still in break in mode)
    i had to crack it open on a little downslope past my house,i was cruisin.
    this is on gravel,btw.i dont get much pavement driving.
  8. dchevygod

    dchevygod Member

    Motobecane 400ht w/ custom GEBE style belt drive

    I've built my own Zenoah 30cc lh/rc hybrid with a walbro 257 HP carb/ ada filter and an old crusty ADA s2 pipe and i cruise at 25, 35 is no problem and 40 is possible if i pedal really fast. I run a 14t pinion sprocket and a velocity built HD wheel from gebe.
  9. Greg58

    Greg58 Member

    I like to cruise at 25/26 on either of my bikes, my op with the gt2b grubee 48cc and 44t rear sprocket does 32on flat ground. My crandbrook with the bgf48cc and 41t sprocket does 31, I have ported both and trimmed the piston skirt on the bgf.
  10. adrian101

    adrian101 Member

    70km/h.. though it isn't worth running a HT at that speed. If you ride slow and not at WOT they will last a long time.
  11. Chookawatts

    Chookawatts New Member

    I have got 53.7kms per hour on the flat but I have spent a bit of money on the thing:
    My Specs:
    delorto 16.16 carby
    SBP jackshaft kit
    SBP Expansion Chamber (Chrome)
    Rocksolid reed kit
    NGK spark plug
    Performance CDI(Not the good one Jaguar makes im waiting on delivery of that)
    on a stock 66cc no head mods or barrel mods
    Diamond Back likes this.
  12. Fabian

    Fabian Well-Known Member

    35 miles an hour is crutches time, 45 miles an hour is wheel chair and we don't want to mention what happens at 55 miles an hour on a bicycle.

  13. The_Aleman

    The_Aleman Active Member

    Heck, a crash at even 20MPH can be fatal. I was in an accident in 2009 that destroyed my bike, I got a broken nose, jaw, and both orbitals.

    Doc said most people who crash like I did die at the scene. I was going about 18-22MPH when a car pulled out in front of me. These are dangerous!
  14. Fabian

    Fabian Well-Known Member

    I agree, it's not the speed that is the problem as is plainly evident in motorcycle racing, where those guys fall off their bike at 150 mph; sliding to a stop, then pick themselves up and walk back to the pits.

    The issue is all about what kind of things you hit along the way. A sharp faced rock sticking 2 inches out of the ground will kill you if falling off your bike at 5 miles an hour and landing on the pointy part with the side of your head.

    Having said that, a person tends to wear either no safety gear or next to no safety gear when riding a bicycle, causing shocking levels of skin abrasion when taking a spill, and at 40 miles an hour, it's going to get seriously messy, even at 30 miles an hour it's going to be messy and that's well within the speed capabilities of a non motorized bicycle.
  15. FelipeCobu

    FelipeCobu Member

    Such a serious accident, do you had/have titanium hardware to stick your bones together?

    Let me know please, was you wearing a helmet?


    Felipe Cobu
  16. V 35

    V 35 Member

    Road conditions limit speed more than anything. Here in New England, roads are often steep, curvy, and full of cracks. Torque is more useful than speed under these conditions. The Cops recently set up a ' Your Speed ' trailer on a straight, smooth road, right near my place too. I made a bunch of runs Highest speed 35 MPH 70cc w. 44 tooth sprocket 25 MPH 50cc Grubee 44 T sprocket.

    Given enough straight away, the 50 cc can keep up, but gives up too much torque on hills, compared with the ' big ' motor.
    Last edited: Aug 9, 2012
  17. Chookawatts

    Chookawatts New Member

    Ive hit a car at 35mph and been hit 6 times by cars at high speeds over 30mph on my racer bike gets mangled but so far im still here, I ride a harley and a drz400 which both go twice s times the speed and ill die if i hit a car on one of them too so is there a difference?
    Last edited: Aug 10, 2012
  18. Chookawatts

    Chookawatts New Member

    Well guys I found the issue with my motor, why I wasn't getting expected power, the heads on these chinese motors look like they have been milled with an angle grinder! the gasket only seals for about 1-2mm and is not tightened more than finger tight! and leaks like you would not believe. I remedied the problem by hand milling the head (my hand still hurts) and making my own copper gasket, I milled about 1.5mm off the head checked the barrel surface (was fine) then made a copper gasket out of 1.6mm copper sheet (original head gasket is 1.45mm) therefore I have increased compression a little. hard to start first time round but much easier now! I will take it for a speed test soon and tell you if it made a difference.
  19. Fabian

    Fabian Well-Known Member

    The aluminium head gaskets are quite soft - you just need to re-torque the head studs after the first 50 and then 150 kilometers; keeping an eye on the stud tension every 800 kilometers after that!
  20. Chookawatts

    Chookawatts New Member

    well got a top speed of 55.5kph which is 1.8kph increase over my first top speed which was 53.7kph which quickly deteriorated to a top speed of 47.6 kph within a week, so I basically got an increase of 7.9 kph by torquing the head properly and machining the head flush, but an actual speed increase of 1.8 kph by upping the compression a little, I know my fuel to air mixture is too much fuel, so a change in size of the main jet to a smaller one will fix that, and then trying to tune the exhaust with out a dyno, not sure how I'm going to do that, and I'm still waiting for Jaguar's CDI to arrive. I'll get to 60 kph somehow haha