Electric Bikes - The Bionx transformer

My Bionx powered mountain bike has now become a transformer. This is the human powered only off-road form.

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AUTOBOTS TRANSFORM!

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And that's in it's Bionx eBike form.

In one form it has no battery or motor. The Bionx cabling, controller and mounting rack stay on the bike. These only add a few ounces to the overall weight. This is the offroad form where it uses knobby offroad tires and can only be human powered. You'll notice that right in the middle, slightly ahead and up of the crank is a cap that goes over the Bionx connector to protect it from debris.

In its other form it becomes a road going eBike. The protective cap gets moved to the bike rack. The rear wheel gets swapped out for the Bionx electric wheel which has a street tire. The cables are reconnected. The Battery is mounted to the Bionx rack. The front wheel is swapped out for one with a street tire. It's now a street configured eBike.

For the anti-eBikers... ha... I've got the best of both worlds! I can work, sweat and get full of mud with the off-roader and I can commute to work without breaking a sweat, and not stink, with the electric on-roader. It's my choice. It only takes 2 minutes to go from one form to another including minor adjustments to ensure the disc brakes aren't rubbing.

TRANSFORMATION COMPLETE

PS: Sorry for the transformers movie "theme". I just have a sense of humor.

Zeuser,

This is the bike that I am thinking for adding motor. The bike is very light and pleasure to pedal.

It has an 7005 Aluminum frame with no suspension which is a "Trek" bike came together with an VW purchase. It is made in USA.

If I am going for BionX system, should I keep the whole set of the rear wheel (rim, tire and gear spocket) so that it could be a "transformer" like your?

In such case, a new rear tire and gear spocket are needed for the BionX. The new tire would look different from the front! Will it look odd?

Do you think that this bike is strong enough for adding motor?

Zeuser,

This is the bike that I am thinking for adding motor. The bike is very light and pleasure to pedal.

It has an 7005 Aluminum frame with no suspension which is a "Trek" bike came together with an VW purchase. It is made in USA.

If I am going for BionX system, should I keep the whole set of the rear wheel (rim, tire and gear spocket) so that it could be a "transformer" like your?

In such case, a new rear tire and gear spocket are needed for the BionX. The new tire would look different from the front! Will it look odd?

Do you think that this bike is strong enough for adding motor?

It looks fine for a Bionx system. You really ought to get a new tire and gear for the rear wheel. Bionx doesn't use a cassette system so you may have to anyway.

You can set it up as a "transformer" like mine easily. All you need is a spare rear wheel+tire and front wheel_tire. You can put the same tire on the Bionx wheel as your human powered wheel. But Why? The whole point of my setup was to use the mountain bike chassis as a eBike commuter and offroad toy. I've found the Bionx to be less enjoyable offroad so this is why I switch over to human power offroad.

I've found the Bionx to be less enjoyable offroad so this is why I switch over to human power offroad.
Could you tell us why you've found the Bionx to be less enjoyable offroad ?

Is your Bionx hub the same width as your standard hub? No need to spread the dropouts to get it to fit?

Could you tell us if the Bionx is good at "pulling" a trailer ?

I've found the Bionx less enjoyable offroad because the wheel isn't well suited for rough terrain. It really was built for on-road usage and I'll be sticking to that type of usage as well.

The Bionx hub uses the same dropout as a regular bike. No need to spread anything. It's just as easy as removing any other rear wheel.

I've never tried pulling a trailer so I don't really know. But I can't see why not.

Could you tell us if the Bionx is good at "pulling" a trailer ?

Yes, it's great for that. I pull my kid in a trailer up steep hills often and there's a world of a difference between using my regular bike and the bionx bike.

Zeuser,

This is the bike that I am thinking for adding motor. The bike is very light and pleasure to pedal.

It has an 7005 Aluminum frame with no suspension which is a "Trek" bike came together with an VW purchase. It is made in USA.

If I am going for BionX system, should I keep the whole set of the rear wheel (rim, tire and gear spocket) so that it could be a "transformer" like your?

In such case, a new rear tire and gear spocket are needed for the BionX. The new tire would look different from the front! Will it look odd?

