Electric Bicycle Road Racer (R&D)

Interesting... I went to a lot of work to make individual posts so that people could quote specific sections. Oh well. Still, if people want to comment please slice out just the sentence or paragraph you are quoting.

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Discussion...

Today in the Tour De France the Time Trials leader that had been wearing the Yellow jersey had mentioned before the days ride (through a mountain stage) that because of his larger body (weight) that he didn't expect to do well... which later turned out to be true.

Seems that heavier riders have more trouble carrying their weight up the hills than the lighter ones even though they have more strength. On the downhills the heavier rider has a slight advantage, but since aerodynamics limit downhill speeds (and safety concerns) the heavier rider never gets "paid back" for his losses.

Thinking about EBRR (Electric Bicycle Road Racing) since the Go Kart tracks tend to be on fairly flat land the heavier riders should not have any significant reason to worry compared to the lighter ones. Time Trials are aften won by cyclists that cannot climb hills very well. It seems like Time Trial racers are the type of racing physique that would do well in EBRR.

So the "bottom line" is that the 1000 watt input restriction rule seems secure in the face of everything learned from the Tour De France.

Being heavy doesn't hurt much on flat land...

(it was impressive that the peloton was riding at 33 mph for stretches today)
 
Buy a bike and put a motor on it and then we will be brothers........no ideas shared unless your an MBer!
 
I guess I need to state my "history".

First built my original ebike in 2006.

Conceived of EBRR in about 2007.

Am just at about 8000 miles on the first bike.

Top speed was 60 mph downhill.

Top speed on the flat was (once) 50 mph with a stronger motor.

Top speed now on flat due to the 1000 watt restriction is 36 mph.

Currently working on the new bike. (pictured as my avatar)

...so I'm an "old guy" in the sport in that I've been around a long time.

I'm not an "Outlaw" character though, so rivalries and personalities don't interest me much. For me it's all about the sport, the technology and potentially a business venture down the road. I'm not looking to join a sort of MB bikers club.

My hope is to attract the "business demographic" who will be the actual people that determine the course of the sport. The individual riders are sort of a different category of people from the folks that determine what gets built. However, you can't build a product or a sport unless all things come together like rules, laws, riders and business. I'm trying to prepare arguments that might be taken to "corporate headquarters" some day to convince the CEO that an idea is worth pursuing.

So I'm not like most people that post on these types of forums... I have motivations that others don't have. (so I'm probably not a "brother" kind of guy in the sense you suggest) I'd be described as "white collar" and not "blue collar".

More Observations About The Tour de France

It's an interesting race to watch that's for sure... there is a lot of long term strategic thinking that really makes the sport intriguing.

Crashing On Downhills

Frankly it's hard for me to imagine them going 50-60 mph downhill and then falling off wearing nothing without dying or at least getting more road rash than I've seen. For EBRR I had envisioned racers wearing some kind of special racing gear that was somewhere between motorcycle road racing leathers and something a cyclist would be used to. I guess the logic for Cycling is that crashing without protection of any kind is "okay" as long as the brain is protected... and that rule didn't come into being until recently.

Anyway... those racers take risks on the downhills, but I did notice when the camera's follow them downhill that their turning speeds aren't that great. Skinny little tires don't give all that much traction, though what they do is still impressive.

I wonder what would happen if EBRR became a sport and people had their road racing fairings and all and then a regular bicycle showed up and was able to do well. In some ways the real people that EBRR needs to compete against is the Cyclist, not the motorcycle or the moped.

Within "Outlaw" MB culture there is not supposed to be respect for Cyclists (everyone has their cliques) but I see Cycling as being very impressive. They go really fast considering they are not powered by anything but pedals.

Any type of electric racing needs to reflect on how it relates to other sports. With EBRR there has to be a legitimate advantage over the Cyclist without going so far as to make it purely motorcycling. It's a very delicate balance.

Elbows To The Head?

"This is a bike race, not a gladiator's arena. Everybody could have ended up on their backs."

http://www.espnstar.com/other-sports/news/detail/item467255/Renshaw-headbutt-mars-Cavendish-win/

In the Tour De France today Mark Renshaw literally "headbutted" another rider and then swerved back and forth in the front of the peloton when it was racing to the finish at above 40 mph.

He got disqualified and sent home.

