# Range and power testing of different motors - EP8, E8000, Brose, Bosch



## Francis Cebedo (Aug 1, 1996)

What is the range of an emtb? How much power does the motor deliver? These are two questions that almost impossible to answer and very difficult to get data on. Specialized tells us 5 hours, Bullsbikes says 108 miles. Bosch says 'use our calculator.'

I have a lot of motor systems and I'm interested in testing and gathering data. Surely some useful info can be derived right?

Some things I've learned, Power is measured in Watts. Average watts is 250 max as required by law but the real power is measured in peak watts where the motor is allowed to heat up a little bit (the Levo is about 570 watts). Torque is measured in Newton Meters. Battery capacity is measured in Watt Hours.

So to test range of a battery, the best possible measure for EMTB is altitude gained. That's because hours is meaningless and miles is almost irrelevant. A Levo battery can last 20 miles or 110 miles depending on how much climbing is involved.

There are hundreds of variables too but those can be eliminated. And the best way to test a battery's capacity is with hillclimbs. I know it's not a normal ride but it eliminates variables. The biggest variable is rider weight and rider power. Rider power can be normalized with a heart rate monitor (same rider/effort/time of day/fatigue level). A better way is to use a power meter that can be transferred to each bike perfectly.

*So to minimize variables:*

climb the same 2000 foot hill in the same week, same conditions.
rider effort is moderately hard to get the most boost out of the motor. 125bpm target range out of 180bpm max
pedaling cadence is fast at 80-90 rpm
no braking, no line choice options
same rider 150 lbs, peak power is 200 watts sustained at full effort
same tires, same pressures. MInions DHF/DHR 22/24 psi
same sag setting (30%)
motor set at turbo or boost
battery is whatever it came with, 100% charged. See the %charge left after the 2000 foot hill.
measure the time to climb the hill
rider pedals at an average heart rate of 120-125 bpm, warmed up, not tired
bike weight is around 50 lbs for all full-powered ebikes.
stay off the low battery levels which throw the motors in protect/conservation modes

*Motors in house:*
Specialized Levo with 700wh battery
Specialized Levo SL with 320 wh battery
Trek Rail with Bosch Gen4 and 625 wh battery
Canyon Spectral with E8000 and 500 wh battery
Canyon Spectral with EP8 and 630 wh battery
Orbea Rise with EP8 RS and 360wh battery
Intense E8000 with 500wh battery
Fezzari Wire Peak with E7000 and 5000 wh battery
YT Decoy with 540 wh battery

Results:
Time to climb 2000 feet - will determine motor output
Battery left at the top of climb in 1-100% - will determine range

Interesting? Comments, Suggestions, predictions?


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## RBoardman (Dec 27, 2014)

From my experience, the EP8 motor in boost is very inefficient. A lot worse than most others I would say. But riding it in eco it is as efficient or better than any other bike. 

630wh battery, EP8 motor, stock power settings, 56lbs bike built for DH smashing, 160lbs rider. 

Full Boost and steep terrain: I’ve run out with less than 4k’. Maybe 3800’ is the quickest I’ve seen it drained. 

With Full trail mode and steep terrain: When riding solo I usually run trail mode the whole time and don’t try to conserve. I get around 4500’ - 4800’. 

Mix of trail and eco: I use these setting when trying to conserve battery. Can get 5500-6k’ pretty consistently. 

All eco: I’ve never actually run a full ride on all eco. But I have done 6700’ and had around 20% battery left and at least 1500’ of that was jamming in trail mode up two steep hills. I honestly think I can get 7500’ if I wanted.


