e-Power Challenge 2008 update

General Discussion about electric bicycles.
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mi7d1   100 W

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Re: e-Power Challenge 2008 update

Post by mi7d1 » May 27 2008 6:18pm

I had never been on the track before. I was expecting some nice sweeping gentle turns perhaps some banked ones. That wasn't the type of track I was on, no sir! Tom, the club president cautioned me saying that in years past some trikes have flipped going around the turns. I never lifted a wheel but my tires sure were squealing in my fender wells due to weight transfer.

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I don't know about registering dirt bikes here in Oregon, perhaps Cal has more information he can give you.
Jay64 wrote:Good job man! Congrats. I've heard stories from friends who have raced on that track with motorcycles. Sounds like a crazy track for motorcycles.

Sorry to hijack your thread, but did ya'll mention that you can get dirt bikes licensed for the street in Oregon???? I got a couple of bikes that need to be registered and I got some friends in Oregon.
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calinb   100 W

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Re: e-Power Challenge 2008 update

Post by calinb » May 27 2008 6:28pm

Yeah--my first race at PIR! I've attended the Pridmore rider school on the track in Seattle and was a motorcycle club racer in my youth and frequented Sears Pt., RIverside, Laguna Seca, Willow Springs, and I'm even old enough to have run Ontario, before it was destroyed. What a beautiful track and loss (Ontario).

[hijack]
It's been a few years, but it used to be you could just put the obvious stuff on your dirt bike (lights, mirrors, signals, etc.) and march down to the DMV and tell 'em you built the bike and they'd give you a plate. I don't think they even wanted to see it run, but best to have a good quiet muffler on it too.
[/hijack]

Well to not hijack the entire post, I'll mention that Bill was going fast enough in his velo that he related to me that track lines and suspension tuning were issues. That's why he spent so much time at that track. Very cool that his speed was so high that racing techniques became important, rather than just the usual and expected ebike energy management stuff. This racing is gonna get interesting in the future!

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calinb   100 W

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Re: e-Power Challenge 2008 update

Post by calinb » May 27 2008 6:34pm

mi7d1 wrote:Cal, I beg to differ with you but as I understand it:

1.The rider must be eligible for a drivers license. If one has a suspended license or are underage then by law that person can't ride an e-assist bike
2. The electric motor must not have a power output of more than 1000watts.
3. The motor must be incapable of exceeding on level ground 20mph for e-assist bikes and 24mph for e-scooters

Ya might want to take a look at this website. http://www.oregon.gov/ODOT/DMV/vehicle/ ... heet.shtml and dig further into the Oregon Revised Statutes. Where I'm confused is the difference between an e-assist bike and an electric scooter. Both have pedals and a motor. One can only go 20mph unassisted the other is allowed 24mph unassisted.
Interesting, BIll! Yes--we must go to the statutes. In my experience, government agencies are worthless at interpreting law--both statutory and administrative law. At least they've defined it in Oregon:

801.258 “Electric assisted bicycle.” “Electric assisted bicycle” means a vehicle that:
(1) Is designed to be operated on the ground on wheels;
(2) Has a seat or saddle for use of the rider;
(3) Is designed to travel with not more than three wheels in contact with the ground;
(4) Has both fully operative pedals for human propulsion and an electric motor; and
(5) Is equipped with an electric motor that:
(a) Has a power output of not more than 1,000 watts; and
(b) Is incapable of propelling the vehicle at a speed of greater than 20 miles per hour on level ground. [1997 c.400 §2; 1999 c.59 §233]

The difference between Scooter vs. electric assisted bike? It's usually the pedals but I don't have time to dig deeper into the ORS right now. Despite the above definition, a quick search of the ORS for "electric assisted bicycle" resulted in only one hit to the definition, itself. Without any references to the definition, I think we are still very much in an operational gray area in Oregon. I guess one could argue, in court, that anything that lies outside of the this definition is a motor vehicle, subject to registration, user licensing, etc., though I don't know how they'd register and license either the vehicle or the user--that's the gray area! Conversely, anything that falls within the definition is a simply a bicycle under the law, in lieu of any other ORS references to the definition.

