Quarter Mile times

[sudjim]

Hi all,
I was wondering if anyone has ever done 1/4 mile runs just to see what the times and speeds would be. I'm thinking of measuring off a flat straingt stretch of road near me and just using a stopwatch get some prelim data. Might be fun. I'd say if anyone else is thinking of doing this for comparison purposes, we should have some guidelines. I say you can pedal as much as you want. The only rule should be that you start at a dead stop. If you have speeds, all the better, but if not, times would be great. (imagine showing up at test and tune night at the local drag strip...)

Anyone game?

Jim

 

[BarelyAWake]

Funny you should mention that

I've a near perfect 1/8th mile stretch on my way to work that I use to test the lil mods I've done to my bike, while I do have an almost perfect 1/4 mile run I find to reach and hold redline I only need 1/8th... Maybe a scaled down run is appropriate for these lil machines?

I've not actually timed it as I use my GPS and achieved speed to judge, (and I haven't a watch w00t!) but I heartily recommend this to anyone interested in getting the most outa their bike - "a little better" is tough to figure without a constant to compare it to.

I'm on this - I'll try to pick up a stopwatch this weekend, you still want a 1/4 mile? Or the 1/8th which might yield clearer results?

 

[sudjim]

1/8 mile is fine for real testing and such. I will probably do some 1/4 mile times so I can relate that to people not familiar with what is a good 1/8 mile time. So many people know what 14 second quarter mile is. Or know that a 10 second car is really smoking. If you give an 1/8 mile time, they cant figure it out since you don't just multiply by 2. I can't wrap my head around 1/8 vs. 1/4 sometimes.

I was thinking about parameters of the tests. I think a dead stop with the motor already started (clutch in) would be a good point. What about only pedaling until able to let the motor run you? What would be the best way of getting an accurate baseline considering others around the country (globe) may want to try so they can see where they and we stack up?
Thoughts?
Jim

 

[freewheeling frank]

i think 1/8 is good as far as pedaling it doesnt take but maybe 100 feet or so and i am outrunning the pedals, so i say pedal as much as you want, i think i can set my gps to give me elapsed times and speed but its been snowing like crazy here so ill have to wait till things dry out some before i can set up a cours and do some runs , later guys frank

 

[scooterhoot]

We got a 1/4 mile kinda flat spot back in the trailer park that was never finished, never went for E.T., just top speed. I'll have to hunt up a stop watch.

 

[BarelyAWake]

From a dead stop is a definite, I too think pedaling makes little difference - even if it did, you'd pedal to race then too - so it all works out.

When I get the chance I'll do a 1/4 mile run just to get some numbers - don't expect much lol, I've a mountain bike complete with knobbies and laden down with a ton of tools and crap

 

[Venice Motor Bikes]

WOW... A 'top speed' thread that hasn't been locked or deleated? Let's see how long this one lasts?

 

[BarelyAWake]

Well - nobody's posted any numbers yet Venice, let alone ridiculous ones

 

[Venice Motor Bikes]

I started a similar thread a few days ago, & the thread was deleated within minutes!

Oh-well... I hope this one lasts!! (we need somewhere to brag without dumping on Foureasys thread!)

 

[BarelyAWake]

Well the "tricky" bit is validation (not that it should be necessary lol), It'd be nice to see some numbers with a pic/vid of the run. Like a second person with cam and stopwatch in hand shootin' both the bike and the watch as the line is crossed...

But of course gettin' that second person is a bit of a problem sometimes lol

 

[Ghost0]

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.

 

[Quenton Guenther]

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,

 

[impression]

sounds good.

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

 

[BarelyAWake]

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

 

[sudjim]

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

 

[BarelyAWake]

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.

 

[sudjim]

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

 

[scott83]

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

 

[sudjim]

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

 

[scott83]

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.