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## Francis Cebedo (Aug 1, 1996)

First round was today with 2 bikes that were the most similar. Both bikes weighed 49 lbs, Minion tires, mullet:
Bike 1: Canyon Spectral:On with Shimano E8000 and 500wh battery
70 nm of torque

Bike 2: Canyon Spectral:On with Shimano EP8 motor and 630wh battery - the latest and greatest motor from Shimano
85 nm of torque

Test Results:
*Bike 1: Shimano E8000*
Altitude climbed: 2001 feet
Time: 24:16 minutes
Average heart rate: 123bpm
Battery left: 55%

Battery left is 55%. So with elevation gain of 2001 ft,
*Estimated range is 4447 feet for E8000 motor with 500wh battery*









*Bike 2: Shimano EP8*
Altitude climbed: 1999 feet
Time: 25:17 minutes
Average heart rate: 124bpm
Battery left: 61%

Battery left is 61% So with elevation gain of 1999 ft,
*Estimated range is 5125 feet for EP8 motor with 630wh*









*So these results are shocking so this test needs to be repeated.
The Shimano E8000 was faster than the EP8 up the climb.
and*
*The Shimano EP8 battery is 26% more capacity but the range is only 16% more. This says the E8000 has more efficient and will have more range with the same battery size.

But... it is kind of confirming what I and others are experiencing with the Shimano EP8 motor vs. the E8000. Of course this is in full turbo mode and other modes may vary. But we find Turbo or Boost is the best indicator since Eco and Trail on different motors are fairly random in assist levels.








*


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## RBoardman (Dec 27, 2014)

Francis Cebedo said:


> First round was today with 2 bikes that were the most similar. Both bikes weighed 49 lbs, Minion tires, mullet:
> Bike 1: Canyon Spectral:On with Shimano E8000 and 500wh battery
> 70 nm of torque
> 
> ...


The battery percentage on the E8000 drops almost instantly when it gets below 20%. And I mean instantly. Whereas the EP8 is a lot more linear. So when you are seeing 55% battery left on E8000, it is more like 40% at most.


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## Francis Cebedo (Aug 1, 1996)

RBoardman said:


> The battery percentage on the E8000 drops almost instantly when it gets below 20%. And I mean instantly. Whereas the EP8 is a lot more linear. So when you are seeing 55% battery left on E8000, it is more like 40% at most.


Very true.
On the Ep8, half a bar pretty much gives zero assistance. On the E8000, it just shuts off usually.
At some point, I'll have to ride these til the batteries go into shutdown mode, which is not too hard in turbo/boost... aka less than an hour on this hill.


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## fos'l (May 27, 2009)

Great test which should give some relative real world information. Lots of changes possible as temperature changes, and too bad you can't measure battery voltage to get better assessment of remaining wh's.


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## Francis Cebedo (Aug 1, 1996)

fos'l said:


> Great test which should give some relative real world information. Lots of changes possible as temperature changes, and too bad you can't measure battery voltage to get better assessment of remaining wh's.


Thank you. I gotta get this all done this week. Same temps, same trail conditions. Funny though I'm draining half the battery in 24 minutes. 

Battery voltage huh? Isn't that indicated by the battery level in 1% increments? I use STUnlocker Blevo and Mission Control to get that info.


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## zorg (Jul 1, 2004)

I guess those motors crank out more than 250W. Assuming losses are not that great, with a 500Wh battery, you should be able to get about 2 hours of runtime at 250W.


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## Francis Cebedo (Aug 1, 1996)

zorg said:


> I guess those motors crank out more than 250W. Assuming losses are not that great, with a 500Wh battery, you should be able to get about 2 hours of runtime at 250W.


Correct. The law states 250watts maximum average power. I looked into that and there is a clause that it's average power for an hour without raising the motor temperature more than a couple degrees.

Soo... if the motor temperature increases, then over 250watts is ok. That's why one motor is more powerful than the other even though they area all capped by the 250 watt law. The Levo motor for example is 570watts peak power.


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## Jack7782 (Jan 1, 2009)

RBoardman said:


> The battery percentage on the E8000 drops almost instantly when it gets below 20%. And I mean instantly. Whereas the EP8 is a lot more linear. So when you are seeing 55% battery left on E8000, it is more like 40% at most.


