Rider's effort inconsequential

PianoJohn

New Member
Hi folks,
I fell in love with E bikes a week ago. But I have since learned that when I am using the motor, I can only increase the speed of the bike by a couple miles an hour, no matter how hard I pedal. This is true on all assist levels and on throttle only.

I have a Diamondback Lindau.

Is this normal? Is this a consequence of the gearless hub motor this bike has? Do all gearless hub motors behave this way?

It is still fun to ride, but I would like my peddling to matter! When the motor is off, I can ride it at about 15 miles an hour on a flat road. But, when the motor is on, the speed is almost entirely determined by the motor' output.

Thanks a lot, everyone.
 

George S.

Well-Known Member
The wind resistance makes the lower speeds cost less in terms of watts. It takes around 150 watts to go 14 mph, whether it is your power or the power of the motor. You need 300 watts to go about 20 mph, so not much difference in speed.

Most people pedal steadily on an ebike, with the pedal assist, but maybe not as hard. It's still good exercise.

You can work out the numbers with this calculator. Probably several things in play. You would be working pretty hard to go 15 mph on an ebike for long periods.

As you go faster the motor does do most of the work. On the 28 mph speed ebikes, you need about 800 watts and the rider is likely to contribute 100-200, at most.

The Europeans take the view that even a fit cyclist is limited to about 250 watts of output, so they limit the motor output to about that number. It helps the weaker riders, but it's not good on hills and into stiff winds. The US limit is around 750 watts.

Besides, like you say, ebikes are fun. We could just stop there:).
 

J.R.

Well-Known Member
Hi folks,
I fell in love with E bikes a week ago. But I have since learned that when I am using the motor, I can only increase the speed of the bike by a couple miles an hour, no matter how hard I pedal. This is true on all assist levels and on throttle only.

I have a Diamondback Lindau.

Is this normal? Is this a consequence of the gearless hub motor this bike has? Do all gearless hub motors behave this way?

It is still fun to ride, but I would like my peddling to matter! When the motor is off, I can ride it at about 15 miles an hour on a flat road. But, when the motor is on, the speed is almost entirely determined by the motor' output.

Thanks a lot, everyone.
That's fairly typical of many cadence sensing PAS drives. There are more sophisticated cadence sensors, but many only know the crank is spinning, not how much effort the rider is putting in. Torque sensing better approximates how a human rides a bike, it senses the effort the rider applies to the cranks and responds with the appropriate power. Even more sophisticated are systems that sense both torque and cadence.
 

Saratoga Dave

Well-Known Member
The more I do this, the more I think I'd like to try a torque sensor system (Specialized Turbo). Love my bike but it is true that it's a pretty straightforward equatiOn within each level of assist... 10mph, 15mph, 19. That's it.
 

harryS

Well-Known Member
I replaced one of the controllers in my kit bikes with one that claims "torque simulation". It uses 5 PAS levels, and limit the motor current in each level, same as limiting the motor wattage.

Am example would be PAS 1, where the motor only delivers 50 watts and shuts off round 8 mph. Just enough to help. And this reduced level is applied thru the five levels, until you have full power in level 5. In my opinion, it does feel better, but I know it's not torque sensing. More like power steering with less assist.
 
What you are describing is not the property of the bike but physics. It takes MUCH more energy to go from 25-30mph than it does to go from 10-15mph. If you want to go faster you need to become more aerodynamic.
 

MLB

Well-Known Member
Hi folks,
I fell in love with E bikes a week ago. But I have since learned that when I am using the motor, I can only increase the speed of the bike by a couple miles an hour, no matter how hard I pedal. This is true on all assist levels and on throttle only.

I have a Diamondback Lindau.

Is this normal? Is this a consequence of the gearless hub motor this bike has? Do all gearless hub motors behave this way?

It is still fun to ride, but I would like my peddling to matter! When the motor is off, I can ride it at about 15 miles an hour on a flat road. But, when the motor is on, the speed is almost entirely determined by the motor' output.

Thanks a lot, everyone.


