66.9 Mph

markeatmark · #1 12-14-2009, 05:17 AM

OK it sounds incredible. I have a Grubby sky-hawk 66 on a Italian race bike Colnago 700c aero rims 36 flat spokes brass nipples 300 grams. 23cc race tires 150PSI. [very fast without a motor] Ok I started out to hit 40MPH. On my first ride with the stock 44 tooth I hit 42 MPH, The need for speed was on. i went to a 36 tooth I hit 50+. Then i remembered a trick I learned back in the days of racing RC boats. I raced a 48" cracker box with a 32cc two stroke gas motor I mixed NITRO RC fuel with gasoline 50/50 and at high RPM the nitro fuel will fire before the spark plug turning a two stroke into a glow motor. So that is what i did for the gas bike. I made several speed runs on flat ground and was unable to get the RC fuel to fire so i tried a down hill run and WAM the extra RPM did the trick the fuel fired off doubling the RPM. I hit 66.9 MPH

Quote:

**Bikeguy Joe** · #2 12-14-2009, 05:22 AM

I will only say a bike speedo on a table with 66.9 can be done by anyone.

**Bikeguy Joe** · #3 12-14-2009, 05:24 AM

For all your trouble you should be able to get some one to get it on video, and use a radar gun.

**Bikeguy Joe** · #4 12-14-2009, 05:25 AM

Plus it was the hill "doubling" your rpm, not the R/C fuel, which will only make your engine run lean unless it's already terribly over rich.

**BarelyAWake** · #5 12-14-2009, 05:53 AM

66.9 MPH on what appears to be a bone-stock HT? Yer speedo is screwed or...

The math doesn't work with the engine engaged and downhill it doesn't matter if you've an engine so it's a moot point. Actually come to think on it, with the added drag of the secondary drive chain I seriously doubt you could hit this almost 70mph yer claiming... clutch in or not.

For outrageous claims like this that are almost twice as fast as any verifiable results you simply must provide better proof - like a filmed GPS, not a $10 POS bell speedo. You've been around long enough to know what we think of downhill and "results" like this and what happens when people make threads like these... I'm gonna leave it open for now - if it gets out of hand, it's gonzo.

I call shenanigans. o.o

wildemere · #6 12-14-2009, 06:58 AM

By my calculations come you were turning over 12,000RPM.

Better get your lead plated undies ready next time...

camlifter · #7 12-14-2009, 07:08 AM

i call BS even on the 42mph claim, a 36t on that set up would be really slow to take off with. lot of lurching at low speed, probably wouldn't pull the 36 into it's upper rpm range anyway unless you were going down hill.

and down hill doesn't count.

**Bikeguy Joe** · #8 12-14-2009, 07:20 AM

One time, at band camp.....

**paul** · #9 12-14-2009, 03:19 PM

the magnito on these 2 strokes make an electronic speedo worthless 99% of the time. very seldom will they work properly with one. also its fun to get some extra speed but remember these are bicycles and they were not designed to do great speeds. they will fall apart trust me