Yes Derrick, the Forza would have to be ridden with power shut off a lot of the time to match the Panasonic unit's range, and with a hub motor bike that would be very difficult to do.

 

Range sometimes isn't all that important though. For the many doing up to 10 miles each way on a commuting journey, most newer e-bikes handle that, so for them, performance can be used to the full, regardless of the effects on range.

 

As commuters value their free time of course, the quickest possible journey can be more important to them than outright economy.

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Yes Derrick, the Forza would have to be ridden with power shut off a lot of the time to match the Panasonic unit's range, and with a hub motor bike that would be very difficult to do.

 

I can understand that the Panasonic drive is fairly low drag, so doesn't impede pedalling very much, but why should a hub motor necessarily be worse?

 

I'll have to admit not having finished mine yet, but I have the wheel mounted in the forks and it seems to free wheel very easily indeed, in fact I can't detect any appreciable drag from the hub motor. I believe that Frank has done a "real world" test recently by riding his bike with the motor off and found similarly that there's no real drag from it.

 

Even the big Crystalyte motor I have doesn't really give much drag, although the magnetic cogging at low speed makes it feel as if it does (a bit of analysis soon shows that cogging is a virtually drag-free phenomenom, even though it fooled me into thinking otherwise for a short time!).

 

I'm guessing here that some of the geared hub motors with no freewheel (are there any?) would give some added resistance with power off, from driving the epicyclic gearbox, but this doesn't seem to be the case for all, or even, perhaps, the majority of hub motors.

 

Jeremy

Another thing to consider is battery life,the ezee lithium batterys have a hard life with all that power, and there are many cut out problems reported on this forum,the kalkhoff battery should last far longer as it is using a lot less power(better suited to lithium batteries),with replacement batterys costing around £300 each this can add a lot to running costs.

Wait 'til you ride it Jeremy!

 

Most wheel hub motors spin very freely when it's manually done, but if you glance at a speedo while doing that, you'll typically see around 3 or 4 mph.

 

In practice on the road, all hub motor bikes are a pain to pedal without power compared with the Panasonic system, there being no comparison. The reason is not the motor of course, since that almost always has a freewheel, it's the orbital gears that have to be driven by the wheel. Quite why they create so much drag at 12 to 15 mph is a bit of a mystery, but as all of us who've ridden both know, they certainly do.

 

Basically, a good Panasonic powered bike with power off on the flat feels just like an ordinary bike, something no hub-motor bike can ever seem like if it's switched off. I strongly disagree with anyone who says hub motors add no drag. That's why hub motor bikes have no off-switch on the handlebars, since it would be no use, while all Panasonic powered bikes do have that off-switch right next to the handgrip, where riders can and do use it all the time.

 

N.B. A few hub motors have no freewheel, notably the original Suede motor and those intended for regeneration of course, like the new Twist.

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Edited January 10, 200818 yr by flecc

Hmm... So even a geared hub motors that can free wheel would ride with enough resistance that you would notice it? I thought the new ezee hub motor kit that they sell at ebikes would have little to no motor drag.

I know my crystalyte motor does have a fair bit of drag. If I keep the speed below 20km/h, it's not too bad. But I wouldn't want to ride much faster manually.

Yes, speed is the answer as I indicated jha07. They all feel very free to the hand, but as road speed rises the drag sets in.

 

I've tried everything on the eZee motor from the Torq and Quando bikes to achieve completely free running when creating the Q and T bikes as those who've read about those know, but even when all conditions are made as perfect as they could be by optimising, they don't begin to compare with a good ordinary bike, or the Lafree Twist or Kalkhoff Agattu.

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In practice on the road, all hub motor bikes are a pain to pedal without power compared with the Panasonic system, there being no comparison.

 

Well, this is simply incorrect, as I have pedalled my Crystalyte at speed and the only adverse effect is the peculiar gyro-like effect from the heavy motor. Similarly, Frank pedalled his hub motor bike recently, power off, for about 10 miles, I believe, and reported that the hub motor made little difference.

 

I can accept that, as I said above, if gears are rotating then there will be some drag, but there are no gears to rotate in many hub motors, plus some seem to have a free wheel that disconnects the gears anyway.

 

Sorry, I can't see how all hub motors can be said to be draggy, when it's quite clear that a large number of them aren't.

 

Jeremy

The Tonxin motor does have less drag than most hub motors I have tried. I am sure that the drag is more than the Panasonic drive (which I have never tried) but it is very different to the Ezee motor (in the Torq) which feels difficult to ride without power. There are disadvantages to roller drive but the payoff is the ease of riding without power.

the powabyke and sakura motors also have very little drag,they really pick up speed quickly downhill with all that weight.

