TSDZ2 OSF - Road legal in UK

Nealh

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Aug 7, 2014
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I have one of these on my ute frame for my 48v 250w tsdz2.
2x-eBike-sticker-decal-250W-road-legal-for.jpg

The motor CE label doesn't state 250w.
 

soundwave

Esteemed Pedelecer
May 23, 2015
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DSC_0300_03.JPG
:p
 

Bikes4two

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Feb 21, 2020
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Hi @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.
Please don't think I'm trying to wind you up because I'm not - I just want to be sure of the law, but can you substantiate where it states that just having the means available to change controller power and speed settings makes the bike illegal?

Yes, I can see that if there are 'end user' controls such as hidden switchs or menu options on the handlebar display to alter the settings, then one might have a problem, but just having the ability to change settings via software/laptop/dongle etc surely doesn't in itself make the bike illegal?

I mean, on my 250w 36v TSDZ2, I could if I wished fit a larger voltage battery and alter the software to give around 750w, but being able to do so surely does not make it illegal - if it did, then every TSDZ2 sold in the UK could be deemed illegal, as could motors from the Bafang BBSxx range and the like.
 
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soundwave

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Derestriction, ‘off-road’ switches or modes and dongles

The Department of Transport say that electric bikes fitted with off-road switches or modes, that enable a bike’s motor to continue assisting to speeds beyond 15.5mph, do not comply with UK EAPC law. The term ‘off-road’ suggests that these bikes can be ridden on parkland, forests or other places away from main roads, which isn’t accurate. E-bikes with increased motor power (continuous rated power above 250w) or increased speed (with motor assistance not cutting out at 15.5mph) cannot be used legally as bicycles anywhere on land accessible by the public; when riding on private land you would need permission from the landowner.

https://www.pedelecs.co.uk/electric-bike-guides/uk-electric-bike-law/

so most diy kits have modes that allow you to change the settings where as on my bike this is not a option and why i use a dongle as got no other choice.

it is a point of law but it has never been enforced and these days with scooters skateboards with throttles ect it is now pointless.

i could rip out my controller in the motor and use a 3rd party one but even set at uk law i would still be able to now change the settings and up the amps and dump the dongle.

now go on ebay and try find any diy kit that you cant change anything i doubt you will find any these days but they sell them none the less and gets through customs so they dont give a crap either.

nearly all the riders on just eat use high powerd hub motors round here like 3kw+ and if i order a big mac it comes on one of those lol.

m8 has also had a bafang hd for commuting to work on for the last 2 years with it turned up to the max and that thing can pi$$ all over my bike speed wise and never had a problem.

just dont kill anybody but the first test case was this one and even i could not believe that outcome.

 

peter.c

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Apr 24, 2018
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The option to change a setting to increase the power up or from the supplied programming is more than a minor problem. This changes the type approved / certified as supplied specification so is between the lines or a grey area. Which would open a big can of worms if investigated and the motor was set to 25 amps and 30mph but still marked 250watt and 15.5 mph
 
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Bikes4two

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Thanks for your replies folks - I'm now content that just because I could change my TSDZ2 settings through OSF, providing I don't (and my TSDZ2 was sold as a 250w version), then my motor IS NOT illegal.

And fortunately converting my bike with a kit doesn't require type approval (that's only for bikes manufactured/sold as ebikes).
 

soundwave

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May 23, 2015
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well you are wrong as the fact that you can change the settings means it is not road legal none of them are.

i dont have this choice with a bosch motor unless i use a dongle and that's the point of law that any ebike diy or not must comply with the law.
 

sjpt

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Jun 8, 2018
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Thanks for your replies folks - I'm now content that just because I could change my TSDZ2 settings through OSF, providing I don't (and my TSDZ2 was sold as a 250w version), then my motor IS NOT illegal.

And fortunately converting my bike with a kit doesn't require type approval (that's only for bikes manufactured/sold as ebikes).
I think it depends how easily the switch is made. The law mentions but does not define 'switch'. If it can reasonably be switched while riding the bike, eg by switch or by controls on connected display or phone, then it is illegal even if you don't switch.

