TSDZ2 OSF - Road legal in UK

[votive]

I have successfully flashed my TSDZ2 with the emmebrusa firmware. I've set the "Street Power Limit" to 250W as I'm based in the UK. This keeps it legal, but it appears to stop the motor from "peaking" above 250W when I climb hills--a relatively steep hill and I have no assistance from the motor, even at level 4 (I'm using Power Assist Mode). Should I set the street power limit to 500W and then essentially cycle on level 1 and 2 (which are both under 250W) to stay within the law? I have set the Street Speed Limit to 15mph.

 

[StuartsProjects]

Should I set the street power limit to 500W and then essentially cycle on level 1 and 2 (which are both under 250W) to stay within the law?

What is the rated power of the motor ?

 

[votive]

It was sold as a 250W 48V TSDZ2 if that's what you mean? I should say, that with the stock firmware, there was noticeably more power up hills at level 4 than the OSF but perhaps that's because I'm using the wrong assist type?

 

[Bikes4two]

You say when climbing hills you get NO assistance, as in the motor cuts out?

What is your pedal cadence when climbing hills. Anything much over 95rpm will see reduced assistance and above about 115rpm, just about nil assistance (at least, that's how I understand things).

 

[votive]

You say when climbing hills you get NO assistance, as in the motor cuts out?

What is your pedal cadence when climbing hills. Anything much over 95rpm will see reduced assistance and above about 115rpm, just about nil assistance (at least, that's how I understand things).

I don't think the motor is cutting out, more that the assistance isn't enough, given the weight of the bike. Interestingly, if I turn street mode off (which increases the max power to 500W) I fly up the hills, which is why I wondered if the 250W limit means that the firmware doesn't do bursts of power up hills like the stock firmware does.

I cycle with a relatively low cadence. Perhaps one rotation a second?

 

[Bikes4two]

I've not played around with this area of OSF - so I'm just guessing but have you tried un-ticking the 'Street power limit enabled' box even though the dialogue box for 'Street power limit (W)' suggest that peak power's of 500w are achievable (but the accompanying PDF manual with the configurator does say anything either way)?

 

[FJC71]

The legislation refers to a continuous output of 250w for a given period of time. if you exceed that time presumably the motor should fail.

The 250w thus refers to the continuous rated power output, not the maximum available. The screen shot implies you are putting an absolute limit on. This is not how it should work, in practice the continuous output, 250w can be exceeded for a limited time. I dont know what maximum current your controller is set to but at say 15A that's 620w power input available. The street power limit setting on the face of it does not relate to the legislation.

Have you checked the current limit that may be where your issue is, if its adjustable that is.

I have a 48v 250w model and it feels quite lively on hills as you describe, the OSF I believe allows a higher cadence and makes it a bit smoother and quieter, I have not seen any reports of a drop in power. I would conclude that others are not turning on a street limit.

 

[Bikes4two]

As @FJC71 says, peak powers of 500w+ are quite legal (you'll find internet comments on this in plenty and the commercial ebike motors from the likes of Bosch and Shimano and Yamaha are the same)

As an experiment I fitted a handlebar mounted watt meter to see what amps/watts etc were being drawn under different pedalling scenarios, and although my motor is rated at 36v 250w, I saw peak powers of 500w in some cases. (I only use the power assist mode and generally only cycle in ECO where 150w-200w is more like my power demands).

I've just looked at my last configuration - note the arrowed settings - are yours similar?

 

[votive]

These are my battery settings, which I believe are correct:



And these are the settings for Street Mode:



I notice that when I turn Street Mode OFF, I can power up the hills with no problem, so I'm pretty sure it's that 250 Street Power Limit that is causing hills to be so difficult in Street Mode. I think it could be as simple as changing the Street power limit to 500W, and the previous comments have suggested this is entirely legal as long as the upper end of this power is used fleetingly?

 

[jimriley]

Isn't legality covered by what is written on the motor? If it says 250w 48v on motor casing then you should be ok?

 

[FJC71]

I think it could be as simple as changing the Street power limit to 500W, and the previous comments have suggested this is entirely legal as long as the upper end of this power is used fleetingly?

