Bikeon, "cassette drive" torque sensing motor

[rivers]

Glad to hear that Aram finally has the new parts because I have been waiting as well. A while back I purchased a BikeOn kit to go on a 10-speed carbon road bike. However, the bike's fat chain stays caused the roller/sensor to position too low so there was no engagement to the chain. Therefore, was never able to ride the bike with the kit installed. I returned the kit.

Later I was told that that a new torque arm that was adjustable in length would solve the problem. Hopefully Aram's new parts will include this fix. If so, I will repurchase the kit and try again.

 

[Gruesome]

I can see how with a carbon chain stay you would not want to even try running the torque arm without the bracket. Having the torque arm metal axle pushing directly against the chain stay worked ok for me, so I was at least able to do a trial run (which was a lot of fun, and answered a few of my questions already). I'm excited to get the kit back.

Did you send Aram some measurements of your chain stay? He showed me a CAD screen capture of the new torque bracket with increased adjustment range, and he is also making the torque sensor (different part) height adjustable, so hopefully it will work for your bike as well (and for a lot of others).
But since you already had to return once, it would probably be good to sort out the fitment before you order again.

 

[Gruesome]

It took a while and a few back-and-forth shipments and no doubt lots of work for Aram, but now he has adapted the BikeOn motor kit so that it also works for bikes like mine. Many thanks, Aram!
My bike has an 11 speed Shimano mountain bike cassette and cassette hub and a chain stay with derailleur cable boss right where the previous BikeOn version would have wanted its torque bracket. This Shimano cassette hub is 1.8mm shorter than the road hub, and therefore has smaller clearance for the BikeOn motor between wheel and chain stay.
Both of these issues needed adaptations on the BikeOn side.

On the bike side no extra parts or adjustments are required, the kit has good clearance to the spokes without any changes or spacers added to the cassette, the derailleur cable moves freely, and 7 of the 11 cassette sprockets are useable. The derailleur comes to a safe stop against a fixed (non-rotating) part of the BikeOn kit, and there is sufficient clearance of the chain to the BikeOn front baseplate.
The torque sensor can be height adjusted to allow for different chain stay and motor torque bracket (the part below the chain stay) heights.

I did a 30 mile test ride with an almost-final version, including a 2.8 mile uphill section with 5.2% average grade (Turnbull Canyon near Whittier, CA), and the unit meets all my requirements. I can easily go 20 mph on flat ground (actually 22 mph at 20% motor support level, and 25 mph at 45% motor support level) at my normal exercise level of pedaling (~100W human power, I'm estimating), the unit supports continuous uphill riding at a good speed (9 mph up a 5.2% grade) and most important, cadence (70-80 pedal rpm). This takes the larger lowest gear due to the lost sprockets into account. The motor doesn't overheat; for most of the uphill test it was actually smoothly regulating at its thermal limit, and when pushing it like on this test uses about 10-12 Wh/mile. I used about 1/2 of the capacity of the smaller of my two 48V batteries, discharging the 15Ah unit from 54.5V to 48.5V, which agrees pretty closely with the energy input recorded by the BikeOn unit.

The 30 mile ride ended when I accidentally kicked the battery cable from the motor while pedaling (I had routed it in a 180 degree-turn right at the motor, which probably left a bit too much tension on the connection), and blew the fuse and possibly also the FETs (still waiting for Aram to confirm). Dismounting the unit and pedaling home the remaining ten or so miles worked just fine. Apparently disconnecting the cable from the motor while the motor is running is a no-no.

Below I'm including some plots of power and energy used and of speed vs time. I'm still working on converting the torque sensor reading to something more closely related to pedaling torque. One can nicely see the near constant power output and speed while on the 2.8 mile climb between 12:14pm and 12:37pm, interrupted by a five minute break, and the two occasions where I used the motor at 60% support level for a short time until it started to reduce power to keep the temperature under control. Ambient temperature was in the high 80s, if I remember correctly.
Motor output for the climb is about 130W for the constant part, and my output was about the same, and about the maximum I can do (pulse rate close to 170, which is a good rate for somebody ten years younger than me...
I believe speed is km/h, but I noticed the BikeOn calibration was maybe 10 or 15% off (low); for the constant speed part of the climb the actual speed was about 9 mph or 14.5 km/h.

