Bosch Range Tests - Comparisons

[Plummet]

I think there's a lot of misleading comments about motor "efficiency" going around.

Motor efficiency is correctly defined as Power-out/Power-in. Sadly the industry hasn't yet got its act together and decided on a standard way to quote power-out, so this adds to the confusion. Is this power delivered at the crankshaft or the rear wheel? (Some may even be quoting electrical power from the battery, but of course this is really power in.)

I doubt whether there's really much difference in the electrical losses in all these motors, but there could be more variation in the mechanical losses across the different gear reduction designs.

What the quoted Pinkbike test did (and also the Loam Wolf) was to compare height gain (and/or distance) in metres for a given usage of battery in Wh. This may well be a more useful statistic for us riders, but it is not power-out/power-in.

You may think I am being pedantic here, but there's another relevant statement in the Pinkbike review which Suns_PSD did not mention. It is ....

"Here’s another plot twist though: the other four bikes took about 45 minutes to complete the test loop. The Avinox knocked ten minutes off that time. That might explain why the Avinox had the lowest efficiency in this test."

You may choose to consider that two motors have the same "efficiency" if they achieve the same height gain for the same Wh consumed. But clearly that cannot still be said if one motor achieves the same height gain at a significantly faster speed. Interestingly the Avinox took 10 minutes less than the 45 minutes of the other bikes, and 10/45 = 22% which (coincidently??) is exactly how much more battery Wh it consumed!

A more genuinely useful test for us riders would be to perform the comparison rides while regulating the bike's speed so as to achieve the same height gain in the same elapsed time and then compare battery consumption in Wh.

I have a Trek Rail with the Bosch gen 4 motor so I don't have any skin in the game and I am not trying to claim the Avinox is a "better" - or even more efficient - motor. But I just think that the media reviewers are unintentionally misleading us with these invalid statements about motor "efficiency" and "performance".

Yeah, I agree. To measure actual efficiency a test needs to occur where they measure output from the battery and output at the crank arm. The losses measured define the motor efficiency.

What Suns is talking about is not actual motor efficiency. Its more related to the power output algorithm each motor brand uses.

I am reasonably convinced, until I see testing to the contrary, that most motors will have similar actual efficiency ie battery power in/crank power out.

The variance in vert meters climbed of distance ridden that Suns talks about is algorithm based. Take a 100kg human that climbs 1000mtr vert in 1 hour that takes 236 watts of power. If one system uses less 20% less watts to get to the top than means the human is putting that 20% more in. Its that simple.

Also if the the rider gets to the top of the hill faster. That is in increase in power requirement of the motor not a decrease in motor efficiency given that the max output of the human remains constant .

All these "efficiency" tested are actually algorithm tests measuring how much more or less the human or the motor applied the power over a given about of work done.

 

[Suns_PSD]

Except when the motor that used less battery ALSO climbed faster as has happened in a couple of instances.

 

[rzr]

Interestingly both riders said they would choose the 600w battery if they had their choice for their own bike. That surprised me a bit.

Why did it surprise You ?

 

[Plummet]

Except when the motor that used less battery ALSO climbed faster as has happened in a couple of instances.

I would argue that that is algorithm based with more work done by the human than the motor.

Its literally physics.... get to the top of the hill takes X number of watts to do it in X time. Either the motor applies that wattage or the human does.

 

[rzr]

Would love someone to do an actual review back to back (Gen 5 vs Avinox) pick the closest two modes (possibly Auto on Avinox vs EMTB on Bosch) whatever velo say is closest to output. Control tyres and same rider. Settle this once and for all.

Watts used and time taken etc, would be interersting to see.

What's the point? what do you want to learn from it ?
Most motors have very similar efficiency, you can easily extrapolate distance/elevation from the battery capacity. (and if you know how much assistance you get from a motor)

 

[Suns_PSD]

Why did it surprise You ?

They were both bigger guys, one said he could 'feel' the RE, but the 800w battery, not so much. And honestly the weight and cost going from the 600 to the 800 isn't that much.

But it comes down to the same position that I'm in, 600w is enough for 99% of what I do, so why carry around the extra weight 100% of the time? However, I'm considerably lighter than those guys and probably don't have the climbs either.

