Pedaling resistance with motor off

[anfos]

Hi, I have a Stance e+2 and wanted to ask if it's normal to have a lot of resistance while pedaling with the motor off (it's like going uphill)

Even on a flat road it seems like the clutch? engages and slows down the bike like it happens when the motor is on and hitting the speed limit.

Also what I noticed is that the resistance increases gradually when I apply more torque to the pedals. Is this normal or should I go to the dealer to check it out?

 

[7869hodgy]

A 25kg bike is hard to get off the mark but once you’re going it should not be super-hard.

 

[flash]

Take the chain off and turn the pedals and you'll see how bad it is. Likely you're pedaling a 24kg bike with knobbly tyres, more than the motor.

Gordon

 

[anfos]

Thanks for the replies! By taking the chain off and moving the pedal with my hand with a little effort it does 3 revolutions, so there is no issue there I'd imagine. What is puzzling is why would the resistance increase when I apply more torque through the pedals while riding? Would that be the tire rolling resistance mostly?

I live in a hilly area and I would like to ride to a mountain that is 20km away and save the most battery to ride there since it's a 30km climb, but with that kind of resistance even the Eco modes are a bit hard to ride.

On a side note, I am also going to test if using Eco (1/5) and going slow would save more battery than using the Normal mode (3/5) and riding harder.
My theory is that by going slower using Eco it could consume more battery because the time spent riding uphill would be more than actually going faster on the Normal mode which would make you reach the destination faster (would only apply to hilly rides and not flat terrain).

I am basing that to the fact that going slow uphill even in Eco would create more resistance and the motor usage could be consuming more battery than speeding up through the climbs since you will have better momentum (so letting physics do most of the work).

 

[Akiwi]

Nope, your theroy doesn't sound right.
You have to think that the output from the motor to go up a hill is combined with the output from your legs. As the motor is only contributing 1/5 of the power, the slower you go, the more time you have to use your leg power.

Here is a graph explaining it. Sorry it's in German,

Y Axis is Height (metres)
X Axis is Time. (minutes)
If you assume you are putting in a constant amount of energy with your legs the more time you have, the more energy comes from you, and therefore the higher you can ride.

Translating the texts.
Eigenleistung = Own contribution
Höchste Unterstützung = Highest support
Mittlere Unterstützung = Middle support
Minimale Unterstützung = Minimal support

 

[anfos]

Yeah but that doesn't take into account the rolling resistance that is created when going uphill, with the combined weight of the rider and the bike. Meaning if there is a steady long climb and you are going at a very slow pace even the Eco mode will be wasting a lot of battery because of how physics work (the more you are staying at a slow pace the more inefficient you will be due to gravity etc). Also having a higher mode than eco and spinning at higher cadence would make both the bike and rider more efficient uphill, wasting less energy (that's just a thought based on riding experience).

Sorry for going off topic, I will do test it out and will probably provide data and battery consumption on another topic when it's done

 

[flash]

Try a faster rolling tyre or at least use a higher pressure while you're commuting to your ride. Tyres make a huge diference.

Gordon

 

[Jaspy]

Anfos I have a Yamaha Moro Pro that does the Exact same thing as yours. I have also noticed that if I exceed the 30km regulated speed by coasting down hill and then attempt to pedal it’s like I just threw out a boat anchor. Immediately the bike slows down. On several occasions I have actually got off my bike looking for a flat or something because the drag is so noticeable. I have checked wheel bearings and dragging brakes etc. Nothing has shown up. I am starting to think it’s normal. If I attempt to pedal with the power off it’s like I’m starting out in sand or something. This bike certainly doesn’t “glide” freely like my other mt bikes do unless No input is attempted.

 

[anfos]

Anfos I have a Yamaha Moro Pro that does the Exact same thing as yours. I have also noticed that if I exceed the 30km regulated speed by coasting down hill and then attempt to pedal it’s like I just threw out a boat anchor. Immediately the bike slows down. On several occasions I have actually got off my bike looking for a flat or something because the drag is so noticeable. I have checked wheel bearings and dragging brakes etc. Nothing has shown up. I am starting to think it’s normal. If I attempt to pedal with the power off it’s like I’m starting out in sand or something. This bike certainly doesn’t “glide” freely like my other mt bikes do unless No input is attempted.

Yes that's exactly how I would describe it. It could be the one way sprag clutch bearing if I am calling it correctly?
@Bearing Man could probably give an answer to why this is happening

Seems like these motors have been over engineered to cover the safety rules and speed limits which unfortunately have these negatives when riding with the motor off (just a guess).