Do you think that this bike is strong enough for adding motor?

If the dropouts on that frame are also made of aluminum, you may need to add a steel torque arm to the axle on the motorized hub to keep it from spreading the dropouts. All of the torque from the motor is applied through the axle, which has parallel flats that to keep it from spinning. On a frame with steel dropouts a torque arm isn't always necessary -- depends on how well the axle fits inside the dropout and how strong it is -- but I'd definitely want one on aluminum dropouts.

If the dropouts on that frame are also made of aluminum, you may need to add a steel torque arm to the axle on the motorized hub to keep it from spreading the dropouts. All of the torque from the motor is applied through the axle, which has parallel flats that to keep it from spinning. On a frame with steel dropouts a torque arm isn't always necessary -- depends on how well the axle fits inside the dropout and how strong it is -- but I'd definitely want one on aluminum dropouts.

Thanks for the advice.
Use an magnet to test.
The rear dropout is aluminum.
The front fork dropout is non-aluminium and is marked "chro-molly".
What is "chro-molly"? Some kind of steel alloy? Is it stronger than steel?

If it strong enough, may install the hub motor in front.
Where is the best place for hub, front or rear?

Yes, chrome-molly is a steel alloy. Light, strong and can handle being welded. You should be ok to put a motor on your frt forks. It isn't recommended to put a motor on alum frt forks. The torque arm idea..Hmmmm. I never thought about the jaws spreading. But when you think about it..What is the difference between the torque of the motor or the torque from the rider? My 406 puts out some where around 35lbs-ft. (as per online simulator) I weigh over 250lbs x crank throw= Lets say a lot more then 35 lbs ft of torque.. I think the key is to check the axle mount nuts regularly*. If they loosen and the axle does rock back and forth, it will pound out the jaw and re-tightening the nut will do little as the main struct. support feature (jaw) has been ruined. Specially if flat washers are used.

"depends on how well the axle fits inside the dropout and how strong it is"..I agree with that line. If the jaws are poorly machined to start with..You'll have a problem with a motor axle because the only thing holding the axle in place will be the compression of the axle nut/washer to the side of the drop out. There isn't as much strength with that.

*Using nuts that have a built in washer with locking serrations, and kept tight will help to hold the jaw together also.

The torque arm idea..Hmmmm. I never thought about the jaws spreading. But when you think about it.. What is the difference between the torque of the motor or the torque from the rider? My 406 puts out some where around 35lbs-ft. (as per online simulator) I weigh over 250lbs x crank throw= Lets say a lot more then 35 lbs ft of torque.. I think the key is to check the axle mount nuts regularly*. If they loosen and the axle does rock back and forth, it will pound out the jaw and re-tightening the nut will do little as the main struct. support feature (jaw) has been ruined. Specially if flat washers are used.

The torque applied by a rider is much different than with a hub motor. With a rider, all the torque is applied through the crank to the chain and then to the freewheel/freehub pawls, which then transfer it to the hub. There is no torque between the wheel and the frame as in a hub motor. With the hub motor, you have the windings that are attached to the axle, which stays stationary by means of the flats that are held inside the dropouts. Torque is applied to turn the wheel, and the axle flats against the dropouts allow the wheel to turn instead of the axle turning.

Having a re-think about the hub motor applied torque, you're right...ooopps.

I'm sure a steel torque arm would be easily fitted to an aluminium rear end. The motor firms must provide them since so many bikes are aluminum now, and the torque of the axle trying to spin in the drop out would wreck them easily. It isn't just about the quality of the machining in the drop out, the flats on the axle must mean some space between the flat and the drop out, unless the axles are oversized and the flats take the dimension down just enough to slot them in. Anyway, there's no penalty in clamping a torque arm onto the rear fork. It's only a few ounces of steel. By comparison with the other weight you'd have added t would be nothing.

