Road Legal 250W - wow never again

Steve Dyson

Pedelecer
Oct 13, 2018
72
13
I put together a road legal 250 watt MTB conversion kit for someone last week and tested it out, all power tests show that its pulling the right power, but my god its slow.... and up hills, especially around OL13 are a drag


stick to my 1500 watt machine and restrict the speed to 20KPH
 

minexplorer

Esteemed Pedelecer
Aug 22, 2017
488
85
51
Four Lanes,Cornwall
I put together a road legal 250 watt MTB conversion kit for someone last week and tested it out, all power tests show that its pulling the right power, but my god its slow.... and up hills, especially around OL13 are a drag


stick to my 1500 watt machine and restrict the speed to 20KPH
youve been spoilt rotten by your 1500 watt machine...
 

LeighPing

Esteemed Pedelecer
Mar 27, 2016
2,392
1,853
The Red Ditch
youve been spoilt rotten by your 1500 watt machine...
They do spoil you a bit. Although, personally I wouldn't use it on the road. Each to their own on that. I've a 1 KW machine that I use off road for walking the dog. The battery's about had it. But it'll still do a couple of miles in 10 minutes. Plenty for the mutt to stretch his legs, without tiring me out. :)

 

Nealh

Esteemed Pedelecer
Aug 7, 2014
8,184
3,096
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West Sx RH
I have no issue with power from my 250/350w hubs.
Depends what you want at the end of the day a low powered assisted pedal bike or a moped.
 

Steve Dyson

Pedelecer
Oct 13, 2018
72
13
I have no issue with power from my 250/350w hubs.
Depends what you want at the end of the day a low powered assisted pedal bike or a moped.

I agree, i have never built or ridden one so i was shocked at how under powered they around my location as its very hilly with steep inclines.

Even my 1500W i have to pedal up some of the hills
 

VillageIdiotDan

Pedelecer
Apr 28, 2019
37
16
I'm with Neath, I'm very happy with my 250w rear hub conversion, good to 25mph if unrestricted but it's not very hilly here and its useful reminder never to have a go on a 1500w one! :)
 
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anotherkiwi

Esteemed Pedelecer
Jan 26, 2015
7,789
5,758
The European Union
Silly me here I was changing down a gear or two when I got to a hill...

My "250W" hub will (well it used to when I was younger) climb 13.8% hills @ a steady 25 km/h. Plenty enough for me and very annoying for MAMILs. On 17% gradients it does slow to 18-19 km/h. The 250W mid motor is slower but in the right gear it will climb until the front wheel loses contact with the ground. I'm not sure I would want to be going too fast up that kind of gradient.
 

vfr400

Esteemed Pedelecer
Jun 12, 2011
2,864
830
Basildon
If you use a normal 250w geared motor at 48v, you get all the hill-climbing power you need. It will be light and pleasant to ride both with and without power. You get an on the road speed of about 24 mph flat-out, which is very well suited to bicycles. Best of all, it's legal.
 

Steve Dyson

Pedelecer
Oct 13, 2018
72
13
If you use a normal 250w geared motor at 48v, you get all the hill-climbing power you need. It will be light and pleasant to ride both with and without power. You get an on the road speed of about 24 mph flat-out, which is very well suited to bicycles. Best of all, it's legal.

That sounds like what i need to look at for this one as i want the person that this is built for to have a good experience, on the flat it will do fine and pull at 20+ mph but as soon as it hits a hill it just slows down to a crawl.

I have no doubt that there will have to be pedal power to get up the hill but i was so surprised at how much pedaling was needed.

With the controller connected to my 1500W bike today on the way to work, the hill that i climb up at 20+ everyday, it managed to push enough power to get up at 12 mph so its defo the motor that just cant do the hill.

I will do some further testing and see if i can tweak the power to give the best possible power output without killing either motor or controller
 

Nealh

Esteemed Pedelecer
Aug 7, 2014
8,184
3,096
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West Sx RH
Problem is you will never be happy because as mentioned you have been spoilt with the moped power anything else will always appear to be under powered.
 
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minexplorer

Esteemed Pedelecer
Aug 22, 2017
488
85
51
Four Lanes,Cornwall
I have no issue with power from my 250/350w hubs.
Depends what you want at the end of the day a low powered assisted pedal bike or a moped.
i mostly ride my 350w bbs01 with two batteries, theres no place i cant go, my arse always gives out before the batteries. i use high assist and feel like im really cycling too.its just perfect.wouldnt want to go down to 250w tho. My bbshd is awesome but i have to run it at low PAS most of the time to get any worthwile range .its simply too much power. Even on the lowest PAS level mostly ,around 10-12amps (more power than the 350w on max) i have to turn around for home after 12 miles with the 15ah 52v batt...very frustrating
 
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