Not that roller drive way I hope Hal!

 

I think the Suzhou Bafang used in the Quando is a much better proposition, using nylon gears. There's a small amount of the usual electric growling whine from very low revs, but it's quiet at normal speeds. Only slightly larger than the Nano and a half kilo heavier which I don't see as crucial, it comprehensively outperforms the Nano.

 

15 mph on a low battery, 18 mph fully charged, coupled with climbing 12% on an all up weight of 100 kilos including standing starts, without any pedalling. The controller seems tough too. I've often left it switched on when fully charging, which is supposed to be a bad thing according to the maker, but it's never protested, and will tolerate slight over-voltage.

 

Snag is, it's only geared for that in a 20" wheel, though they may make different versions. And of course, with that performance the range is shorter, though I can squeeze over 30 miles on the Q bike from 10 Ah at 36 volts on a new Li-ion.

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I am sure that the Suzhou Bafang works well in a 20 inch wheel but doesn't do it for me in the Torq. Now I am fitter what I want is less drag above 15mph so looking forward to the Agattu and its zero drag. That will do the business for me.

Of course Hal. As I said in my intro to the Q bike, I think putting that Quando motor into 28" wheel was the wrong way to go, hopelessly overgeared and provoking more noise, just for the sake of a headline speed.

 

The Agattu or any Panasonic motor bike is an infinitely better pure cycling experience than any hub motor though, no matter how free the motor. Bike wheels are best just as bike wheels, nothing added.

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I think my problem is controller but it could be motor - I can't tell for sure. As there's no alternative sensorless controller that I can get for my type of motor, wherever the current problem lies, I am exposed to controller faults. Since I got my kit there have been more problems with not just controllers but the motors too. In particular, the chap in Australia who i based my set-up on, has had his motor (not controller) fail. Now John has had motor problems.

 

Given all of this, I can't get enthusiastic about fiddling around with it further. I do hope that everyone's motors continue to perform as they are truly great when they work. If an alternative 36v sensorless controller emerges, I'll certainly get one and give it a go. But I can't get enthusiastic about trying to get another Tongxin one, fiddling around with it and having it fail within a forthnight.

 

I did toy with the idea of getting a Suzhou Bafang (which comes in a broad range of speeds) and doing something similar. The motor seems, powerful, reliable and robust, but, as Hal says, it doesn't quite have the wow factor of the Tongxin - it might work better, but it's a bit bigger, a bit more resistance, a bit noisier, a bit heavier...

 

So I've given up on electric kits for the moment at least.

The Agattu or any Panasonic motor bike is an infinitely better pure cycling experience than any hub motor though, no matter how free the motor. Bike wheels are best just as bike wheels, nothing added.

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I would agree with that absolutely for every other hub motor I have used - certainly including the Suzhou Bafang on my Wisper. But I do think the Tongxin is in a different class! I've not ridden an Agattu but I feel my diamond frame bike with a Tongxin is at least as pleasant to ride unpowered as a Lafree, with the more rigid frame helping and the tiny motor almost unnoticeable.

 

I feel my diamond frame bike with a Tongxin is at least as pleasant to ride unpowered as a Lafree, with the more rigid frame helping and the tiny motor almost unnoticeable.

 

So I understand Frank. I was thinking more of the added weight and inconvenience of a hub motor's connections when remarking a bike wheel is best just as that, nothing added, and the least weight to react with the road surface.

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I agree with that - from a cycling viewpoint, I see Tongxin hub motor as the next best thing to no hub motor at all!

I agree with that - from a cycling viewpoint, I see Tongxin hub motor as the next best thing to no hub motor at all!

 

But not as good as a Panasonic unit in the middle though! Weight in the best place, low and central.

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I think my problem is controller but it could be motor - I can't tell for sure. As there's no alternative sensorless controller that I can get for my type of motor, wherever the current problem lies, I am exposed to controller faults. Since I got my kit there have been more problems with not just controllers but the motors too. In particular, the chap in Australia who i based my set-up on, has had his motor (not controller) fail. Now John has had motor problems.