So true. 20% left on E8000/Shimano battery is when one needs to be back at the trailhead. Is this why Shimano promotes a fast charger that will go from 0-80% in 2.5 hrs?


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## Crit Rat (Mar 13, 2008)

Just want to say that I really appreciate you testing this metric. My biggest complaint of my current and last bike both with Shimano E8000 and 500wh battery is the lack of range. If I eke out a ride at place with quite steep terrain the max I can get in mostly all eco is 4500' vertical. I really want more and why a Levo or Kenevo is starting to be so appealing, they appear to be range and therefore efficiency kings.


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## Francis Cebedo (Aug 1, 1996)

Jack7782 said:


> So true. 20% left on E8000/Shimano battery is when one needs to be back at the trailhead. Is this why Shimano promotes a fast charger that will go from 0-80% in 2.5 hrs?


Battery management on most of these motors is pretty atrocious at 20% and below. They all go in very low power, crawl mode. Some motors like Shimano, just shut off, pretty randomly, especially if you're in Boost Mode. Shimano EP8 gives you almost zero assist. Specialized goes into a mode with almost no assist.

I like to end my rides and finish off the battery but getting on the last 20% is so weak and inconsistent, I tend to stay away.

I asked them why is it so unreliable and why is the power so weak. They say current technology doesn't give them enough information about motor drain and battery health so they just play it safe and go int shutdown/protect mode sooner to protect the battery.


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## Francis Cebedo (Aug 1, 1996)

Crit Rat said:


> Just want to say that I really appreciate you testing this metric. My biggest complaint of my current and last bike both with Shimano E8000 and 500wh battery is the lack of range. If I eke out a ride at place with quite steep terrain the max I can get in mostly all eco is 4500' vertical. I really want more and why a Levo or Kenevo is starting to be so appealing, they appear to be range and therefore efficiency kings.


The #1 selling advantage of the Levo is the 700wh battery and range. The other two are it's dead quiet with smooth power and it looks cool (like a normal bike). They dominate the market because of these elements. They really don't ride that well and don't offer great value but they are fixing that.


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## Sean SVMTB (Jan 13, 2014)

You might consider the life of the battery. This is from Orbea manual: "Avoid discharging the battery repeatedly below 10% of charge. This may affect the lifespan of the cells".


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## Francis Cebedo (Aug 1, 1996)

Sean SVMTB said:


> Might need to also consider the life of the battery. This is from Orbea manual: "Avoid discharging the battery repeatedly below 10% of charge. This may affect the lifespan of the cells".


For sure yes!. All my bikes are newish and the apps like STUNlocker and Blevo will show how many charge cycles each one of my battery has. It's like an iPhone. 2 years later, the battery is tired.


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## RBoardman (Dec 27, 2014)

Francis Cebedo said:


> Battery management on most of these motors is pretty atrocious at 20% and below. They all go in very low power, crawl mode. Some motors like Shimano, just shut off, pretty randomly, especially if you're in Boost Mode. Shimano EP8 gives you almost zero assist. Specialized goes into a mode with almost no assist.
> 
> I like to end my rides and finish off the battery but getting on the last 20% is so weak and inconsistent, I tend to stay away.
> 
> I asked them why is it so unreliable and why is the power so weak. They say current technology doesn't give them enough information about motor drain and battery health so they just play it safe and go int shutdown/protect mode sooner to protect the battery.


Really? My EP8 motor will allow me to run boost mode until it gets to 0% and dies.

Sent from my iPhone using Tapatalk


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## fos'l (May 27, 2009)

Francis Cebedo said:


> Thank you. I gotta get this all done this week. Same temps, same trail conditions. Funny though I'm draining half the battery in 24 minutes.
> 
> Battery voltage huh? Isn't that indicated by the battery level in 1% increments? I use STUnlocker Blevo and Mission Control to get that info.