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Re: e-Power Challenge 2008 update

Post by TylerDurden » May 27 2008 6:51pm

It is nice to see they specifically exempted e-bikes from park restrictions!

http://www.portlandonline.com/auditor/i ... 93&c=28627

  • D. No person shall operate any motorized vehicle or motorized wheeled vehicle or motorized wheeled device in any Park, except on Park roads or in designated vehicle parking areas, or by permit. The prohibitions of this Section do not apply to authorized service or emergency vehicles or to the following electric mobility devices used by persons who need assistance to be mobile, and used in accordance with all applicable park and traffic rules:
    1. “Electric assisted bicycle” as defined in ORS 801.258;

    2. “Motorized wheelchair,” “Mobility scooter” or “Power chair” defined as an electric powered transportation device for one person in a seated position, with feet resting on floorboards or foot rests, and incapable of exceeding a speed of 20 mph; or

    3. “Human or personal transporter system” defined as a self-balancing, electric-powered transportation device with two wheels, able to turn in place, and designed to transport one person in a standing position, with a top speed of 20 mph.
Have a Nice Day,

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calinb   100 W

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Re: e-Power Challenge 2008 update

Post by calinb » May 27 2008 6:56pm

Okay--I found some hits. You're right, Bill. The stupid ORS search engine only hits on the definition for "electric assisted bicycle" (with quotes) but does find the relevant references for "assisted bicycle." Well--what-d'ya expect for a government search engine!

http://www.leg.state.or.us:8765/query.h ... iso-8859-1

Here are a couple in interesting ones:

814.405 Status of electric assisted bicycle. An electric assisted bicycle shall be considered a bicycle, rather than a motor vehicle, for purposes of the Oregon Vehicle Code, except when otherwise specifically provided by statute. [1997 c.400 §4]

and

814.410. (1) A person commits the offense of unsafe operation of a bicycle on a sidewalk if the person does any of the following:
....blah blah
(e) Operates an electric assisted bicycle on a sidewalk.

The crappy search engine may be why the visforvoltage summary draws a blank for Oregon too. I'll send them an email, when I get a chance. Washington state and California are there.

http://visforvoltage.org/book-page/ev-c ... cycle-laws

At least the Oregon legislature gave us a bit more hill climbing capability than the fed's manufacturing limits permit. Whatever "1000 watts" means (measured how, where, say what???) ;)

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Re: e-Power Challenge 2008 update

Post by mi7d1 » May 27 2008 7:00pm

I had to links already but chose the short posting. Here you go. http://www.leg.state.or.us/ors/801.html

RE: 801.348 and 801.258


801.348 “Motor assisted scooter.” “Motor assisted scooter” means a vehicle that:

(1) Is designed to be operated on the ground with not more than three wheels;
(2) Has handlebars and a foot support or seat for the operator’s use;
(3) Can be propelled by motor or human propulsion; and
(4) Is equipped with a power source that is incapable of propelling the vehicle at a speed of greater than 24 miles per
hour on level ground and:

(a) If the power source is a combustion engine, has a piston or rotor displacement of 35 cubic centimeters or less
regardless of the number of chambers in the power source; or
(b) If the power source is electric, has a power output of not more than 1,000 watts. [2001 c.749 §2]


801.258

801.258 “Electric assisted bicycle.” “Electric assisted bicycle” means a vehicle that:

(1) Is designed to be operated on the ground on wheels;
(2) Has a seat or saddle for use of the rider;
(3) Is designed to travel with not more than three wheels in contact with the ground;
(4) Has both fully operative pedals for human propulsion and an electric motor; and
(5) Is equipped with an electric motor that:

(a) Has a power output of not more than 1,000 watts; and
(b) Is incapable of propelling the vehicle at a speed of greater than 20 miles per hour on level ground. [1997 c.400 §2;
1999 c.59 §233]

The motor assisted scooter can be propelled by motor or human propulsion. The e-assist bike must have fully operative pedals. I was thinking with scooter as a low powered moped with had pedals. I now think it is meant to read as a push scooter (non-pedaled). That's why a seat or saddle isn't required. I had misinterpreted the laws. Imagine that :roll: Though the laws might not be strictly enforced still I don't want to be caught doing 40mph down the street in my velo, less I'm heading down hill. That is one reason I've regeared it so I may power via pedals beyond the motor.
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Re: e-Power Challenge 2008 update

Post by calinb » May 27 2008 7:01pm

Also interesting that the bike may go over 20 mph while being assisted. The 20 mph limit is an unassisted limit. This is more lenient than the fed manufacturing limits, as I recall.

