Fuel EXe Is motor drag normal?

[Casting_Shadows]

Hi all,

I just bought my first e-bike last weekend, It is a second hand Fuel EX-e 9.7 '22 model with 2500km's on it and I'm not sure if it's functioning correctly and hoping for some clarity.

Is there supposed to be some sort of "engine" braking when you stop pedalling? What i mean by that is, sometimes, not always, when i stop pedalling the bike drags and slows down like there is engine braking like a 4 stroke motorbike when you let off the accelerator.
When it happens, if you don't start pedalling again it feels like it will bring you to a stop. It's like it doesn't disengage.

This can happen at any speed, even when switching modes and changing gears. It really throws my momentum off.
It happens even when I hold the "down" button on the lever to disengage the motor, when i pedal it feels like I'm being held back, even rolling down a hill.

The thing is, I don't think it does it all the time, sometimes it doesn't do it.

I thought it was a battery power thing and was only doing it once the battery was a like 30% depleted but it done it yesterday at 100% for the entire ride.

I went to a local trek sub-dealer and rode one of their exact same demo bikes and my bike back to back in the carpark but they felt the same but i think it was when the issue wasn't occuring.

Thanks

 

[RustyIron]

Is there supposed to be some sort of "engine" braking when you stop pedalling?

No, there is no engine braking. The freehub freewheels as you coast, like on any other bike.

 

[Casting_Shadows]

No, there is no engine braking. The freehub freewheels as you coast, like on any other bike.

Okay, thanks.
Looks like I need to get it looked at.
I’m trying to get a copy of the original receipt as it’s still under subsequent owner warranty I believe.

 

[ohiomoto]

I've had the same sensation when using full assist while climbing. It happens cresting hills and undulations where I expect to get a bit of relief. I have noticed this on the Fuel EXe and the TQ powered Scott gravel bike I own.

But as pointed out, it's "impossible" because the freehub disengages when you STOP pedaling. I think it's the assist dropping as I ease up on the pedals expecting a free ride over the top of a hill, but I'm not sure.

Also, the Maxxis Minion tires that came on my bike are slow. I love the traction but they are by far the heaviest/slowest tires I've ever used which might contribute to the slowdown.

 

[Mteam]

Hi all,

I just bought my first e-bike last weekend, It is a second hand Fuel EX-e 9.7 '22 model with 2500km's on it and I'm not sure if it's functioning correctly and hoping for some clarity.

Is there supposed to be some sort of "engine" braking when you stop pedalling? What i mean by that is, sometimes, not always, when i stop pedalling the bike drags and slows down like there is engine braking like a 4 stroke motorbike when you let off the accelerator.
When it happens, if you don't start pedalling again it feels like it will bring you to a stop. It's like it doesn't disengage.

This can happen at any speed, even when switching modes and changing gears. It really throws my momentum off.
It happens even when I hold the "down" button on the lever to disengage the motor, when i pedal it feels like I'm being held back, even rolling down a hill.

The thing is, I don't think it does it all the time, sometimes it doesn't do it.

I thought it was a battery power thing and was only doing it once the battery was a like 30% depleted but it done it yesterday at 100% for the entire ride.

I went to a local trek sub-dealer and rode one of their exact same demo bikes and my bike back to back in the carpark but they felt the same but i think it was when the issue wasn't occuring.

Thanks

as per others there should be no significant drag when you are coasting, it should just feel like any normal bike when coasting along.

if you lift the bike off the floor, do the wheels spin freely if you spin them by hand? Maybe the brakes are binding causing drag? or maybe there is something wrong with the bearings in the wheel hub causing them not to spin freely?

 

[Casting_Shadows]

I've had the same sensation when using full assist while climbing. It happens cresting hills and undulations where I expect to get a bit of relief. I have noticed this on the Fuel EXe and the TQ powered Scott gravel bike I own.

But as pointed out, it's "impossible" because the freehub disengages when you STOP pedaling. I think it's the assist dropping as I ease up on the pedals expecting a free ride over the top of a hill, but I'm not sure.

Also, the Maxxis Minion tires that came on my bike are slow. I love the traction but they are by far the heaviest/slowest tires I've ever used which might contribute to the slowdown.

That's exactly what i noticed too. When i get to the top of a hill where i'd expect to start coasting, it would feel like someone pulling the brakes on. It's a noticeable resistance.

