How to design "Classes" for Ebike Racing?

NEDRA classes according to voltage.
You could class by power, but that would be difficult to verify in the field.
I thought that motor weight would be a good denominator, but again difficult to verify in the field.
Total vehicle weight would be the next best.

This is good because I'm working on getting the city I live in to host an e-bike convention of sorts this year. I don't see why we can't have some friendly races, but it's difficult to put e-bikes into a "class" that would be fair all around (48 volt SLA vs. 48 volt NiMH vs 48 volt Lith for example)

Voltage and Amps seem the way to limit things. (pretty easy to measure at the track) From that you get power MINUS whatever inefficiencies exist. Since anything that goes to waste is "bad" for "progress" in ebikes it would encourage the creation of near perfect performance... a good thing to encourage.

As for weight, I'd have to say that there should be some lower weight limits just so people don't hurt themselves on something that would break, but as for the various battery types again we want "progress" to be seen on the track, so any battery type that is "rechargeable" should be allowed. Fuel Cells aren't "rechargeable" nor are a lot of other things out there. So people (and manufacturers) would get into an "arms race" to make better batteries. Again, this is "progress" that is desired.

Set the "goals" correctly and force people to improve and you will see the performance of the ebike expand over time at the race track.

Possible Classes:

36 Volt - 50 Amps Limit (minimum 65 lbs)

48 Volts - 50 Amps Limit (minimum 75 lbs)

72 Volts - 50 Amps Limit (minimum 85 lbs)

In this age of fast advancing technology, transportation modalities change very quickly. Today, ebikes are the new thing on the road. Tomorrow it'll be personal hovercraft and helicopters sailing above.

To avoid costly legislative re-do's, loopholes, etc, classes of transportation should be defined with an eye towards the future. For proper effect and fair adjudication, definitions ought be testable and documented in the field, like speed is using a radar gun, or a truck at a weigh station. Electrical metrics are not so easy testable, far more easily fudge-able, and generally less salient when it comes to public safety.

Hence, like Fechter, I prefer class definitions predicated on fairly obvious-to-the-eye parameters like size, weight, speed, etc, focusing most on user's behavior piloting the EV, rather than presuming guilt by setting onerous and costly restrictions in advance.

http://ohgizmo.com/2005/10/19/the-gen-h4-personnal-helicopter/

xyster said:

Hence, like Fechter, I prefer class definitions predicated on fairly obvious-to-the-eye parameters like size, weight, speed, etc...

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How do you know someone isn't "sand bagging" in practice?

That's the oldest trick in the racers book... you go out for practice and do a slower than normal lap time and that allows you to get a "handicap" in the real race. Some have even placed physical "sand bags" in their cars when they went to be weighed and then took them out for the race. (thus the term)

I'd rather have it be about Voltage and Amps... how can you trick the measurement of that? What percentage of a "trick" can you pull off?

Remember the old race track motto:

"Never get behind in your cheating!" :wink:

And the idea of Voltage alone seems fine too. There is a limit to how many amps can be pulled at any voltage for any given motor. It allows the better motor designs to rise to the top.

How do you know someone isn't "sand bagging" in practice?

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What would be a motivation for doing so? We're generally talking public policy and not racing. Higher weight would equate to more restrictions/licensing requirements, not fewer.

Maybe on the subject of weight, both bikes could be balanced to be the same weight (just in case one bike has a burly 220 lb guy and another has a skinny 130 lb dude). Some clamp on lead weights could help balance it out, so if voltage is the same and the battery techs (same AH) are kept in line (NiMH vs. NiMH or Lith vs Lith) that should put it down to technology of both the motor and controller then.

I know it can't be perfectly fair, but it could be close.

The fat guy needs to lose some weight or switch to a larger more powerful bike class. (where weight doesn't matter as much) The weight helps to allow the smaller guys to have a place that they can win at. If you balance it out like you said you are defeating the "progress imperative" that racing is supposed to encourage.

You WANT the fat guy to lose.

And you WANT the better bike to win.

That's the whole point of racing.... to improve the "breed"... to be "lean and mean"... "natural selection" and "survival of the most fitting and winning" solution...

Let's keep in mind that weight is LESS important than aerodynamics. And in a racing situation the winner will be the one that uses the wind to their advantage the best... of course the small guy is usually both lighter AND smaller, so he wins both ways...

I would want the best to win too, but if by chance you had two identical bike setups going to race, the lighter one would probably win because of well, less weight to carry.

If the light man's e-bike is the best, it should still win should you scale up the weight to match the competitor wouldn't it?

I think if we could hash out which is "already" better, then the classes could be easier to define and allow for some crossover.