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Re: e-Power Challenge 2008 update

Post by mi7d1 » May 27 2008 7:07pm

This is my reason for using a 60t chain ring and an 11-34 freewheel. 36.5mph at 90rpm's 48mph at 120rpm. All I need to do is have a series parallel switch for the batteries. A 406 at 36v and the velo will hardly do 19mph flip into racing mode for "off road racing" and that 406 at 72v be singing doing 47mph on the "track" A bit of creative engineering.
calinb wrote:Also interesting that the bike may go over 20 mph while being assisted. The 20 mph limit is an unassisted limit. This is more lenient than the fed manufacturing limits, as I recall.
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Re: e-Power Challenge 2008 update

Post by calinb » May 27 2008 7:19pm

mi7d1 wrote:I was thinking with scooter as a low powered moped with had pedals. I now think it is meant to read as a push scooter (non-pedaled). That's why a seat or saddle isn't required.
and 24 mph on a push scooter without a seat (vs. only 20 on an ebike)? Geesh--go figure!

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Re: e-Power Challenge 2008 update

Post by calinb » May 27 2008 9:47pm

mi7d1 wrote:The Pak-Lite is an interesting little light. Basically it's a cover that snaps onto a 9v battery and has two LED bulbs and a switch. 20Hrs of light is the claim. The Pac-Lite itself also glows in the dark. I've been interested in the Pak-Lites since I first read about them years ago. A very nice and small emergency light.
I forgot to mention that I've already tucked my Pak-Light into my ebike tail case for the next night time roadside mechanical or inspection. Very cool and I know what stocking-stuffers to buy this Christmas!

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Re: e-Power Challenge 2008 update

Post by safe » May 28 2008 7:37am

calinb wrote:This racing is gonna get interesting in the future!
I'm more focused on the racing aspect than the efficiency, though they are related. What they really ought to do is use a go-cart track which is a little smaller and tighter which would force the machines to perform better. Then some rider skill will enter into the race. As it is now you can race a wobbly craft and simply take it easy through the worst of the turns and then just focus on the straight aways.

:arrow: It's really early on this stuff...

Given the way public interest in electric vehicles is growing (in all areas) I figure that 2010 is when things really "go big" and these events will blossom.

Maybe by then there will be a racing series?

At all the race tracks around the country so that everyone can make it to one. :)

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Re: e-Power Challenge 2008 update

Post by mi7d1 » May 28 2008 9:14am

safe wrote: I'm more focused on the racing aspect than the efficiency, though they are related. What they really ought to do is use a go-cart track which is a little smaller and tighter which would force the machines to perform better. Then some rider skill will enter into the race. As it is now you can race a wobbly craft and simply take it easy through the worst of the turns and then just focus on the straight aways.

Given the way public interest in electric vehicles is growing (in all areas) I figure that 2010 is when things really "go big" and these events will blossom.

Maybe by then there will be a racing series?

At all the race tracks around the country so that everyone can make it to one
One can just race as you say,
a wobbly craft and simply take it easy through the worst of the turns
as easily on a go-cart track as any other track. The same thing would happen, a driver with better skills and machine would win. In past events pedal trikes have flipped on the track at PIR during the HPC event. I was cautioned before the race to be careful of the turns. Had I been on a fully faired bike rather than a trike, my times would have been faster. On my first lap, I was expecting gentle sweeping turns. I got instead a rude awaking with my tires squealing going to fast into the first few turns. A tune-up on my suspension Sunday helped me get an addition 5mph through the turns.

Some people like Nascar and some like Indy. Some folks like flat track and some like road racing. So far as I've seen there are too many people doing nothing. One group has stepped forward and threw the gauntlet down. They didn't bother talking, they took action and the first sanctioned e-assist bike race has taken place. I don't believe that you were putting down the e-assist race. If I understand, it's just that your interest are in other racing venues. Still your post reminds me of the old Randy Draper postings, in that if it isn't his way it's wrong. When the truth is that there are many ways to do things. Now who else will step forward and take action. There's plenty of room for additional racing formats.
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Re: e-Power Challenge 2008 update

Post by Herrsprocket » May 29 2008 7:39pm

I'm here!

I just needed to take a break from the duties of the race for a couple of days. After several months of non stop action, it felt gooood take a bit of time away, albeit last night was spent getting all the human part of the Human Power Challenge results posted on our website. Anyway, sorry for the delay, but not sorry to say we had a great time at the races and we were particularly happy that we got our first ever ePower Challenge event under our belts! Not only did we have some fine exhibitions of e-savvy racing from our racers, but the pedal only crowd really dug the e-assist rigs and guys. Several people (of the cycle gang) commented on how cool the power assist rigs were and that many of them are now looking at them as possible "every day type users" as well as getting something together (to race) for next year's event. EVERYONE was impressed by the efficiency, speed, and range that afforded the pilot greater utilitarian use. Sweet!