 

[Casting_Shadows]

as per others there should be no significant drag when you are coasting, it should just feel like any normal bike when coasting along.

if you lift the bike off the floor, do the wheels spin freely if you spin them by hand? Maybe the brakes are binding causing drag? or maybe there is something wrong with the bearings in the wheel hub causing them not to spin freely?

Yeah the wheel spins freely if you lift it off the ground and there is ample brake pad clearance and no rubbing of the brakes.
Some times it it rolls like a dream but other times its very noticable.

 

[whitymon]

The momentum/gravity of an heavier bike should carry you further on flat and dh when stop pedaling by physic law.

But uphill this is the opposite, an heavier bike have to fight gravity therefore will stop moving before the lighter one.

If you have find yourself out of these case there might be something very odd!

 

[Winford]

rear brakes will drag, when they are beyond their wear limits, because the calipers get cocked a little sideways, causing drag. worth noting

 

[Casting_Shadows]

Sorry, i should have mentioned in the original post, although it's my first e-bike it's not my first bike, i've been riding bikes for almost 40 years and worked for a bike company for 15 years so i have a pretty good understanding of pedal bikes but just not with e-bikes haha.

It's definitely a drag caused by the motor. I can physically feel it and it feels like it's not disengaging when I stop pedalling. Sometimes I can even feel the drag when pedalling at a high enough cadence that the motor should be working.

I wouldn't have thought it was an issue but it does it sporadically. Sometimes it doesn't drag at all, even on the same spot where it would drag previously on a trail.

I think i just need to take it to a dealer and hopefully I can replicate it there.

 

[Mteam]

Sorry, i should have mentioned in the original post, although it's my first e-bike it's not my first bike, i've been riding bikes for almost 40 years and worked for a bike company for 15 years so i have a pretty good understanding of pedal bikes but just not with e-bikes haha.

It's definitely a drag caused by the motor. I can physically feel it and it feels like it's not disengaging when I stop pedalling. Sometimes I can even feel the drag when pedalling at a high enough cadence that the motor should be working.

I wouldn't have thought it was an issue but it does it sporadically. Sometimes it doesn't drag at all, even on the same spot where it would drag previously on a trail.

I think i just need to take it to a dealer and hopefully I can replicate it there.

Check the speed sensor magnet on the rear wheel is completely clean, metal particles from the brake pads can gather on the magnet and prevent it being detected properly by the sensor on the bike. The magnet is located near the centre of the wheel on the brake disc side, it's attached the same way as the brake disc, either bolts in the case of a 6 bolt brake disc or centre lock.


Also check the speed sensor itself is clean, it is located on the non drive side chain stay.

 

[whitymon]

I do not understand how the motor could do anything if the pedal are not moving.

If the chainring does not move it cannot impact the rear wheel no?

 

[Mteam]

I do not understand how the motor could do anything if the pedal are not moving.

If the chainring does not move it cannot impact the rear wheel no?

From the op latest reply I Presume the op didn't actually mean drag when he was coasting or free wheeling, presume he meant drag when pedalling

 

[Mteam]

It could also be the freehub not free wheeling like it's supposed to and therefore rotating the chain ring and motor? But that should be obvious when you look at the bike and spin the back wheel.

 

[Casting_Shadows]

Check the speed sensor magnet on the rear wheel is completely clean, metal particles from the brake pads can gather on the magnet and prevent it being detected properly by the sensor on the bike. The magnet is located near the centre of the wheel on the brake disc side, it's attached the same way as the brake disc, either bolts in the case of a 6 bolt brake disc or centre lock.


Also check the speed sensor itself is clean, it is located on the non drive side chain stay.

Okay, I’ll check that today and report back.

 

[Casting_Shadows]

No

From the op latest reply I Presume the op didn't actually mean drag when he was coasting or free wheeling, presume he meant drag when pedalling

no, it does the most when coasting that’s what got my attention. Even on flat ground, as soon as I stop pedaling you can feel a very noticeable resistance and you start to slow down.
You can feel it through the cranks.

It doesn’t feel like brake rub would feel.

I don’t understand how it would be possible either because the drive train doesn’t move when you coast, just the freewheel spinning in the hub.

