Electric Hub Kits for Push Bikes

[Wendelspanswick]

The other half commutes to work 6 miles, she drives in the winter and uses a Peugeot scooter in the summer, the scooter is getting on for 12 years old now and it's struggling even after I put a new cylinder and piston on.
We've been mulling over the idea of converting one of our existing push bikes with an electric rear hub but fitting a bigger hub than is allowed so that the performance better matches the scooter.
Legal limit is 250W but for a similar price you can get 500w, 750w or even a 1000w hub and the associated kit.
£150 buys you everything you need apart from the battery.
http://www.ebay.co.uk/itm/322364987166
Brushing aside the legal niceties any one have experience of riding a bike with a bigger hub and what sort of range could you get, she could charge her bike for free while at work and the route is mostly flat although there are a couple of gentle hills at one end of the journey.

 

[CompoSimmonite]

You are better using a bottom bracket drive rather than hub motor. That way the power goes through the same gear selection as the pedals. I've had numerous electric bikes and as long as you pedal as well even 250 watts is better than you'd think. If you go larger watts then they tend to be 36v rather than 24v so need extra battery. Decent batteries are dear. Then you will need 2 chargers - one for home and other for work. By the time you have bought the hub motor kit and 3 decent batteries plus chargers then I suspect the total will be near to £300 which could be more than a good used scooter might cost. If you go with Lithium batteries then it'd going to be probably even £100-150 more !

 

[Wendelspanswick]

Definitely want to go away from petrol scooters, the annoyance of the yearly MOT, tax and insurance is the reason for looking at pedal elec.
She only weighs about 70KG so it's finding a motor and battery combination that will allow her to do at most about 25mph, the legal kits and bikes restrict you to 15mph.

 

[james butler]

Definitely want to go away from petrol scooters, the annoyance of the yearly MOT, tax and insurance is the reason for looking at pedal elec.
She only weighs about 70KG so it's finding a motor and battery combination that will allow her to do at most about 25mph, the legal kits and bikes restrict you to 15mph.

i thought the reason they were limited to 15mph was so the rider doesnt need a licence and doesn't require insurance?
surely by going over that limit your opening yourself up to prosecution if caught or heaven forbid have a serious accident?

 

[knighty]

I've built a few electric bikes, some for me and then some for my nephew, I've always used hub motors, more power means you don;t really need gears, my first hub was a ebay 500watt one I ran at 1.5kw and later at 2.5kw

important bit is the batteries and balance charging them properly

if you just want something to ride around sometimes, not really go that fast or far, then you're best off buying a ready built batter with a BMS built in (BMW = battery management system) - that way you can just plug it in to charge and forget about it

my first battery was like that, 72v lifepo4 10ah that was a few years ago now, lithium iron is a much better choice now

with 72v at 10ah, I never managed to flatten it with normal riding on the road - once had my nephew on the ebike towing me on a normal bike, rode to the arcades about 5miles away and the back again later and the battery didn't run out
(most at I'm guessing 30mph, bike did 40 flat out)


higher voltage essentially means higher top speed - and to me, faster is safer... if you're doing 30mph cars aren't shooting past you or trying to squeeze through when there isn't room

and more watts = faster pulling away, which is safer pulling away from traffic lights etc.


must have done more than a thousand miles on ebikes, they're awesome.... get a helmet better than a bike tho! I got a full face one, make for off road motorbikes, saved me when some idiot did a U turn right in front of me


THSE horns are awesome too, didn't use mine much, but a quick toot it all it takes to let someone know you're there

 

[Wendelspanswick]

i thought the reason they were limited to 15mph was so the rider doesnt need a licence and doesn't require insurance?
surely by going over that limit your opening yourself up to prosecution if caught or heaven forbid have a serious accident?

Did you not see the sentence "Brushing aside the legal niceties"?

 

[wookie]

She only weighs about 70KG so it's finding a motor and battery combination that will allow her to do at most about 25mph, the legal kits and bikes restrict you to 15mph.

