Tonaro and Momentum reviews in new A to B issue 92

[NRG]

I like my Panasnic PCs but I'm under no illusion that there are better systems out there now. It still works really well though and it's best point is the reliability and the very natural way it rides without the power on...really extends the range.

 

[10mph]

the Panasonic "clunk" is always being discussed on German pedelec

Eddieo,
Which thread? I dont know German, but I tried searching for Panasonic Knacken and found this thread:
"Knackgeräusch" beim Panasonic Mittelmotor Kalkhoff Agattu XXL
Reading the results of a Google "translation" makes me wonder if they are discussing the "tick" or rather faint click that is sometimes observed on these units, eg the discussion here at http://www.pedelecs.co.uk/forum/electric-bicycles/6379-panasonic-kalkhoff-crank-play.html.

I have ridden on 3 Panasonic Kalkhoff Agattus and I also had a one week test ride of an Agattu with the new Impulse motor. None of these has emitted anything like a clunk from the motor. The worst you get is a loud click from the hub gear if you try to change gear without freewheeling for half a second or so.

I have occasionally heard faint tick apparently synchronised with the pedal rotation, but it does not seem to indicate a significant mechanical problem, and it is quiet enough not to be annoying given the woosh of the tyres on the road surface, and the sound of the wind in one's ears.

 

[flecc]

The way in which the power delivery is controlled on the Panasonic units means it's inevitable there will be some pulsing, it's meant to work that way, tracking the muscle effort and adding to it. There are some people who just cannot get on with this system, I think because their physiology doesn't naturally reconcile the mismatch of effort input and response output, For everybody this is momentarily disconcerting when they first try the system, particularly when a light press on a pedal produces a fast getaway, but the majority quickly adapt to it.

Hub motor systems don't have this problem since they are clearly a separate power source divorced from personal effort, particularly when throttle controlled, so there's no physiological balance disturbance.

 

[Deleted member 4366]

Just to make it clear, the clunk I experienced on the 36v Panosonic unit was like a pre-engagement. When I rested my foot on the pedal there was some mechanical activity in the motor even though I didn't move - like when you engage first gear on a car before you set off and there's a small amount of clutch drag. I don't remember this happening on the 26v Panasonic.

 

[Patrick]

So what happens with my Kalkhoff Agattu, with the proportional torque control, when I hit one of the hills which you describe? I often ride on minimum assist - I provide 2/3 of the power, and the motor provides 1/3. That way I get some good quality exercise taking into consideration my age and fitness. When the slope increases and I realise that I will soon start to slow, with my left thumb I can give the assistance-increase button either one press (which gives 1/2 power from me and 1/2 from the motor) or two presses (which gives 1/3 power from me and 2/3 from the motor). That is up to a fourfold increase in motor power if my power remains constant, and this can get me up all but the steepest of hills without increase of my effort. Actually if the hill is not too long I may also increase my own pedalling power, because I can look forward to some recovery after cresting the summit.

Not having completely independent control of the amount of assistance I get when climbing wouldn't suit my riding style. I take having fine moment-by-moment control of the motor for granted, and having just three modes which influence but don't in themselves determine the level of assistance would feel cumbersome unless I changed the way I rode.

You're right that the loss of power when you make hand signals does feel cumbersome, I've resigned myself to having to do without any help when I'm turning right, but for me that is offset by the level of control I have over the motor when I'm climbing.

I suppose that any control system will feel cumbersome or crude if it doesn't match your riding style.

 

[flecc]

Just to make it clear, the clunk I experienced on the 36v Panosonic unit was like a pre-engagement. When I rested my foot on the pedal there was some mechanical activity in the motor even though I didn't move - like when you engage first gear on a car before you set off and there's a small amount of clutch drag. I don't remember this happening on the 26v Panasonic.

It sounds like they've added a form of start control to deal with the increased power on that unit Dave. The usual kick-off the mark with some pedal pressure could be even more disconcerting for many with the higher power, so there may be a torque sensing pressure point to get past before the motor is permitted to start driving the transmission.

A bit crude if so. I doubt the power pulsing system that the Panasonic unit uses is really suitable for high powers, it was certainly smoothest of all on the original unit which was lower powered and had no high power mode. Interestingly member 10mph mainly uses the low power Eco mode so would also get the smoothest results for most of his riding.