It should be, but some of those systems have funny response curves and whether the manufacturer applies this in their software may not be accurate whereas, AFAIK, the actual voltage can be pretty exact. Should note that I'm a Chemist (our method of birth control is our personalities) and not an electrical expert. Probably some EE will emerge with correct info.


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## Mojave G (Jan 30, 2015)

Thanks for the interesting test FC! My Meta Power should be here in a few weeks so I'm nerding out on all this info lately. 

Maybe try throwing an extra 60-80 lbs in your backpack to mimic us heavier riders (vs 150 lbs) as a test for battery life too, that would be cool to see the difference!


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## Francis Cebedo (Aug 1, 1996)

Mojave G said:


> Thanks for the interesting test FC! My Meta Power should be here in a few weeks so I'm nerding out on all this info lately.
> 
> Maybe try throwing an extra 60-80 lbs in your backpack to mimic us heavier riders (vs 150 lbs) as a test for battery life too, that would be cool to see the difference!


That is not a bad idea!!!! Certainly, once I have a control baseline, I can do many variations. Do it on Eco mode, Carry weight on a backpack, increase my effort, light/heavy tires.


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## Francis Cebedo (Aug 1, 1996)

fos'l said:


> It should be, but some of those systems have funny response curves and whether the manufacturer applies this in their software may not be accurate whereas, AFAIK, the actual voltage can be pretty exact. Should note that I'm a Chemist (our method of birth control is our personalities) and not an electrical expert. Probably some EE will emerge with correct info.


True, I'll have to do a couple drain battery runs and compare to see if consistent.


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## Francis Cebedo (Aug 1, 1996)

RBoardman said:


> Really? My EP8 motor will allow me to run boost mode until it gets to 0% and dies.
> 
> Sent from my iPhone using Tapatalk


In your observation, how many feet of climbing do you get on the first bar (20%) of battery? And the last bar?


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## RBoardman (Dec 27, 2014)

In full trail mode I’d say first bar is 1500’ and last bar is 500’ elevation gain.


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## Francis Cebedo (Aug 1, 1996)

RBoardman said:


> In full trail mode I'd say first bar is 1500' and last bar is 500' elevation gain.


Dude, that's my observation exactly. Battery bar bait 'n switch. It upsets me sometimes.

I was just talking to Specialized and they said this is the nature of Lithium batteries and voltage dropping. Their fuel guages have a hard time being consistent. Specialized seems to have just released new motor firmware that corrects this, more power and runtime at the end of the battery charge cycle.

fc


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## seamarsh (Mar 5, 2012)

Francis Cebedo said:


> That is not a bad idea!!!! Certainly, once I have a control baseline, I can do many variations. Do it on Eco mode, Carry weight on a backpack, increase my effort, light/heavy tires.


80lbs!!! I gotta see this!


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## seamarsh (Mar 5, 2012)

Fwiw I haven’t noticed any difference with heavier tires.. went from 2.4 maxxis exo dhr2 to 2.6 eddy currents and added coil bomber cr and smashpot on a large yt decoy... I didn’t perceive any change.


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## Mojave G (Jan 30, 2015)

seamarsh said:


> 80lbs!!! I gotta see this!


😄 😄 definitely have to make a video on this one FC , real life scenario tho since alot of folks think emtb riders are all fat and lazy! _sucks in beer belly_


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## Francis Cebedo (Aug 1, 1996)

seamarsh said:


> 80lbs!!! I gotta see this!


The climb is not a biggie but the descent on 25% loose rocks might be.


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## Francis Cebedo (Aug 1, 1996)

seamarsh said:


> Fwiw I haven't noticed any difference with heavier tires.. went from 2.4 maxxis exo dhr2 to 2.6 eddy currents and added coil bomber cr and smashpot on a large yt decoy... I didn't perceive any change.


Same. But we're not paying too much attention, right?

I think it will be like analog bikes. Big knobs on soft, low rebound tires, affects efficiency. Coil front and rear shocks affects efficiency too.