 

[rzr]

I can feel differences between batteries (if it's around 1kg). With my mates, we would prefer 2x600Wh batteries, instead of one massive (800-900).
At least now I ride with 700Wh and 500Wh (and only sometimes, when I really ride fast on a twisty trail, I can feel the difference, but Levo batteries have the same size, if the battery is shorter and that ~1kg difference is next to a headtube - it's really noticable)

 

[Ndanger]

Yeah, I agree. To measure actual efficiency a test needs to occur where they measure output from the battery and output at the crank arm. The losses measured define the motor efficiency.

What Suns is talking about is not actual motor efficiency. Its more related to the power output algorithm each motor brand uses.

I am reasonably convinced, until I see testing to the contrary, that most motors will have similar actual efficiency ie battery power in/crank power out.

The variance in vert meters climbed of distance ridden that Suns talks about is algorithm based. Take a 100kg human that climbs 1000mtr vert in 1 hour that takes 236 watts of power. If one system uses less 20% less watts to get to the top than means the human is putting that 20% more in. Its that simple.

Also if the the rider gets to the top of the hill faster. That is in increase in power requirement of the motor not a decrease in motor efficiency given that the max output of the human remains constant .

All these "efficiency" tested are actually algorithm tests measuring how much more or less the human or the motor applied the power over a given about of work done.

If I understand correctly the rider input was a control "they used power pedals" with that being said I do not understand the following rebuttal, as my understanding that rider is not putting in 20% more if the pedal force was part of the calculation. I would be inclined to believe the results are factoring in rider input.

"If one system uses less 20% less watts to get to the top than means the human is putting that 20% more in. Its that simple.

 

[rzr]

if you put 200W motor to that 'efficiency' test, it'll win, because motor takes only 200W all the time, and let's say human was putting another 200W. so motor was giving the same power as human.
but if you take 600W motor, then that ratio is 3:1 (600W motor, and only 1/3 - 200W rider).
At the end 200W motor will use less energy, because rider put another half of the energy to get to the top (1:1 ratio) - thus will be 'most efficient'

 

[Suns_PSD]

In the review above they used power pedals and the Bosch climbed faster AND further than 2 Avinox bikes. I think they found the specific circumstances that derated the Avinox, steady climbing in turbo on a hot day.

But I think this one has played itself out.

 

[Bogdan_CH]

I can feel differences between batteries (if it's around 1kg). With my mates, we would prefer 2x600Wh batteries, instead of one massive (800-900).
At least now I ride with 700Wh and 500Wh (and only sometimes, when I really ride fast on a twisty trail, I can feel the difference, but Levo batteries have the same size, if the battery is shorter and that ~1kg difference is next to a headtube - it's really noticable)

You can clearly feel the differences but not that bad as the weight is still roughly in the same position, not towards the top tube.

On the other hand that RE would feel way more as the position on 99% of the bikes (except Whyte) is way above the central balance point of the bike.

 

[Ndanger]

Yes good point and something I have noticed, the center of gravity / mass is a huge factor and I would hope a priority in design.

 

[G-Sport]

As long as batteries are such a major part of the weight of the bike efficiency is going to be super important to me.
Ideally someone will combine power meter pedals with a power meter rear hub, then run all the motors in all the modes until flat.

By looking at the actual power at the hub (subtracting the power at the pedals) we should be able to get a good idea of efficiency in each mode. Motors have a sweet spot for efficiency so if a motor is designed to give it's optimum at nearly full power (and high rpm) then it might well be down 20% or more in trail mode (at lower rpm).

 

[Suns_PSD]

E-mtb magazine did something similar to what you are describing. Power pedals, steady cadence, a hill (no rider skill required), and of course how much time it took to reach the top to calculate efficiency.

 

[G-Sport]

E-mtb magazine did something similar to what you are describing. Power pedals, steady cadence, a hill (no rider skill required), and of course how much time it took to reach the top to calculate efficiency.

Unless you have a clear measure of power output the results are going to be hard to quantify and compare

 

[Plummet]

E-mtb magazine did something similar to what you are describing. Power pedals, steady cadence, a hill (no rider skill required), and of course how much time it took to reach the top to calculate efficiency.

My experience of the drag race up an easy road is that the lightest guy wins the battery drain competition regardless of motor type.