For example, a race in which the voltage limit is 36 volts. If someone has a space age motor that can run at 24 volts and compete with the 36 volt crowd, why not give him a chance? Of course, we wouldn't let the 36 volt crowd bring their e-bikes into the 24 volt race just to be fair.

Trying to "please" everyone is impossible.

You simply need to focus on the "goal" which is to IMPROVE the ebike through competition. ANYTHING that detracts from that "goal" is a bad idea no matter how "pleasing" it sounds. Racing is not supposed to be about making people "feel good" it's about forcing people to struggle to make themselves win in any way they can within the rules. (what "feels good" is to win and not lose)

The rules need to be simple and strict or you get chaos...

I'd rather have it be about Voltage and Amps... how can you trick the measurement of that? What percentage of a "trick" can you pull off?

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You can trick the measurement with tricky, hidden switches and such.

Another problem with electrical metrics insofar as public policy (not racing) is concerned:

Common Joe out for a walk can't tell or report an EV with an illegal voltage level just ran him off a path. Whereas if he got creamed by an illegally massive device, well, he has a chance to report it as such.
------------------------------
Dream Sequence Shimmer Effect

"Hello 911? I was walking along Peripatetic Path in City Park when I almost got mowed down by some clown in a vehicle as big as Trump Tower!"

"Sir, are you reporting something illegal? Didn't you get a voltage reading on that vehicle!? Can you tell me it's power?"
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Sometimes I think I must be related to Dr. Seuss too

xyster

You're not in the "bike laws" area. This one is about "racing" and so you're posting the wrong ideas for this area. This is a "racing classes" topic. It seems like you've been answering it not realizing that... (either that or you just keep changing the topic)

NEDRA Classes

http://www.nedra.com/class_rules.html

A3 349V and above
A2 301V - 348V
A 241V - 300V
B 193V - 240V
C 169V - 192V
D 145V - 168V
E 121V - 144V
F 97V - 120V
G 73V - 96V
H 49V - 72V
I 25V- 48V
J 24V and below

I'd suggest going with three classes:

H 49V - 72V
I 25V- 48V
J 24V and below

It seems like you've been answering it not realizing that...

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Yes I have been! I read the heading the first time then came back and forget it...

Oh no....a sign of senility!

Sorry.....

safe said:

NEDRA Classes

http://www.nedra.com/class_rules.html

A3 349V and above
A2 301V - 348V
A 241V - 300V
B 193V - 240V
C 169V - 192V
D 145V - 168V
E 121V - 144V
F 97V - 120V
G 73V - 96V
H 49V - 72V
I 25V- 48V
J 24V and below

I'd suggest going with three classes:

H 49V - 72V
I 25V- 48V
J 24V and below

Click to expand...

Great link, thanks!

It's certainly a great place to start.

Max bike weight 40kg, usable bike pedals required.
This should prevent motorcycles from posing as bicycles



Some kind of function between top speed, acceleration and vehicle
weight would be used to determine classes for an event.

For example, all e-bikes present get their numbers calculated, and the
results get divided into a handful of pretty much even groups. Depending
on who shows up and how many groups there are, you could be at the
top, middle or bottom of a class. This way, it should be possible to just
build a good e-bike without worrying about exceeding X voltage and
getting stuck in the lower segement of a class. Regardless how your
e-bike is made, you'll always be matched with more or less similar e-bikes.



Having seen the mount Saint-Anne bike competitions, the big hairy dudes
from BMX backgrounds go faster then the road wasps towards the end of
steep hills, and they can keep going faster longer in the rough because
they've got more tonus. The road bike dudes take their place anytime it's
flat. I'd guess the big hairy dudes would fare better with Ebikes, because
these bikes are extremely heavy.

Still, I'd put a minimum rider weight. The british jockeys have had issues
with this, a study by Limerick University two years ago showed that
jockeys were suffering constant dehydration, inadequate body fat and
bone density, and hightened risk of osteoporosis. The Jockey Club's chief
medical adviser, Michael Turner said the minimum weight today should be
8st 4lb. This equates to 119lbs, 54Kgs. This is rock bottom that should
prevent medical conditions, should this sport go in that direction. So the
way that works is, anyone who weighs less then the min would have to
lest themselves.

Mathurin said:

Max bike weight 40kg, usable bike pedals required.
This should prevent motorcycles from posing as bicycle.

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I 100% disagree with the idea of pedals. The point is to create small sized electric vehicles it's NOT to recreate the bicycle. And it also (if you allowed pedals or encouraged them) would make the stronger bike riders favored over regular non-atheletes.

We're missing the point here...