But that's one of the great things about ebikes. You get all the benefits of these things and barely feel the downside!

fc


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## Varaxis (Mar 16, 2010)

The ep8 torque graph shows that it assists with higher torque than the e8000.










It's really hard for me to hypermile with an e8000. When I put out more pedaling watts, it spins out the gear, and I end up at a speed that causes more aero drag. I once tried to just turn off assist and turn it back on, but that got old pretty fast as the difference between off and eco is pretty big.

I wish I had more detailed info regarding Wh usage, to better plan my usage to be more efficient.

I think I'm a candidate for low-power motor. Forestal Siryon with 350Wh battery booster (700 Wh total) would be my dream bike, but I don't want to pay for carbon and I worry about ordering/ownership experience hassles, dealing with such a remote company. I wouldn't mind if I could change the limiter to step down the assist at lower speed for eco-mode.

BTW, the Eddy Current tires roll pretty fast despite their weight. I had a 27.5x2.8 Eddy current at 1500g, that rolls waaaay faster than a bald Assegai.


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## zorg (Jul 1, 2004)

Francis Cebedo said:


> Dude, that's my observation exactly. Battery bar bait 'n switch. It upsets me sometimes.
> 
> I was just talking to Specialized and they said this is the nature of Lithium batteries and voltage dropping. Their fuel guages have a hard time being consistent. Specialized seems to have just released new motor firmware that corrects this, more power and runtime at the end of the battery charge cycle.
> 
> fc


That makes sense. If the gauges are linear, then it'll be misleading. Li-ion tend to have a pretty flat voltage curve during discharge with an abrupt drop at the end.


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## Varaxis (Mar 16, 2010)

Voltage drops when you're pulling heavy current. If you run max assist until you read 1 bar less, then change to the lowest assist setting, then you might "regen" a bar back.


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## Jack7782 (Jan 1, 2009)

Varaxis said:


> Voltage drops when you're pulling heavy current. If you run max assist until you read 1 bar less, then change to the lowest assist setting, then you might "regen" a bar back.


On a E8000 ride last week, it appeared that I went from 3 bars, back to 4 bars, but minute later it was back to 3 bars. I wonder if it was a "regen" bar?


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## Francis Cebedo (Aug 1, 1996)

Jack7782 said:


> On a E8000 ride last week, it appeared that I went from 3 bars, back to 4 bars, but minute later it was back to 3 bars. I wonder if it was a "regen" bar?


Exactly. The Shimano battery meter is so poor that it will waffle between battery level bars sometimes depending on motor load.

Where this sucks is when you're on Boost mode with one bar left with a mile or two to get back to the car or home. All of a sudden.... the battery will say dead and the motor will shut down. 10 minutes later, in the garage, it will go back to one bar and motor is alive again. The software/firmware really needs to account for this behavior. Specialized is a bit better and it looks like the latest Specialized firmware addresses this very issue.


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## Francis Cebedo (Aug 1, 1996)

zorg said:


> That makes sense. If the gauges are linear, then it'll be misleading. Li-ion tend to have a pretty flat voltage curve during discharge with an abrupt drop at the end.


Lithium Ion is not flat. From the onset, it just drops in a linear fashion from 4.2v each cell to 3.2v. NIMH has that pretty steep drop.


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## Salespunk (Sep 15, 2005)

This is a great test. The only thing I would add is outside temp as a variable. I below 55* there is a noticeable deterioration of battery life on my Kenevo.

Not surprised by the low battery life on the Shimano setups. The 630 wHr capacity battery on the Shimano gives about 50% of the distance of my 700 wHr Specialized setup in our riding group. The 500 wHr distance/elevation on Shimano is horrendous. It is actually pretty shocking how different the efficiencies are in real life.


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## Varaxis (Mar 16, 2010)

Francis Cebedo said:


> Exactly. The Shimano battery meter is so poor that it will waffle between battery level bars sometimes depending on motor load.
> 
> Where this sucks is when you're on Boost mode with one bar left with a mile or two to get back to the car or home. All of a sudden.... the battery will say dead and the motor will shut down. 10 minutes later, in the garage, it will go back to one bar and motor is alive again. The software/firmware really needs to account for this behavior. Specialized is a bit better and it looks like the latest Specialized firmware addresses this very issue.