If it can be switched but not on the bike, eg by connecting a laptop via a cable, then I believe it is legal as a pedalec as long as you don't ride with it switched.
 

votive

Finding my (electric) wheels
Oct 12, 2022
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I think it depends how easily the switch is made. The law mentions but does not define 'switch'. If it can reasonably be switched while riding the bike, eg by switch or by controls on connected display or phone, then it is illegal even if you don't switch.

If it can be switched but not on the bike, eg by connecting a laptop via a cable, then I believe it is legal as a pedalec as long as you don't ride with it switched.
This sounds correct to me, given the wording of the gov.uk page on EAPCs. It seems like there needs to be 3 things in place in order for the OSF TSDZ2 to be legal in the UK (I'm not a lawyer :) )

1. "electrical assistance must cut-off when the vehicle reaches 15.5 mph" (already in place)
2. "maximum continuous rated power of the electric motor must not exceed 250 Watts". Not sure how this is enforced but I assume it's a physical limitation of the motor? (i.e. the motor will overheat if it runs > 250W for any length of time). Either that or there's a more complex algorithmic software definition of "continuous rated power" that I'm not aware of?
3. The OSF can be flashed to the motor such that settings such as "off-road mode", assist type, max power etc. cannot be changed on the controller in any form (aside from the assist level 1 - 4). Setting are locked in at the point of flashing the firmware.

Regarding point 3, I don't think this is currently in place in the OSF at the moment. You can make it harder for yourself by having to enable the settings mode on the controller before changing settings but in my view that makes it illegal as it currently stands. What's needed is an additional setting in the Java app to say "settings are read-only".

Assuming point 3 is addressed I wonder if that's enough to qualify it as road-legal, or whether there might be additional work needed to address point 2 also.

The gov page: https://www.gov.uk/government/publications/electrically-assisted-pedal-cycles-eapcs/electrically-assisted-pedal-cycles-eapcs-in-great-britain-information-sheet
 

matthewslack

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Nov 26, 2021
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The 'in the public interest' test is probably where the implementation of the law sits right now.

Pedantically all conversions are not legal to EN15194 . But if a conversion respects 250W continuous, 25km/h and not switchable to higher settings without a trip to the workshop, then it is unlikely to be in the public interest to prosecute.
 
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Nealh

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Tsdz2's do get hot when over powered this is borne out by heat issues on ES with their 500/750w models.
My 250w model thus far appears to stay cool and the display shows it stays under 65c when towing, on ES temps in the 90's and above have been noted when they eke out the current and power

My 48v 250w model cuts out at 17mph so still legal and within the rules of EN15194 that permits 10% +/- of 15.5mph/25kmh cut off, the 250w is set at 12a in the firmware.
 
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Danidl

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Sep 29, 2016
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Sure you make a 750w motor road legal just with software ?
I did a little research on this topic back about 3 years ago, and it is actually rather complicated. The pedelec rules regarding power assisted speed is very simple ..eg 25km.hr and no assistance beyond that.
But the motor is a different beast. It is not feasible or desirable to put into law a maximum power to the wheel , so they put in a definition of average sustained power . This is defined in other legislation as relating to temperature rise in the motor over sustained operation. BSI and EU and ISO standards are a huge collection of interrelated standards and any standard can refer back to other standards designed for slightly different purposes. So in essence, if the pedelec has been built or imported by a recognised importer or manufacturer , they are warranting that the bicycle as a system meets the standard for type approval . The motor can be throttled back or protected by voltage or current limits to work legally protected. If you build a self build, you are essentially warranting by yourself that the bike is road legal. For instance were you to buy a hub motor intended for a 16 inch bike and respoked it into a 28 inch wheel , then with the same controller and battery ,it will potentially power assist to 40km.hr...so such an action would be illegal.
To illustrate the difficulty in making a definition of maximum motor power to the wheel.imagine using a 250 watt motor winding up a coiled spring or a flywheel , while you waited the 5 minutes for the lights to turn green. If you released that along with the 250 watts ,you could have a power rating of 5 KW for the ten seconds. As it is any of the motors within the EU /BSI pedelec range can develop perhaps 750 watts over a few minutes ... And still be rated as 250 watt sustained.