Conclusive proof gearboxes are awesome.
- Thread starter Teh Stork
- Start date
Chalo
100 TW
neptronix said:
Okay, why? 6000 RPM on a 25 inch wheel is 446 mph. That's not useful. It implies an unnecessary ratio reduction.
750 rpm on the same 25 inch wheel is 56 mph, and that's more than enough to kill yourself and others with.
he us just messin with u
it is the old unroll a motor
take a rotary rotor and stator
unwrap it so it lays flat on a train
not it is a "linear" motor
now how do you make the train faster if the power is on the train
power to weight ratio is all that matters
it is the old unroll a motor
take a rotary rotor and stator
unwrap it so it lays flat on a train
not it is a "linear" motor
now how do you make the train faster if the power is on the train
power to weight ratio is all that matters
Chalo
100 TW
neptronix said:
That's what I was talking about. Otherwise I'd have said 27 inch wheel and kill yourself (but not others).
Edit:
Unnecessary transmissions are unnecessary in cars too. The same principle about making the torque you need at the RPM you need applies.
mdd0127
100 kW
- Joined
- Sep 30, 2008
- Messages
- 1,084
Well, someone build us some batteries, motors, and controllers that only weigh a few pounds, use a minimum of rare earth materials, and that are capable of hundreds of amps of current and we'll all ditch our gearing and reduction drives. ..........I'm waiting.................Still waiting...............Stiiiilllllll waiting......... 
mr.electric
10 kW
Would it be an advantage in electric drag racing to use a transmission if the race was divided into wattage limit categories. Say for some stupid reason they had a 10 kw category and unlimited category. I could see the unlimited category being owned by anyone with the perfect motor. 10 kw is far too small for an optimum drag time. Wouldn't the transmission serve as a crutch for this hopelessly underpowered motor?
Humans are the most underpowered motor you will find on any vehicle. Hence the need for dozens of gear ratios and obsessive weight reduction in bicycles.
Humans are the most underpowered motor you will find on any vehicle. Hence the need for dozens of gear ratios and obsessive weight reduction in bicycles.
Hillhater
100 TW
mr.electric said:
Well , to a certain extent they already are, but by voltage rather than watts.
http://www.nedra.com/class_rules.html
voltage is easier to measure and control than Watts, but there is indirectly a limit to how many watts you can generate if you are restricted to 24 or 48 volts as compared to 400+ volts.
John in CR
100 TW
Hillhater said:
No there isn't. Just use thicker copper and pass more current.
Hillhater
100 TW
John in CR said:
Technically , yes of course, but in practical reality running 24v, 20,000 amps would be a little tricky !
I'm not saying I approve, but...here's a 1964 Chevelle EV drag racer that used the stock 2-speed automatic and set records at several lower voltage classes. 24V , 48V, 72V, 96V...of course higher voltages using fewer amps are more desireable...
Who...in their right mind, would race a 3,000-lb car with 24V??
http://www.poormansev.com/
Who...in their right mind, would race a 3,000-lb car with 24V??
http://www.poormansev.com/
Hillhater
100 TW
love that adapter plate ! :?Zero S vs Brammo Empulse R
1-speed vs 6-speed
Same controller(not true!!!!!). Similar HP. No hard data. No clear winner...
“The Empulse left the Zero for dead in an acceleration contest from a complete stop, as the torque-multiplication benefits from its gearbox makes the Empulse the drag racer’s choice,” says EiC, Kevin Duke. “Yet, to declare the Brammo the clear winner in terms of power isn’t telling the whole story. A roll-on contest at 55 mph (with the Empulse in fourth gear) showed the Zero has a slight edge.”
The roll on contest should have been done with the Empulse in 3rd probably
This need to be settled on track
Zero got 13 miles more range though. I kind of expected even more considering how heavy the Brammo is with a L2 charger and heavy duty components, and the fact the zero has a 1+ kwh on the Brammo.
I wonder how much power the liquid cooling for the motor/controller/battery uses on the Brammo.
I wish they would have done a flat out test to see when the turbo modes on the controller cut outs. I wonder if the liquid cooled sevcon allowed Brammo to disable the cut out? Also a winter/summer test to let the liquid cooling/heating shine.
http://www.motorcycle.com/shoot-outs/2013-brammo-empulse-r-vs-zero-s-zf114-91574.html
1-speed vs 6-speed
Same controller(not true!!!!!). Similar HP. No hard data. No clear winner...