Bicycles are for athletic competitions. Electric vehicles are about finding out a new way to have transportation that uses electricity. While we DON'T want to allow electric motorcycles (with their 15 -20 hp motors) we DO want to have races that involve the 1-2 hp motors that are street legal electric bikes. (the whole point of the race is to see how efficiently you can use the resources that are available based on motor limits)

Somehow we're losing sight of the purpose if we mandate something like pedals. (if people choose to run pedals they should be allowed to do so, but if not they also should be allowed... whatever wins, wins)

Weight minimums are fine however... (but why would anyone enter a heavy bike, like a motorcycle, if the voltage is limited... that makes no sense :? )

Power Limits

In most racing situations they simply limit the size of the motor to a certain number of cubic centimeters. This still allows people to fiddle with other variables to arrive at the final engine performance.

Voltage is very similiar to the cubic centimeter concept because it's difficult to create a motor that varies much from the way the "ideal motor" works. As voltage rises you get an increase in the current and the relationship is close to be the same in very different motors. The physics is pretty constant no matter what you do.

The other option is to have race official supplied current limiting.

Before you get to race you have to install a "race approved" current restricted controller that guarantees that (within 5%) you are getting the exact current that your competiton is getting. This could be cheap and easy to enforce. (this is like those "intake restrictors" they did in NASCAR where everyone got plates with holes that were of a certain size)

Maybe everyone is required to use the same brand of controller and on race day you draw straws about which one you get... so they get passed between bikes to keep everyone honest.

Weight Limits

Okay, how about this...

Set the minimum weight limit as being the TOTAL of the rider and the bike. Make this limit so that the smallest riders are easily underneath the weight (so they might have to add 5-10 lbs), but the heaviest riders are well over it. Keep a minimum on the bike too, just to prevent someone from riding something that isn't safe. This way there is still an incentive to build a light bike, but it sets a lower bound on light weight riders having a big advantage.

Aerodynamics

The biggest factor in one of these races will be the bikes aerodynamics and the effects of "drafting" during the race. I think that weight and power would be insignificant compared to aerodynamics if you really think about how power is used on an electric bike. (try one of those calculators)

My electric bike weights 140 lbs but because it's aerodynamic I can get it up above 40+ mph with a 750 Watt motor. No matter how light you get your bike if you are sitting in an upright position (like a mountain bike) the power goes to "virtual infinity" at 30 mph.

So one wonders if down the road (when people realize this) the rules might begin to focus on aerodynamics... My guess would be that the recumbents and the tightly tucked "road racers" would < < < DEMOLISH > > > the upright bikes no matter how much they weighed and even if they had to give away a little in power, which they shouldn't have to if no one cheats.

Power could be "restricted" with appropriate fuses. Fuses can be handed out and "sealed".

Calling something without pedals an ebike is a bit misleading. If someone wants to all it a lightracer, speed - e - bike (heh), or whatever, hey, great - I'm all for it. I'd prefer soemthing that at least sounds sporting......

Tires - bicycle only?

Sprint racing? Endurance racing? What sort of course?

This would be far cheaper than electrathon. Far more practical and fun as well, in my opinion. Even with exotic batteries. Count me in..........

One pet idea I've had in my head for a long time is that the vehicle weight should be a percentage range of the rider's own weight.

Yes, the aero bikes will crush the MTBs and cruisers - if the course is nice and fast - as it should be......

rohorn said:

This would be far cheaper than electrathon. Far more practical and fun as well, in my opinion. Even with exotic batteries. Count me in..........

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I could see myself racing you and others of similiar thinking. You and I would show up at the track with radically different designs but be constantly seeking to find ways to make what we have better. Over time a range of theories get tested and the sport would evolve. This would be all about vehicles that are restriced to small power limits like the 1-2 hp limits set on "non-licensed" vehicles. There are still kinks in the way the laws are set up, but I could see a whole manufactured product line of race machines that are also something you could ride home on... legally... (we hope)

rohorn said:

One pet idea I've had in my head for a long time is that the vehicle weight should be a percentage range of the rider's own weight....

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That's an interesting idea. A very good idea. Make the minimum weight for the bike be some percentage of the rider weight... that's good... REALLY good. 8)

Wait a second... I like the proportionality of that, but now the power factor is backwards... (light riders get lower weight limits AND full power)

How about this...

Take the total weight of the bike and rider and then assign a voltage based on the total. Heavier people get higher voltage, lighter people get less voltage... it's proportional, but in a different way....

Or maybe current limits? Heavy riders are allowed to draw more current?

No. that's wrong... that extra current would give more top speed and the light weight bikes would get blown away.

Hmmmmm....