Hello guys,

I have read a few things about this and note that if the hub were to spin in the drop outs (worst case scenario) the wires could spaghetti around the axle and be pulled and any wire damage might be undetectable when repaired and put back together, possibly seeming like a bearing failure, when electronics may be permanately damaged, needing for new imput cables if at all possible.
I am a machinist by trade and think that the torque are would make a great addition to the aluminum drop outs, but also would add some type of metal sleeve to transfer some of the minor torque left after the torque arm is installed. The aluminum on my Rock Hopper looks pretty flimsy at best and obviously from an as intended design standpoint is not an issue in stock configuration.
This discussion has intrigued me not to think about just buying a system, bolting it on, and riding without taking this into consideration from the get go, its kind of like being in a hurry to try out the car you just put together and only had 3 lugnuts on a wheel instead of 5, it will work, but will surely fail with time.

Awesome community to learn from.







Looking at the Bionx but want more than the 20 mph max as Illinois allows 25



Braxas

Yes, it's great for that. I pull my kid in a trailer up steep hills often and there's a world of a difference between using my regular bike and the bionx bike.

hello adamtki. did you setup your bionX to have a good support driving uphill? the following codes seem to me important if bionX should drive uphill with a trailer (more weight..)... codes 3773 - speed, 1234 - reaction of a sensor, 0007, 0008. do you have any experience with programming those codes? i have 3773 20 mph, 1234 = 3, 0007 = 1.2, 0008 = 1. ... and the support is not very good when i drive strong uphill. thank you. tt_ch

Direct drive hubs ie. Bionx have limitations on steep hills and or big loads, they don't have a lot of torque.
If you want to do steep hills your best bet short of going to a 72 volt monster system is a geared hub or if you are a tinkerer a BB drive.

For the anti-eBikers... ha... I've got the best of both worlds! I can work, sweat and get full of mud with the off-roader and I can commute to work without breaking a sweat, and not stink, with the electric on-roader. It's my choice. It only takes 2 minutes to go from one form to another including minor adjustments to ensure the disc brakes aren't rubbing.

For the e-bikers...

Ha! I can have two different bikes: one for the road, one for off-road. I can dress appropriately, change my clothes, and wear deodorant so I don't stink when I get to work. And I can maintain my dignity by not looking like an extra from "Minority Report!" Shazam!

You can add the BionX to any bicycle you please, provided that the dropouts are 135mm. The BionX is a very lightweight system as far as demands are concerned, it doesn't require special frame considerations, torque arms or any sort of special additions. Put it on as you would any other wheel, and as long as you haven't screwed anything up, it will be fine. Oh, you do have to make sure that the frame case will mount on your bike too, otherwise you'll need the rack bag instead: pretty simple logic there :)

As geebee has pointed out, the torque output of a BionX is low, even relative to some other direct drive hub motors. These kits are pretty timid compared to most other systems as far as power output.

As an addition to his comment however, this depends on the design of the hub motor. Picking up one with more winds of copper like a 408 will get you significant hill climbing capacity. A 408@36v will handle steep grades pretty well, my kit running at 48v is quite a mountain goat. No exact specifics on it, but it'll take me, my university books, and this weeks groceries up any hill in Calgary faster than some people will ride on flat ground.

For the e-bikers...

Ha! I can have two different bikes: one for the road, one for off-road. I can dress appropriately, change my clothes, and wear deodorant so I don't stink when I get to work. And I can maintain my dignity by not looking like an extra from "Minority Report!" Shazam!

Ha! I can do that too but if I want to go electric, I can do that too. It's my choice. e-Bikes = more choice.

hello. i've got my bionX since two days.. so i'm really a bionx newbie. i was just wondering why i have such a big difference with the assistance when i'm driving uphill. the first 300 meters the bike goes very fast and from one moment to the other the assistance is very low. i tought i could change somethin with the 1234, 2007, 2008 codes for better support uphill...i was testing today... couldn't find any logic adjustment with the codes 1234,2007,2008... : (. the difference how the bike gives assistance is very big after a few 100 meters uphill!...as soon as the battery is a little bit used almost 0 support. does anyone have any experience with bad quality battery/motor or configuration the codes? i couldn't find one info on the interent... bionx canada has removed their files and users do not have access anymore to learn how to config the bionx.thanks a lot for ideas...tom

Depends on the effort you put in. If you put in a lot of effort, so does the Bionx. If you don't pedal quite as strong, the Bionx backs off a bit.