Where to start? So much to talk about. Something I think Bill mentioned was about the TV coverage that we were going to get on Sunday morning,,, drats,, due to the truck having difficulties getting their antenna to deploy correctly, we were only able to get the first couple of segments of the live broadcast in before I had slated Bill to talk about the ePower Challenge and his eVelo. Bummer! Though they did use his rig as a background shot during the interviews. All in all though, the media (including the large Portland Suday paper) did eat up the e-assist theory along with the diet of HPV rations I dealt them. The reporters were all very intrigued by the event and the vehicles. So from that view point, I think we made a strong impression on the general public's "awareness radar" for our cause ( "our's" being, anyone who is on this planet !).

The number of racers was to be about expected, we certainly had hoped for more, but given the short notice, we were pleased with the variety of vehicles there, virtually representing each category of racing division we had. The mix of the guys and their rigs was very good. It gave us some great feedback on what we can expect to see in the future, including adjustments to compensate for aerodynamic enhancements, etc. As you can see from Bill's posting, the fotos do a lot of justice as to the mix of the bikes there. Each had a different mix of watt hours on board and each wa really a different type of set up from the others. Event though the two velos were similar in appearance, their power sources and consequent results showed remarkable performances from both of them. Bill may have mentioned that Mitch (in the Go One) did not have his speed governor disabled, ah ha! So he could not get his power assist to help him much beyond twenty niles per hour. But, the guy consumed far less energy to do what he covered ( we assume since Mitch didn't indicate as to whether his onboard Bionx readout could give us that info, rats). This all gives us a huge insight as to where we can take this event in terms racing formats for the future. It is exciting! And particularly now that we have established this type of racing in the public's eye and the insurance's too, we may have the ability to broaden our scope of racing. Good stuff. All we need is a beginning.

Another intrigueing aspect of the racing was simply that by showing off the variety of flavors that an ebike can come in, so many people's eyes were opened up to a virtual kaleidoscope of ways to make an e-assist bike a reality in their life. The buzz about e assist was overwhelming, certainly one of the most yakked about topics at the event. I love it!

Some of you may know this, others maybe not, but we did have a couple of forward thinking fellows who helped us out with contributions to the event. Now hang on just a minute here all you guys, don't skip past this part of the message because you think I'm going to get all flowery about these guys, I ain't. But you do have to know that these guys did step up, took a stand for us, what we all want to promote. They are Dick Anson of DO Enterprises, who sponsored us by giving out to one of the racers, a bonus prize of having the best "practical commuter" assist bike at the event. OMG! This had to be the toughest decision I had to make over the entire weekend! Even though we had a secret committee to talk it over, every single vehicle there was undeniably deserving, they all were perfect in their own regard. However, in the end, from input from folks who knew a thing or two about ebikes and from those uninitiated in the ebike world who knew what they thought was important criteria, we went with ,,,, Brent Bolten's Eco Speed semi faired recumbent rig! Brent's set up was amazing and the universal applications were many, but then again, so were all the others, and they were very gracious about it. I think they knew that it was a very subjective thing to call, and that they knew I thought each of them were deserving,,,, the judges had spoken !!!! :wink: And then we had Josh Kerson of RunAbout Cycles give us a very generous amount of $'s to help cover the costs of the event and to distribute it however we could to best spread the butter. It came out that I wanted to give part of the donation back to the racers in the form of covering their entry $'s to partake in this inaugural event. I thought it would be a cool thing to do and I'm sure Josh would agree that the "first" to take the steps along with us deserve more than just applause. It's a small gesture of our thanks for getting involved!

A lot more to say, racing results will be officially posted on the race website soon. We have a million things to keep wrapping up right now, so hang with us and keep the feedback coming, it's all good!

Regards,

Thomas Breedlove
Director of the ePower Challenge '09

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Re: e-Power Challenge 2008 update

Post by calinb » May 30 2008 12:41am

Thomas,

I had a great time, thanks to Mitch's last minute suggestion that I enter. (I'll twist his arm to join this forum!) Thanks for creating this wonderful event!

Okay--time to start thinking about next year. ;) I'd planned to send you an email, but it may be more productive to open up my notions to public discussion here. Please PM or email me if you wish to take any discussion offline.

I'd like to reference a few race rules and race information here:

> One last thing, in accordance to the agreement stipulated on the insurance, we will also be limiting the motors used > to conform to a 750 watt continuous power rating that should be visibly marked on the motor casing, no switchero of > stickers folks. Too many of us know what to look out for. The 750 watt limit is to “honor” the Fed output limit
> and will showcase to the public what amazing things can be done with that amount of assist. Of course you
> can certainly use a less powerful motor, it could be an advantage!