 

Given all of this, I can't get enthusiastic about fiddling around with it further. I do hope that everyone's motors continue to perform as they are truly great when they work. If an alternative 36v sensorless controller emerges, I'll certainly get one and give it a go. But I can't get enthusiastic about trying to get another Tongxin one, fiddling around with it and having it fail within a forthnight.

 

I did toy with the idea of getting a Suzhou Bafang (which comes in a broad range of speeds) and doing something similar. The motor seems, powerful, reliable and robust, but, as Hal says, it doesn't quite have the wow factor of the Tongxin - it might work better, but it's a bit bigger, a bit more resistance, a bit noisier, a bit heavier...

 

So I've given up on electric kits for the moment at least.

 

Yes I remember at the time advising people to buy the hall sensor version as this doesn't tie you in to the Tongxin controller. From memory I think that you had already bought your motor so the advice didn't help you. I can see you would lose enthusiasm for the project after all the problems you have had. And I agree with you that it is the nearest thing to not having a hub motor, I do notice it when setting off but once on the move it is pretty good.

 

I did toy with the idea of getting a Suzhou Bafang (which comes in a broad range of speeds) and doing something similar. The motor seems, powerful, reliable and robust, but, as Hal says, it doesn't quite have the wow factor of the Tongxin

 

- it might work better, but it's a bit bigger, a bit more resistance, a bit noisier, a bit heavier...

 

 

But compared with the other geared hub motors, it's a bit smaller, a bit less resistance, a bit quieter, and a bit lighter.

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Yes I remember at the time advising people to buy the hall sensor version as this doesn't tie you in to the Tongxin controller. From memory I think that you had already bought your motor so the advice didn't help you. I can see you would lose enthusiasm for the project after all the problems you have had. And I agree with you that it is the nearest thing to not having a hub motor, I do notice it when setting off but once on the move it is pretty good.

 

Yes, I remember you saying that, and yes, it was after I'd bought mine!

But compared with the other geared hub motors, it's a bit smaller, a bit less resistance, a bit quieter, and a bit lighter.

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I actually find it pretty similar in those respects to the one on the Powacycle. I've not found a label on that one - maybe it's because it is a Bafang as well?

I actually find it pretty similar in those respects to the one on the Powacycle. I've not found a label on that one - maybe it's because it is a Bafang as well?

 

Unfair comparison Frank, the Powacyle is a peak power of 276 watts, the Suzhou 576 watts, more than double. In fairness it has to be like with like.

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That's true, but isn't that output driven by the controller not the motor?

I've no idea what a Powacycle motor could do if someone was minded to fit a 36v controller and battery. I suspect it would be able to do a lot more. I really wouldn't be surprised if it was a Bafang as it is a similar size as that on my Wisper - and they do share a lot of other components!

Yes, it would produce just over 400 watts on 36 volts, but that's still a very long way short of the 576 watt Quando motor, which isn't the same as the Wisper one. The Wisper had some construction differences, is a lower geared hub, and judging from performance reports has a bit less power, though more range.

 

As a major supplier to manufacturers, I'd guess Suzhou have a few motor models. The new Torq 2 has yet another variation.

 

I still say that the Quando motor is very much lighter smaller etc than other geared hub motors, when compared like for like. It's natural competition is with Heinzmann, Powabyke and eZee's Sprint motor, siting around the same power areas, and it's very much smaller, lighter and quieter than any of those.

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They do have a lot of models with different speeds and configurations.

 

Presumably with a different controller the Powacycle motor could be given more Amps too? For all I know that might fry it but I can't otherwise see why it couldn't be done. The Austrian chap who sells kits on ebay once told me that the different spec motors were basically the same but it just depended on what power you got the controller to give them. Anyway - I will shut up as don't want to make a big deal of it as I agree with your main point that it is a pretty neat hub motor!

 

Yes, the Wisper one is significantly slower geared than the Quando motor. I think the Quando/Torq is a 280 rpm and the Wisper one is most likely 235.

 

Presumably with a different controller the Powacycle motor could be given more Amps too? For all I know that might fry it but I can't otherwise see why it couldn't be done. The Austrian chap who sells kits on ebay once told me that the different spec motors were basically the same but it just depended on what power you got the controller to give them.