It's your bikes gearing. If the bike isn't geared tall enough to be able to peddle faster than the motor supports, you'll feel what you are feeling.
My Haibike and Easy Motion are like that, and that's at 20mph! So the gearing is very low on those two bikes. Peddle very hard to go 21mph.

On the STromer ST1 I've since sold I could pedal another 3-4mph over max motor with decent effort. (and that's a 28mph speed pedalec!)
On my Catrike trike with Falco motor (also 28mph) I can easily peddle 5mph over that.
ALL about the gearing. And it's easy to change.
 

PianoJohn

New Member
OK, I've made my peace with the bike. It's heavy, and I can't go much faster than 22 mph because of max motor output and wind resistance. I am still helping the motor by pedaling, and I'm getting good exercise. And I can now ride my bike instead of taking my car into work. It's great!
 

Dunbar

Well-Known Member
On my e-bike you will be fighting the controller if you try to go faster than it's designed to at that assist level. Literally the harder you pedal the less power it will send to the motor. It starts to feel like you are up against a wall of resistance that keeps getting harder the more you push it. That's actually a good thing if you're looking to burn some calories. You can dial down the assist level and get a pretty decent workout. I don't like e-bikes that ride like an electric scooter.
 

Trail Cruiser

Well-Known Member
A relatively fit person can reasonably reach 16-18 MPH on heavy pedaling.
(Link Removed - No Longer Exists)
That translates to 100-150 watts of sustained effort. Factor in the weight of the motor and battery (~20 lbs) and that slows down your ride significantly. Factor in the "cogging" resistance of the direct drive hub motor and that slows down your ride even further (if you just pedal and not use the motor). Assuming there is no speed limiter, a 500 watt motor can sustain a 28 MPH with very little part on the rider but then you drain out your battery very quickly. A 350 watt can also reach 28 MPH (see Juiced CrossCurrent)
https://electricbikereview.com/juiced-bikes/crosscurrent/
but it needs the active participation of the rider, at about 150 watts of heavy pedaling.

The Diamondback Lindau is rated at 20 mph top speed so power cuts off above that speed.
https://electricbikereview.com/diamondback/lindau-exc/
Interestingly Diamondback also has another 500 watt direct drive (Diamondback Trace EXC) that is not limited to 20 mph, it continues to supply power even above 28 MPH. https://electricbikereview.com/diamondback/trace-exc/

I have the Izip version (2015 Izip E3 Dash)
https://electricbikereview.com/izip/2015-e3-dash/
and was surprised to reach 33 mph on a level road while trying to beat another electric bike (Trek XM700+).
https://electricbikereview.com/trek/xm700-plus/
 
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Dunbar

Well-Known Member
Assuming there is no speed limiter, a 500 watt motor can sustain a 28 MPH with very little part on the rider but then you drain out your battery very quickly. A 350 watt can also reach 28 MPH (see Juiced CrossCurrent) but it needs the active participation of the rider, at about 150 watts of heavy pedaling.

It's not quite that simple. Hub motors are only about 80% efficient so that 500 watts going in only translates into 400 watts of actual work. Also, nominal power ratings for motors are not really useful. The 'peak' numbers some manufacturers publish are representative of the maximum continuous power that the controller will output on the top assist level.

I have a lot of miles riding with a power meter on road bikes and the numbers I have seen are about 450-500 watts to maintain 28mph on a road bike with a reasonably aerodynamic position. I basically can't hit 28mph for more than a few seconds on a road bike without gravity or a massive tailwind assisting me. On a more upright bike (like most e-bikes) it's probably more like 600-700 watts with the added rolling resistance factored in. The other factor is wind and incline. Even a small amount of incline makes a huge difference in the power required to maintain those speeds. Similarly, a strong enough headwind will make it all but impossible to maintain 28mph on an e-bike without some massive power to assist you.
 

Trail Cruiser

Well-Known Member
It's not quite that simple. Hub motors are only about 80% efficient so that 500 watts going in only translates into 400 watts of actual work. Also, nominal power ratings for motors are not really useful. The 'peak' numbers some manufacturers publish are representative of the maximum continuous power that the controller will output on the top assist level.