It’s inconsistent to “honor” the federal 750 watt manufacturer limit while not honoring the federal 20 mph limit. I think that Mitch, by mistake, was the only entrant honoring either limit. I think we should just forget about the limits--at least in an explicit sense. As the classes are defined, the energy allotment vs. distance constraints of each class already serve to limit the rider’s usable power while remaining competitive. For example, in order to complete the 40 mile race, I had to throttle back to something around 500 watts. I recommend changing both the rules and the rationale for the rules to something like this:

“The energy and race distance, as specified for each class, is designed to preclude average electrical power output in excess of the U.S. Federal ebike manufacturing law limit of 750 watts, i.e., the rules are designed such that motors operating at output levels higher than 750 watts of power will deplete the available electrical energy allowed for the class before completing the race distance. Thus, a competitive effort requires managing electrical power to levels below 750 watts. The energy and distance limits will showcase to the public what amazing things can be done with a commercially manufactured bike providing a legal amount of assist.”

Well--the verbiage can be tweaked, but that’s my idea. Forget about explicit power limits and forget about the 20 mph limit too, and it appears that everyone but Mitch, by mistake, has already done so. ;) No one’s interested in racing at 20 mph. Furthermore, defining and measuring electrical output in any reasonable manner is impossible. So much so that the feds didn’t even try to specify how power is measured (and how it's measured makes a HUGE difference). Simply let the energy and distance constraints do the job for the event.

> Of course you can certainly use a less powerful motor, it could be an advantage!

A less powerful but. perhaps, lighter motor would only yield a significant advantage on hilly courses, due to the possibility of reduced weight and the difficulty of re-couping the additional potential energy "stored in the extra weight" in the faster and aerodynamic draggy, downhill segments. It’s actually a little complicated, but weight isn't a big performance factor at PIR. You may certainly keep the comment, but it’s a false notion for PIR.

As you are probably aware, specifying the battery capacity limits is a thorny challenge. but the additional energy permitted by the rules for lead acid packs is unjustifiable. Take my class, for example:

Battery Chemistry Watt Hour Limits (calculated V X Amps)
Division 3 40 miles (20 laps)

Lithiums Nickels Lead Acids

960 1152 1440

Apples to apples specifications? I get 50% more energy, if I run SLAs? Whoaa! I’ll take lead acid, thank you! This is a no-brainer and my preference for lead acid batteries is not even close; the extra weight of a lead acid pack won’t be a factor at PIR (or nearly anywhere) and the higher internal resistance, compared to the other chemistries, won’t be a factor either, given the low power limits implied by the energy vs. distance requirements of each class. There’s no standardized way to measure battery capacity and this is also very much a problem. I don’t know how to solve it fairly, without a bunch of complications or the use of very specific “formula” class type rules, but different allotments for different chemistries doesn't solve it and it's not justifiable, given the "under-powered" nature of the classes. By underpowered, I mean, if my Division 3 class were something around 20 miles, then the LiFePO4s I ran would have an advantage over SLAs, simply because they have less internal resistance than SLAs and I can pull much more peak energy out of them than I can pull out of SLAs--but not for 40 miles! At 40 miles, if measuring capacity "apples to apples," the only advantage LiFePO4s offer is reduced weight over SLAs, which, again, is not a significant advantage on the flat PIR course or any race track I've ever raced (including the hilly Sears Point in CA--it's just not hilly enough for the weight difference to be a large factor for an ePower Challenge at the low electrical power assist levels that are in the ballpark of the federal manufacturing standards power levels). Or, taking my argument to an extreme, LiFePO4 batteries offer a huge benefit over SLAs for Killacycle drag racing, but not the ePower challenge at PIR.

Much fun and, once again, thanks,

-Cal

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Re: e-Power Challenge 2008 update

Post by docnjoj » May 30 2008 6:24am

I have to say this is simply wonderful! Finally, some recognition of the power and effectiveness of electric bikes. Can U quys get a national write up in one of the Bicycling magazines??????
oldDoc
E-bike stable at our house

Steintrike Mad Max full suspension trike rear Cute 100H going on: Whoops, Cute wheel broke but I fixed it.
Sun USX delta trike EbikeKit small geared front wheel sort of front suspension for wife

Agniusm/A123 AMP 20 36 volts on the Steini has been taken off.
2x16000 Multisport from HK now gone as they died after 2 years
New Luna 10S bottle battery 13.6AH now on mine
Relatively New 10S4Px2 for wife's bike giving 20ah @ 40 volts home made Panasonic from Tumich. BMS's rule.