Wrong.

 

No orbital gear hub motor bike has the same drag as a normal bike.

 

To claim so is simply irrational, since the orbital gears cannot have zero drag.

 

Perhaps those who say that they add no drag will explain why none of them have an off-switch to hand when riding to improve the economy, while every bike over seven years using the Panasonic system does have, giving them the big marketing advantage of a comparatively long range.

 

Jeremy, you've misinterpreted the freewheel function in hub motors, the freewheel disconnects the motor from the gears, the gears are always connected to the hub via it's orbital ring which is embedded in the hub, and therefore always engaged with the wheel, the orbital set having to be turned by it all the time. The drag on the Tongxin hub will be lower since it's a roller drive, no gear tooth engagement drag.

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Edited January 10, 200818 yr by flecc

No orbital gear hub motor bike has the same drag as a normal bike.

 

That I have already clearly accepted, twice, so please don't tell me I'm wrong when I had already agreed this point. You wrote this though, which is what I take issue with, as it seems unfair:

 

In practice on the road, all hub motor bikes are a pain to pedal without power compared with the Panasonic system, there being no comparison.

 

"All hub motors" includes many, like the Crystalyte, Goldenmotor etc, that have no gears, rollers or other mechanical connection (other than bearings) between the axle and the hub. Quite obviously a gear-less hub motor cannot be significantly different to a normal hub, particularly as they most probably have better bearings than some cheap bike hubs. I can also say with confidence that the freewheel drag from the roller drive TongXin seems very low, it certainly doesn't feel as if it will be significant, even at speed. This is further borne out by the Brompton Nano road test, where the ease of pedalling resulted in the rather extreme range reported!

 

If you are being specific about one particular hub motor, based on your experience, as I believe you are, then it seems unfair to imply that all motors of this type suffer from the same defect to the same degree.

 

Jeremy

If I understand correctly, the Panasonic system drives the chain. So at the very least, there is still a sprocket rotating when its turned off and the rider is pedalling. It shouldn't be that different in drag to a well engineered hub motor. If they both have a freewheel to disconnect the motor, surely there are broadly equivalent amounts of rotating parts left turning.

 

Nick

Jeremy, this arose from my answering specifically a question about the Forza versus the Agattu, from which it is abundantly clear that I was speaking of the mainstream orbitally geared hub motors. Do you really require me to state in every subsequent reference all of those italicised words, when I come in here to post in help of other members as I was doing then, and not to have to defend myself as I increasingly seem to have to lately?

 

As for your comment on experience, I've had a long association with e-bikes and can instantly recall ten hub-motor bike/kit models and six Panasonic equipped bike models that I've experience of over the years, plus ownership of both types. You're aware of the limits of your experience in this area.

 

And that highlights the difference. Yours is a subjective comment, mine is based on experience of the comparisons. The fact that a rider like yourself or Frank Curran find a motor easy to pedal has no meaning in comparison with what another person finds, each being merely an expression of rider capability. Experience has to be like with like. Every orbitally geared hub-motor bike I've ridden has been a bit of a pain for me to ride with power switched off for more than a short distance, while I've often ridden for miles on the Panasonic equipped bikes with hardly any more effort than on a normal bike.

 

That ratio of effort difference will hold good for any other rider, and it's been the often commented on universal experience of those who've ridden both to any extent. And I repeat the important point you've ducked, that's why these hub motor bikes don't have an off switch on the handlebar, it having no possible function for the great majority of riders.

 

All the Panasonic equipped bikes do, as it's useful enough to be frequently used for range advantage.

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Edited January 11, 200818 yr by flecc

If I understand correctly, the Panasonic system drives the chain. So at the very least, there is still a sprocket rotating when its turned off and the rider is pedalling. It shouldn't be that different in drag to a well engineered hub motor. If they both have a freewheel to disconnect the motor, surely there are broadly equivalent amounts of rotating parts left turning.

 

Nick

 

See my comments above on experience Nick. Ride both and the theory instantly disappears, there being no comparison, as all who've ridden both to any extent confirm, and have done so in here many times.

 

In fact there isn't engineering equivalence, but I won't go into the lengthy explanation of the reasons why that's so.

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I used a Heinzmann kit and would not recommend buying one. They are well engineered but very heavy and noisy. The whine from the motor (downside of metal gears as opposed to plastic) is irritating and ruins country rides when all you want to do is ride along quietly. The motor is a brushed motor which will at some point require brushes (Heinzmann said after 10,000 miles but I'm not sure about that) Also, the Heinzmann kit is 100% throttle controlled. The throttle assembly is actually Italian and very bulky. It interfered with the brake lever and gearchange lever on my bike. Because the kit is not pedal controlled in any way, it's easy to use the throttle (and therefore battery power) and not pedal enough. Also, the kit is expensive.