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Electric Bicycle Road Racing (EBRR) has the potential to degenerate into this type of riding very easily because the Go Kart tracks have tight corners that will tend to bunch up the riders. If this type of riding behavior is tolerated it will make the sport more about survival than about speed.

I support the decision to disqualify the guy.

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Since this stage had a long gentle downhill and a favorable wind at it's back the peloton was carrying 35 mph to 40 mph for a long time. That's some impressive speed for just bicycles.

Also, they said that Mark Cavendish is capable of 1500 watts (2 hp) on those sprints at the end, so if you coupled a Mark Cavendish level sprinter with the EBRR limit of 750 watts you would have a total of 2250 watts which is 3 hp. That's enough power for people to get some decent speed going on a Go Kart track.

Long Distance Electric Racing

In a typical stage of the Tour de France the riders are producing roughly 400 watts for five hours.

So if you assume that it took 500 watts of electrical input power into a motor to get 400 watts out and you needed to know how big of a battery would be required then:

500 watts * 1 hour = 500 Wh

500 watts * 5 hour = 2500 Wh

...so you would need:

2500 Wh / 48 volts = 52 Ah

A Thundersky LiFePO4 cell weighs 6.6 lbs and is 12 volts and 20 Ah or a total of 12 * 20 = 240 Wh. Since you would need 2500 Wh worth of battery it would take:

2500 Wh / 240 Wh = 10.4 Thundersky cells

10.4 Thundersky cells * 6.6 = ~70 lbs

Maybe Lipo might be a little better, but the cyclist carries a powerful battery just because he has legs. (the longer a bike race goes the harder it is to beat it with electric power unless you allow for a very heavy battery and then you are essentially riding a motorcycle)

P.I.N.O. ?

"Pee No" - "Pedals In Name Only"

sbmotoped2.jpg


http://www.motopeds.com

An interesting product and something that might do very well in the Open Class of gas powered motorized bike racing on Go Kart tracks. (if you made a bunch of modifications to it) Weight is about 110 lbs and you can mount larger displacement motors onto it if you want more power. Given the fact that the suspension is built to withstand heavy loads this bike would probably do well. Wheelbase is 54" which is about right for a road racer bike. The suspension might need to be lowered for street racing and the spring rates changed and obviously the seat, handlebars and most everything else needs to be changed too. The frame / motor / pedals would provide a good base though. Probably a good idea to switch the front wheel from 26" down to 24" to match the rear and this would also steepen the steering geometry.

It does stretch the limit of what a "bicycle" is supposed to represent.

But it does have pedals... in name only...
 
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I see you haven't looked far into the seller of this bicycle setup safe
first half of the video is of downhill riding without the motor turned on
rode downhill on pedal power back up with motor. Watch video.

http://www.motopeds.com/video/
 
True, I did not delve into all their advertising material.

It does seem a great example of a PINO bike.

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As far as EBRR it does show the path of "Unlimited Power" and how it could go. They sell 110cc motors that can be installed on that frame and at that point the pedals are really unnecessary. The same kind of mindset applied to electric bicycle road racing will produce similiar results.

I see this as a "shot across the bow" for all those still clinging to the idea that "Unlimited Power" in ebike racing is a good idea. Over time the machines would look more and more like motorcycles.

In a sense this product proves my point.

(even though it's technically not in the electric category, the idea is the same because the pedals become "in name only" at the higher power levels)

I quote myself from the theory study guide:

Unlimited Power

The most natural urge is to want to allow Electric Bicycle Road Racing to use as much power in the motors as the designer can achieve. On the surface this even seems like a good idea until you start to anticipate where the designs will naturally progress. If you can increase motor power on an unlimited basis you will also need to increase battery capacity to feed this higher power level. More battery means more weight and that means a stronger frame and possibly suspension to make it usable. At some point the machine resembles a motorcycle only it retains "faux pedals" to satisfy the bicycle definition. An acronym PINO (Pedals In Name Only - "Pee No") describes this type of machine.

Selling The Sport

I've been getting ideas from the Tour De France as it's becoming a major TV event these days. One of the controversies in the Tour De France is whether the use of onboard cameras, radio communication and other technologies are good or bad for the sport. In the discussions "on the tube" they arrived at the conclusion that more technology is better if it allows the audience a chance to get into the action.

In EBRR the best feature would be onboard video cameras for all the race bikes. If the sport was broadcast on ESPN or other major network you could make use of the onboard cameras to compliment the external cameras of the event. NASCAR has already taken this to an art form (as has INDY cars) and I would see no reason that all the technology couldn't just be transferred over.