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Re: e-Power Challenge 2008 update

Post by mi7d1 » May 30 2008 8:48am

Hey Cal, I'm not quite following you here. Are you saying that if you had a 48v 20Ah Li pack and I had a 48v 20Ah pack of SLA we could have gone the same distance if we were ridding the same bike because we both have the same watt hours? That's not how I understand it. Now I've never run anything other than SLA's but I've been told that there is more energy available in a Li pack than an SLA. In fact it was feedback from forum members and folks in the ebike business that helped form the best formula on short notice so that the different battery chemistries could race together. With my SLA's no matter the category there is no way I could have pulled out anywhere near the total watt hours available to me. If I were to have raced in eCat-2 Div-3 with SLA's I'd been allowed 1440Wh. You running Li were allowed 960Wh. As far as I know and understand you could draw just about all of the watt hours from your pack but if I drew much more than 960Wh from the SLA pack I'd be walking real soon and also damaged the pack enough to shorten it's life. I'm against mandating that we all have certain battery voltages or chemistries within reason and due to the way the batteries work and are built I don't think we'll ever have an exact match. I have a feeling that Tom might be considering giving the more efficient vehicles even less power. I'm against that idea also. I think that having different categories of bikes like what was done is sufficient. If I would have raced you in eCat-2 Div-3 with my 1080Wh pack I'd have walked all over you not because my SLA's were better but my bike was more efficient. According to http://www.kreuzotter.de/english/espeed.htm my velo takes 308W to do 31mph but a mountain bike takes 1032W to do the same speed. Had our race have happened it's my understanding that you would have come in first in the stock class and I'd have come in first in the streamliner class. I had been considering that race and made a trial run of 37.5miles before my batteries started sagging Saturday morning on the track averaging 35mph. Due to some tire problems with the velo I chose to run my normal pack voltage and race in another category rather than risk a front tire blowout by carrying 12lbs more of battery. If I'm not understanding this battery chemistry thing please enlighten me, I'm eager to learn but sometimes slow :?
Bill
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Re: e-Power Challenge 2008 update

Post by mshults99 » May 30 2008 11:49am

Bill, thanks for the reference to the speed calculator. According to that site, I should be able to hit 101mph in the Go-One while descending from the top of the Sylvan Hills! Since I've already hit 70mph on that descent before applying the brakes, and I was still accelerating, I believe his numbers.

I think you're right in your comments, but I'll let Cal respond. My understanding is that the nominal Watt-Hour rating of an SLA has to be much higher than that of any of the more exotic materials in order to actually deliver the same total output, for the reasons you cite. I thought that was why the power ratings for the classes were set the way they were.

Cal's point about the weight disadvantage of the SLA's being irrelevant at PIR is a good one, though I think you bring up a good counter-point with your tire issue - carrying capacity isn't infinite, even on a flat course!

The question of how to make this an actual race is a very interesting one. It's kind of like the problem of doping in real bike racing, only carried to a much greater level. It seems to me that there are just too many variables involved to allow a realistic handicapping to be done. Perhaps 'demonstration' is a better term than 'race'.

I'd like to propose that we take a page from the automotive rally club manual and do an electric-assisted vehicle rally, where all participants follow a map, and the goal is to arrive at various checkpoints as close as possible to the predicted time. The route should trace some of the hillier portions of Portland, so as to showcase the importance of power/weight ratios in HPV assist applications. I always make the biggest impression when I blow past a group of racers who are struggling up the Sylvan Hills when I'm riding the Go-One. The look of shock on their faces when the guy in the obviously heavy velomobile goes by them on the 7% grade is amusing. They just can't believe it, until they hear the motor buzzing along.

I think we'd make a real contribution to the cause of demonstrating the viability of electric-assisted HPV's as alternative commuter vehicles by doing this kind of thing, especially if we published some of the engineering data for our various rigs to go along with it.

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Re: e-Power Challenge 2008 update

Post by calinb » May 30 2008 12:30pm

mi7d1 wrote:Hey Cal, I'm not quite following you here. Are you saying that if you had a 48v 20Ah Li pack and I had a 48v 20Ah pack of SLA we could have gone the same distance if we were ridding the same bike because we both have the same watt hours? That's not how I understand it.
Yup! I've run both SLAs and my latest, the Yesa LiFePO4s. It's actually a bit more complicated than my brief review so I'll now elaborate. First of all, battery capacity is specified in terms of ampere-hours. That is, the current supplied by the battery multiplied by the time it's producing the current. If the current is changing during this measurement, it's actually the area under the time vs. current curve or, in terms of calculus, an "integral" that must be measured. I think all batteries have a smaller capacity if they are drained quickly, i.e. if the current is high, the total area under the curve shrinks because the battery poops out sooner. Less energy is obtained from the battery before it is depleted, if it is depleted quickly. LiFePO4 batteries may be depleted more quickly than SLAs before they begin to suffer from this effect. But this fact must be considered in light of the energy dynamics of the race AND how the battery manufacturer does their capacity specs. The conditions the manufacturers use for the amp-hours capacity specs are all over the map! For example, my SLA batteries a spec'ed at a constant 18Ah drain over a 24 hour period! They won't even come close to producing 18Ah of current over the course of the 1.5 hour race. I think this is what motivated the energy allotment rule but I'm sure I could find an SLA pack that tested capacity much more as tested by Yesa:

