The Great "Gearing vs Hub Motor" Debate

[safe]

I have to thank you for being the only one to ever offer an explanation for the 'clutch' prohibition.

Motorcycles use a "clutch" and if you've ever seen a beginner learning about a motorycle the first thing they have trouble with is the clutch. By removing that as a "learning issue" it makes it easier for children to ride an electric bike.

My position still stands regarding chidren verses adults on electric bikes. The chidren should be allowed to "keep" the existing laws and the adults should get new ones that allow more power if you hold a drivers license. If you are "safe" to drive a 3000 lb "death mobile" then it should be "okay" to ride something that only weighs around 100 lbs.

 

[xyster]

The chidren should be allowed to "keep" the existing laws and the adults should get new ones that allow more power if you hold a drivers license. If you are "safe" to drive a 3000 lb "death mobile" then it should be "okay" to ride something that only weighs around 100 lbs.

What about older adults, the handicapped, city dwellers or others who often don't hold a driver's license? Would you have a third overarching category for these folks, or let 'em only ride the kiddie bikes?

 

[Toorbough ULL-Zeveigh]

By removing that as a "learning issue" it makes it easier for children to ride an electric bike.

Are you just guessing that's the reason or do you know from some legal reference that is the underlying intent? It'd be interesting to find out who originated the law cuz it seems to have been rubber stamped all over. But that's okay if you don't know precisely. At least I have an answer now that I can propogate if someone asks.


The way the law came about in Canada was around 1995 the stakeholders in the ebike business pitched it to the government that power assist is for the elderly & the handicapped. So the government committee's rationale was that the assist should only be enuf to level the playfield so-to-speak. To allow the disadvantaged group to be on par with able bodied cyclists when motor & human input is combined, no more than that. Yet the law still ended up looking pretty much the same as everywhere else. hmmm.

 

[Lowell]

Slightly off topic, but speaking of 3000lb deathmobiles, there's a ritzy private club near my house called the Arbutus Club. This morning a lady drove her 5 series BMW *over* a BMW Z3 and another nice car in the parking lot. The 535 ended up on it's side in between the other 2 cars, which were parked side by side in parking stalls.

 

[xyster]

Yet the law still ended up looking pretty much the same as everywhere else. hmmm.

Must be the U.N.'s doing then.

 

[Lowell]

Quarter Mile Retest

I found a perfectly flat piece of road and marked off a quarter mile. This is roughly how the speeds went...

10 seconds - 20 mph

20 seconds - 35 mph

30 seconds - 40 mph

After three almost identical runs I ended up with 31 seconds at a final speed of 41 mph. (best top speed)

So my "best quarter mile" (which will not likely change much for this bike) is 41 mph top speed and 31 seconds elapsed time.

And I managed to find a tighter "tuck" position that is giving me a little more top end speed and on the downhill I managed to reach 51 mph for 2 seconds. (so all in all it was a "good day") Seems that a quarter mile is just about exactly how long it takes my bike to get up to full speed so all testing beyond this will favor top speed over acceleration. It will be interesting to see your "elapsed time" because on average the last third of the run is at high speed where my higher top end does well. But massive power should get you there quicker, so if you beat 30 seconds that's "good", but if you beat 20 seconds that's really smoking!

My "average speed" calculates to 29 mph.

Had the chance to do a quick spin around the block after work today, and clocked 0-40mph in about 10 seconds. I was expecting quicker, but given the small problems I've been having, I suppose it's a good start. Running these two bikes side by side wouldn't even be a race... I think I'd be 500+ft in front by the end of the 1/4 mile.

1/4 mile time should be in the low 20's with an average speed somewhere over 40mph.

 

[xyster]

1/4 mile time should be in the low 20's with an average speed somewhere over 40mph.

I have a similar setup and also figured low 20's was reasonable for the quarter mile. Safe vehemently disagreed. But I'm not going to push my bike up to it's top speed of 44mph, so I won't know. It's good Lowell is here to post real-world, high-power hubmotor results.

Is that 10 second 0-40mph time done in a tuck, or downhill? Based on tests at a lower voltage than I run now, I'd be 15-18 seconds to 40mph on the level, in a normal upright position.

 

[Lowell]

That test was done upright with a stopwatch, so call it +/- 1 second. Don't forget my speed control current is ~60 amps with IRFB4110 MOSFETs.

