Removing Bionx 20mph speed limit

Thank you, Andrew for your reply!

So, i have to wait untill i will receive my bionx-system and hope that it won´t be the 2.2 version...

But does it run faster by entering a smaller wheel size? I did not totally understand your explainations concerning this...sorry!

You need to hope you get 2.2 or lower. Version 2.3 is the one that he couldn't remove the limiter on.

Entering a smaller wheel size should make the BionX turn the wheel faster to achieve the maximum perimeter speed of 32kmh.

I have not adequately tested this theory because it is still too cold here for riding. However, my theory is as follows:

1) Determine your wheel size and circumference (26" - 2075mm)
2) Enter a circumference equal to the kilometre-to-mile conversion factor (2075 x .62 = 1281mm)
3) Set the console units to miles
4) Pretend the console is in kilometres

The speedometer and odometer will indicate miles but should be equivalent to kilometres. Your max speed will theoretically be 52kmh, which should effectively remove the limit. However, the thing can really only push you up to about 36 or 38 kmh on the flat at best I think.

Hi, Andrew!
Of course i should hope for the 2.2-version(i mixed it up but ment it...).
Thanks a lot for your advice! Now i got it!
What i´m looking for is to be able to ride about 30 km/h with support of the motor.
quite modest, isn´t it?
Has anybody ever tried what Andrew is suggesting?

I just finished installing my new 500W motor and Li-Ma batteries that came with my Bionx kit. The 3773 code worked just fine on the new kit. I took it out for a test ride for about 15 miles and was cruising at about 27 mph. A few stats, I weigh 180, bike (diamondback Response '07 hardtail MBK) with kit weighs about 48lbs. I did have to exert some effort to maintain 27mph, but it is sustainable. I have already fallen in love with my new kit and it has only been one day. The additional $150 to go from 350W to 500W is so worth it. A few times during my ride I was hitting over 30mph on slight downhills. Hope this info helps settle the curiosity for some people. I don't have any testing equipment...just my own two legs and the pavement.

RoyalCW

Hey Royal ..

What version of code do you run? It comes up on the console when you power up ..

Here's a link to a thread with useful info:

http://www.bikeforums.net/archive/index.php/t-297387.html

Some documentation, facts, and theories expounded which I found interesting.

Andrew

RoyalCW,

At those speeds what did you anticipate the battery life to be? I need to go 30 miles each way. I was hoping to maintain about 27 MPH, but I am worried about the battery life. I don't mind recharging at work. I don't mind if I have to pedal on my own the last few miles, but I don't want the battery to be out after 15 miles at 27 MPH.

I priced out a second battery and charger, as I was going to try to commute 30 miles each way, and that is about another $1000. So, it is a huge expense. I guess I will be carrying my charger with me if this works out.

I have been riding my 500W kit for about a week now. I can consistently ride at 27mph. So far, I havn't drained the battery to empty on a single day of riding about 20 miles. I think I can get about 35-40 miles out of a single charge at that speed. I had to contact my dealer in California for that notch tool...apparently I was losing alot of efficiency with the noth off by 20 degrees. I did alot of research and tweeked some settings on the system. I can hit 30 mph with some effort now. I adjusted the code 3773 to turn off the speed limit, adjusted code 0007 to be more sensitive to my pedal input, and code 0008 to increase the amount of assist.

Here is a full list of codes and what they do:
2001: KM or Miles
2002: Generative breaking On or Off
2003: Time Last with Battery
2004: Set Clock
2005: Wheel Size
2006: Programming Brake Sensor (part of generative breaking)
2007: Polarity Throttle (0-5 volts or 5-0 volts)

3771: Wheel Size (different than 2005)
3772: Diagnostic Mode
3773: Speed Limit On or Off
3775: Throttle Max Speed (default is actually off, surprisingly enough)
3776: Speed that Motor will Start (default is 3km, if you set lower..the motor may start running while you are pushing/walking your bike and ride off without you for a bit)
5000: Full System Reset (highly suggest not doing this...doesn't restore the standard defaults, it actually disables just about everything to the lowest settings)
1976: Motor Direction (clockwise or counterclockwise, suggest that you don't change this or your tire will start reversing when the motor kicks in)
1234: Sensor Speed Signal (1 - slow and 5 - fast)
1970: Configuration activation backlight and DCDC automatic
0007: Sensor Signal gain, 0.1 to 4.0 (high means it is more sensitive to your input/more responsive)
0008: Configuration of extra assistance (1.0 to 4.0...I increased this and the system seems to put more assistance per watt of effort I do)
0041: activation of the I2C (not sure what that means)

These codes are courtesy of other sites that I have found and tried quite a few of them for fun so far. Have fun playing with the codes as well...
oh, and my new 500W runs the 2.3 firmware system.