I have a lot of miles riding with a power meter on road bikes and the numbers I have seen are about 450-500 watts to maintain 28mph on a road bike with a reasonably aerodynamic position. I basically can't hit 28mph for more than a few seconds on a road bike without gravity or a massive tailwind assisting me. On a more upright bike (like most e-bikes) it's probably more like 600-700 watts with the added rolling resistance factored in. The other factor is wind and incline. Even a small amount of incline makes a huge difference in the power required to maintain those speeds. Similarly, a strong enough headwind will make it all but impossible to maintain 28mph on an e-bike without some massive power to assist you.

I completely agree with you. I am just stating the simplistic general idea and you are fine tuning it to be more specific and more precise. And I like that. I acknowledge the motor efficiency factor and the peak loading factor vs nominal. Aerodynamics is also a very big factor especially at speeds above 20 mph.
https://lonniemorse.files.wordpress.com/2013/03/aero-drag-power-for-hpvs.jpg
https://lonniemorse.wordpress.com/
http://static.wixstatic.com/media/e...681d_55f31214154645bc921108426bbbd8e9~mv2.png
http://www.dimeperformance.com/single-post/2016/07/11/Is-Aero-Everything-Or-A-Triathlon-Myth

Another confounding factor is the motor gearing. Class 2 geared hub drives will be over spinning above 20 mph. On mid drives, almost all brands do not provide support above 90 RPM cadence, resulting to unnatural feel and desastified riders, esp the experienced road cyclists.. The only mid drive that has a natural feel of support even at higher cadence above 100 rpm is the Bosch performance speed line.
 
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Cameron Newland

Well-Known Member
Hi folks,
I fell in love with E bikes a week ago. But I have since learned that when I am using the motor, I can only increase the speed of the bike by a couple miles an hour, no matter how hard I pedal. This is true on all assist levels and on throttle only.

I have a Diamondback Lindau.

Is this normal? Is this a consequence of the gearless hub motor this bike has? Do all gearless hub motors behave this way?

It is still fun to ride, but I would like my peddling to matter! When the motor is off, I can ride it at about 15 miles an hour on a flat road. But, when the motor is on, the speed is almost entirely determined by the motor' output.

Thanks a lot, everyone.

I think that the issue is primarily that you're riding a 20MPH ebike. If you were riding an IZIP E3 Dash or the Diamondback Trace EXC Bike (both basically the same bike and both capable of 28MPH), you'd see your increased pedal input mirrored with additional power all the way up to 28MPH. Instead, because your bike's pedal assist is limited to approximately 20MPH, your increased pedaling input at 17MPH might only result in an additional 3-5MPH of speed, and the motor assist would drop off as your pedal input increases when near the speed cutoff. If you were riding a 28MPH ebike, the motor assist would be more predictable up to 28MPH, and that at that point, you'd experience the same phenomenon that you're experiencing around 20MPH, with the only difference being that 28MPH is pretty fast, and many folks don't really feel the need to go much faster, so it wouldn't seem like as much of a problem as it does around 20MPH.
 

James Kohls

Active Member
The Diamondback Lindau's gearless hub motor will work against you when it is not helping you. When the motor de-engergizes, you have the magnets to contend with and they are strong magnets. If you've ridden your bike with the power off and felt that on-off-on-off resistance, that resistance exists past the motor cutoff point. Add in wind resistance and weight—pedaling past the motor cutoff point is significantly more difficult. This is just a downside of all gearless direct drive motors like that.

The same thing happens on my Specialized Turbo at its top assisted speed of 26MPH. I've gotten it up to 30MPH on windless days on flats, but it is not in any way sustainable.
 

Trail Cruiser

Well-Known Member
On my 2015 Izip E3 Dash I feel that there is no power cut off beyond 28 mph. The bike simply would not go any faster due to the enormous wind resistance. So if there is a good tailwind, I get lucky and reach more than 30 mph. On the other hand, I am draining the battery too fast and lessen my range tremendously. Rule of thumb, keep your speed at 20 mph or below and you will have good battery range.