I never understood the 15mph limit, I average faster than that on my mountain bike when I'm on the road. Back when I used to ride a racer I was looking at 24 mph average on my own, usually 30+ if there was a few of us and we could slipstream each other.

The faster you go the more respect you seem to get from car drivers, if your up there in terms speed and ride dominantly on the road they will give you more space, which in my opinion makes for a safer cycling enviroment.

I'll try and find an article about someone's home brewed electric mountain bike, the acceleration was impressive, it had a good top speed and the range was decent.

 

[Wendelspanswick]

I agree, the 15mph limit is pants which is why we are looking at alternatives.
Nothing worse than cycling at 20mph with some numpty who thinks that as there is a solid white line they can't overtake you sat on your rear wheel, they then create a huge tailback of drivers who are frustrated at being held up.
Much safer, in my opinion, to be at 30mph and keeping up with the traffic flow.

 

[knighty]

law says 250watts, 15mph and 40kg total weight... anything bigger than that is a motorbike

I always ignored those limits and didn't have any problems


EDIT: as above, keeping up with traffic is safer in my experience

more power is a bit bonus when you need to pass a parked car etc. too, you have the power/speed to look for a gap, move into it, pass whatever is in your way and then move back in

 

[Jim Davey]

I want one!

 

[pedrobedro]

I wouldn't mind one of they came down in price a bit. I managed 48mph down a local hill on my hybrid bike and I don't come down it that fast on my Honda.

 

[Burdekin]

A mate has built a few. First was the bottom bracket style but the last two are hub mounts. He builds the frame and all, they look like a light weight moto-cross bike. The frame is mainly water jet cut. He did a 3.5kw one and looked awesome. Think it could about 45mph but he thought it was too powerful for the frame design. His latest is less powerful. He's currently working on making his own bespoke battery cell shape to better fit the frame design.

 

[Burdekin]

Found his thread, not sure how up to date it is: https://endless-sphere.com/forums/viewtopic.php?f=3&t=75457

 

[MattH]

£6000 of bicycle...

50 odd mph...on a bicycle :-D :-D

Why not just buy one of these as you will be breaking exactly the same laws when riding it on the road.
It's cheaper, faster, better built and has a warranty.

http://www.fowlersoffroad.co.uk/pag...KE=HONDA&MODEL=CRF450&ENGINECC=0#.WODVLZF4Xxw

 

[wookie]

Found his thread, not sure how up to date it is: https://endless-sphere.com/forums/viewtopic.php?f=3&t=75457

Oh dear, another project to add to the list....

 

[Jim Davey]

You won't get caught anywhere near so fast on an electric bike. As long as you keep pedalling who's to know the bike is electric?

 

[MattH]

You won't get caught anywhere near so fast on an electric bike. As long as you keep pedalling who's to know the bike is electric?

50MPH!

 

[Wozzaaah]

You won't get caught anywhere near so fast on an electric bike. As long as you keep pedalling who's to know the bike is electric?

Anyone with a pair of eyes.

 

[Jim Davey]

People don't notice electric bikes zipping along but you can bet if you pottered through your local park on a bike that sounds like 40,000 angry hornets having a fight in a biscuit tin, while leaving a trail of blue tinged Castrol R smoke behind you'd have your collar felt fast.

Mod edit: seriously inappropriate comment removed!

 

[Burdekin]

I think my mate can just switch it to 250w mode. He's taken it to the extreme, done a lot of work on the controls and battery design etc. E-bikes are very popular in Europe and getting more popular here. Max torque at 0rpm so you can get great acceleration. Cities would be much more pleasant with quieter roads and less pollution so all for it but still a way off for the technology but it's getting better.

I'm all for my folk cycling, when you go to places like Copenhagen and Amsterdam and see how little congestion there is because so many folk cycle and how healthy folk are in comparison to the UK.