Pedal Assist Query

[DJH]

On my Cluad Butler glide 1 on reaching 15mph the motor cuts out as you would expect. If you carry on pedalling but the speed drops below 15mph the motor doesn't automatically cut until you momentarily stop pedalling. I can't say as I mind this system as it makes me continue pedalling without assistance for a longer period therefore conserving battery power. But I would like to know how other makes operate. I might add that the controller is due to be changed (when I can get to the shop) as the battery lights on the handlebar do not indicate the state of the battery, just off and on.

 

[Eaglerider]

From my meagre experience, Bosch and Panasonic crank drive systems cease all power above the pre set speed circa 15.5 mph, the power returns as soon as the speed drops back with no requirement to stop pedalling, it is purely speed and pedal torque related.

With my hub drive bike, at 15.5 mph the power is restricted to that level and will not increase, but the power assistance remains, meaning that all pedalling effort is used to increase speed above the pre set 15.5 mph making cruising at around 18mph pretty easy with light pedalling. If I continue to rotate the pedals but with no actual power (pedalling air so to speak), then the bike slowly returns to 15.5 by itself.

In contrast, the crank drive set ups, (at least the two I have tried) cease all power above 15.5 mph and thus all subsequent leg power is used to maintain that speed. To re-acquire assistance the speed must drop back below 15.5 mph.

I much prefer the hub drive system on my bike for general use.

 

[DJH]

Thanks Eaglerider, which bike do you have?

 

[Eaglerider]

Hi DJH,
I have a 2011 Freego Eagle 17 A/H Mountain Bike with hub drive.

The Bosch and Panasonic crank drive systems are better at climbing really steep hills, but everywhere else my Eagle outclasses anything else I have ridden to date, and its still pretty good at hills anyway.

I have only been E-Biking for a couple of months, so hopefully the more experienced members will appear and provide a more authorititave opinion.

 

[flecc]

There's quite a lot of variation. On many pedelec hub motor bikes there is a sharp cut-off of power at about 15 mph, no help above but power returns as soon as speed drops below 15 mph again.

Some others have motors effectively geared to run out of steam at around 15 mph, this therefore determined by the battery voltage which declines as the charge is used.

Both can be found within one maker's products. For example, the eZee F series bikes cut off at 15 mph with no assist above, while their Quando model is like the second case. My Quando assists to about 17 mph with the battery fresh off the charger but near the end of charge content the assist is over at about 14.5 mph.

With those unrestricted bikes not having a sharp cutoff, if the internal gearing of the motor is on the high side, it's difficult to detect exactly when there is no more assistance since it phases down so gradually.

Of course the only EU/UK legal way is having the full cut-off at 25 kph / 15.5 mph.

 

[DJH]

Yes, I've only been ebiking for three months but I have never had the oportunity to try different makes so all info is useful for when I come to get a second bike so that my wife and I can pedal away together!

 

[DJH]

Thanks flecc but do you know of systems like mine that require you to stop pedalling momentarily to get the motor to kick in when below 15mph. I'm just wondering if it's the controller at fault?

 

[flecc]

I don't, that's a new one on me, but I can't say it's definitely a fault. It could be related to the continuous stream of pulses from the pedelec sensor needing to cease for the controller to restart the power, but it seems odd.

 

[NRG]

Yes, seems odd as the motor stator is still effectively 'spinning' above the cutoff speed... its just unable to provide any drive because the wheel RPM is greater....unless the clutch is not disengaging for some odd reason.

 

[bode]

On many pedelec hub motor bikes there is a sharp cut-off of power at about 15 mph, no help above but power returns as soon as speed drops below 15 mph again. Some others have motors effectively geared to run out of steam at around 15 mph...
Both can be found within one maker's products. For example, the eZee F series bikes cut off at 15 mph with no assist above, while their Quando model is like the second case.

Tony, is the eZee Sprint one of their F series or like the Quando? I ask because my Sprint seems to behave exactly as Eaglerider described:

With my hub drive bike, at 15.5 mph the power is restricted to that level and will not increase, but the power assistance remains, meaning that all pedalling effort is used to increase speed above the pre set 15.5 mph making cruising at around 18mph pretty easy with light pedalling. If I continue to rotate the pedals but with no actual power (pedalling air so to speak), then the bike slowly returns to 15.5 by itself.