RoyalCW

Hi, it´s me again!

I´m from germany and in my country and in whole europe the max speed of the Bionx system PL250HT ( which is the limited european version of the PL350 ) is limited to
25 km/h.

Bionx disabled the 3773 code on newer products which means that there is no possibility anymore to disable the speed limiter by entering this code.

But my aim is to be supported by the motor up to approximatly 30 km/h!

My theory is:

To reach the limit of 25 km/h Bionx programms the motor in a smaller rim to rotate faster than a motor in a taller rim.

If i take a motor from a 20" or 24" rim and respoke it into a 26" or 28" rim the result should be a moderate lower torq but also a HIGHER top speed.

What do you think about that?

Hi

I am from Holland and my mother has Multiple Sclerosis so her legs just don't react very well on signals from her brain.
My father ordered a Bionx 250 system for her handbike and he installed it.
Yesterday we did our first tests and we had a couple of problems. The system just doesn't react very well. I think it is because a leg is much stronger than an arm and so the system doesn't measure enough biker's power so it doesn't activate the motor.

Thanks to Davew for giving us the information about the speed limit. We changed the size of the wheel (which is a 20") into 28". We did that because we wanted the system to react faster (we reached the minimum assistance speed earlier)
But then we also reached the speed limit earlier so thanks to Dave!

Can anybody help us?
Does Bionx provide special systems for handbikers? Is there an other possibility to help my mother?

Thanks for reading this. I'm sorry for my bad english :(

Willem Wouters
Netherlands

Hi Willem,

Your English is just fine .. as I've said earlier, better than my [insert any other language here].

I suggest looking carefully at the business of the notch in the rear axle. That is crucial for smooth, predictable operation of the BionX system. I would go so far as to say nothing else can be reliably set or expected unless that notch is pointing straight down.

Once done, crank the wheel on tightly. The BionX produces enough torque to jolt that notch out of position surprisingly easily.

That dealt with, take a look at the tables in the last few posts with configuration codes. I think you might find a solution to your problem by lowering the speed at which the assistance kicks in, or the relationship between pedalling effort and assistance power.

The BionX is amazingly configurable, but unfortunately it has a crude interface. Once you have played with it a little you will get familiar with the codes and what they do. You can always do a factory reset if things get too far out of whack.

Andrew

Hello.

I've been reading this long thread for a while. I am about to buy a PL-350 kit. I live in a mountain area sou it seems there is no other choice for me.

I gathered all the info I need, but still have 2 questions left that I hope you can answer:

1) Having a freewheel means that my pedals are constantely linked to the rear wheel? I mean if the bike is moving are the pedals always spinning?

2) my bike at present is a Shimano 11-30 cassette, the freewheels webshops offer for bionx kit are usually 13-28 or 13-32... Is it recommended to change this "default" freewheel with another one? Which is the difference? That with 11 I can pedal much faster? Will any frewheel work or only specific ones are ok to use with Bionx?

Thanks a lot!

Gee, I was certain this thread would die once oskar reported that the speed limiter can no longer be disabled on recently shipped Bionx units.

Re: Freewheels. Wikipedia is your friend:

http://en.wikipedia.org/wiki/Freewheel

Go for the highest gear set-up you can find. The electric assist makes pedal speed the main limiting factor.

On second thought, the limiter would be the main limiting function on the current Bionx setups. Sorry for the misaprehension.

I just took a long (2.5hr) ride on my new recumbent with BionX installed. The 'bent is a different animal, and the BionX setup is different. For those who haven't tried it, a 'bent is tough going uphill, but faster everywhere else. Level ground bucking a headwind is much easier than on a mountain bike, but even a 1% grade is noticeably harder work.

Default setup on the BionX has the assistance sensitivity (setting 0008) set to 1.0. I was finding it really tiring going up hills on the 'bent so I upped it to 2.5 and Whoosh! Does it ever go! It can go as high as 4.0 but that seemed like overkill.

OK Nice.

Every time i Punch in 0008 it just goes back to the main screen, so I cant get it to work. I wish it did.