When it becomes interesting is the tech climbing at the edge of whats possible. Then superior application of power with less wheel spin wins the efficiency game.

I noticed a step change of improvement between gen 4 and 5 Bosch, and its even bigger now with 100nm on tap. I can clean more technical sections than my buddies on gen 4 Bosch, Shimano and specialized can. I then carry on riding. I can back off a mode or two in the easier sections while buddies are burning turbo to catch up. I get to the top faster with less battery burn.

Now its not that im a better rider to be able to clean sections. When I had gen 4 we we level pegging it. I got gen 5 and immediately it was see ya later on the bleeding edge tech climbs..

More power definitely helps but it can also make it worse. Dependent on the situation. That same is true for run on.

I am more interested in tech climbing prowess than the ultimate easy road drag race.

I have two dji's hitting the local seen shortly. Im real keen to see how they go tech climbing.

 

[volts]

Hopefully these batteries will retrofit in place of existing batteries.

I mean...yeah that would be awesome, but having watched this industry for a while, they are ALL about making you buy completely new shit as often as possible.

Unless regulated this industry will actively be making things obsolete with no other purpose than that. Unrepairable motors without part availabilty and all that. It really sucks and i will be the first to jump ship as soon as a sustainable alternative shows up. Sadly i don't like any of the befang frames.

 

[rzr]

E-mtb magazine did something similar to what you are describing. Power pedals, steady cadence, a hill (no rider skill required), and of course how much time it took to reach the top to calculate efficiency.

i doubt it's efficiency 'test'

 

[ripp3r884]

I think the askol and the maxxon motor right now are the best bet for the future, in terms of efficiency and raw quality maxxon wins but askol is a genius idea, and if they pull it off certainly will change emtb forever.

I was all set to receive the forbidden druid core 2 and ended up cancelling because i got caught up in the hype and was spending money on something that probably wouldn't have been the right choice for me. I test rode the unno mith and it felt like a tryke, same for the kado rsx and it was pretty shocking, I was sat on a medium and it felt like a little tykes and im not even that tall.

bosch gen 5 is the best motor right now I feel, avinox whilst great it's just cadence based, with 48 sensors on the bike and nothing to reward torque input whatsoever.

solid state battery is a neat idea but the bike will prob cost 3-4 grand more then normal just because of that battery.

 

[Bomble]

I think the askol and the maxxon motor right now are the best bet for the future, in terms of efficiency and raw quality maxxon wins but askol is a genius idea, and if they pull it off certainly will change emtb forever.

I was all set to receive the forbidden druid core 2 and ended up cancelling because i got caught up in the hype and was spending money on something that probably wouldn't have been the right choice for me. I test rode the unno mith and it felt like a tryke, same for the kado rsx and it was pretty shocking, I was sat on a medium and it felt like a little tykes and im not even that tall.

bosch gen 5 is the best motor right now I feel, avinox whilst great it's just cadence based, with 48 sensors on the bike and nothing to reward torque input whatsoever.

solid state battery is a neat idea but the bike will prob cost 3-4 grand more then normal just because of that battery.

What’s a “tryke” and a “little tyke?”
Any other thoughts on the Unno Mith after your test ride?

 

[irie]

I think the askol and the maxxon motor right now are the best bet for the future, in terms of efficiency and raw quality maxxon wins but askol is a genius idea, and if they pull it off certainly will change emtb forever.

Thanks to Askoll proprietary cutting edge technology, the Askoll ULTRA C90A will deliver a maximum engine torque power of 90 Nm, or 95 Nm with the BOOST Mode, while working 20% more efficiently than anyone.

All, in 2,9 Kg. All designed and made in Italy.

"While working 20% more efficiently than anyone"?

What do Askoll know that nobody else knows? Hmmm ...

 

[ripp3r884]

What’s a “tryke” and a “little tyke?”
Any other thoughts on the Unno Mith after your test ride?

uncomfortable to pedal like a kiddies tricycle, the kado felt scrunched up all in the centre and it felt like my knees were coming up to my ears when riding regardless of how high the dropper post was, the mith has extremely intuitive turning capability similar to the rsx but just does it better, size is way more thought out too. not test rode an amflow or any other dji to compare.

"While working 20% more efficiently than anyone"?