I would like to see if it's possible to replace this clutch bearing with a normal one and avoid all these issues if it's caused by it? although maybe there would be a red light on the computer unit itself if that would be possible.

 

[Sherman]

Anfos I have a Yamaha Moro Pro that does the Exact same thing as yours. I have also noticed that if I exceed the 30km regulated speed by coasting down hill and then attempt to pedal it’s like I just threw out a boat anchor. Immediately the bike slows down.

Have you checked with a speedometer? Because it's not possible to slow down with pedaling, because there's a freewheel in your rear wheel. At 30km/h you are fighting a lot of tyre and especially air resistance and with no assistance it's really hard work. It"s your mind playing funny tricks with you.

 

[anfos]

No he is right, that's how the speed limit works on these bikes, the clutch engages whenever the sensor detects going over the speed limit even when going downhill. To not feel the resistance from the speed limit/clutch mechanism I need to be going on about -3% or more which the weight of the bike and speed makes it less noticeable.

Now if it's the clutch bearing or another mechanism slowing you down I don't know, but it would be interesting to see how it would work without it on the motor. Anyone knows if that's a possible tweak?

 

[Sherman]

No, you're wrong. Exactly how would the rear wheel slow down as the freewheel is in the rear hub?

Go check with a speedometer and come back with the results.

 

[anfos]

No, you're wrong. Exactly how would the rear wheel slow down as the freewheel is in the rear hub?

Go check with a speedometer and come back with the results.

We are talking about pedalling while going downhill - not just freewheeling

 

[Sherman]

We are talking about pedalling while going downhill - not just freewheeling

Exactly. You can't slow down with pedalling because the motor has no way to slow down the rear wheel. You can't brake with the chain. Check with a speedometer and be surprised.

 

[anfos]

Exactly. You can't slow down with pedalling because the motor has no way to slow down the rear wheel. You can't brake with the chain. Check with a speedometer and be surprised.

The motor is not slowing down the rear wheel, it simply puts resistance on the cranks which happens even when pedaling downhill over the speed limit, do you disagree with that?

 

[Bearing Man]

Here's how it actually works:
Uphill or downhill will make no difference, at 15.5mph / 25kph all that happens is that the electric motor is switched off. Then, if you pedal above 15.5mph the clutch will disengage and your pure pedal power will transfer directly from your feet to your chain. After being assisted, this can feel like you are putting the brakes on (try jumping off your ebike straight onto a normal bike and it will feel exactly the same).

There are some exceptions:
The Bosch Gen 2 motor with the small chain ring has a gear between the crank and the sprocket which turns the sprocket at 2.5 revolutions per single revolution of the pedal. This gives noticeable drag when pedaling but will not physically slow the bike down.
The Bosch Gen 4 motor can stay engaged sometimes up to 16.5mph and this will act as a resistance against the pedals and feel like it's slowing the bike but it's only slowing the pedals.

All Yamaha motors have a clutch bearing to disengage the electric motor drive and a freewheel ratchet and pawl system to drive the crank shaft (same as in your rear cassette). If the motor stopped and you stop pedaling this freewheel disconnects the motors drive system from the crankshaft output, so again the motor should not be able to physically slow the bike.

And lastly, even if the motor seized completely, it would disconnect from the rear wheel drive by the rear hub freewheel mechanism as Sherman has said.

The sense of slowing whilst going down hill is usually due to misperception of how much effort the motor is still putting in while going down hill. The bike will still be accelerating faster than gravity can propel you, so once the speed limit of the motor is reached or you stop pedaling, the bike will naturally slow.

 

[Cyclopath1000]

My experience is entirely with the Shimano e8000. I have recently been experimenting with getting greater distance out of a single battery charge with the 504 battery.commencal meta power.
1. There is some kind of spinning device in the motor that stores rotational speed. The easiest way to extend range is to learn how to maintain the exact stored momentum by matching your effort to the momentum carried by the motor. Way too much work to make the motor spin faster with just pedal power. So use of battery needs to be intermittent to maintain that. If the batt is dead, certain climbs will become near impossible. Level areas of the trail become useful for battery conservation but I find that sweet spot to be at a considerably slower speed.
2. Descents are different and seem pretty independent of the battery.
3. However you plan your ride what you don't want is no batt and a gigantic mountain to climb because you are going to be pushing your ride up which from personal experience can be brutal.

 

[Bearing Man]

1. There is some kind of spinning device in the motor that stores rotational speed.

Sorry, but there is no flywheel or motion storage device within this motor. Nice idea though!