 

[Mteam]

No

no, it does the most when coasting that’s what got my attention. Even on flat ground, as soon as I stop pedaling you can feel a very noticeable resistance and you start to slow down.
You can feel it through the cranks.

It doesn’t feel like brake rub would feel.

I don’t understand how it would be possible either because the drive train doesn’t move when you coast, just the freewheel spinning in the hub.

Very strange, can't think what would cause that sensation aside from something like brake drag, wheel bearings etc.

 

[Sherman]

Most of the new ebikers go thru this. When the assists stops, it messes up your senses. It feels weird in the beginning, but you get used to it.

 

[Casting_Shadows]

Most of the new ebikers go thru this. When the assists stops, it messes up your senses. It feels weird in the beginning, but you get used to it.

That was pointed out to me by another customer in the bike shop when I went to ask someone about it which I get, the only thing that made me question it is because it does it with the motor in the disengage mode. So technically the motor shouldn’t do anything

 

[Streddaz]

That's certainly a strange one. I feel that it might just be a perceived feeling of drag rather than and actual drag. When coasting the rear wheel freehub should totally remove any connection to the motor and the motor. As long as the free hub is working fine you shouldn't get any drag. You motor will also have a clutch/freehub, which disconnects the cranks from the motor drive train, so when you are pedalling unassisted you aren't getting the drag from spinning the motor and associated gears.
As a couple of people have noted, when riding an Ebike you do get this feeling of drag when you have been riding assisted and then either lower the assistance or turn it off altogether. This typically is when you are pedalling, and I haven't had the feeling when coasting. Maybe your bike has slower rolling tyres than you are used to, or it's the extra weight maybe.
I know if I ride my Levo SL in Turbo and then turn it off and pedal it feels sooooo draggy, but if I start the ride with it off it doesn't feel that much worse than a non-Ebike.
If it isn't a perception thing then I can only think that it could be an intermittent fault with your freewheel hub and the clutch freewheel in the motor which I would have thought would be fairly slim chance that they are both faulty.

 

[rod9301]

No

no, it does the most when coasting that’s what got my attention. Even on flat ground, as soon as I stop pedaling you can feel a very noticeable resistance and you start to slow down.
You can feel it through the cranks.

It doesn’t feel like brake rub would feel.

I don’t understand how it would be possible either because the drive train doesn’t move when you coast, just the freewheel spinning in the hub.

Your bike is heavy, of course it will slow down when you stop pedaling

 

[Casting_Shadows]

Y

That's certainly a strange one. I feel that it might just be a perceived feeling of drag rather than and actual drag. When coasting the rear wheel freehub should totally remove any connection to the motor and the motor. As long as the free hub is working fine you shouldn't get any drag. You motor will also have a clutch/freehub, which disconnects the cranks from the motor drive train, so when you are pedalling unassisted you aren't getting the drag from spinning the motor and associated gears.
As a couple of people have noted, when riding an Ebike you do get this feeling of drag when you have been riding assisted and then either lower the assistance or turn it off altogether. This typically is when you are pedalling, and I haven't had the feeling when coasting. Maybe your bike has slower rolling tyres than you are used to, or it's the extra weight maybe.
I know if I ride my Levo SL in Turbo and then turn it off and pedal it feels sooooo draggy, but if I start the ride with it off it doesn't feel that much worse than a non-Ebike.
If it isn't a perception thing then I can only think that it could be an intermittent fault with your freewheel hub and the clutch freewheel in the motor which I would have thought would be fairly slim chance that they are both faulty.

Yeah, I understand the perception side but it’s a very noticeable resistance and it’s sporadic. Sometimes when I ride with the motor turned on but in no assist mode it will roll fine on flat ground but other times it it feels like someone cranked the rear axle up to the max haha.
To rule it out though I’ll take the back wheel off and service the cassette to make sure 100% that nothing is binding up internally.

Thanks.

 

[Casting_Shadows]

Your bike is heavy, of course it will slow down when you stop pedaling

It’s only 3kg heavier than my acoustic bike.
There is a difference between a bike slowing down due to its own weight and a bike slowing down due to force.

 

[ohiomoto]

What you've described matches my experiences.

I think our minds have been conditioned to decades of acoustic riding. The decreased effort is creating an expectation that isn't being met.