I was actually surprised when I first saw the data that I had pulled up to 500W out of the unit. But for 25 mph on the slight grades leading up to Whittier that actually makes sense. Having the motor support makes it very tempting to go faster, even uphill. All in all I believe I got a better exercise with the motor than on the same tour without.

The jump in the blue curve (Wh) actually indicates some missing data between 11:30am and 11:50am. The horizontal time scale is not necessarily linear.

 

[Gruesome]

I briefly experimented with mounting the battery to brackets bolted on in the bottle holder location to the down tube, but anything involving zip ties just feels like it would allow too much swaying of the battery, plus the battery is in an exposed location there.
So I moved the battery back to the bottom of my slide-in rear rack bag, into which it fits perfectly. There it sits somewhat high for an additional 8 pound load, but it is well padded and protected, and easily removable.
I added a 30A breaker as a disconnect switch, since both my batteries came without built-in switches. I also added a 10kOhm resistor bridging the breaker that precharges the motor controller capacitors to minimize sparking when the breaker is turned on.

Below is a pic of the bike with the BikeOn unit installed. I think it's pretty light as a 37-38 lbs. (see below: 49 lbs!) E-Bike with 60 to 80 miles range (0.75 or 1 kWh battery), starting from a 23 lbs Canyon Roadlite 6 gravel bike.

 

[Zambam]

It took a while and a few back-and-forth shipments and no doubt lots of work for Aram, but now he has adapted the BikeOn motor kit so that it also works for bikes like mine. Many thanks, Aram!

Good work between the 2 of you to get your issue resolved! Will this mod be on all future BikeOn kits or unique to your bike?

The 30 mile ride ended when I accidentally kicked the battery cable from the motor while pedaling (I had routed it in a 180 degree-turn right at the motor, which probably left a bit too much tension on the connection), and blew the fuse and possibly also the FETs (still waiting for Aram to confirm). Dismounting the unit and pedaling home the remaining ten or so miles worked just fine. Apparently disconnecting the cable from the motor while the motor is running is a no-no.

There is no "lock" on the battery cable to motor connector? Just a friction fit? If it smokes electronics when unplugged while riding, some kind of securing mechanism is required IMO. Was dismounting the BikeOn kit required to ride home w/o assist? I thought it wasn't?

 

[Gruesome]

Good work between the 2 of you to get your issue resolved! Will this mod be on all future BikeOn kits or unique to your bike?

I'll leave answering that to Aram; I'd assume he will produce one universal version. Note that it worked before for bikes with fewer gears on the cassette, at least some of them with the same cassette hub width (for Shimano). I don't know whether tests have been done with newer 12 and 13 sprocket microspline cassettes. I believe (don't know) those cassettes are wider, so the distance from the center plane of the driven sprocket to the spokes should not shrink anymore compared to my cassette (spoke clearance was one issue), and likewise the distance to the chain stay should also be the same or larger. See e.g. A guide to freehub body and cassette compatibility , but that page does not list the cassette widths, only the hub widths.

There is no "lock" on the battery cable to motor connector? Just a friction fit? If it smokes electronics when unplugged while riding, some kind of securing mechanism is required IMO.

Again, Aram should comment. From my observation, it's a very tight friction fit, and if the cable is routed straight away from the motor socket and is properly tied to the chain stay it should be virtually impossible for the connector to pop out. I had taken a cable routing 'short cut' to the battery on the rear rack, involving a cable U-turn right as it left the motor, and that was apparently too small a bending radius and too much tension on the relatively thick cable. Aram wanted me to send the unit back anyway for other modifications, but I hope something like this would have been covered under warranty.

Was dismounting the BikeOn kit required to ride home w/o assist? I thought it wasn't?