On the condition of (15--25)℃,charge the cell at 0.2 C to3.9V then charge at stabile voltage ,until the current is lower than 0.01A.Put the cell for 10 minutes,then discharge at 0.5 C to 2.2V."

This is a much faster discharge than 24 hours and the SLA pack would be competitive vs. a similar capacity LiFeP04 in my race, if its output were specified in the same manner. This is because the 0.5C test discharge rate is about 10A and that's much closer to the current output needed for the race. It turns out that the capacity specs are all over the map but as long as the discharge is relatively fast (much faster than 24 hours) the SLA disadvantage is minimal in a low power (lower than the power the battery is capable of delivering) application.

Then we have other "specmanship" issues. Notice that my battery capacity is determined by discharging the battery cells all the way down to 2.2V. In normal use with the Yesa supplied BMS, those cells hit the low voltage cutoff at something like 2.9V. So I'm not getting all the amp-hours (power) they specified unless I change the BMS, lower the cutoff voltage and sacrifice battery life.

Then there's the difference that a fully charged "48 V" SLA pack puts out about 4 x 12.7 V or 50.8 V at room temperature whereas LiFePO4 packs vary. My "48 V" Yesa pack put out about 52.8 V. Of course this is open circuit voltage and the voltage varies with load because of the Thevenin internal resistance of the battery (another way of saying its current producing capability).

It's a giant rules quagmire! But the bottom line is, with the given energy rules and race distances, a racer who wish to be maximally competitive should shop for lead acid batteries with capacity specs that were generated over relatively fast discharge periods. Then, most of the "50% lead advantage" in the rules would be realized!
mi7d1 wrote: You running Li were allowed 960Wh. As far as I know and understand you could draw just about all of the watt hours from your pack but if I drew much more than 960Wh from the SLA pack I'd be walking real soon and also damaged the pack enough to shorten it's life.
That's because your SLA pack is spec'ed very "aggressively" compared to the Li pack. Even though you think it's a 960Wh pack, from their specs, it won't put out anywhere near that much energy during the short time frame (short compared to the capacity testing) of the race. Find a SLA pack that's spec'ed over a shorter interval--more in line with the discharge interval of the application (the race period, in this case). That'll even them up!


I'm against mandating that we all have certain battery voltages or chemistries within reason and due to the way the batteries work and are built I don't think we'll ever have an exact match.
mi7d1 wrote: Agree! But we are way off base, currently.
There are way more facets to this problem than I've related here. Racing rules for electrical vehicles is a quagmire, I tell 'ya! ;) The "fuel" rules are some of the most difficult to manage, too. The capacity specs simply make a night and day difference. It's not like specifying a BTU level for a combustion fuel--it's way, way, more complicated.

If I wish to win again next year (hopefully with a full pack of race competitors) I'll return with a recumbent and an optimally "spec'ed" SLA or AGM lead acid pack. :)
Last edited by calinb on May 30 2008 12:48pm, edited 2 times in total.

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Re: e-Power Challenge 2008 update

Post by mshults99 » May 30 2008 12:41pm

Congratulations to Mr. Bolton!

I completely agree with his selection as the e-commuter poster boy. I was blown away when Brent came ripping down the straightaway on his first lap at what must have been 45mph. Truly awesome! His EcoSpeed system is a wonder of compact, lightweight, efficient and very powerful e-assist. I can't wait to get one on my Go-One!

And when I do, and when I've jiggered the drive train to accomodate a 60-tooth big ring on the front, and I've got a Nexus hub gear on the back, and I've enclosed the rear of the Go-One in an aero canopy to reduce drag, I'll be flying down that same straightaway at a significantly higher speed, thanks to the better aerodynamics of the velomobile!

Then, if we could just arrange for the entire event to be conducted in a raging downpour at a temperature of 35 or so, I'd be able to fully illustrate the advantages of being fully enclosed, vs. only partially faired.

And then I think I may be able to take home the prize!

