Quarter Mile times

I would recommend an 1/8 mile as well. Heck the TF guys are doing it now at most tracks. Besides an 1/8 mile is much easier to find than a 1/4 mile.

__________________
Design is easy, execution the hard part.
www.sickbikeparts.com

Hi Everyone,

Each year at the motobike/scooter event in Dawson Springs, KY we "dirt drag".

My Whizzer [modified & does wheelies] turns 40.3 MPH in 150 feet. Is the current champion for both 2008 & 2009. Was able to outpace the OHV Whizzers at the event also. RPM maxed at 8220 [not bad for a 4 stroke single cylinder flat head]

My picture is the bike at the event in 2008 running against a stroked & bored vintage Pacemaker.

Have fun,

__________________
Quenton
www.ezmotorbike.com

sounds good.

wonder, can we have engines @ idle to start with?

I'd say "yes" to that one impression - having to start the bike changes everything

For a 1/8 mile strip, I need to measure off 660 feet. I'll try to do that by finding the circumference of my front tire while I am sitting on the bike (so tire squish is taken into consideration) I'll throw a thin duct tape loop through the spokes and on to the tire and count off until I reach 660 feet.

I really didn't' intend this thread to be about bragging or top speed or competition. If we have enough data from various configurations of builds, we may be able to set a baseline of performance, so someone who has no second bike as a point of reference can realize their bike may perform better. Just another troubleshooting technique like reading spark plug color...


Having said that, It would be nice to see some true ETA's and find out what tricks squeeze out better times. There are several measures of performance. (MPG, longevity, top speed, acceleration, cost effectiveness) Where you put your dollars determines your output.

Jim

While generally I'd like to not need such things, it may prove in our best interest to provide validation (as described previously). While I for one am interested in performance comparisons, that in fact I'm somewhat desperate for some numbers to provide a baseline - oftentimes such things naturally devolve into bragging and competition.

There is a second bike near where I live, though I see it infrequently. When that build was completed mine was still completely stock, we made a few laps at speed around an empty lot and we remained almost perfectly equal in times - the only way I could pull ahead was cornering better (a sketchy business with knobbies heh).

Much later, after I had made endless alterations to my bike but he had not - we did the same again. This time it was a mere matter of giving my throttle a hearty twist and I'd leave the poor kid behind.

While I knew my bike had been running better the more I tinkered, most of what I had done had improved acceleration while my top speed remained much the same. This made it very difficult to gauge the effectiveness of my modifications as it was often subjective, my mood would "change" how my bike felt.

In retrospect I should have kept time records, gotten a stopwatch (doh - I forgot to do that lol) and recorded my findings.

I think that this thread could be a valuable enough tool that if it were subject to just a little regulation through requiring pictures in addition to times - that the end result would be worth the inconvenience of diggin' up a buddy to take shots of the action.

OK, I did 5 runs of 660 feet. I had the motor started and peddaled as fast as I could until peddaling did not good. I had my son at the finish line with the watch. He averaged the times to the nearest second.
Bike info:
20" wheel chopper with ape hanger handlebars. No suspension
BOYGOFAST 70cc motor, all stock
34 tooth sprocket (similar to 44T on 26" wheel)
RUN 1 21 sec
RUN 2 20 sec
Run 3 19 sec
Run 4 19 sec
Run 5 19 sec

I don't know what the speed was. Maybe later I'll re-do the run with a speedometer.
I think the first run could be thrown out. There you go. No bragging, no top speed and something to measure against. I'll try to get one of my other bikes out there within the week
Jim

5280/660 = 1/8 mile 19*8 is 152 seconds a mile. 3600 seconds in an hour. so 3600/152=23.68421mph

Hi Scott,
23.7 MPH assuming every 1/8th mile takes 19 seconds. I would like to know how fast the second 1/8 mile would be, since I don't have to accelerate form a stop and have already attained top speed. I'll get back to you all on this. If I can get enough volunteers, (one more kid) I'll do a 1/8 and continue on to do a second 1/8 and get a time for each.
Jim

True im sure its much faster than 23.7 once she's going. Im getting ready to put a spedo on mine. Dont think it'll last from what ive read though. $10 wally world special.