Without the battery connection, the BikeOn motor needed to be unclipped, otherwise there is a large additional pedaling resistance from driving the motor via the belt. Before I actually had to do it, I thought it would be an unnecessary hassle, but it turned out to be as easy and quick on the road as on the bike repair stand. The motor was also very easy to clip to the top of my rack bag. That being said, of course I would have preferred to continue with working motor support...
The added dead weight from the battery (over 8 lbs) and from the motor (4 lbs) didn't affect my speed noticeably, it's mostly air drag at my speeds anyway. So I had worried about that unnecessarily.
If the motor is working, one can simply switch the support level to 'none', and then the motor just spins along. I think I noticed a very minimal positive support at this level, but I could be wrong.

 

[rivers]

The torque sensor can be height adjusted to allow for different chain stay and motor torque bracket (the part below the chain stay) heights.

Question: When you shift to the smallest sprocket does the chain still clear the chainstay?. From the photo it looks like it's close to rubbing.

 

[Chalo]

Question: When you shift to the smallest sprocket does the chain still clear the chainstay?. From the photo it looks like it's close to rubbing.

The idler above the chainstay doesn't move just because the gear changes. That minimum clearance point should stay the same regardless of gear choice.

 

[spaceman]

Will this mod be on all future BikeOn kits or unique to your bike?

All these modifications will be implemented on all production kits, except the motor heat sink, which will be an optional extra. We'll post this product on our store soon.

There is no "lock" on the battery cable to motor connector? Just a friction fit? If it smokes electronics when unplugged while riding, some kind of securing mechanism is required IMO. Was dismounting the BikeOn kit required to ride home w/o assist? I thought it wasn't?

The connector fit is quite tight. However, a simple lock is currently being designed and tested, and it should be finished by next week.

 

[spaceman]

The idler above the chainstay doesn't move just because the gear changes. That minimum clearance point should stay the same regardless of gear choice.

Yes, that is correct.

 

[spaceman]

Question: When you shift to the smallest sprocket does the chain still clear the chainstay?. From the photo it looks like it's close to rubbing.

Gruesome's unit features a new design of a torque sensor arm that is expandable, allowing for adjustments to the arm length. This, in turn, enables the adjustment of the idler position above the chainstay tube.

 

[Gruesome]

Question: When you shift to the smallest sprocket does the chain still clear the chainstay?. From the photo it looks like it's close to rubbing.

I think it has good clearance. The chain could still slap down onto the chain stay, but I rarely jump with this bike
Worst case, the kit does come with several of the rubber bands that pull the motor and torque bracket against the chain stay. Aram also recommended to slide the rubber band loops further up and down the chain stay, to maximize clearance at the torque sensor.
.

 

[Gruesome]

I just weighed the bike: with everything incl. cable lock, rain jacket, spare tube, chain repair tools etc. it's at 22.2kg, or 49 lbs. Ooof! 5 kg or 12 lbs more than planned. :-(
From the factory the bike itself supposedly weighs 21.8 lbs (Roadlite 6 ), so the rear rack and tools and suspension saddle post + saddle must add more than I thought. Oh well.

 

[rafalg]

your saddle looks like 5 kg

 

[Zambam]

I just weighed the bike: with everything incl. cable lock, rain jacket, spare tube, chain repair tools etc. it's at 22.2kg, or 49 lbs. Ooof! 5 kg or 12 lbs more than planned. :-(
From the factory the bike itself supposedly weighs 21.8 lbs (Roadlite 6 ), so the rear rack and tools and suspension saddle post + saddle must add more than I thought. Oh well.

My Raleigh M80 was 28 lbs before conversion. After converting to TSDZ2 mid drive it went up to 41 lbs. You can see pic of it here

Ebike weight

What's the weight limit of your ride that you wouldn't mind carrying up a flight of stairs day in and day out?

endless-sphere.com

I don't carry tools or flat repair stuff. Seldom get flats here. If I do, I'll walk it home if not too far. If too far, remove battery (easy to steal), lock it up, take bus or Uber home, get car and haul it home.

 

[neptronix]

your saddle looks like 5 kg

Always be comfymaxxing!