Can't trust the "estimated range remaining" if you aren't using your battery in a very steady manner. A single steep hill can wreck that estimate.

It also happens due to the cold. For example, if you stop by a store for grub on the way back home with the battery low but warm from use, you might come back to your ebike to find that its battery reads empty, after being exposed to the winter air for 15 mins.

I'm envious of the information that DIYers get with their eggrider displays.


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## Varaxis (Mar 16, 2010)

My latest fascination is trying tire drag's (rolling resistance) effect on efficiency.

I got fed up pinch flatting EXO/EXO+ Maxxis Minion DHRII 2.3 (MaxxTerra, rear tire), not trusting to ride 20 miles away from civ on them, so I overcompensated by putting on a MaxxGrip Assegai (29x2.5 DH 1350g). My range was cut by ~20% from that single change. I suspect the Assegai DH is 50% draggier than the DHR II EXO. Feels like losing at least 20W.

I had to readjust what gears and/or what mode I used to climb familiar hills with that rear tire change. My average pace on asphalt dropped. The continuous drag was a huge efficiency killer. It's like a reverse ebike, taking away watts. My max range is about 40 miles and 4000 ft combined in cold temps with Assegai DH, vs 55 miles and 5500 ft in warm temps with EXO tire. I even wore the Assegai bald, down to the harder 70 durometer rubber, and it still drags. Got my money's worth out of the tire and didn't get stranded at least. I do believe I got fitter, on top of gaining experience; expanding my comfort zone in a non-linear way was much needed, but it burned me out.

Eddy Current Rear 27.5x2.8 was much closer to the DHRII in drag. Didn't have to do any of this adjustment when I switched from DHR II to Eddy Current. It gave me joy seeing the moto-like tire tracks it laid down, pleased that I didn't have to suffer drag. It weighed over 1500g, but that didn't matter. I still had a similar range. Its only con is that I overestimated it when testing its limits; I was smashing it into things carelessly and the rim was what gave out first.

I generally ride in eco, making every ride an epic, and am fine with cruising at 8-15 mph, so I figure this tire drag adds up. It's like a constant drag, like the resistance found on an old exercise bike.


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## Stroganof (Jan 28, 2006)

Very interesting test, really looking forward to future installments. Thanks for the major effort!

IME, the Levo motor is noticably sronger than the Bosch Gen4 on my Orbea Wild. It has more grunt, and if the gauge is to believed, it is more efficient as well. The Levo is also "on" all the way with relatively low pedal effort, which is nice at least in turbo mode. That sense is just from riding both a bit - no objective testing.


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## Jack7782 (Jan 1, 2009)

Varaxis said:


> Eddy Current Rear 27.5x2.8 was much closer to the DHRII in drag. Didn't have to do any of this adjustment when I switched from DHR II to Eddy Current. It gave me joy seeing the moto-like tire tracks it laid down, pleased that I didn't have to suffer drag. It weighed over 1500g, but that didn't matter. I still had a similar range. Its only con is that I overestimated it when testing its limits; I was smashing it into things carelessly and the rim was what gave out first.


E-Bike specific product endorsement Thanks for your review, but how on earth can that heavier tire with bigger knobs give you similar or more range?


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## Varaxis (Mar 16, 2010)

I'm just stating that this happened to be anecdotal evidence. I might have had a soured outlook on how poorly some lighter-duty tires have held up.









- lack of rubber material under the knob, allowing it to tear off easier. visibly thin. That's casing showing underneath.









^ can see a swollen bulge under the yellow thingee at top of pic; typical of broken fibers in the casing/carcass

BTW, it's backwards to think of a conclusion and ask for evidence to support it.