The motor has a torque sensor. The more torque the rider puts in, the more torque the Bionx adds.

I don't have hill climbing issues at all. Of course I have to shift down to a lower gear but if I pedal hard enough, the Bionx rewards me with more power. Pretty soon I find myself upshifting because I'm pedaling too fast going up the hill.

Depends on the effort you put in. If you put in a lot of effort, so does the Bionx. If you don't pedal quite as strong, the Bionx backs off a bit.

Interesting??? The Panasonic drive I'm familiar with seems to offer (in many instances) more assist the lighter you pedal. In fact, one of my "tricks" is to pedal in an uneven (pulse) fashion - more force on one pedal than the other - to help make the controller think it should deliver more average motor power.

Obviously, different logic for different products - but another example of the wide design variations constantly evolving in this industry.

For the e-bikers...

Ha! I can have two different bikes: one for the road, one for off-road. I can dress appropriately, change my clothes, and wear deodorant so I don't stink when I get to work. And I can maintain my dignity by not looking like an extra from "Minority Report!" Shazam!

Us non snobs don't have showers, change rooms and the like at our offices.

PS: Looking like an extra from Minority Report is actually cool man! Get with the program... geek is chic!

hello. i've got my bionX since two days.. so i'm really a bionx newbie. i was just wondering why i have such a big difference with the assistance when i'm driving uphill. the first 300 meters the bike goes very fast and from one moment to the other the assistance is very low. i tought i could change somethin with the 1234, 2007, 2008 codes for better support uphill...i was testing today... couldn't find any logic adjustment with the codes 1234,2007,2008... : (. the difference how the bike gives assistance is very big after a few 100 meters uphill!...as soon as the battery is a little bit used almost 0 support. does anyone have any experience with bad quality battery/motor or configuration the codes? i couldn't find one info on the interent... bionx canada has removed their files and users do not have access anymore to learn how to config the bionx.thanks a lot for ideas...tom
Try code 1234 = 0 (OFF). I used to use 1234 = 3 and my motor died on the long uphill. I got this change from a telephone talk with a BIONX engineer. I use codes 0007, 0008 = 3 and get smooth power assist up a five mile hill in middle gears on my mountain bike with PL350. I believe that setting code 1234 to bigger numbers gets quicker assist, but also gets quicker loss of power, causing rapid on/off assist because uphill pedaling is not measured constant in the strain gauge sensor. I think this on/off behavior eventually kills the motor. He also pointed out that a few degree misalignment of the sensor is NOT critical to the strain measurement. Try those codes - let us know if performance improves.

It only takes 2 minutes to go from one form to another including minor adjustments to ensure the disc brakes aren't rubbing.

.

I have read (from the Bionx dealers) that Bionx is incompatible with disc brakes. How do you make this work?

Be careful young sir. I repaired Bionix bikes in B.C. which were ridden daily for two years. Because the rear wheel with the motor weighs 15 pounds, then you add the battery box, then the normal weight of the rider.... you get my drift. The spokes should have been thicker to compensate for weight. After two years of just on-road riding, the spokes were all failing at the threaded end. Your bike looks like it's going to be ridden off road on top of that. Have your wheels trued up regularly and make sure someone checks the threaded ends for stripping.
Other mechanics who told me about e-bike problems in B.C., said that motors on the front wheel caused the forks to break because of the extra stress on the forks. The forks on those bikes with front wheel motors should also be tougher. For that matter, I believe your frame is not protected by the normal warranty one you start modifying your bike by making it electric.
E-bikes made in China have tougher frames, 3 1/2 mm spokes on the wheel that contains the motor and 3.2 mm spokes on the front wheel. They don't get into fancy computer circuitry so there's no electrics to go bad if they get wet. Speaking of wet, the Bionix I repaired had an electrical connector joining two parts of the wiring harness right under the left chain stay. The thing was constantly unplugging right from the start, according to the owner. It had to be kept taped up to keep the connection dry also. What a dumb place to put a connection plug!

The spokes should have been thicker to compensate for weight. After two years of just on-road riding, the spokes were all failing at the threaded end.

"At normal loading, no spoke should ever break..." - Jobst Brandt, author of The Bicycle Wheel.