 

[Gruesome]

So I weighed all components, and the extra 5kg are about 50:50 due to the bike itself with rear rack, saddle and add-on grips, phone holder etc. and to the rear bag with non-battery stuff in it. The bike is 3.6 kg over the factory weight with all that stuff, of which rack and seat post account for 1 kg. The rear bag with contents comes in at 6.9 kg, minus 4.1 kg for the battery leaves 2.8 kg.
The motor weighs 1780 gram, including the extra rotor heat sink.

Your expert opinion notwithstanding, I doubt that the comfy saddle weighs more than the old saddle + saddle post combined. I know what the new seat post and the rear rack weigh (1 kg total), and the Ergon grips + phone holder + aero bars can't add up to more than a few hundred gram. So that extra 2.5kg is a bit of a mystery. I'm not going to remove all add-on parts from the bike, just to prove that Canyon fudged the weight a little bit.

Bottom line: battery and motor only add 5.9 kg/13lbs. I'm just carrying too much other crap.

 

[Gruesome]

Another brief update: I have now done one 70 mile ride, two 30 mile rides, a twenty mile ride and the initial twelve mile test ride. Aram and I discovered that my riding style of using relatively high user pedal input and relatively low motor assist is actually harder on some of the components, to at least my surprise, and Aram has reengineered a few parts. One of the inner rollers supporting the large red rotor (the one closest to the centerline that takes the brunt of the intermittent loads from hard pedaling) is now made from a tougher material, and the sleeve and underlying material of the torque sensor roller have been updated as well.

I'm hopeful that we have found the last of the weak spots, and that the motor will now provide continuously reliable assistance for me. I had already reported on the Turnbull Canyon ascent (in very hot weather), which went without incident (the roller damage during that ride most likely happened before, judging from the onset of increased noise); the 70 mile group ride (with people who are normally faster than me) to Pasadena and downtown LA also went without a hitch, except that I discovered the damaged roller sleeve afterwards. That did not impede the ride, and has now also been fixed.

I think it would not be the end of world should some parts like the roller sleeve and the sprocket clamp O-rings turn out to be wear parts that need occasional replacement for my style of riding.

For the 70 mile ride I used a 20% assistance setting, but with the full 20% motor power kicking in before the torque sensor reached its limit, due to the default torque sensor calibration offset of 7. After Aram explained what that offset actually does, and after I had a look at my torque sensor reading statistics, I reduced the offset to 1, using the full range of the torque sensor, and upped the assistance level to 25%. I feel this gives a bit better exercise at higher speeds, since one doesn't ride on an assistance plateau.

For both rides I used about 8 Wh per mile, including several miles on the final stretches with assistance increased to 45%.
That means that for anything up to 30 miles I could actually do with a much smaller battery, like one of Aram's 250 Wh water bottle batteries.
My large 700Wh and 900Wh batteries should in turn be sufficient for the longest rides I'm contemplating.

So far my cycling buddies are not complaining, on the contrary: my slightly increased speed means no more waiting, and riding at closer to their preferred training speeds.

At this point I think I can recommend the BikeOn kit for anybody who, like me, bikes for exercise and needs a few miles per hour boost. I believe the kit was already working fine before for people who want more motor power with less pedaling, but with the latest improvements it's now sturdy enough for sustained higher and more spirited pedal input.

Now that Aram has hopefully more time, I'm looking forward to enhanced software features

 

[Gruesome]

I forgot to mention: I have now mounted and dismounted the BikeOn motor many times, and it's really fast and straightforward, and much less of a hassle than I initially thought. The cable can stay in place without any extra precautions at either end. The biggest part is repacking my rear bag because of the big battery.
I'm looking forward to leave the motor on permanently, because even for shorter solo rides it allows me to go faster, and further in the same amount of time, with the same exercise, which is more fun.

Also, another note on motor power: I think Aram had stated that the maximum power with a 48V battery is 810W (15A * 54V = 810W). I assume that my 25% assistance setting then translates to a maximum motor assist of 200W, which makes sense, since it would correspond to doubling my input under most circumstances, both while climbing and on the flat.