 

[safe]

Well let's look at the chart... depending on your top speed if you stay below 40 mph you will not break 20 seconds... no way, no how... so you would need "about" 50 mph top speed to actually beat 20 seconds... (you can't change the laws of physics here... these are the "average" speed numbers for a quarter mile distance)

Can you go faster than 50 mph? (maybe 47 mph might do it)

Don't forget that you need to accellerate to reach these "average" speed values so you need to go slighty past them to compensate for the standing start.

If your top speed is 40 mph then your time will be about 25 seconds. Xyster can't go faster than 36 mph so he can't get into the low 20's at all...

O-40 in 10 seconds translates to about 4-5 hp, so you have a very powerful bike (like 3500 Watts or more) closer to a motorcycle in power.

 

[Lowell]

21-22 seconds would be about right if I'm hitting 40mph just before half time. Clearly the average speed is over 40mph so it's under 22.5 seconds for sure.

Looks like hub motor 1, gears 0.

 

[safe]

21-22 seconds would be about right if I'm hitting 40mph just before half time. Clearly the average speed is over 40mph so it's under 22.5 seconds for sure.

Looks like hub motor 1, gears 0.

So let me get this straight...

Did you ACTUALLY do the FULL quarter mile or are you a "weenie" like Xyster that chickened out on the actual race? I want you to measure a quarter mile in advance of the run. Then do the run and count the seconds. Don't look at the speedometer or odometer when doing the run I want ACTUAL SECONDS for a full quarter mile. About three to four passes with nearly identical speeds will suffice. Until then you don't get the title of "fastest quarter mile time".

 

[xyster]

Don't forget my speed control current is ~60 amps with IRFB4110 MOSFETs.

Oh yeah!!!
.
.
.
The 5304 then really can put 5,000 watts to good use. How's does it "feel", this 60 amps compared to 35?

Before considering a similar upgrade, I'd need to upgrade the battery system -- either by exchange for next generation lithium, donating what I currently have to the scooter, or running maybe 3-6ah of next gen lithiums (like emoli's) in parallel to provide the added current capability.

 

[Lowell]

21-22 seconds would be about right if I'm hitting 40mph just before half time. Clearly the average speed is over 40mph so it's under 22.5 seconds for sure.

Looks like hub motor 1, gears 0.

So let me get this straight...

Did you ACTUALLY do the FULL quarter mile or are you a "weenie" like Xyster that chickened out on the actual race? I want you to measure a quarter mile in advance of the run. Then do the run and count the seconds. Don't look at the speedometer or odometer when doing the run I want ACTUAL SECONDS for a full quarter mile. About three to four passes with nearly identical speeds will suffice. Until then you don't get the title of "fastest quarter mile time".

I'm having some problems with power (amps) above 45mph, so it still has not gone faster than 47mph. Once that issue is solved, there will be plenty of power to push WELL past 50mph. The controller isn't even breaking a sweat, so I have the option of adding more current, batteries permitting. I will most likely test out Fechter's new adjustable current resistor values.

The weather here hasn't exactly been ideal, but at least this gives an idea of the hub motors potential.

 

[Lowell]

Don't forget my speed control current is ~60 amps with IRFB4110 MOSFETs.

Oh yeah!!!
.
.
.
The 5304 then really can put 5,000 watts to good use. How's does it "feel", this 60 amps compared to 35?

Before considering a similar upgrade, I'd need to upgrade the battery system -- either by exchange for next generation lithium, donating what I currently have to the scooter, or running maybe 3-6ah of next gen lithiums (like emoli's) in parallel to provide the added current capability.

60 amps = have to be careful in corners on wet roads, where 35 amps you just give it full throttle all the time. 60 amps also = easy to control wheelies.

 

[safe]

The weather here hasn't exactly been ideal, but at least this gives an idea of the hub motors potential.

Understood.

I went out just now to try to break my 51 mph on the downhill and the cold air and wind was so bad the best I could do today is 46 mph. So weather conditions are a big factor. A strong headwind (or tailwind) can make a huge difference on my bike. For a bike with 4-5 hp you should have less of a problem with that.

I EXPECT the big horsepower bikes to beat mine... but until you do "officially" beat it I still hold the title for fastest COMPLETED quarter mile...

 

[xyster]

Did you ACTUALLY do the FULL quarter mile or are you a "weenie" like Xyster that chickened out on the actual race?

At least I'm a living weenie

And I already told you Safe that I'd video a 1/4 mile run when weather permitted and I find a good spot to do it. I also said I'm not about to ride my back-heavy, high-speed-wobbly bike above 37mph, when it is quite capable of attaining 44mph. Between that fact and Lowell's 60 amp controller, Lowell will "win" the 1/4mile ebike competition easily. I'll be a distant second, and Safe, you'll be a distant third if you're lucky.