I have had my BionX 350 with NiMH battery mounted on a TREK Navigator for about 3 months now and I have logged about 1000 miles. If anyone has some questions about performance, etc I would be pleased to respond.
JDJ

Do we know there is not a new code to remove the 20 MPH limit on a Bionx? After all, it would seem silly for Bionx to not have the feature built in for potential buyers that may need it removed (law enforecment, those using it on totally private property, ect).

Just curious. I am still considering this as an option to cut down commute time. I am not saying I want it to propel me at 27 MPH anymore, but I would just like for it to not max me out.

Lonnie, there has been no change in the code to remove the 20 MPH limit. If you read several of the above postings, yespecially davew, you will see how to do it and the specific reasons why. Once you do this, regardless of your riding habits, you will never return to having the limiter set to the on postion. You really can't exceed the speed limit by anything significant and it just removes the annoying "wall" you start to encounter about 19 to 19 1/2 MPH.
Good luck, JDJ

JDJ,

Thanks for your comments.

Okay, not trying to be obtuse, but I realize my language is not always accurate.

I just want to make sure that with a new bionx wheel, you will still receive power assistance at speeds over 20 MPH and that the code works. For example....

I am pedaling at 210 watts of my own power and I have it set on level II (just as an example). Thus, it matches my watts by 70 percent and thus another 147 watts for a total power output of 347 watts. If I am on a straight away, even with a bad aero profile, I would be going about 25 MPH. At that speed, is t he bionx still matching me at 70 percent or did the assist turn off at 19-20 MPH?

I know I am being redundant, but I just want to be sure before I shell out $2k.

Hey Everyone,

Just read all the entries on this thread and I'm really impressed with everyone's knowledge of and dedication to the E commute; especially with the Bionx product. I'm on the verge of making the plunge into a 500 watt LiIon system. I'm completely interested in and comfortable with the electronic and practical aspect of running the thing (sounds like I can learn all that from you folks). Can someone tell me the make/model of the rim and tire size limits of the rim that the Bionx system is built onto? I'm gonna get a 700c. Any comments or complaints concerning the quality of the wheel/rim as a bicycle wheel?
Does Bionx build a wheel with a customer's choice of rim? Is that custom stuff necessary or can the rim they use carry a chubby boy like me (240lbs) with some load on the bike, through the rough'n tumble streets in the boroughs of New York City without loosing trim and turning into a hoop of horrors?

Thanks in advance
brucedpac

Lonnie, I will try to answer as best I know of the system and from my own experience. I sure don't purport to be any sort of expert on the electronic workings of the BionX unit, but between my wife's unit (a 250 watt) and mine (a 350 watt) we have well over 2000 miles this spring and summer alone. Your theory of the assistance as to what watts "you" are putting out and what the unit will add to it are basicaly correct but you do have to realize the essential limitations of the motor, wheel, and gearing in themselves. Any particular bike this unit is mounted to will have an upper speed that a 350 watt motor can propel it to with a given rider and his weight and this speed can't be exceeded just with the multiplying factors of the BionX unit. i.e 35, 70, 150 or 300 %. If such were the case, then one would simply expend enough energy (human wattage output) to reach 15 miles per hour in 0 assistance and then simply switch to level 4 while continuing to pedal at the same amount of effort and you would suddenly jump to 45 miles per hour! Not going to happen!! But you would be able to reach the maximum limit of the total unit and maintain that speed with less effort on your part progressively thru assist levels 2, 3, and 4. For me, a 63 year old, 220 pound male with 52 pounds of TREK bike and BionX unit, on fairly level pavement with no great wind or even good tail wind, the max I can hit is about 25 to 26 MPH in level 4 and the unit just cannot go any faster and I am working pretty hard at this speed myself. I can comfortably hold about 22 MPH without risking heart failure and I am sure that some of you 40 year old, 155 pound kids can do better still, but there "WILL" be an upper limit that you just can't go past without some sort of major changes to the stock unit you have purchased. I know this is long winded and not a very scientific response but I believe it is essentialy correct and if anyone else out there can correct me or add to the above, I sure would be happy to learn more. I sure love my system, so does my wife (who at 115 pounds with her 250 watt can very marginally outperform me) loves hers as well and we think they are well worth the nearly 4 grand we have in them. Hope this is some help.
Regards, JDJ

Hello everyone. I just purchased a BionX PL350 system last week and converted a spare bike of mine for commuting duty. I just worked up the courage to remove the speed limiter. It seems to have worked. Under full throttle it doesn't seem to have the juice to much faster then 32kph on it's own, but it will continue to assist me when I pedal well past 32kph. I just took it for a quick spin at 1 am in the rain....lol...I was excited to try it. With the limiter on I was having trouble getting past 35-36kph on the flats. Just trying it now I could hit 38-40kph. Man I won't be able to sleep tonight. I'm looking forward to my commute. I think I'll be looking at a new personal best time....lol.