 

[raylo32]

Sounds great! One point of etiquette I learned from doing group rides on my pedal bike with a couple of folks on e-bikes is that those riding e-bikes should not be too chatty. One lady who I hadn't seen in awhile kept trying to have a conversation with me as we climbed some hills and I was frankly breathing too hard to participate. How does one nicely say "go away"?? LOL.

 

[spambait111]

Just received my kit today, and am sad to note a couple things - not BikeOn’s fault, but maybe something to help others:

1. For my 10-speed Shimano HG cassette (11x42T), my closest sprocket is 37T and I purchased BikeOn’s 36T sprocket size. Bottom line: make sure you have a matching sprocket size to match the BikeOn sprocket. I just assumed I has a 36T without checking.

2. My 10 speed SHIMANO XT derailleur has a curved cable guide which angles toward the cassette (probably for more efficient cable pull). This means the BikeOn sprocket can’t lock together because the angled cable guide arm hits the big red BikeOn sprocket preventing the sprocket’s closure.

My solution for now is to get an 11x36T cassette and a SHIMANO Deore derailleur which looks to have the traditional straight down cable guide. I’ll also need to shorten the chain. Hopefully this modification can be done this weekend. I’m looking forward to seeing how BikeOn works!

 

[Gruesome]

Just received my kit today, and am sad to note a couple things - not BikeOn’s fault, but maybe something to help others:

1. For my 10-speed Shimano HG cassette (11x42T), my closest sprocket is 37T and I purchased BikeOn’s 36T sprocket size. Bottom line: make sure you have a matching sprocket size to match the BikeOn sprocket. I just assumed I has a 36T without checking.

2. My 10 speed SHIMANO XT derailleur has a curved cable guide which angles toward the cassette (probably for more efficient cable pull). This means the BikeOn sprocket can’t lock together because the angled cable guide arm hits the big red BikeOn sprocket preventing the sprocket’s closure.

My solution for now is to get an 11x36T cassette and a SHIMANO Deore derailleur which looks to have the traditional straight down cable guide. I’ll also need to shorten the chain. Hopefully this modification can be done this weekend. I’m looking forward to seeing how BikeOn works!

I'm glad that I finally have a co-conspirator here, but the fitment issues are of course a bummer.
A 37T sprocket is only 2mm larger in radius than a 36T, but at least my BikeOn sprocket clamp does not leave 2mm clearance, so you do need a 36T sprocket.
You don't need to buy the whole cassette, if yours is like mine, the three largest sprockets sit on a carrier together, and you could replace just that. You'd end up with an odd probably overlapping sprocket sequence for pedal-only use, but you might keep larger useable sprockets for BikeOn use. Good luck!

I just came back from a 30 mile ride; I tried 100% assist for the first time. It's ridiculously fast, 25 mph into the headwind with not much effort (by my standards). I did most of the ride at the 45% assist setting, and used 450 Wh, so 15 Wh per mile. That about scales with the 8 Wh per mile at the 25% setting.

 

[Deacon Blues]

I vaguely remember someone saying (Grusome?) that the bike couldn't be ridden with the motor in the off position.
Is that true?

 

[spaceman]

My 10 speed SHIMANO XT derailleur has a curved cable guide which angles toward the cassette (probably for more efficient cable pull). This means the BikeOn sprocket can’t lock together because the angled cable guide arm hits the big red BikeOn sprocket preventing the sprocket’s closure.

Could you please send me a picture of your bike?

We’ll extend your trial period by an additional week to give you time to address the fitting issues. Feel free to reach out if you have any questions or concerns.

Aram

 

[spaceman]

I vaguely remember someone saying (Grusome?) that the bike couldn't be ridden with the motor in the off position.
Is that true?

If the battery is turned off, you can still ride the bike, but you'll notice some resistance from the motor. However, if the battery is on, the app has a 'no assist' setting (assist level: none) that eliminates the resistance, and the battery consumption is minimal in this mode. This is probably similar or close to the 'walk' mode found on some e-bikes.