Looking forward to the challenge. Thanks for all the hard work putting this together, Tom. It was very well-organized, as usual. Please think about my electric-assist rally idea. I think it'd be a good way to draw press and public attention to our cause. It's not too late to put it on the agenda for PedalPalooza. Let's discuss.

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Re: e-Power Challenge 2008 update

Post by calinb » May 30 2008 12:42pm

mshults99 wrote:My understanding is that the nominal Watt-Hour rating of an SLA has to be much higher than that of any of the more exotic materials in order to actually deliver the same total output, for the reasons you cite. I thought that was why the power ratings for the classes were set the way they were.
Except there is no standard method used to obtain the rating--and it's a A-hour rating specified by battery manufacturers too (not exactly the same thing as W-hrs).

I'm pleased to see you here, Mitch. Thanks for joining!
mshults99 wrote: Cal's point about the weight disadvantage of the SLA's being irrelevant at PIR is a good one, though I think you bring up a good counter-point with your tire issue - carrying capacity isn't infinite, even on a flat course!
But we don't need to have infinite capacity--just enough to carry the heaviest motor reasonably expected to be employed in an ebike application, like my C-lyte X5. Except for a drag racing setup, it's probably the heaviest and, potentially, most powerful motor commonly available (it can dissipate up to 5kW, if you can feed it--but who can feed it that much!) I don't believe the extra weight of my motor was a significant factor at PIR. Aerodynamics is another matter for me! ;) I do believe that, with an intelligent selection of an SLA or AGM battery pack, I could've gone significantly faster than I went with my LiFePOs. I can calculate it, but haven't done so yet. See my post above on the "50% advantage."
mshults99 wrote: The question of how to make this an actual race is a very interesting one. It's kind of like the problem of doping in real bike racing, only carried to a much greater level. It seems to me that there are just too many variables involved to allow a realistic handicapping to be done. Perhaps 'demonstration' is a better term than 'race'.
I'm interested in racing, Mitch. I'm not nearly as interested in demonstrations. I'd rather not give up on the race format yet--even if the rules stay the same. I'll simply return with SLAs or AGMs next year and so will everyone else who desires to maximize their chances. I have some other ideas. We have a year and I don't have time to type much more here today.

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Re: e-Power Challenge 2008 update

Post by mi7d1 » May 30 2008 3:42pm

Wow! where do I begin...

Mitch, so good to see you here. I'm envious of you getting a EcoSpeed system. I've spoken with Brent in the past about putting one in my velo but was concerned about the noise. Now that I've seen his system run I'm not concerned with that anymore. I've only had my WAW up to 45mph once and the steering became rather sensitive. I was on the 205 bike path heading north out of the Gateway transit center down the hill. Chain link fence on one side and a drop off into a field on the other. There wasn't enough room on the bike path for me to feel comfortable.

I like the idea of a timed road race event where one has to arrive at a check point at a given time and late or early is docked points. I can't speak for the club but I think this is an idea that should be looked into for both human and e-assist. Perhaps another summer event, even at the Recumbent Retreat wold be fun for all.

Cal, one thing I like about the forums here at E-S is mostly the people and information available. My guess is that about 85% is over my head so please keep that in mind while explaining things to me and forgive my ignorance :lol:
The only thing I got out of your reply to me and it was a major step in my understanding of batteries was that do to the nature of the race and track conditions I was able to use my batteries to the best of their abilities by keeping a less than half c draw on them. This is why safe said
(this should be a lesson for all people using SLA... keep that "C" rate low)
and others have said that I should look for a SLA that is rated at the one hour rate. I'll need to go back and read your post several time and then more pieces of the puzzle will fall into place. There's bound to be rule changes next year, I hope that there's a next year. I'm looking into enter two bikes next year. My velo and my Cruzbike running a drive system through the gear train
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Re: e-Power Challenge 2008 update

Post by Herrsprocket » May 30 2008 7:01pm

Hi, this is Tom's wife. He wanted me to let you know he just had some minor surgery and will be unable to answer any posts for a couple of days. Talk it up amongst yourselves and he will catch up with you either on Sunday or Monday.

Elizabeth

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Re: e-Power Challenge 2008 update

Post by Link » May 30 2008 7:02pm

That sucks. :(

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Re: e-Power Challenge 2008 update

Post by mi7d1 » May 30 2008 7:35pm

I've been told it is from his knee again.
Link wrote:That sucks. :(

What for?
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Re: e-Power Challenge 2008 update

Post by kbarrett » May 31 2008 2:00pm

Tell Tom thanx for hosting the challenge.

Hopefully I will have a working 'bent ready for next year's challenge.
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