The audience would be drawn into EBRR because the main race length is only 20 minutes long and that's enough for the attention span of a typical viewer.

Some accomodation to the TV format might be needed if you are trying to fill out a full hour time slot. Heat races could be used much like in Supercross racing to pad the time. Three heats, a last chance qualifier, and then the main is a nice format. (all edited with a cool soundtrack of course)

It's all about action... can EBRR produce video that people want to watch?

...and like in the Supercross or NASCAR series they build points at each race so the viewer gets to watch a sort of mini-series to see the overall champion selected.

Anyway... EBRR needs to be explosive and action oriented to get the ratings. This doesn't mean it needs to be like rollerball with bad rider behavior on the track, but a crash here and there does boost ratings. The viewer doesn't want to see people crash because of a foul, so the there is a vested interest in the profit motive to keep everyone playing fair.

1000 Watt Limiting Issues

In the beginning as long as someone is in the ballpark of 1000 watts on the input side they would be allowed to race, but over time the need for greater precision will mean that some attention is given to this problem.

The first "issue" about a standard controller is that they limit current to some constant value. Let's do the math on that:

Battery Voltage 50 volts * Current Limit 20 amps = 1000 watts

...but our battery voltage is at the beginning of the ride when it's at it's highest and by the end of the ride let's assume the voltage has dropped to 45 volts. Now we have:

Battery Voltage 45 volts * Current Limit 20 amps = 900 watts

...so with any standard controller the power being allowed varies from beginning to end and it gets worse as the ride progresses.

What would be a better alternative is an "adaptive" circuit that could sense the active voltage and adjust the current limit to arrive at the desired overall power limit. So we would want:

50 volts ---> 20.0 amps
49 volts ---> 20.4 amps
48 volts ---> 20.8 amps
47 volts ---> 21.3 amps
46 volts ---> 21.7 amps
45 volts ---> 22.2 amps

...so racers will actually appreciate the adaptive circuit because as their battery drops in voltage they will get more amps to compensate. Hopefully the extra amps don't overheat their motor (a real problem) but at least having the extra power available would be nice.

The power input limit of 1000 watts should be non-changing from the beginning until the end of the race for all battery voltages.

Ideally the manufacturers would build controllers with this design. To my knowledge no one does this and all the controllers simply set a limit on the current that is constant.

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The effect of a changing voltage and current limit is to shorten the peak rpm of the motor and to lower the overall efficiency if it's designed to work best at peak voltage. However, the smart engineer will realize that he can "tune" his motor so that it works better later in the race so that the maximum performance exists over a wider spectrum.

The Debate Rages On...

http://www.endless-sphere.com/forums/viewtopic.php?f=3&t=20030&start=15

Over on ES they are still searching for good ideas for EBRR rules.

A weight limit is a natural performance limiter, and a natural way to force the choices in design that make racing and setting up a racing machine so exciting and fun.

The problem with weight limits can be quoted from the study guide:

Unlimited Power

The most natural urge is to want to allow Electric Bicycle Road Racing to use as much power in the motors as the designer can achieve. On the surface this even seems like a good idea until you start to anticipate where the designs will naturally progress. If you can increase motor power on an unlimited basis you will also need to increase battery capacity to feed this higher power level. More battery means more weight and that means a stronger frame and possibly suspension to make it usable. At some point the machine resembles a motorcycle only it retains "faux pedals" to satisfy the bicycle definition. An acronym PINO (Pedals In Name Only - "Pee No") describes this type of machine.

The next logical step is to limit the overall weight of such an overpowered machine so that a limited battery weight places a self induced restriction on effective power usage. Let's say the bike is limited to 100 lbs overall. You now have a situation where a 150 lb racer has a 50 lb advantage over a 200 lb racer because the bikes are limited to a fixed amount of weight.

In order to still try to salvage this approach you have to figure out some sort of indexed relationship of power, body weight, and bike weight to equalize things. It simply gets too complicated and no one will perceive it as being fair.


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Search back to the old days of 50cc motorcycle road racing. Over time all the racers were these little guys weighing 100 lbs. Unless you want a sport for genetically rare people (or children) going for a static weight limit is a very bad idea. "Indexing" body weight to bike weight might work, but then it's getting really complicated. The 1000 watt limit is so perfect because it allows for extra speed over pedaling alone, but does not overly spread out the acceleration potential of different riders because of their weight.