 

[Cyclopath1000]

Funny that you say that because you can feel the inertia stored in the engine and I use it all the time if you match your effort directly to the store inertia the bike is much easier to ride with the battery off so whether or not you say there is one and I know you take things apart I know you do fix things and I'm not saying that you're right or wrong I'm just saying that there is stored inertia and you can feel it. Maintain it and it's easy to ride without the battery on and that's why it's easy to maintain it on a slight descent and hard to maintain it on anything more than the slightest rise.

 

[CraigR]

All this is very interesting, but I just wanted to let the original poster know that I have a Stance E+1 and yes if you turn the motor off there is a a moderate amount of resistance pedaling. For whatever reason, weight, motor, clutch, etc.... you are not imagining it.

 

[Cyclopath1000]

Here's another way on e8000 to maximize what the motors inertia will accomplish for you is if you go out riding on relatively up and not too steep but a roller coaster type of stuff and you'll find that if you let the bike slow down too much on the way up the hill vis-à-vis what gear you're in you will not be able to turn the cranks it'll just get slower and slower and you'll get weaker and weaker whereas if you can match this inertial spin of the e8000 motor perfectly you can use all of this passive energy to get you to the top of the hill. In fact if you're looking to train a perfect stroke that has equal pressure in all 360° try doing that on an e-bike with the motor off.

 

[flash]

In a previous life I rode adventure rides. Think trans-continental stuff (Cairo to Capetown or Cooktown to Melbourne). My old steely 26er with panniers and gear was about 35kg, although I was much lighter than the old fart I see in the mirror now.

Pedaling that bike felt exactly like my eBikes do with the motor off. If you really think there's an issue with your bike, get a regular bike with the same tyres and just make it 24kg and go for a ride. There really is nothing going on in the motor to slow you down except the felling you get pushing a heavy bike around. You're trying to accelerate a big heavy bike with big heavy tyres. Most eBike motor systems have less than 5 watts of drag. A normal BB has maybe 2 watts drag. It's a tiny tiny difference.

Gordon

 

[Labrador29]

Hi, I have a Stance e+2 and wanted to ask if it's normal to have a lot of resistance while pedaling with the motor off (it's like going uphill)

Even on a flat road it seems like the clutch? engages and slows down the bike like it happens when the motor is on and hitting the speed limit.

Also what I noticed is that the resistance increases gradually when I apply more torque to the pedals. Is this normal or should I go to the dealer to check it out?

I've got a 2019 Trance e +1Pro. It too, is demanding to ride even on the flat, with no motor assistance. I rode 3 km back to the LBS when my RCO crapped out, and I was absolutely stuffed when I got there. Maybe other brands of e-mtb motors are different?

 

[Nicho]

I've got a 2019 Trance e +1Pro. It too, is demanding to ride even on the flat, with no motor assistance. I rode 3 km back to the LBS when my RCO crapped out, and I was absolutely stuffed when I got there. Maybe other brands of e-mtb motors are different?

I have a Trance SX E+0 Pro and I often switch off the assist when I am going down hills. Frequently I forget to switch it on again and only realise it is off a couple of miles later when I start going up the next hill.

 

[brutale]

Hi, I have a Stance e+2 and wanted to ask if it's normal to have a lot of resistance while pedaling with the motor off (it's like going uphill)

Even on a flat road it seems like the clutch? engages and slows down the bike like it happens when the motor is on and hitting the speed limit.

Also what I noticed is that the resistance increases gradually when I apply more torque to the pedals. Is this normal or should I go to the dealer to check it out?

I have a Stance e+1 and have recently noticed the same problem. This pedaling resistance definitely wasn't there when I first started riding, so something has changed on my bike in the last month or so. When I first bought the bike I experimented with riding up some hills with no power. The bike is a little heavy, but still not too difficult to pedal. I even ran out the battery completely on a longer ride and had to climb the last hill with no assistance. Difficult but nothing I couldn't overcome by shifting into a bigger ring. But the resistance coming from the pedals now is like I'm fighting the motor, and it happens slow speeds. It's still under warranty, so I plan on taking it in. I just don't want to be without my bike for very long.