Posted link with pics of my precious. Check her out, she is a beauty.

Your's in cycling. Electric or otherwise,

LesMcLuffAlot

www.flickr.com/photos/30690403@N02/

Thanks JDJ, you answered the question. So, in other words, the unit will help you over the 19-20 MPH limit, but there is still a mechanical limit as the unit can only produce so much power.

Just another note, I used to use a power meter a lot when training. The relationship between power output and speed is not linear. I do know it is generally accepted that a person can average 24.7 MPH/ 40KPH on a time trial bike with decent aerodynamics at 285 watts. On a road bike in the drops, my guess is about 310. So, I am thinking that even on a hyrbrid with bad aerdynamics a person should be able to reach 24.7 at 350-360 watts. But, in the tour to hit 35-40 MPH in a sprint finish, those guys are putting out 1700 watts of power. Having trained with power a lot, I know generally, on a flat on a road bike, hands on hoods, you need to generate about 210-220 to go 20 MPH. So, as you can see, for me to generate another 5 MPH it is about 50 percent more work, even though I am only increasing my speed by 25 percent.

The reason you are reaching a peak with the Bionx 350, is due to the fact the most the unit puts out consistently is 350. No matter what level you have it on, it will only put out 350 on average. So, given your weight, weight of the bike, ect, it would seem normal for you to be working very hard at 25-26 MPH even with the assist of the Bionx 350. If you had a bionx 500 though, you might not feel that same effect until 28-30 MPH as that 150 watts at those speeds only gains you a few MPH. Of course, gearing and cadence are also limiters into the amount of speed you can produce no matter how much power is generated.

My numbers are just guesses, but I am just trying to illustrate that power-to-speed is not a linear relationship due to the fact that as speed increases you need to move more air exponentially and that is the biggest thing slowing you down on a flat.

Just as background, my commute is just over 31 miles. Right now I can do it in about 2 hours 5 minutes. I am looking to get that down to 90 minutes. That is why the removal of the speed-assist limiter is important to me. Even when I don't commute, I still ride my bike 90 minutes in the morning. It is just on some days, leaving my house at 5:10 am is not as appealing as being able to leave at 5:40 am, especially as we have less day light.

Lonnie
You have a complete understanding of the concept. You have stated it better than I did and you are so correct that power output is not linear with speed. A 100 % incrrease in power will not yield a 100% increase in speed and as speed increases, the drag increases as well until it finally reaches a peak where not much further increase in speed is possible. In actual fact, if you download the BionX users manual, their basic idea is to make a couch potato who usually peddles 8 to 10 MPH, now have the ability to go 15 to 18 MPH with the same effort. They aim at a market of people who turn the crank about once per second or 60 times a min. Some of the questions and chatter on this site about removing the speed limiter is sort of like guys talking when I was a kid, about how to make their 327 stock Chevy's achieve 150 plus MPH from the norm of say, 115. You can tune and tinker all you want but until you make major modifications to the stock engine you won't get much over the factory production limit. Also, with the BionX, if you use any assist level and go very much over 14 or 15 MPH you are not going to get anywhere close to 60 miles on a charge in level 1 assist and in level 3 or 4 you will be down to 20 miles or less almost certainly. To do your 31 mile commute in 90 min or less, you will need to re-charge while at work and you will probably not make it all the way, one way at 20+ MPH. I have gone as far as 50 miles and used only 1/2 of my battery but I did lots of peddling in regen and/or regular bike mode. You can travel 10 to 12 miles very quickly around town but if you want to go leisurely riding on bike trails all day, carry a picnic lunch and 2 or 3 beers on ice, and still want to have help getting home if needed, then you really have to experiment with your individual unit and fine tune the 0007 and 0008 codes to your weight, fitness level and terrain. I am sure you are going to have lots of fun and enjoy your unit. Good riding,
JDJ

... Can someone tell me the make/model of the rim and tire size limits of the rim that the Bionx system is built onto? ... Any comments or complaints concerning the quality of the wheel/rim as a bicycle wheel? ...

