Post your DRAG RACE ebike run !!

Doc,
I think you are in too high a pedal gear if you can assist all the way to 30kph. Where the motor needs the most help is 0-1kph.
 
John in CR said:
Doc,
I think you are in too high a pedal gear if you can assist all the way to 30kph. Where the motor needs the most help is 0-1kph.
Click to expand...

I agree. Even with a human body, power is torque x rpm. I would get into a really low gear, maybe a gear where just 10-15kph makes your legs be spinning at peak cadence (if that's possible with the gearing). Then just explode your legs to a blur right off the line for the first ~20-30ft, and once they cant keep up the cadence, just go into a tuck and let the motor do the rest. Just a massive pedaling effort for the first 1-2 most critical seconds, the start.
 
liveforphysics said:
John in CR said:
Doc,
I think you are in too high a pedal gear if you can assist all the way to 30kph. Where the motor needs the most help is 0-1kph.
Click to expand...

I agree. Even with a human body, power is torque x rpm. I would get into a really low gear, maybe a gear where just 10-15kph makes your legs be spinning at peak cadence (if that's possible with the gearing). Then just explode your legs to a blur right off the line for the first ~20-30ft, and once they cant keep up the cadence, just go into a tuck and let the motor do the rest. Just a massive pedaling effort for the first 1-2 most critical seconds, the start.
Click to expand...


Yes.. maybe i just miss explained my point..

I mean.. i'm using the low gear for the first kmh.

But what is difficult is to keep the ebike stable while exploding on the pedal

remember it's a DH bike.. not a thin carbon bike.. but probably that stifning the rear suspension will help

Doc
 
Doctorbass said:
D-Man said:
Ok. Did pretty good! That 408 hauls butt.
Click to expand...


D-Man, How can you hit 92MPH with... a... 408 ???? :?

and 2.2sec 0-60ft would require incredible power into it!!

It's certainly with a car!!!.. not an ebike!

so what does mean the 408 ?

Doc
Click to expand...

Ok, the truth is that it's a 20 year old time slip. Barely readable anymore. I still have the car. A bone stock '70 dodge dart with a 318 and 4 barrel carb and 120,000 miles at the time. Now approaching 200k but I rebuilt the engine about 15 years ago after it got a rod knock. I don't drive it much. It eats gas. At $3.20 a gallon it stays parked. :|
 
I think I could hold on to you for the first 10 seconds or so....

What's your time to 30mph? As far as off the line, I know I can reach 16mph in 17 feet. It seems that if you did 60ft in 2.2 seconds, then your 1/8 mile time should be faster...Well maybe not, I guess I was looking at the first run which was much slower than the later runs you posted. What do you feel is the strong and weak points during your runs?


That's definitely not on my ebike though, but on my roadie.


You know, I'd REALLY like to drag race, heading up a steep hill.
 
It was the only time I went to the dragstrip. Just something I wanted to do. One thing that was amazing was that the track was so slippery that its like trying to accelerate on a wet road. All the pavement is covered in burnt rubber. Street tires just spin on top of it. You can do a burner almost all the way down the track if you want to.
 
Ok. I'll try a 1/4mile run with my ebike. One pedalling+motor power and then one motor power alone. I'll just use my speedometer to measure it and then once it hits .25 mile I will rotate it off the mounts to stop the clock. Then post pictures.
 
D-Man said:
It was the only time I went to the dragstrip. Just something I wanted to do. One thing that was amazing was that the track was so slippery that its like trying to accelerate on a wet road. All the pavement is covered in burnt rubber. Street tires just spin on top of it. You can do a burner almost all the way down the track if you want to.
Click to expand...

...D-Man...they ain't spinning tires coz its 'slippery' its because they are producing alot of power and
trying to get it to the ground, you probably noticed them spraying the track? Thats VHT Track Bite it
increases the traction. I definitely wouldn't call a drag strip "slippery"
not any i been to anywayz, they must be different in USofA Luke? :mrgreen:

A dragstar couldn't get down the 1/4 mile in under 6 seconds if it was slippery buddy ..although
they often do spin their tire a considerable length of the track if they dont get clutch settings right LoL


KiM
 
D-Man said:
It was the only time I went to the dragstrip. Just something I wanted to do. One thing that was amazing was that the track was so slippery that its like trying to accelerate on a wet road. All the pavement is covered in burnt rubber. Street tires just spin on top of it. You can do a burner almost all the way down the track if you want to.
Click to expand...


Every track I've ever been to is crazy sticky. Sometimes so sticky they pull your shoes right off if you try to take a step. When cars break on the line, trying to push them backwards by hand takes about 3-4 guys to get them to roll off the track, then one guy can push them fine back to the pits, because normal asphalt isn't sticky.
 