“The Empulse left the Zero for dead in an acceleration contest from a complete stop, as the torque-multiplication benefits from its gearbox makes the Empulse the drag racer’s choice,” says EiC, Kevin Duke. “Yet, to declare the Brammo the clear winner in terms of power isn’t telling the whole story. A roll-on contest at 55 mph (with the Empulse in fourth gear) showed the Zero has a slight edge.”
The roll on contest should have been done with the Empulse in 3rd probably
This need to be settled on track
Zero got 13 miles more range though. I kind of expected even more considering how heavy the Brammo is with a L2 charger and heavy duty components, and the fact the zero has a 1+ kwh on the Brammo.
I wonder how much power the liquid cooling for the motor/controller/battery uses on the Brammo.
I wish they would have done a flat out test to see when the turbo modes on the controller cut outs. I wonder if the liquid cooled sevcon allowed Brammo to disable the cut out? Also a winter/summer test to let the liquid cooling/heating shine.
http://www.motorcycle.com/shoot-outs/2013-brammo-empulse-r-vs-zero-s-zf114-91574.html
I'd like to see two teams racing Zeros against each other with identical battery/controller/motor/voltage. One with the stock one-speed, with final drive sprockets changed to help 1/8th mile times as much as possible...and the other Zero with a custom-designed 3-speed, or possibly a scaled up Thudster 2-speed. Rear wheel diameter on both open to change to whatever helps. Just daydreamin....
Developing a multispeed is expensive. Brammo basically admitted the 6 speed is overkill but it was off the shelf (they are now developing a new box). I mean even Ford and GM are working together now on new trasmissions! Arch Rivals!
Note the Brammo race bike is a single speed...I think Brammo wanted to appeal to tradition gas bike riders. I want to see the Zero S with the bigger Sevcon vs the Brammo with a bigger Sevcon. There will be a point where the bike can't use more gear during takeoff. The funny thing about ev's is when you install a bigger controller they get more efficient (to a point of course)
Note the Brammo race bike is a single speed...I think Brammo wanted to appeal to tradition gas bike riders. I want to see the Zero S with the bigger Sevcon vs the Brammo with a bigger Sevcon. There will be a point where the bike can't use more gear during takeoff. The funny thing about ev's is when you install a bigger controller they get more efficient (to a point of course)
Ykick
1 GW
flathill said:
Cycle World or Motorcyclist published a recent test ride report which basically echoed that statement. IIRC the reviewer also mentioned getting a little tired of all the "clicking" into the next gear and started leaving it in higher gears and shifting less, LOL...
Personally, give me oversize electrics and forgo gearboxes.
The theories stop, when the green light drops.
liveforphysics
100 TW
flathill said:
It's weird they don't mention that the bike with the 6spd also uses the Gen4 size6 (660phase amp) and the single speed bike uses only 420phase amps from a Gen4 size 4.
http://www.sevcon.com/media/2104/gen4_web.pdf
Dude. My bad spreading misinformation. I also assumed they had the same controller given similar hp! The article needs to be revised and mention the hollywood electric size6 upgrade available for the Zero
How about the pack voltage? How do they compare?
How about the pack voltage? How do they compare?
liveforphysics
100 TW
flathill said:
Both use 28s of NMC pouch cells. ~102vdc nominal.
John in CR
100 TW
Same power but 83lb less even with the longer range battery....gimme the lighter more nimble bike every time. There's no way the pig with a gearbox wins in a race across town. 
frodus
10 kW
liveforphysics said:
That would require them to assume the Gen4 Size6 is programmed for the full 660phase amps.
liveforphysics
100 TW
frodus said:
You've got one and a Sevcon programming cable right?
frodus
10 kW
No, but I'd like to get one. Just to dial down regen a little in sport mode.
Tommy L
100 kW
I've read thru this whole thread. Awesome! Sorry that I missed it!
But here are some questions.........
I want to go DARKSIDE and build a build with an In-Frame Motor.
Do you go direct from motor to big rear sprocket/belt pulley?
Or do you use reduction?
Or does it all depend on the rear wheel diameter?
Or all of the above?
Tommy L sends.....
But here are some questions.........
I want to go DARKSIDE and build a build with an In-Frame Motor.
Do you go direct from motor to big rear sprocket/belt pulley?
Or do you use reduction?
Or does it all depend on the rear wheel diameter?
Or all of the above?
Tommy L sends.....