 

[Labrador29]

Been the same on my 2019 Giant Trance E-mtb +1 pro since new. I thought it was normal. Had to ride 3 km back to town once when the Ride Control One packed it in. It was like I had 3 bags of cement on the bike.!!!!! Be interested to follow this posting

 

[Bearing Man]

Here's another way on e8000 to maximize what the motors inertia will accomplish for you is if you go out riding on relatively up and not too steep but a roller coaster type of stuff and you'll find that if you let the bike slow down too much on the way up the hill vis-à-vis what gear you're in you will not be able to turn the cranks it'll just get slower and slower and you'll get weaker and weaker whereas if you can match this inertial spin of the e8000 motor perfectly you can use all of this passive energy to get you to the top of the hill. In fact if you're looking to train a perfect stroke that has equal pressure in all 360° try doing that on an e-bike with the motor off.

Sorry but I have to counter this. The picture below is the only thing in an ebike motor that will offer inertia. All the weight of this motor armature is very close to the shaft to allow it to spin up and stop very quickly. It weighs 300g and stops within seconds when you stop pedaling. The inertia would be infinitesimal and very short lived. Are you sure you're not confusing inertia with power?
Power is added as you add pedal force, so if you pedal less, you get less assistance but it's still there. Power is also fed in according to cadence. This comes from your battery and there is no "passive energy" it's just how mid drive motors work!

 

[Zimmerframe]

Sorry but I have to counter this. The picture below is the only thing in an ebike motor that will offer inertia.

I have to disagree ..

You're putting physics, logic & knowledge ahead of magic.

This was my solution from a couple of years ago, I guess Shimano have sneakily retro fitted it to certain motors with some modifications ...

On my bike I've attached a second hand formula 1 Kers flywheel system. It only weighs 24kg's and fits nicely in the frame. At the start of a downhill run I attach a hook to a tree which is connected to a 200m titanium cable which is wound round the kers flywheel. As I descend, the cable unwinds and spins up the flywheel. After about 200 meters the flywheel is normally upto it's maximum 64,000 rpm. When I reach the bottom I engage a mechanism which uses this energy, through a small gearbox, to drive the chain and take me almost back upto the top rather than using the battery. Once the flywheel is upto speed it acts like a massive gyroscope. I'm not sure if you ever played with a gyroscope, but once they're spinning they don't like to move. So this has the positive effect that it's completely impossible to knock the bike over (you can actually get off and it just stays upright, which is great for photos, no need for a stick), but it also has the negative effect that it's impossible to change direction so I can only take the straight "Strava" lines down a run.

Of course the other possibility is that by concentrating so much on his cadence, cyclopath has unwittingly unleashed "The Force" , maybe @skywalker @Darthvader or @TheForceusercare can comment if this is the case.

 

[Jackware]

I have to disagree ..

You're putting physics, logic & knowledge ahead of magic.

This was my solution from a couple of years ago, I guess Shimano have sneakily retro fitted it to certain motors with some modifications ...

On my bike I've attached a second hand formula 1 Kers flywheel system. It only weighs 24kg's and fits nicely in the frame. At the start of a downhill run I attach a hook to a tree which is connected to a 200m titanium cable which is wound round the kers flywheel. As I descend, the cable unwinds and spins up the flywheel. After about 200 meters the flywheel is normally upto it's maximum 64,000 rpm. When I reach the bottom I engage a mechanism which uses this energy, through a small gearbox, to drive the chain and take me almost back upto the top rather than using the battery. Once the flywheel is upto speed it acts like a massive gyroscope. I'm not sure if you ever played with a gyroscope, but once they're spinning they don't like to move. So this has the positive effect that it's completely impossible to knock the bike over (you can actually get off and it just stays upright, which is great for photos, no need for a stick), but it also has the negative effect that it's impossible to change direction so I can only take the straight "Strava" lines down a run.

Of course the other possibility is that by concentrating so much on his cadence, cyclopath has unwittingly unleashed "The Force" , maybe @skywalker @Darthvader or @TheForceusercare can comment if this is the case.

As helpful as ever, a simple explanation for simple folk.

 

[Jaspy]

I happened to come across this posted on Avdweb.nl.

Yamaha PW-X2

Here, I share technical solutions that arised during the development of my solar-bike.

www.avdweb.nl

“Most mid-drive motors (like the Bosch) have just one freewheel, this is used for pedaling without turning the motor. With just a single freewheel, the motor can never drive the rear wheel without the pedals turning, this requires an extra freewheel.

The Yamaha has 2 freewheels, so we can do both:

• Pedaling without turning the motor
• The motor can drive the rear wheel without the pedals turning

A disadvantage of the Yamaha is that gear wheel 3 and 4 will rotate during pedaling without motor assistance, which will give some loss.”

Could this be what we are feeling ? A year later and I still experience the “loss”.