holy grail of battery range with a Shimano e8000 steps motor attained. AKA: how to get 10+ miles and 2200+ ft out of one battery bar

[hokkane4]

@Gary probably says 50, but I think he draw little bit wrong conclusion from he's test drive(s). I haven't seen anywhere data supporting that claim.

 

[Gary]

I haven't seen anywhere data supporting that claim.

If you read everything I wrote. You have.

 

[hokkane4]

@Gary, you said earlier in the post, you were riding one climb with other bikers on their normal MTBs. I’d assume you were also riding slower than you’d normally ride with eMTB (or are your friends Olympic level athletes)? And if the climb has any gradient and you were going slowly, you were probably grinding on the smallest gear?

So are you comparing that ride to your “normal ride” with eMTB, where you use higher speed and assistance level?

If you would like to make any conclusion of the efficiency of cadence, you should keep all other variables constant, most importantly the speed. Because more you have speed, more you need to put energy through the drive line. Not only by rider, but also from motor. As you posted, Shimano motor adds level of assistance based on rider input. When rider adds more power (cadence and torque), the assistance level goes higher as well (until it is limited to max. setting for each mode). And even your low cadence was less efficient, you were still using less energy because of low speed kept the motor power mapping so much lower that you still saved power compared to “normal” eMTB ride with higher speed.

So your observation is exactly as expected (laws of physics), but your conclusion that you used less energy because of low cadence is wrong. As you said, “nothing scientific at all” ?. You used less energy just because you were moving slower.

I would be happy if you are correct, then on my next ride I could get maybe 2000hm climb with one charge!

 

[knut7]

Lifting 100kg 2200ft takes the same ammount of energy regardless of speed, if we disregard wind resistance. Unless there was headwind one day and tailwind the next, wind resistance is most likely neglible. So I can't see how difference in speed would explain this. It could be BMS programming.

 

[hokkane4]

Lifting 100kg 2200ft takes the same ammount of energy regardless of speed

Yes, but only if the motor mapping stays the same. But it does not stay same, as more you pedal, more you get assistance.

 

[knut7]

By lowering cadence, you will decrease motor assistance. If you don't increase rider input it might not turn out to be more efficient. But if the goal is to get to the top with as much charge left as possible, dropping the cadence will allow the rider to do a bigger share of the work.

For a Shimano motor at least... For other motors that allow more tuning with the app, dropping the assistance % and keeping cadence higher could be more effective. Possibly. This is difficult when we don't know how the motor is programmed.

 

[R120]

The speed is going to be a result of the cadence and whatever gear you are in, no?

I.e this observation is about range, not speed.

 

[Gary]

And if the climb has any gradient and you were going slowly, you were probably grinding on the smallest gear?

Nope

I don't really use the smallest two gears on my Emtb at all unless it's switched off

Grinding with slow cadence uses higher gearing. not lower.

The rider I climbed with is a really fit 15yrs old, weighs about 6st less than me and is a really good rider.
I hope he never becomes an olympic rider as the IOC is a corrupt organisation I wouldn't wish on anyone.
The way he's going there's a good chance he'll go on to become elite in DH or enduro

The thread is about range. not speed and I've already given an example of how to drain a battery in one hour where anyone with the slightest amount of common sense should be able to work out why it drained so quickly.

I honestly can't be bothered answering any of your other questions as you've missed the point entirely.

 

[hokkane4]

The thread is about range.

Correct, and you said in message #3 that you achieved it: "By riding the entire time (at a cadence of 50rpm "

But there is lot of research based information in Internet about most optimal cadence(angular speed) for electrical motors. So there is no need to discuss about it with "opinions". Every one can ride what ever cadence feels best and be happy

 

[Gary]

But there is lot of research based information in Internet about most optimal cadence(angular speed) for electrical motors. So there is no need to discuss about it with "opinions". Every one can ride what ever cadence feels best and be happy

Seriously. what are you even talking about now? (rhetorical. please don't answer).

Before your next long climb switch your E8000 display to read cadence and watch what happens to the power assist level indicator bar along the bottom of the display when you change from grinding at 50rpm to 100rpm+
I wouldn't really even call 50rpm slow enough to be properly grinding. Proper grinding to me would be a 20% climb on a roadbike in 36x25 stood up and barely being able to turn each crank. 50rpm with a motor helping you barely needs any strength to turn. but I'm perfectly happy riding at any cadence between 50rpm and 100rpm+ for sustained amounts of time. Even more so on a motor assisted bike.

 

[Mike D.]

And I'm not talking about riding with the motor off at all for once.

Ok. Firstly a little background.
I don't have range anxiety and never have. I just like to know how things work and happen to b such a nerd I have pretty much the opposite trait to gullability when it comes to new information if not backed up by solid science and experience. This means I like to figure stuff out for myself rather than blindly follow advice. (I also happen to hate rules but that's a whole other trait)

So... when watching embn on youtube I generally need to take a deep breath and just roll my eyes at some of the utter bollocks they so often put across. Last night I watched an episode and a read out comment from a viewer that actually sounded feasable got me thinking...

"Utter bollocks..." such as?

 

[Gary]

You've necrobumped a thread from 20 months ago so you're asking me to quote specific information from a youtube channel from 2+ years back.
Watch the channel yourself mate.

 

[Mike D.]

"necrobumped" ?

At least I've learned a new internet word. ?