The loading of hub motor wheels is not that much greater than an ordinary bicycle, so normal 2mm spokes should be a workable solution. Never having seen a Bionx wheel, I can only speculate about the cause of the failures, but too little tension and lack of "stress relieving" at the nipple are prime suspects (particularly the latter since the large hub creates a steeper angle where the spoke enters the rim).

There is something wrong with wheels that use 3mm+ spokes. I have seen pictures of Chinese hub motor wheels with visibly curved spokes - a condition that just screams early failure. Maybe they just don't care to build good wheels and realize that ridiculously oversized spokes might last long enough to avoid warranty issues, even though they know the spokes will eventually break. In any case, it is the wrong solution.

"At normal loading, no spoke should ever break..." - Jobst Brandt

The loading of hub motor wheels is not that much greater than an ordinary bicycle, so normal 2mm spokes should be a workable solution. Never having seen a Bionx wheel, I can only speculate........"

If you have never seen a Bionix wheel why bother offering advice?
You quote Brandt - but the continuous load of a 15 pound motor is not "normal loading"
There are reasons that spokes come in different thicknesses. A modern road race bike can weigh just 15 pounds in total. Are you suggesting that it should use the same spokes as a Bionix?

If you have never seen a Bionix wheel why bother offering advice?

Because I have enough engineering sense to be certain that 3.5mm spokes are the wrong solution to spoke breakage on those wheels.


You quote Brandt - but the continuous load of a 15 pound motor is not "normal loading"

Perhaps, but it is certainly less than the abuse a downhill mountain bike using large disc bakes undergoes. Or tandem wheel (or unicycle), for that matter.

Downhillers often go with straight 14 gauge (2mm) spokes, but their reason for using heavy spokes is stiffness, not durability. Double butted (2/1.8/2mm) would make for a more durable wheel. Please understand that the torque exerted by the motor on an electric assist bike is small compared to disc brake torque.

Tandem wheels have to cope with twice the load of an ordinary wheel - not a measly 15-20 pounds extra, but 80 or more - and the typically do this using standard spokes (though 50% mor of them).

Then there's my mountain unicycle which takes my 200 pounds of weight multiplied by the acceleration encountered when doing drops: a minimum of 400 pounds of force, probably much higher. Its 36-spoke 14-gauge (for stiffness) wheel is holding up quote well, thank you.


There are reasons that spokes come in different thicknesses.

"The idea that spokes are not strong enough is based on failures of
spokes that were not stress relieved after building the wheel. For
wheel builders who cannot understand the concept and refuse to take it
on faith, thick spokes are the only answer..." - Jobst Brandt

The bottom line is that 1.8mm spokes are more than strong enough for a hub motor wheel. The fact that larger spokes are failing suggests a design error or inadequate build quality. The suggestion that 3.5mm spokes are the correct solution to a problem of this nature shows a misunderstanding of the causes of wheel failure.


A modern road race bike can weigh just 15 pounds in total. Are you suggesting that it should use the same spokes as a Bionix?
This choice of example demonstrates a misunderstand of bike wheels. Most modern racing wheelsets feature low spoke count, meaning each spoke on a racing wheel is under significantly higher tension than the spokes on a standard (32 or 36 spoke) wheel. If spokes failed because in proportion to strain/tensile strength, the racing wheels should fail long before a hub motor wheel. The fact that racing wheels are reasonably durable when (some) hub motor spokes are failing early points out the flaw in that assumption.

The reason for the connection on the rear chain stay is so you can actually change a flat tire without disassembling the whole setup. That's a very smart place to put a connection. The connection would have to be submerged to short out the power conntection ( and if you get your bike this deep most likely your hub will get water into it causing a much more catastrophic failure.) The controlling cable has an o-ring gasket that keeps it water tight.

You mentioned you have seen the spokes strip out at the threads. Usually the spoke head or the nipple will fail a lot earlier than this happens. I would attribute this to a wheel that hasn't been built properly and may have been stripped from the machine that built it.

And to address an earlier post, My Bionx wheel has a rotor adapter on it and I run an 8" Hayes disc on the back with no problems what-so-ever.