DIY eTandem ..newbie

[Steve Wilked]

Hi, We have a DIY eTandem conversion. Only intended as a boost to help us up the hills, it works really well ...though I haven't quite finished my diy regen braking system yet. It has a 250w (not allowed any more on a tandem) basic 3-phase front hub motor with which I had to re-seat all 36 spokes using a rotary burr and needle files as they all curved intro the rim end. It has only a small DIY 36v 4Ah Li-Ion battery. With just that, on a recent 10 mile ride, though mostly flat, it had a few really heavy gradients. We arrived back home with plenty of charge left. Should be even better with the regen, planning more ambitious rides now.
Will post more info about it.
Steve & Carol
Pelsall
W Midlands
UK

 

[Cyclezee]

Hi Steve,

Firstly welcome to the forum.

We have ourselves done several tandem conversions or provided kits for them including a tandem recumbent trike.

Just wondering why you say 250w is not allowed on a tandem anymore?

If that is the case it is new to me.

 

[Wander]

Just wondering why you say 250w is not allowed on a tandem anymore? If that is the case it is new to me.

I think he's saying that any more than 250w is not allowed!

 

[GT3]

Hello, from the far side of the Daw End Branch. Never understood electrics on a tandem, I thought you shouted at her to pedal harder

I think the point is that tandems are allowed 350W?

 

[Cyclezee]

I think he's saying that any more than 250w is not allowed!

​

 

[Steve Wilked]

Sorry if it read wrong, I do mean you are allowed no more than 250w on a tandem, including tricycle....

GOV.UK

EU Referendum On Thursday 23 June there will be a vote on the UK’s membership of the European Union.

Electric bikes: the rules
In Great Britain, if you’re 14 or over you don’t need a licence to ride electric bikes that meet certain requirements, and they don’t need to be registered, taxed or insured.

Electric bikes meeting the requirements are called ‘electrically assisted pedal cycles’ (EAPCs). They can be 2-wheeled bicycles, tandems or tricycles.

EAPC requirements
The requirements are:

• the bike must have pedals that can be used to propel it
• the electric motor shouldn’t be able to propel the bike when it’s travelling more than 15.5mph
• the motor shouldn’t have a maximum power output of more than 250 watts

It must also display one item from each of the following:

• the power output or manufacturer of the motor
• the battery’s voltage or maximum speed of the bike

Where you can ride an EAPC
If a bike meets the EAPC requirements it’s classed as a normal pedal bike. This means you can ride it on cycle paths and anywhere else pedal bikes are allowed.

Other kinds of electric bike
Any electric bike that doesn’t meet the EAPCrules needs to be registered and taxed. You’ll need a driving licence to ride one and you must wear a crash helmet.

The vehicle will also need to be ‘type approved’to make sure it’s safe to use on the road.

Last updated: 8 March 201
6

 

[Deleted member 4366]

The information above is incorrect. The requirement is for a motor with a rated maximum output power at no more than 250w. "Rated" is a key word. The actual maximum output power can be much more, and I bet it is on your motor.

 

[anotherkiwi]

If I may... you forgot "continuous" d8veh. "Continuous rated maximum" no mention of peak in EN 15194

 

[Steve Wilked]

The information is correct, it was actually cut and pasted from the govt. website. No mention of 'rated' nor 'contiuous'. It actually says.....

• the motor shouldn’t have a maximum power output of more than 250 watts

!!!!!

 

[Deleted member 4366]

The information is correct, it was actually cut and pasted from the govt. website. No mention of 'rated' nor 'contiuous'. It actually says.....

• the motor shouldn’t have a maximum power output of more than 250 watts

!!!!!

It's still wrong no matter how many times you cut and paste it. It's the law that counts, not something that someone writes on the internet.

 

[Steve Wilked]

OK, accepted! Thanks

Wikipedia quotes the original EU directive 2002/24/EC

"Cycles with pedal assistance which are equipped with an auxiliary electric motor having a maximum continuous rated power of 0.25 kW, of which the output is progressively reduced and finally cut off as the vehicle reaches a speed of 25 km/h (16 mph) or if the cyclist stops pedaling."

Has now largley been adopted into EAPC regs.

Interesting definition I found in the draft for what is meant by continuous, ....

"maximum continuous rated power" by reference to EU Regulation 168/2013. (That definition is in paragraph 33 of Article 3 of 168/2013 and is the "maximum 30 minutes power"

Sent from my HTC One_M8 using Tapatalk

 

[Steve Wilked]

OK, accepted! Thanks

Wikipedia quotes the original EU directive 2002/24/EC

"Cycles with pedal assistance which are equipped with an auxiliary electric motor having a maximum continuous rated power of 0.25 kW, of which the output is progressively reduced and finally cut off as the vehicle reaches a speed of 25 km/h (16 mph) or if the cyclist stops pedaling."

Has now largly been adopted into EAPC regs.

Interesting definition I found in the draft for what is meant by continuous, ....

"maximum continuous rated power" by reference to EU Regulation 168/2013. (That definition is in paragraph 33 of Article 3 of 168/2013 and is the "maximum 30 minutes power"

 

[Deleted member 4366]

If you read through all the standards, they eventually take you to motor testing. The motor test only tests that the motor meets the rating, so if it exceeds it, it'll pass the test. This means that our some manufacturers of ebike motors under-rate their motors, which is perfectly legal. That means that you can get some very powerful "250w" ebike motors. The old Heinzmann brushed hub-motor was provided with a 28A controller, which is about 700w of output power.

As the standards only control the rating of your motor, there's nothing to stop you running it at a power level above its rating.

I can remember the first time I tried a Bosch motor in May 2011. It was about twice as powerful as the 250w Panasonic crank motors of the day, which we knew already took 400w from the battery. That's when I started to get interested in the standards and what's allowed. You can be sure that the Germans wouldn't cheat, who since then, have increased the power of their motors, as there seems to be a bit of a power war going on.You'll notice that they only talk about the torque of the motor, which normally means the maximum current limit. The question is how much further can they go before someone calls "foul".

 

[shemozzle999]

To be totally clear you need fully quote the existing EU law as it now stands Steve:

From the Framework Regulation 168/2013

(35)
‘maximum continuous rated power’ means the maximum thirty minutes power at the output shaft of an electric engine as set out in UNECE regulation No 85;

The other 4 delegated Regulations which are supposed to add the meat to the bones of the framework are still being worked on are due to be rolled out in August 2016 but there are still sticking points that have to be resolved effecting powered cycles, UNECE regulation No 85 being one of them.

Theoretically 168/2013 is meant to achieve from the opening preamble:

Whereas:

(1)

The internal market comprises an area without internal frontiers in which the free movement of goods, persons, services and capital must be ensured. To that end a comprehensive EC type-approval system for two- or three-wheel vehicles was established by Directive 2002/24/EC of the European Parliament and of the Council (3) on the type-approval of such vehicles. Those principles should continue to apply for this Regulation and the delegated and implementing acts adopted pursuant to this Regulation.

persons = all persons???

(2)

The internal market should be based on transparent, simple and consistent rules which provide legal certainty and clarity from which businesses and consumers alike can benefit.

Suggest you look up UNECE regulation No 85 for further clarity on motor power.

http://eur-lex.europa.eu/legal-content/EN/TXT/?uri=CELEX:42014X1107(01)

 

[Steve Wilked]

I have a Wattmeter on our eTandem, with just a 250W motor it had peaked at over 380W on our last ride. Have to be careful not to draw more than 2 x C of our small battery cells which with 2 x 10 cell config & C = 2A is about 8A max or 336W at max 42V voltage.