Both of my bikes feel pretty normal when I start a ride. Almost no motor drag when pedaling and they coast like a regular bike when you stop pedaling. If I ride with limited assistance I feel like I'm just losing the assistance when it goes away. But, when I ride with higher levels of assistance, I feel drag and lack of coasting makes the bike unridable.

Did the bike change during the ride or did my perception change?

IDK, maybe it's heat-related but the bike should freewheel normally regardless of the motor. Unless the freehub is somehow pushing the chain wheel forward? (Yeah, I can't quite get past that sensation either. There has to be a cause! )

 

[Streddaz]

Y

Yeah, I understand the perception side but it’s a very noticeable resistance and it’s sporadic. Sometimes when I ride with the motor turned on but in no assist mode it will roll fine on flat ground but other times it it feels like someone cranked the rear axle up to the max haha.
To rule it out though I’ll take the back wheel off and service the cassette to make sure 100% that nothing is binding up internally.

Thanks.

Sounds like a good plan. The back wheel is really the only thing that could be causing the issue when coasting. I hate intermittent problems; they are so hard to track down and it's often difficult to diagnose as it never seems to happen when you are able to test it. Best of luck.

 

[Casting_Shadows]

I stopped by the local Trek dealer today after work and spoke with him and explained what i'm experiencing.
He said that he has had 2 cases with the TQ motors where the bearings in the motor failed causing similar issues and Trek replaced the motors.
I explained that i don't have the original receipt but he said he'll submit the warranty regardless as he looked up the bike serial number and it is a 2023 model so its still covered.

When i got home I put the bike on my stand and spun the wheel to check if the brakes were rubbing and there was no rub at all and the brake pads are near new so i pulled the brakes off completely to 100% rule that out and the wheel spun and functioned fine. There is no signs of the cassette binding up at all and it spins freely. There is some wear in the chain and the cassette so i'll replace those to rule that out too.

I did put it in "walk" mode while on the stand and took the chain off the front sprocket and I can audibly hear grinding and knocking in the motor when engaging the walk function which is what i can hear when sometimes when riding the bike. Most times its dead quiet, other times its very grindy, like there is sand in the bearings.

FIngers crossed the store can replicate the issue when i take it in and it can get fixed.

Thanks all for your input.

 

[Mteam]

I stopped by the local Trek dealer today after work and spoke with him and explained what i'm experiencing.
He said that he has had 2 cases with the TQ motors where the bearings in the motor failed causing similar issues and Trek replaced the motors.
I explained that i don't have the original receipt but he said he'll submit the warranty regardless as he looked up the bike serial number and it is a 2023 model so its still covered.

When i got home I put the bike on my stand and spun the wheel to check if the brakes were rubbing and there was no rub at all and the brake pads are near new so i pulled the brakes off completely to 100% rule that out and the wheel spun and functioned fine. There is no signs of the cassette binding up at all and it spins freely. There is some wear in the chain and the cassette so i'll replace those to rule that out too.

I did put it in "walk" mode while on the stand and took the chain off the front sprocket and I can audibly hear grinding and knocking in the motor when engaging the walk function which is what i can hear when sometimes when riding the bike. Most times its dead quiet, other times its very grindy, like there is sand in the bearings.

FIngers crossed the store can replicate the issue when i take it in and it can get fixed.

Thanks all for your input.

It can't be motor bearings causing drag when you are coasting because the motor is not part of the system when coasting, the freehub in the back wheel means that the back wheel spins without turning the cassette,ie nothing else is rotating when you coast, and certainly not the motor-so it doesn't matter what state the motor bearings are in.That doesn't mean you don't have bad bearings in the motor, it just means that they are not the cause of the drag while coasting issue.

Now if you were complaining about drag when pedalling then that's a different thing entirely and could be caused by a faulty motor (bad bearings or any number of other issues), but you have been very clear that your issue is when coasting, so the bad motor bearings theory does not stand up.

By the way, taking the chain off the chain ring and using walk mode is not a valid test of very much because the motor expects to see the back wheel moving (detected via the speed sensor) when you use walk mode, if it doesn't sense the wheel moving(because the chain is removed) it will throw error after a while, and may not be able to control the walk mode properly, so I wouldn't pay much attention to that test.

The tq motor is known to sound a bit grindy at very low power outputs/load, it's a characteristic of the system.