 

 

Yes, most motors can have more stuffed into them, though for efficiency and range it's better to use the designed job. Designing in the extra capability with adequate safety margins is where the extra size and weight comes from of course, but if small and light is wanted, over-running a lesser model is a good ploy.

 

Some of the motors in the model world have incredible outputs from tiny sizes, but unfortunately their noise outputs are just as incredible usually.

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Rip?

 

A lifetime of engineering instinct tells me the drive system is a rotten design anyway, but doubtless someone will tell me how wrong I am again.

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Your instincts may be correct Flecc, but most of the issues I had appear to be more down to quality control.

 

When I first opened the motor I was surprised at the roller drive. I'd not come across such a design before and wondered why it did not slip. I was also concerned that there didn't appear to be any take-up of wear.

 

However, having dismantled 3 motors now, I believe that the force between the rollers means that there is no way that the motor could produce enough torque to cause a slip. It may be that tension in the outer gear ring is enough to take up any wear. I know that there have been reports of slip, but I have not heard any being confirmed by dismantling the motor, which is necessary. Those reports may be down to a broken gear ring or slipping freewheel or gear components significantly out of tolerance at manufacture.

 

So I wouldn't write of the design just yet. I had hoped that after my early model failed, TongXin might have improved there quality control. Sadly that doesn't seem to be the case and it may be too late for that company now. However, I would say that it could be worth other companies looking at a similar design. They would need to get manufacture and testing right from the start though!

Like you, I believe that QC seems to be the major problem. As I understand it, Tongxin is a university-based company, so the focus is on innovation, rather than production engineering.

 

I think the design is sound, provided the tolerances are maintained. The wear rate of roller bearings (which is really all this is) is extremely low. Car wheel bearings, for example, run under pre-set pre-load as sealed units for virtually the life of the car. I think that the roller drive system has the potential to last several tens of thousands of miles before wear becomes a problem, if engineered properly.

 

I've no doubt that if a good quality-engineering company took on the Tongxin design then the reliability issues would be resolved quickly.

 

Meanwhile, mine is going to start getting a serious work out now. I was involved in a nasty car accident yesterday, so am temporarily minus a car.

 

Jeremy

Yes, I fully agree that QC is a problem with much that we receive now.

 

I'm sure if the Tongxin design was made by Heinzmann or the like, it would be a better prospect for long term use, but it's not, so I tend to warn as I find, real world situations that people buy into rather than what can be.

 

I can only go by US reports of drive slip, mostly on large wheel applications. However, I still don't like the principle and am not so sanguine about long term prospects, especially given the manufacturing source and aforementioned QC problems.

 

Sorry to hear of your accident Jeremy. I hope you were not hurt in any way.

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I wasn't physically hurt at all, but the pedestrian runner who ran across the dual carriageway right in front of me is in a very bad way. I can honestly say that the sickening sound of a fellow human being coming through the windscreen is one that I'll never forget though.

 

Seeing the effect that a motor vehicle can have on the human body has been a pretty traumatic experience. I'm only thankful that I was going relatively slowly; a few miles an hour faster and the outcome would almost certainly have been fatal.

 

Jeremy

A horrible experience Jeremy, but thank goodness that pedestrian's foolishness didn't have a worse outcome.

 

Nothing I can say other than sincerely hope you are able to move on without dwelling on such a disturbing event.

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Heck Jeremy, I am really sorry to hear that for both of you.

 

Not sure what else to say. Perhaps you'll let us know how the pedestrian gets on.

I've just heard from the police that the runner is semi-concious, but stable. The good news is that he is likely to pull through, albeit with a very lengthy stay in hospital. The doctors are hopeful that the surgery to save his foot has been successful, but won't know for sure for a few days yet.

 

Apparently he's not in a fit state to give an account as to what happened, and may never be able to, apparently. His parents seem to be at a complete loss as to why their son was running across a busy dual carriageway, they always believed that he stayed on the footpath. I can't begin to imagine how they feel.

 

My car, which isn't yet three years old, may well be a write-off, apparently, which gives an idea of the severity of the impact. The only thing that contacted it was this poor chaps body.

 

Jeremy

After four mechanical motor failures in a little over a year's use I think it may be time to throw in the towel:( .

 

Make that five motor failures