What do Askoll know that nobody else knows? Hmmm ...

more that they will create multiple firmwares that allow for candence based power delivery or torque based that you can swap over, the motor itself will be availiable to bolt on to any supported shimano powered ebike, with potentially other options for other bike frames in the future. as for efficiency i'd wager it's more about delivering a bit more power then the competition so you get where your going and back again before the battery runs out so u won't care.

 

[Ndanger]

Great to see some new powertrain options becoming available, Interesting motor that I have only recently heard of. Here are specs off of their website:

Our mission to be leader in the development of avant-garde electric motors takes on a new form in Askoll ULTRA C90A, the first made in Italy power unit designed exclusively for e-mtb use and the only one featuring the innovative “Boost Mode”.

• brushless motor developed for high-end e-mtb
• 2,9 kg in weight, built in aluminum and high resistance treated steel
• 162 mm: Q factor
• 750 W: maximum power at drive wheel (250 W: rated continous power)
• 90 Nm: maximum torque optimised between 60 and 80 strokes/min
• BOOST mode, a special mapping can bring the torque to a maximum level of 110 Nm for short periods of time
• 5 assistant modes:
  ECO: 80%, 30 Nm
  TOUR: 160%, 55 Nm
  SPORT: 300%, 75 Nm
  TURBO: 400%, 90 Nm
  BOOST: 460%, 110 Nm

 

[Rob Rides EMTB]

avinox whilst great it's just cadence based

The Avinox is absolutely torque based.

The reason some people think its not torque based is that in the higher modes, it takes very little rider torque to achieve full motor output. Reducing the motor assistance level in the app will require higher rider torque to get the full power.

 

[Rob Rides EMTB]

I asked my contacts at Avinox a bit more about the torque sensing on the motor. Here's the reply:

The Avinox algorithm utilizes multi-sensor fusion, incorporating multiple key sensors (including torque and cadence, more accurate wheel speed, and an Inertial Measurement Unit). Compared to torque sensing alone, this provides more precise control and better insight into cornering situations.

The combination of cadence and torque sensors monitors the rider's pedaling intent, including starting, accelerating, decelerating, and stopping. The Avinox algorithm responds promptly based on these sensors. For example, when encountering a tree root obstacle while climbing a hill and turning, the rider may reduce pedaling, hoping to slow down and adjust the bike's steering and trajectory.

The Avinox system responds promptly, slowing down while maintaining forward momentum until the rider adjusts and accelerates again, at which point the power assist increases rapidly. Multiple sensors are integrated, including higher-precision wheel speed sensors, IMU sensors that monitor riding posture in real time, fast-response motor speed sensors, etc., to monitor the dynamic situation of the bicycle in real time, including whether the bicycle is tipping over or the rear wheel is slipping, so as to adjust the power to the rear wheel and maintain optimal traction.

 

[shakazulu12]

The Avinox is absolutely torque based.

The reason some people think its not torque based is that in the higher modes, it takes very little rider torque to achieve full motor output. Reducing the motor assistance level in the app will require higher rider torque to get the full power.

Just looking at the adjustments in the app, I can't figure out why nobody is simply not realizing that you can adjust it down all you want. They send them out pegged to the max, because that's what most people want to feel. Got a ride one one recently and the owner had dialed his way back and it felt similar to the Bosch on my Canyon and had similar power draw at the end of the ride, as I would expect. Cranked up, yup, it's going to burn more juice, because it's providing a hellevua lot more assistance. Can't understand why this isn't obvious and everyone seems to be blowing this out of proportion. That youtube guy who hated it clearly spent absolutely zero time learning how to adjust it, though I absolutely understand what he's trying to say based on the settings he rode it in. It's a non-issue in real life. Just read the manual like we did back in the day.

 

[Ndanger]

Just looking at the adjustments in the app, I can't figure out why nobody is simply not realizing that you can adjust it down all you want. They send them out pegged to the max, because that's what most people want to feel. Got a ride one one recently and the owner had dialed his way back and it felt similar to the Bosch on my Canyon and had similar power draw at the end of the ride, as I would expect. Cranked up, yup, it's going to burn more juice, because it's providing a hellevua lot more assistance. Can't understand why this isn't obvious and everyone seems to be blowing this out of proportion. That youtube guy who hated it clearly spent absolutely zero time learning how to adjust it, though I absolutely understand what he's trying to say based on the settings he rode it in. It's a non-issue in real life. Just read the manual like we did back in the day.