Face it guys... I've seriously thought this through...

I say do it like F1 racing, use the tires as the limiting factor. Basically you can only go as fast as the tires allow.

This is the best "new to me" idea I've seen. This has a lot of potential because if everyone was forced onto the same tires then people could decide how they might make use of the traction they have available. Since EBRR is almost entirely about turning speed the most significant factor in the sport is how much traction you get on the road.

ES: Whiplash deserves recognition for good input.

But what size tire?

I run 24" x 3.0" road racing slicks and they give lot's of traction. Many people prefer 26" rims and thinner tires. It has potential as a rule, but it also constrains technological development early on.

Also, light riders will be able to turn faster because the relationship of weight to traction is what defines corner speeds. (so it still is favoring the lighter rider)

It still comes back to pedal power being the "Great Equalizer" when it comes to power. Heavy people tend to produce more power and so they equalize their weight.

The Tour De France on VERSUS has very deeply gone into into all the effects of body type to bicycle performance. Each body type tends to do better in different environments. For EBRR we want sprinters like Mark Cavendish because they are able to produce short bursts of power. (up to 2 hp just by pedaling) Lighter riders are better climbers. Heavier riders do better time trials. But overall the performance is more equal than different across rider body types. EBRR might give some benefits to the smaller rider if they can get a tighter tuck on the straight aways, while the heavier and stronger sprinter might gain coming out of a tight turn. It should even out.

The best way to look at it is:

"The 1000 watt rule primarily determines how much wind can be pushed by the motor alone."

...all other factors reduce back to normal Cycling conditions.

Respect "Cycling Wisdom"... they are a lot smarter than you think!

Disconnecting From The Death Race

The "Death Race" was a blessing and a curse. On the positive side it was the first time that any type of functioning pedal machines got onto Go Kart tracks. On the negative side the gas powered machines are based on moped laws and so they are not in the same classification as bicycles.

In the early days of Harley Davidson the first motorcycles they produced were essentially bicycles with motors. They (Harley and Davidson) nearly failed until someone ELSE (forget who, but I saw a show on it) came in and redesigned the bicycles with stronger frames and components. At this point the motorcycle was born.

harley-first.jpg


(note that this has "functioning pedals")

We are in effect "re-enacting history" only this time it's with electric power rather than gas power. Part of the reason that the board track "retro" look is popular is that the first incarnation of motorcycles came from bicycles. But we know the ending... over time with unlimited power the machines got bigger and faster and stronger until now the motorcycle road racer has almost nothing in common with the bicycle.

The "Death Race" helped to wake people up and get the dialogue flowing, but the next step is to discover where Cycling has gone for the last 100 years. The two philosophies diverged and the idea of EBRR is to reconnect them in a modern technological setting.

We need to remember we are to be racing BICYCLES and not motorcycles. We need to study Cyclists more and motorcycles less.

We don't want to be PINO.
 
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We need to remember we are to be racing BICYCLES and not motorcycles. We need to study Cyclists more and motorcycles less.

We don't want to be PINO.

OK...so what is this?

Electric Motorcycle.jpg

Seems you are deriding others with the PINO remark when you do not even have the P(edals) on your bike.
 
Stan4d...

I have two bikes.

The old one (blue) used to be at 2 hp and has now been limited to ~1000 watts (1 hp) in order to test how things will work for EBRR. (it's still fast at 1 hp)

The new (white) bike is the one that is involved in the Halbach Disc Motor project (unfinished) and has operable pedals.

...if you actually followed my projects you would know, but I'm not chastising you for not knowing because I do write about a lot of things.

So I'm legitimately testing 1000 watt (1 hp) bike behavior for the purposes of EBRR and also building towards the ultimate machine that has operable pedals.

I'm "legit", so to speak.

The definition of "integrity" is that you do what you say you will do and I'm on my way there. You only lose "integrity" when you diverge from your stated goals and I've never done that. However, since technology has bottlenecks you sometimes have to terminate a branch and start over in order to achieve the larger goal. I knew in 2007 that the old bike was not the destination for EBRR because it lacks operable pedals and I have been very open about that fact all along.

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Probably the best way to look at the old bike is that it's a "legacy" from 2006 when no one knew where things might go. I didn't even begin to imagine where EBRR would go until about 2007 after the old bike was already running. Today EBRR is beginning to focus and narrow towards it's inevitable shape, but it's hitting bumps on it's way there. That's why the thread was created... to help to guide, form, direct theories towards a more desireable outcome for EBRR at a more rapid pace than if it just got there by accident.