 

[flecc]

Tony, is the eZee Sprint one of their F series or like the Quando? I ask because my Sprint seems to behave exactly as Eaglerider described:

It's not an F series bike, the Sprint behaves like the Quando, controlled by the battery voltage and giving power assistance beyond 15 mph, gradually phasing off with increased speed but the assist speed reducing as the battery runs out.

 

[bode]

Thanks for that clarification. At +15mph it can be a bit difficult to judge if the propulsion is coming from the pedals or the motor!

 

[DJH]

Thanks for that clarification. At +15mph it can be a bit difficult to judge if the propulsion is coming from the pedals or the motor!

Not with mine, you know instantly when the motor cuts out unless you happen to be starting to go downhill! Not that I wish to appear to be slating my Claud Butler as it does the job that I want, is well built but probably lacks the sophistication of more expensive models. I'll have to wait and see if it's the controller at fault unless there is anybody from Claud Butler out there to clarify the situation?

 

[flecc]

I'll have to wait and see if it's the controller at fault unless there is anybody from Claud Butler out there to clarify the situation?

Claud Butler is a name owned by Falcon Bicycles and used as the brand of some of the bikes they import, including yours. They should be able to answer your question, here is their web contact page.

 

[DJH]

Claud Butler is a name owned by Falcon Bicycles and used as the brand of some of the bikes they import, including yours. They should be able to answer your question, here is their web contact page.

Yes I realised Falcon owned the Claud Butler name but I wanted to see how the system operated on other bikes before contacting them, which I have now done. This bike is replacing a Falcon Olympic that I have had since the 70's and still going strong.
There does seem to be a variety of pedal assist systems available and if you are not fortunate enough to be near a dealer to try different systems you are left taking pot luck. That's why forums like this are very useful.

 

[Eaglerider]

"Of course the only EU/UK legal way is having the full cut-off at 25 kph / 15.5 mph."

I wonder if that's how the wording would be interpreted. If the motor will not assist above the set speed of 15.5 mph then it should be legal.

Of course, if the legislation included the word "motor will not provide ANY assistance above 15.5 mph", then I believe it could still be argued that all assistance related to the 15.5 limit as evidenced by the bike only managing 15.5 if no pedalling takes place. Certainly, in light of the already fairly muddy waters surrounding E-Bike legislation, I think the case could be argued that the system does not have to cease all assistance, merely that it must not by itself be capable of exceeding the set speed by way of power alone on a flat road with no wind at all. As such, it would be a 'legal' bike. Maybe?

 

[steve.c]

Eagle

Hi EagleRider. I also have a Freego Eagle (my 2nd) and one thing I have found is that if you have the throttle button (red) pressed in for throttle only it cuts the power while peddling by about 50% wether its intentional I don't know but I keep checking while riding that it's not pressed in (can't remember the last time I used it on throttle alone??? ) but the Freego Eagle is a great bike and I find on high pedal assist I can keep up a good 18/20 mph on the flat!!.Steve (mines called Eddy????? I know sad eh)

 

[NRG]

The EN15194 regulation states cutoff as: cut off speed: speed reached, by the EPAC, at the moment the current has dropped to zero or to the no load current value...

For production testing there is a 10% tolerance allowed so assistance may continue up to 17MPH...

 

[flecc]

Yes, both the EAPC and EU regulations are clear that the limit is a cut-off of power, not a cessation of assistance.

The EU regulations further provide that the power must phase down as the bike's speed approaches the limit, but the profile of the phase down is not specified. Pity the poor Japanese, their power phase down profile is tightly specified in law with the power reduction starting at 9.4 mph! (15 kph)

 

[Eaglerider]

Wellll! I mean, EU regs are silly anyway, but you are probably right Flecc and NRG.

Hi Steve C. Great to hear from another 'Eagler'. I dont use the throttle much at all these days, a bit of light pedalling just seems appropriate. If I do use the throttle, I switch the pedelec off completely with the minus button and then switch the throttle on. I was told by the seller that if the controller receives signals that conflict from the throttle and the pedelec sensor at the same time, it can get confused and shut off the power, so I avoid the issue.

One feature I had not anticipated was the automatic steering. Regardless of what direction I set off, I always seem to arrive at the pub sooner or later. Funny that!