I've ridden the ebike tires on non-ebike too. It's totally fine on a bike that weighs 40 lbs.









- that was the gear I was in before I stopped to take a pic. 30x13. It's my way to compare the dragginess of tires, compared to others.


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## zorg (Jul 1, 2004)

Francis Cebedo said:


> Lithium Ion is not flat. From the onset, it just drops in a linear fashion from 4.2v each cell to 3.2v. NIMH has that pretty steep drop.


You had me google. Turns out that the curve is more linear at higher discharge rate.


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## RBoardman (Dec 27, 2014)

Jack7782 said:


> E-Bike specific product endorsement Thanks for your review, but how on earth can that heavier tire with bigger knobs give you similar or more range?


Well when he ran the maxxgrip assguy, that's probably the slowest rolling non-mud spike tire money can buy.


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## RBoardman (Dec 27, 2014)

Francis Cebedo said:


> Dude, that's my observation exactly. Battery bar bait 'n switch. It upsets me sometimes.
> 
> I was just talking to Specialized and they said this is the nature of Lithium batteries and voltage dropping. Their fuel guages have a hard time being consistent. Specialized seems to have just released new motor firmware that corrects this, more power and runtime at the end of the battery charge cycle.
> 
> fc


And I wouldn't have much of a problem with this if Shimano put a battery percentage on their displays. Cannot be that hard, so I assume they don't do it on purpose.

I literally bought a garmin watch so I can see my live battery percentage as I ride. Get range anxiety when I don't know if my bike is at 40% or 59%, which is all within the same bar.


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## Mudguard (Apr 14, 2009)

Would it be easier to test something like this using a trainer? Actual trail riding seems to have too many variables. Take the tyres, rider and bike weights out of it. Rig up something to spin the cranks at a set speed and use the resistance of a trainer to simulate the hill climb. Time how long it take to flatten the battery and note kms as well?


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## artnshel (Jul 10, 2004)

I rode my EP8 and my friends E8000 back to back. We both thought his older motor was stronger. I'd love to see more testing.


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## Varaxis (Mar 16, 2010)

RBoardman said:


> And I wouldn't have much of a problem with this if Shimano put a battery percentage on their displays. Cannot be that hard, so I assume they don't do it on purpose.
> 
> I literally bought a garmin watch so I can see my live battery percentage as I ride. Get range anxiety when I don't know if my bike is at 40% or 59%, which is all within the same bar.


It was on purpose to get the display compact. You'd rather have a smartphone-sized one? They prob only have enough memory to handle firmware updates. They followed K.I.S.S...

Others probably have to deal with stuff like security to avoid their computers from getting hacked or whatever.

Full system monitoring software that smoothly interprets the readings from the hardware isn't very simple. Garmin specializes in GPS signals and it took ages to improve accuracy with low power consumption, and I bet even that took lots of back-end software work. Garmin doesn't have to deal with differing power drains... the voltage reading from a battery under light load and under high load reads differently. How would you solve this problem? Monitor battery health and measure capacity from charging and draining? This is a parasitic drain that hurts range and battery health.

Shimano just has a dumb estimated range function, that goes off of your recent average speed, assist level, and battery voltage.


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## lotusdriver (Sep 15, 2013)

There's a lot of stress and "range anxiety" on this thread.
l've got a Shimano E8000 in my Kona FS and have had none of the issues people are stressing about on here.
l rarely use "turbo"
l've got trail and eco both set to "medium" in the assist settings. Turbo is set at medium as well, so l get a maximum of 200% assistance in that mode. lt seems more than enough and l rarely feel the need to use it.
l can get 30 miles of fairly extreme off road, technical climbing and on road with power to spare.
l've never had the battery level
meter drop a bar then go back up again, although the estimated range on the display varies depending on use.

Last ride l did the last few miles with one bar showing. l would never use "turbo" at that stage, why would you, it's obviously going to run out of power.
l put the bike in eco and get the leg work in, l can still make much better progress than on my regular bike.


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