The track was Firebird in Arizona. My first run was just a burner for like a 1000 feet. Even my roommate with a 17sec car did a 500 foot burner. Just street tires. Non-posi rear ends. They probably don't put the vht on the track unless its a major event. Maybe they want to save money. I don't know. :?:

Anyway, I did my 1/4 mile runs! They suck! But I hope you guys like my participation.

Motor Alone:
 
Motor plus pedalling:

Minus off 1-2 seconds for .26mile!
 
I m preparing a secret weapon to place the bar very HIGH on the ebike drag race! :twisted:

S O O N :mrgreen:


Guess what it is...

( i preffer specifying right now.. IT S NOT A BOOSTED FLUX CAPACITOR !! 8)

Doc
 
Ok. I need to practice my holeshot. I started in the wrong gear and missed a shift when pedalling. I have to be careful not to pop a wheelie or I loose traction. I'll try again soon.
 
D-Man said:
Ok. I need to practice my holeshot. I started in the wrong gear and missed a shift when pedalling. I have to be careful not to pop a wheelie or I loose traction. I'll try again soon.
Click to expand...


Great!! keep us updated!!! :mrgreen:

Doc
 
Since there's no other entry's, I get second place! I guess people can't do a quarter mile with a CA. That sucks. :lol:
 
Doctorbass said:
I m preparing a secret weapon to place the bar very HIGH on the ebike drag race! :twisted:

S O O N :mrgreen:

Guess what it is...

( i preffer specifying right now.. IT S NOT A BOOSTED FLUX CAPACITOR !! 8)

Doc
Click to expand...

2 wheel drive?
 
John in CR said:
Doctorbass said:
I m preparing a secret weapon to place the bar very HIGH on the ebike drag race! :twisted:

S O O N :mrgreen:

Guess what it is...

( i preffer specifying right now.. IT S NOT A BOOSTED FLUX CAPACITOR !! 8)

Doc
Click to expand...

2 wheel drive?
Click to expand...

no.. it's something else :twisted:

Doc
 
13 august 2011


KMX typhoon
5304 on 20"
28s A123 and 233A burst 82V min
total weight 250 pounds with me

BEST SCORE DURING THE DAY ( not on the video):
Best 0-60ft: 2.5sec
Best 1/8 mile time: 12.3sec
Best 1/4 mile time: 21.9sec
Top speed 46.79MPH (75.3kmh)


[youtube]J2IDJKClDCA[/youtube]

My time slip:
 
that is insane!!! :D but i bet you would get to 2.4sec wearing lycras!!!

no clips shoes? :eek:
 
7891025566_28c89227f3_b.jpg


First and only run. I was 'bluetee', 'whitetee' was my friend with a 1000W GM @ 24S.

We attempted to go back for another run, but the bicycles were too fast and they wanted us wearing riding gear.
 
ZOMGVTEK said:
7891025566_28c89227f3_b.jpg


First and only run. I was 'bluetee', 'whitetee' was my friend with a 1000W GM @ 24S.

We attempted to go back for another run, but the bicycles were too fast and they wanted us wearing riding gear.
Click to expand...


Aaaaaall riiiiight!! :wink:

I see you beat my KMX for the 1/8 mile , congrat :mrgreen: The 0-60ft is still really good too!

I think i will try my kelly and 125Vdc on my 5302 on 20" on my trike:twisted:
Doc
 
That was with a 12 FET at roughly 8kW, massively phase limited, and a pack charged to only 96.xV. With 100V on the pack, and the 24 FET thats sitting around, I should be able to shave quite a bit of time off. Trap speed won't change much, this bike barely creeps past 50. I was topped out halfway down the 1/8th.

I have a not that exciting video.
[youtube]btKOu2ZBp50[/youtube]
 
What is your speed at the 60ft mark? I don't have a timing system but I can compare speeds at certain distance markers.
 
veloman said:
What is your speed at the 60ft mark? I don't have a timing system but I can compare speeds at certain distance markers.
Click to expand...

All I know is what's on that time slip. Compared to when I was running only 50 more phase amps, the bike feels slow at the low end. I'm running the little 12 FET harder than it probably should be, and it's lasted me a while without blowing up. When I first put the bike together, I popped FET's twice at only slightly higher phase currents, and it was a wheelie machine at low speeds. Currently it has no hint of lifting the front tire at all, even if you lean back a bit. The controller must really be limiting things, since acceleration really picks up once the bike gets moving. I can probably get quite a bit more out of this motor with a bigger controller, but I'm happy with that time as is. The bike almost feels slow and boring right now, but 12.2 sec in the 1/8 is a second or two better than I expected. I see slow cars or trucks run high 11's to 12's all the time, usually at higher traps. I should note, this was done at a 'cruise night' type of deal. They intentionally don't prep the track at all, so the kids willing to redline neutral drop or clutch dump a DD don't snap axles all night. Traction is worse than the street, but the bike of course had no issues. The rear wheel is heavy and bald.
 
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