 

I was very disappointed with my Heinzmann kit. I may be wrong but, to me, it looks like old technology. Big, solid and heavy and no doubt lasting a long time but still old.....

PS. On my Wisper 905e, I found no resistance at all (that I could detect at any rate) from the motor when pedalling with the power completely off. What kind of motor would that be then? Does it have orbital gears?

The Wisper does have orbital gears Jimmy, and they are reported as low drag by others. However, you would still be surprised at the difference to the Panasonic system.

 

The Heinzmann difference is that it's not a balanced drive system. Orbital geared hub motors normally have three circumferentially equidistant gears between the centre drive gear and the orbital ring, therefore having almost neutral radial thrust, but the Heinzmann has a single gear just ahead of top centre driving the orbital toothed ring in the hub, therefore having an unbalanced thrust present all the time. It also has a fixed motor wall on one side, with the bearings for that at the periphery, an obvious mechanical disadvantage.

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Edited January 11, 200818 yr by flecc

Hi Flecc. Could you explain what the effects are of unbalanced thrust please? The Heinzmann motor felt like the drive was cutting in and out all the time, even though the motor was still spinning and it was working fine (if you see what I mean?) Pretty soon, I'll be able to comment on the Panasonic setup in the Agattu!!

Because the teeth on a typical gear and it's orbital gear ring are tapered in profile, they form ramps, and when drive thrust is applied, the slope of the ramp of an engaged gear tooth tries to force the teeth out of engagement.

 

With a one sided driving gear wheel like the Heinzmann, that means the orbital teeth are trying to force the gear wheel away towards the hub centre.

 

When three slave gearwheels transmit drive from a centre gear wheel to the orbital ring, the thrust is present on both sides of the three orbital gears, so they are held in balance between centre and periphery, hence not suffering the same mechanical losses.

 

In addition, there are two forms of the Heinzmann drive. On the version we call the 200 watt, the gear is nylon, on all the higher powered versions it's steel. I'm guessing you had the 200 watt motor, and the nylon gear teeth had suffered distortion and wear, this giving uneven drag and drive thrust like that you experienced.

 

Why nylon? It's by far the quieter on that mainstream consumer model, the noise of steel gears being less important to the performance types who buy the higher powered versions.

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Edited January 11, 200818 yr by flecc

Actually, mine was the 500W motor with steel gears. A bad choice on my part, I'd say. Presumably it needs steel gears to cope with the power output. It was very noisy, I thought and the whine came and went, to some degree, depending on the speed of the bike and whether the motor was actually under load.

 

Please tell me that the Agattu is quiet.... please.... please.....

Please tell me that the Agattu is quiet.... please.... please.....

The Panasonic power unit is reputed to be virtually silent, so make sure you have a good bell:D

freewheel

 

Thought people might be interested that the Tongxin freewheel comes after the gears so the motor and gears are both disconnected when freewheeling. This makes it almost silent and very low drag.

 

John

Yes, Jimmy, as Ian has said. There's just a very faint whoosh with each pedal thrust as the motor assists, and it's even quieter than the previous Panasonic unit, the component hugging contoured alloy casing probably having less "sound box" resonance than the oblong cavern of the older one.

 

Pedestrians can generally only detect that sound in a quiet lane. In any sort of urban environment it's lost in the background mush.

 

The integrated bell is tiny, but has a distinctive high frequency note. Elderly pedestrians might need something louder, though I prefer to merely slow down and avoid them, rather than shock them out of their reverie.

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Edited January 11, 200818 yr by flecc

lease tell me that the Agattu is quiet.... please.... please.....

 

I couldn't think of anything my older panasonic unit sounds like, but the amount of sound is similar to a good motorized wheelchair. You could probably ride it in a library and people would know you're scooting around on something electric, but not be startled.

Thought people might be interested that the Tongxin freewheel comes after the gears so the motor and gears are both disconnected when freewheeling. This makes it almost silent and very low drag.

 

John

 

Yes, that's an advantage of the roller drive design, the free spinning of which I'd already acknowledged earlier in this discussion.

 

It's difficult to arrange a peripheral freewheel in an orbital geared drive, leaving the choices as a motor to centre sprocket freewheel, or a spindle to gearwheel cage freewheel. The latter can allow either the orbital gears to track the hub toothed ring, or their gear cage to track the hub and spin it's gears on the motor gear, or everything except the armature rotating, hub, gear cage and motor rotor, in which case there's electrical drag in generation mode.

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Edited January 11, 200818 yr by flecc