I've been writing about EBRR since 2007 so it's been a long journey.
 
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More ES Dialogue...

70lbs is plenty! A 100lbs limit would be insanity, it would mean bike prices in the >$5,000 range to be top-tier, and it means a sh*t load of risk and danger on a light kart track (because you're going to have 50hp bicycles!). 70lbs bikes mean cheap, practical, and decently suitable for a kart-track.

Hey AussieJester (salty character that you are) could you slap these guys upside the head and get them to realize that a fixed weight limit is going to favor genetically rare 100 lbs EBRR racers.

It's like reinventing the wheel sometimes... :whistle:

The reason that fixed weight limits don't work is that it gives an enourmous advantage to little people. This was proven over years of racing in the 50cc class where all the top guys were little jockey types that weighed 100 lbs.

Pedaling is the "Great Equalizer" for acceleration, but doesn't effect top speed much, so the 1000 watt rule make racers with different body types run equally because at slow speed the pedaling levels things out and at high speed the wind resistance equals things out.

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Ultimately it becomes a set of formulas:

Power ---> Bike Weight + Rider Weight

Total Weight ---> Traction

...we could get into the grim details, but in the abstract there is a relationship of Power to Weight that determines acceleration. In EBRR there are two components to Power, the motor and the racer. Since bigger racers are stronger the net acceleration of big and small racers is the same if motor power is held to a constant. Traction for turning is a ratio of Weight to Tire size (and grip) and the theoretical limit on that is 1G. (hard to achieve) So in a sense the Traction side has a firm upper limit of 1G and so it's somewhat self limiting.

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From a psychological perspective I suspect the reluctance to embrace Cycling Wisdom is based on a sort of anti-Cycling mindset. This is a bad direction. I still ride my mountain bike (regular) on 15-20 mile rides now and then and I still like regular bikes. We need to think of EBRR as "enhanced Cycling" rather than "downsized motorcycling". The focus should still be on Cycling ability, but with a sort of bionic strength because of the electric motor.

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I'm finding that on my old 1000 watt moped bike (no pedals) that I'm able to go fast enough to make things scary. 54 mph on the downhill with only 1 hp is fast enough for me! Being able to pull 36-38 mph on flat land means that on a Go Kart track most of the time you would be able to go through the corners near 1G Traction. Only on the longer straight aways would you max out. Track selection might favor tracks OTHER than the one in Arizona. The one in Arizona has longer straights than most Go Kart tracks do, so we probably ought to think of it as abnormal by Go Kart track standards. (which it is)

It would be interesting to know what the average longest straight away is for Go Kart tracks worldwide. (500 ft?)
 
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Cycling On Go Kart Tracks

I was looking around the Arizona track website looking for information and found that they have already run Cycling races on that track. Since EBRR is legally about "bicycles" it might actually be better to organize around this group rather than the gas moped crowd.

http://www.p1kartcircuit.com/home/

Criterium Racing
Wednesday Nights
February 10th - March 24th, 2010

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So Cycling has already been there...

(if nothing else this could increase track time)
 

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1000 Watt Power Limiting Circuit Design

1000 Watt Power Limiting Circuit Design

So where's the circuit?

Central to the idea of Electric Bicycle Road Racing (EBRR) is the idea of limiting power going into the motor to 1000 Watts. 1000 Watts was chosen for a variety of legal and human performance reasons and we will not go into that here as that has been discussed on other threads.

It might take months for this to get done. (just to warn people who have little patience)

The necessary elements are:

:D Must be able to run without external power source.

:D Must only require connection to the positive and negative leads coming from out of the battery and into the controller.

:D Must be able to alter the throttle signal so that power levels over 1000 watts are prevented.

:D Must be able to take voltage and current and arrive at a constant overall wattage even when the voltage changes dynamically as the battery drains.

:D Must be able to handle at least 50 volts. (100 volts preferred)

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This provides the guiding principles for the circuit. Once this circuit is created it will blaze the trail for EBRR because no one can ever again complain that things are not fair. Successful completion of this circuit could advance the adoption of EBRR by years over the rate at which things are going now. Without this circuit I expect a lack of cohesion of purpose in EBRR and possibly several incompatible racing leagues.
 
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