Hey Bruce,

Both my BionX wheels have been 26", and both have been awesome in terms of durability, quality, and true. My first one went back for warranty replacement (some internal electronic issue) but the wheel was really solid. The replacement has been the same. Some people have complained about breaking spokes but I think that is a problem that has been fixed on more recent models. Listen for feedback on that point.

I feel I can speak for the durability because I ride a recumbent. All of my weight is on the seat all of the time (no using body English to soak up bumps) and I commute regularly with books, 'puter, change of clothes, etc. I think that means I'm tougher on a wheel than other riders but I'm open to challenges on that point. Thus far there is no detectable wobble, and I check regularly.

FWIW, the hill coming home is 7% and 2-3 km long. I routinely maintain 25 - 28 km/h on the hill, and nobody can beat me up that hill. Not even the hottest sprinter in our co-op student pool. They hate me (and I never let on that I have BionX).

Andrew

JDJ,

If I am on a straight away, even with a bad aero profile, I would be going about 25 MPH. At that speed, is the bionx still matching me at 70 percent or did the assist turn off at 19-20 MPH?

I don't want to look at the math too much, but I want to tell you how the BionX feels with and without the limiter enabled.

With the limiter, I get assistance up to the limit and then it abruptly stops helping. If I were pushing with X force and BionX was chipping in 2X at 31.9 km/h, I add a tiny bit more and all at once you need to come up with 3X + the little bit to sustain 32.1 km/h. Because of this "wall" effect, 32km/h is kind of rough and I'd feel it kicking in and out. Because of this I ended up going 31 all over the place. At least that is what I found.

With the limiter off, assistance is great up to somewhere around 34 - 35 and then it seems to fade out gradually. Speeds around 37 - 40 or higher don't seem to have any help, but the cutting out is gradual. I much prefer it for this reason.

I read elsewhere on this forum that there is a theoretical limit (52 or 54km/h?) derived from calculating the speed the magnet travels and the speed at which the magnetic field can switch and such. I didn't follow the physics completely, but the theoretical limit is one thing, the practical limit of BionX's performance is what I'm describing.

Andrew

JDJ,

If I am on a straight away, even with a bad aero profile, I would be going about 25 MPH. At that speed, is the bionx still matching me at 70 percent or did the assist turn off at 19-20 MPH?

I don't want to look at the math too much, but I want to tell you how the BionX feels with and without the limiter enabled.

With the limiter, I get assistance up to the limit and then it abruptly stops helping. If I were pushing with X force and BionX was chipping in 2X at 31.9 km/h, I add a tiny bit more and all at once you need to come up with 3X + the little bit to sustain 32.1 km/h. Because of this "wall" effect, 32km/h is kind of rough and I'd feel it kicking in and out. Because of this I ended up going 31 all over the place. At least that is what I found.

With the limiter off, assistance is great up to somewhere around 34 - 35 and then it seems to fade out gradually. Speeds around 37 - 40 or higher don't seem to have any help, but the cutting out is gradual. I much prefer it for this reason.

I read elsewhere on this forum that there is a theoretical limit (52 or 54km/h?) derived from calculating the speed the magnet travels and the speed at which the magnetic field can switch and such. I didn't follow the physics completely, but the theoretical limit is one thing, the practical limit of BionX's performance is what I'm describing.

Andrew

My experience is the same as yours Andrew. I have also used code 3776 and set it to zero. It allow the throttle to be used from a dead stop. It is great for starting out at intersections and beating traffic across. It's a new game I play at every intersection....lol

Andrew R.W.

That's great info on the wheel, thanks. Is the manufacturer and the model of the rim stamped or printed on the rims you own? Anyone else in "thread-land" able to read the manufacturer's / model name off their rim (some wheel manufacturers use different rims in separate runs of the same product just want so see if they use more that one brand/model)? I'm just curious, having read so many reviews touting or blasting so many rims - I'm trying to hedge my bet before I consider contacting Bionx with some hair brained scheme like using a rim of my choice to build a wheel. For all I know, the rim they are using could already be the rim of my choice...so if you, Andrew R. W., or someone could be kind enough to take a look at your rim for me and get back in a message, I'd greatly appreciate it.

Thanks,
Brucedpac

My wheel has BionX written all over it, but I cannot see another name. I didn't take the tire off though.

I'm speculating here, but the BionX rim is probably tougher than a lot of other rims because of the additional forces and stresses on it. I'm not overly knowledgeable on rims but this seems a pretty good rim to my eye. Lightweight and road-racer peformance criteria would probably not apply.

Andrew