You could do this but if the current is limited 12A your going to get a maximum input of 576 w anyway. I would say exceed 250w for a short period as much as you need to get you up a hill. The real constraint on how much power you use is the durability of the motor ie dont over do it and overheat the motor. If you've got close to stock factory settings you should be ok.

Isn't legality covered by what is written on the motor? If it says 250w 48v on motor casing then you should be ok?

Some do not, mine doesn't, it was an import sourced from Germany, it also cant be flashed. Where did yours and is it labelled 250w?

 

[Bikes4two]

Some do not, mine doesn't, it was an import sourced from Germany, it also cant be flashed. Where did yours and is it labelled 250w?

My TSDZ2 didn't state the power either so as a belts and braces mesure I bought the labels like are shown in the pic below.

BS EN 15194 explains in some length how the power should be measured - you'd need a lab setup to do this so a police officer on the street isn't going to be able to determine this (and if one were stopped by the police, they are likely to check out the PAS speed cut-off limit as this is a very practical and easy check).

I set my max battery current to 15A simply on the premise that that value was well clear of the 18A max - so why not up your current to something more that 12A and put 500w in the street power limit just to see if that makes a difference.

 

[soundwave]

the fact that you are able to change the settings in the controller means it is not road legal even if you set it to 250w and use a sticker ect.

this is why i have to buy a rip off price dongle to remove the speed limit on my bosch bike as no way to get in to the controller settings and that's the point of the law you cant have off road switch or controllers that the user can change themselves.

but you can blast round on a scooter with a throttle from Halfords and plod does not give a crap and run oap over and nothing gets done about it..

so as long as you dont kill anyone or try race the plod chopper down the motor way going 250mph they wont be interested at all.

 

[votive]

Thanks for all the feedback and suggestions. I changed the street power limit to 500W and that made a huge difference. I may also up the current from 12A. I have a manufacturer's sticker on the bottom of the motor that says 250W 48V 15A.

 

[jimriley]

You could do this but if the current is limited 12A your going to get a maximum input of 576 w anyway. I would say exceed 250w for a short period as much as you need to get you up a hill. The real constraint on how much power you use is the durability of the motor ie dont over do it and overheat the motor. If you've got close to stock factory settings you should be ok.


Some do not, mine doesn't, it was an import sourced from Germany, it also cant be flashed. Where did yours and is it labelled 250w?

I've a bafang bbs01b 250w, it's engraved on the motor.
stickers are available on t'internet.

 

[Nealh]

Afaik one doesn't have to alter the wattage limit, just simply untick the street limit enabled box and write the new tab setting to the motor.

 

[FJC71]

I may also up the current from 12A. I have a manufacturer's sticker on the bottom of the motor that says 250W 48V 15A.

Ignoring motor efficiency this would give you a peak of 720w but you would probably have to disable the street limit to get that. You would also have to input 180w yourself to get it.

 

[Bikes4two]

the fact that you are able to change the settings in the controller means it is not road legal even if you set it to 250w......

Why would changing the controller settings, (providing the parameters left the bike within the UK legal limits), render the bike not road legal?

For instance, you may have a 750w motor that you want to make legal and you use OSF to do this.

I think the wider question is, who the heck is (a) going to read the software settings (b) understand them and (c) determine who loaded them into the controller?

Yes, I know some forensic lab somewhere could do this, but hey, what's the likelihood of that happening?

The stickers are IMHO a worthwhile addition to a motor that may not otherwise be so marked.

In case you're wondering, I'm an advocate of legal pedelecs (EPACS).

 

[StuartsProjects]

For instance, you may have a 750w motor that you want to make legal and you use OSF to do this.

Sure you make a 750w motor road legal just with software ?

 

[soundwave]

because you can change the controllers power and speed settings means under uk law it is not road legal as why not use a 10kw motor and set it to use just 250w you still have the ability to change it to what ever you want.

i can not do this on my bike and why i need to use a dongle to remove the speed limit i can not up the power.

so as above you cant use a motor with 10kw and make it road legal as the power of the motor is above the uk limit and you also have the ability to change both power and speed settings.

so they could pull you over and do you for a non legal road bike but it has never happened to date and no one has been pulled over or had there bikes taken away so this law is not fit for purpose anymore as it is never going to be enforced.

and i also dont know anywhere that these bikes would be taken to to get checked either if a case like this came up but would be pretty easy to see that the user could adjust the controllers settings.