Is that the same "youtube guy" that 2 days ago published a video of the "top 5 ebike motors" but was unable to find a reason to put the Avinox motor on the list?

 

[shakazulu12]

Is that the same "youtube guy" that 2 days ago published a video of the "top 5 ebike motors" but was unable to find a reason to put the Avinox motor on the list?

Looks like him. That review I watched was either absolute incompetence on his part as far as not simply using the app to make adjustments. Or blatant mis-representation to get clicks. It was so far out there from what I figured out within five minutes of getting on the bike that I asked Youtube not to show me anymore of his content. I mean seriously, it was flat out ridiculous. At one point he said he barely had to pedal to the top of the hill, while he was audibly catching his breath. I rode it with everything turned up, and then dialing it back and it's manners can be adjusted from perfectly natural to feeling like a fop fuel drag car in about fifteen seconds. Same as any of the other systems to various degrees, except the ceiling is a whole lot higher. You really can loop it out on pavement from a standing start if you max it out. If you are concerned about range, dial the assistance back and play with the modes. It will feel close enough to the others that it's not worth even really discussing.

Note, just IMHO. And I have an ebike because I only care about going down, but also am an idiot that enjoys going max effort on the pedals while above cutout on said downs. The climb is just active recovery and I use whatever boost level keeps my heart rate where I need it to be. Some times that's almost none and other times it's a ton. So I also have my own bias based on my needs. But the ability to easily adjust the DJI isn't an opinion, it's a fact. And it takes no time at all in the app to verify this. That said, there were some confusing things in there, but if you have been on ebikes before, it's not that hard to figure out and I much preferred it to making adjustments in the Bosch app after the first minute or two.

 

[Fangs2k]

Is that the same "youtube guy" that 2 days ago published a video of the "top 5 ebike motors" but was unable to find a reason to put the Avinox motor on the list?

I don’t watch many eBike YouTubers (Rob being an exception, obvs!) but he’s just expressing his opinion, same as everybody else?

I often read on here that “we’re all just expressing an opinion”, which is true to a point until somebody expresses one that isn’t yours as well.

I don’t know when things became so tribal, and it’s not just this forum, but it’s rubbish. You don’t have to be team this or that, presumably people should be here because they’re interested in e-mountainbikes, not to repeat ad-nauseam why their particular bike or motor (or riding!) is the best and how everybody else’s is crap.

It’s easy to just ignore a YouTube channel, but less so when you’re in an online community and lots of people are in constant transmit mode.

I don’t think there’s anybody on here who is expert in ALL motors and bikes, but there are a few who think they are. Just ‘be better’ and ‘be nicer’ everybody.

 

[xtraman122]

Just looking at the adjustments in the app, I can't figure out why nobody is simply not realizing that you can adjust it down all you want. They send them out pegged to the max, because that's what most people want to feel. Got a ride one one recently and the owner had dialed his way back and it felt similar to the Bosch on my Canyon and had similar power draw at the end of the ride, as I would expect. Cranked up, yup, it's going to burn more juice, because it's providing a hellevua lot more assistance. Can't understand why this isn't obvious and everyone seems to be blowing this out of proportion. That youtube guy who hated it clearly spent absolutely zero time learning how to adjust it, though I absolutely understand what he's trying to say based on the settings he rode it in. It's a non-issue in real life. Just read the manual like we did back in the day.

This is the simple explanation that makes all of these “efficiency” talks silly. These companies all use commodity battery cells from the same small group of manufacturers, they have a very similar looking BMS that sends power out those into motors that are, at this point, designed very similarly, and from there power is sent out via a chain on components that are all the same between bikes again.

Any difference in perceived efficiency is a result of variability in the rider’s input on different rides and mostly how much the motor is actually outputting. Unless the motor is hooked up to a dyno with known input power and something monitoring actual output power there is absolutely no point in trying to claim one motor is more efficient as another with these crude tests. The differences in programming resulting in each motor providing varying levels of assist at each rider input level, how they even calculate assist percentages, how quickly they accelerate in every little circumstance, all plays into this stuff in a large way when added up over an entire ride.