Bafang 250 or 500w for touring

[RichC]

Hi

I have a Ribble CGe for around the forest and popping to the pub/social runs with the wife. I'm looking to build my genesis longitude into a longer distance multi day tourer with a trailer to do the Hebrides next year and then iceland, i fear a hub motor will not be up to the task so i'm looking at a bafang mid drive which ideally i would like to run at 36v as it keeps all my charging the same.

my concern is the 250W bafang may not have enough power but is the 500W legal? also will the 36V battery be a major issue as most seem to use 48?

Thanks Rich

 

[vfr400]

The motor has to be rated at no more than 250w to be legal in UK and EU.

 

[RichC]

The motor has to be rated at no more than 250w to be legal in UK and EU.

but from what I read its 250W continuous rating and most 250W motors can peak at up to 500W? I only really want the bike to do distance and carry load rather than be fast, would a 250W do the job on most things other than really steep hills where i could let the speed drop off as long as i'm still pedalling? I have an 11-42 rear cassette fitted.

 

[vfr400]

The rating is the number written on the motor or in its listing/specification - nothing to do with how much power you put through it.

If you have a motor marked 250w, you can put 1000w through it and still be legal, but if you have a motor marked 350w and only put 100w through it, that's illegal.

 

[RichC]

The rating is the number written on the motor or in its listing/specification - nothing to do with how much power you put through it.

If you have a motor marked 250w, you can put 1000w through it and still be legal, but if you have a motor marked 350w and only put 100w through it, that's illegal.

so is there a way to future proof any forthcoming changes in the law moving up from 250W? if i switch the voltage up from 36v to 48 or can they be reprogrammed for power? its either that or changing the sticker it appears to me!

 

[Wicky]

250W legal motors push out quite a bit more when needed as VFR400 mentioned esp when you need it up hills / into headwinds. 48V will be bit more torquey. Look at getting a high capacity battery (+spare) for longer range.

No foreseeble changes in the law on the horizon.

 

[RichC]

250W legal motors push out quite a bit more when needed as VFR400 mentioned esp when you need it up hills / into headwinds. 48V will be bit more torquey. Look at getting a high capacity battery (+spare) for longer range.

No foreseeble changes in the law on the horizon.

thanks for the input, can i run both voltages on things like bafang mid drives and switch easily? higher capacity will be a must

 

[RichC]

thanks for the input, can i run both voltages on things like bafang mid drives and switch easily? higher capacity will be a must

re changes its just i read the EU were consulting on this at the moment?

 

[Wicky]

Even if EU makes changes - no guarantee that those changes would filter over here with post-brexit uncertainty and in a timescale that could effect your planned tour - unless it's in 5-10 years ;-)

Maybe if you're planning on extending your tour to the USA then that's a different story and would fundamentally alter your choice of allowed specs ...

Major change in US regulations: e-bikes no longer defined as motor vehicles

WASHINGTON, USA - The sales of e-bikes in the US are expected to be given a boost now that the Department of the Interior released final rules for electric bicycle use on public lands. This new regulation more clearly defines electric bicycles and no longer describes them as motor vehicles. This...

www.bike-eu.com

 

[vfr400]

so is there a way to future proof any forthcoming changes in the law moving up from 250W? if i switch the voltage up from 36v to 48 or can they be reprogrammed for power? its either that or changing the sticker it appears to me!

Mid drives are not suited to over-volting. the only way to get more power is with more current, but the internal gears are not really strong enough to take that far on the 250w versions.

I think you'd be better off with a hub-motor. Get a 250w 201 rpm 36v one and run it at 48v 17A to get all the climbing power you need without straining the motor.

Woosh do a 48v hub-motor kit that's pretty powerful if you want a ready-made solution.

 

[jimriley]

Re the 250w bafang Mid drive, you can up the amps from 15 to 17 using the USB lead and laptop. It's then the same as a 350w but badged "correctly". So you have quite a bit more oomph. I've been dragging a dog trailer about, full of shopping, also loaded panniers, with a 250w. No problem on normal roads and canal towpaths.
I had a play with 350w, took maybe 5 mins to change, more power, no problem (legally in the grounds of the mansion, ran an undergardener down but they're expendable).
I've dropped the power back down again, more economical on voles, but if I wanted to play on the steep bridleways "in the grounds" I'd swap it back again.
There is an lcd panel which can do motor programming so you don't need to take a laptop with you. Don't know which one it is though.

 

[RichC]

Re the 250w bafang Mid drive, you can up the amps from 15 to 17 using the USB lead and laptop. It's then the same as a 350w but badged "correctly". So you have quite a bit more oomph. I've been dragging a dog trailer about, full of shopping, also loaded panniers, with a 250w. No problem on normal roads and canal towpaths.
I had a play with 350w, took maybe 5 mins to change, more power, no problem (legally in the grounds of the mansion, ran an undergardener down but they're expendable).
I've dropped the power back down again, more economical on voles, but if I wanted to play on the steep bridleways "in the grounds" I'd swap it back again.
There is an lcd panel which can do motor programming so you don't need to take a laptop with you. Don't know which one it is though.

are you running 36 or 48V?

 

[vfr400]

are you running 36 or 48V?

All 48v versions are illegal. The only way to get a sort of legal one is to get a 48v BBS02 and a 36v 250w BBS01, and swap both the controller and the motor with it's housing, so you have a 250w unit with the 48v controller and motor. the main casings are the same. The problem then is that the cadence will be 33% higher, so only do that if you like pedalling fast.

 

[jimriley]

are you running 36 or 48V?

Bbs01b at 36v with more or less default settings. I've pulled 50kg - 2 sacks of hen food, in the trailer for several miles. Loaded panniers up with a weekly shop. Must be comparable with a full set of camping kit. No problems. It's a hybrid tourer, 700c wheels. Would prefer disc brakes but it has v brakes. I've done about 250 miles in the few weeks since I fitted the kit.

 

[RichC]

Bbs01b at 36v with more or less default settings. I've pulled 50kg - 2 sacks of hen food, in the trailer for several miles. Loaded panniers up with a weekly shop. Must be comparable with a full set of camping kit. No problems. It's a hybrid tourer, 700c wheels. Would prefer disc brakes but it has v brakes. I've done about 250 miles in the few weeks since I fitted the kit.

sounds like its what i'm after, thanks!