Now if the scooter riders would join in too, the competition will get much more interesting! With a couple exceptions, like the ETEK'd Lepton, the scooters here have quicker brushed motors run at higher amps and lower voltages.

 

[xyster]

Hey Lowell,
Is your rear hubmotor staying put in the dropouts under wheelie-popping power? Are you using torque arms? Are the rear dropouts steel or aluminum?

 

[fechter]

60 amps = have to be careful in corners on wet roads, where 35 amps you just give it full throttle all the time. 60 amps also = easy to control wheelies.

I can see it now, bicycle drift racing. Boy, that setup sounds fun.
I'd love to see a video

 

[Mathurin]

Don't need a motor...

<embed src="http://www.youtube.com/v/6GNB7xT3rNE" type="application/x-shockwave-flash" wmode="transparent" width="425" height="350"></embed>

Works on skating rinks too.

 

[xyster]

This and similar rubber-burning antics remind me of a gerbil on his wheel.

Round he goes happily running while going nowhere but round he goes happily running while going nowhere but round he goes happily running while going nowhere but....

We quit reading repetition, why do we so enjoy performing something repetitiously?

 

[safe]

I already told you Safe that I'd video a 1/4 mile run when weather permitted and I find a good spot to do it.

That's MORE dangerous than just doing the quarter mile!

I tried riding my mountain bike on a local dirt track and made it most of the way around until I went down this downhill section and realized "yikes....with one hand I can't really even stop" and I ended up CRASHING while holding the camera. DON'T DO IT. I'd rather that you give me your time. There's no reason to "fudge" the numbers because we are exploring theory and practice of the machines here. If the number were way off we would have to justify it mathematically. So just mark off a quarter mile stretch using the odometer on the first pass, then make several runs counting the seconds. Take the average of the runs, or the best, or report all of them. Then we get an idea of what times your bike can run reliably. Save the video antics for later.

For the 750 Watt bike class mine will do well... though a Lowracer in my class would give me tough competition... as you guys are in the "Open Modifieds" (racetrack lingo) class you will have your own records to establish...

 

[xyster]

That's MORE dangerous than just doing the quarter mile!

I tried riding my mountain bike on a local dirt track and made it most of the way around until I went down this downhill section and realized "yikes....with one hand I can't really even stop" and I ended up CRASHING while holding the camera. DON'T DO IT. I'd rather that you give me your time.

Thank you for your earnest concern, but for my videos I wear the camera around my neck like a tourist, both hands gripping the handlebars at all times. The only thing this prevents me from doing is bending forward to reduce drag.

 

[safe]

Thank you for your earnest concern, but for my videos I wear the camera around my neck like a tourist, both hands gripping the handlebars at all times.

Okay, that sounds okay. I thought you were holding the camera in one hand and using the throttle in the other.... not a good idea, but that's how I shot the video of a mountain bike track. (it was a mix of gravel road, dirt and, well, a downhill with rocks in it! Oops!)

 

[Lowell]

Hey Lowell,
Is your rear hubmotor staying put in the dropouts under wheelie-popping power? Are you using torque arms? Are the rear dropouts steel or aluminum?

The motor seems fine, although I do check the M14 nuts just to be sure. No signs of any movement. The dropouts are the factory Rocky Mountain aluminum bits and look quite good. Retaining plates are on the machining list, but I've been taking care of more important details like installing fenders so the bike might actually be useful for commuting.

After watching one of those chopper shows where the guy pounds out a rear fender from a flat sheet of metal, I decided to try my hand at metal forming. All I can say is you won't see me on any of those shows! :lol:
I grabbed an old car fender from the body shop next door to mine, cut a strip off it and proceded to hammer it on a block of wood. The result was a functional but very ugly rear fender. For the front I modified a $15 bike shop plastic jobbie by heat gunning it until it did what I wanted.

A quick test on a wet road shows no more splashing, and it doesn't seem to have changed the top speed as the bike still went 47mph. Interestingly this was with my feet on the pedals and with a full back pack and extra warm puffy clothing. I've removed the foot pegs in the interests of practicality and comfort

 

[Toorbough ULL-Zeveigh]

This is from a link courtesy lemmiwinks.

It's an EV converted 1972 Datsun 1200 that does the quarter mile in 12.151 sec. You can read all the pertinant specs for yourself, but this one entry is what caught my attention.

Drivetrain: Direct drive (no transmission, clutch, or flywheel)... 8)

http://www.plasmaboyracing.com/whitezombie.php


Would gearing make it any faster?
Debates over. :lol: