Tongsheng TSDZ2

[stodd]

There are very few examples of real cases. (The question also arises quite often on the pelelecs forum). There was one high profile one a bit over a year ago where the rider was clearly riding much too fast and dangerously on a clearly illegal machine and killed a pedestrian. The pedestrian was partly at fault. They only took a fairly high charge to court (?? causing death by reckless riding ?? or similar) and did not add lesser charges for dangerous riding or for the illegal bike. He got off on the high charge because of the contributing carelessness of the pedestrian; and it was then too late for them to bring the lower charges.

I repeat my earlier post ...
All the evidence so far is that breaking the rule is hardly risky at all. Even cyclists (motor-cyclists really) who clearly broke the rules by significant margins and rode very dangerously as well seem to have got off almost scott-free.

There remain two big risks.
(1) If you are involved in an accident and they choose to throw the book at you there is potential for huge penalties.
(2) They may decide to tighten up on enforcement (and personally I hope they do (***)), leading to problems even for safe riders with illegal bikes.

(***) but first clamp down on illegal scooters

[bikes4two]

Thanks for that stodd and I agree about the scooters and so on.

Other risks in my life include many things including general health, heart function and other 'getting on a bit' issues, to say nothing about the impacts of climate change and the plethora of other global events.

Thus whether my TSDZ2 (the subject of this thread) is 250w or more and restricted to pedal assist and 25kmph, is way way down my list of concerns.

[hemo]

No there are no cases to go on, mainly because there haven't been any that have been tried. The risk though still remains, It is ebike forum users duty to point out the obvious so folks know where they stand.
In the last few years only three cases I have come across in the UK of bike cases bought to court /trial only one though involving an ebike.

Police seemingly don't have a mandate or resources to crack down on ebikes, many cases of blatant uses of ebikes can be seen on the roads/ some on a daily basis as well. Many folks on forums discussing there illegal builds and dongling of Bosh bikes et al.
Mostly as long as one is riding sensibly then attracting attention isn't warranted.

I have a seen a guy locally riding a 2 stroke 50cc type engine mounted in to a MTB frame, and he rides on the pavement a lot. He can't be missed from the noise it makes.

[bikes4two]

The risk though still remains, It is ebike forum users duty to point out the obvious so folks know where they stand.

It absolutely is - I couldn't agree more. What is equally important though, it to put the risks into perspective (I get a bee in my bonnet when people claim things like 'high risk' or whatever, without substantiating what they say).

[hemo]

Even if a bike is legal plod can and will confiscate or take the bike away, because they don't know the regs/rules.
On pedelecs sometime ago plod confiscated a 250w e cargo bike because one of them erroneously worked out the watt rating by using the battery spec, It took the intervention of a fellow forum user (by way of a letter pointing out the rules) before the guy was able to get his bike back.

[Slowtwitch]

+1 for the risk factor, plod round our way ignore ebikes completely. They've really got too much to deal with in terms of a hardcore of local criminals who habitually break the law to even acknowledge ebikes, nevermind wattage and power output of an electric bike.

[pete75]

The labels on the four TSDZ2 I've fitted this month only state the voltage and RPM (36v, 4000 RPM)

The label on my TSDZ2 says maximum continuous power 250 watts. It also states conformity with EN 15194, max speed 15.5 and that riders should be 14+. I think the law requires this labelling.

[Slowtwitch]

The law, it appears, is an ass.

[bikes4two]

The label on my TSDZ2 says maximum continuous power 250 watts. It also states conformity with EN 15194, max speed 15.5 and that riders should be 14+. I think the law requires this labelling.

- the label can say anything it likes but what's in the tin?

[pete75]

The label on my TSDZ2 says maximum continuous power 250 watts. It also states conformity with EN 15194, max speed 15.5 and that riders should be 14+. I think the law requires this labelling.

- the label can say anything it likes but what's in the tin?

Presumably as I ordered a 250watt motor that's what it is, unless you've evidence Tongsheng are making false claims about motor power outputs.

Think you need to learn a bit about metallurgy too. The motor casing is aluminium not tin.

[stodd]

Presumably as I ordered a 250watt motor that's what it is, unless you've evidence Tongsheng are making false claims about motor power outputs.

The confusion is that the 250w is a rated/continuous power. Tongsheng (and Bosch, Bafang and all the rest) don't exactly make false claims, but they do tailor their claims to the legal requirements of each market. Most markets apart from the US agree on the 250w 25kph rule. The interpretation of 25kph is fairly straightforward, but the interpretation of 250w most certainly is not.

It's common in engineering to face the problem of not overspecifying, and deciding how large a safety margin to leave. It's less common to have this issue of the need to underspecify.

[bikes4two]

Presumably as I ordered a 250watt motor that's what it is, unless you've evidence Tongsheng are making false claims about motor power outputs.

I'm curious to know who you bought your TSDZ2 from - I'm guessing it wasn't Tong Sheng direct?

Clearly there are many suppliers of this motor and equally clearly labels are easily obtainable to say different things.

It is a fact that the motor can be configured to deliver different amounts of power and although your label says what is does, you'll have absolutely no ready means of measuring the power output.

Let's look at some simple arithmatic here:
> 250w from a nominal 36v battery gives a battery current draw I = P/V = 6.95Amps
> Now lets say you have a 17Ah battery?
> Theoretically then you could draw 6.95A from this battery for 10 hrs implying you could power your ebike along for 10 hrs on max power?
> Clearly this is not the case and that is because the motor at various times during your riding, is drawing more that 6.95A (ie more that 250w.).

Yes, I know that is a VERY simple approach to this but it does show that at various times the motor is taking more than 6.95A (250W)

I'm happy to be corrected on this over simplification as my knowledge of these things is limited.

[rjb]

If you draw almost 7 amps from a 17Ah battery it will be fully discharged after 2,1/2 hours.

[stodd]

but it does show that at various times the motor is taking more than 6.95A (250W) Absolutely.

It's really the controller that determines maximum power; so a 17amp controller at 36v will allow 17*36 = 612w.
Two big caveats: the battery must be capable of delivering the amperage, and that is power in: motor efficiency will considerably reduce the power out. Also a 36v battery voltage will range from over 40v down to around 30v depending state of charge.

The 250w is meant to be continuous power. Most so called 250w motors can deliver 500w for short periods, many 750w or even close to 1000w.

[pete75]

Presumably as I ordered a 250watt motor that's what it is, unless you've evidence Tongsheng are making false claims about motor power outputs.

I'm curious to know who you bought your TSDZ2 from - I'm guessing it wasn't Tong Sheng direct?

Clearly there are many suppliers of this motor and equally clearly labels are easily obtainable to say different things.

It is a fact that the motor can be configured to deliver different amounts of power and although your label says what is does, you'll have absolutely no ready means of measuring the power output.

Let's look at some simple arithmatic here:
> 250w from a nominal 36v battery gives a battery current draw I = P/V = 6.95Amps
> Now lets say you have a 17Ah battery?
> Theoretically then you could draw 6.95A from this battery for 10 hrs implying you could power your ebike along for 10 hrs on max power?
> Clearly this is not the case and that is because the motor at various times during your riding, is drawing more that 6.95A (ie more that 250w.).

Yes, I know that is a VERY simple approach to this but it does show that at various times the motor is taking more than 6.95A (250W)

I'm happy to be corrected on this over simplification as my knowledge of these things is limited.

Is it really any of your business who I buy stuff from? If you must know I can't tell you because I can't remember - it was over two years ago. I do know it came direct from China. BTW a 17Ah battery would discharge in under 2 1/2 hours with a load pf 6.95A.