Hello from Manchester

[shiftspark]

Hi
I have arrived here as I am looking to build a bike for my 15 year old son who has a muscle disability. He is able to pedal but has very little leg power and tires easily so I want him to have as much as normal a life as possible and be able to come out on family bike rides.These will mainly be on tow paths or easy riding off road.
We have had a sit on a Cube mountain bike but it was quite heavy and bulky as it was a crank driven bike, the way I understand it a front or rear wheel conversion would be better as its a. cheaper and b. easier to sell on if it doesn't work out.
He needs a small or Xsmall frame so this limits or necessitates a pannier mounted battery unless you can advise different.
Also needs the be a thumb or twist throttle as he may tire and need to ride on battery alone.
Should I get a rear or front hub drive ? will front drive be more risky or unstable in the wet ? It will be a 250W legal system as I don't want him disappearing into the distance lol
Any other advice or where to get kits from ?
Thanks

 

[Deleted member 4366]

As a general rule, for someone with weak legs, you need a system with a pedal cadence sensor, not a torque sensor. Most bikes with cadence sensors have hub-motors, though not all; however you can eliminate most of the more expensive bikes.

If you want to fit a kit, a rear motor is nearly always better than a front.

 

[shiftspark]

Thanks @d8veh any kits that you would recommend ?

 

[shiftspark]

I have also just read something saying a rear drive hub and pannier for the battery can make the bike very rear heavy , is this true ?

 

[Deleted member 4366]

It's not good to have a rear hub-motor and standard rack battery because the standard racks, put the battery too high and too far back. You can make your own rack or make a minor modification to the standard ones to bring the battery as far forward as possible and as low as possible. Even a couple of inches makes a massive difference.

A rear motor and a down-tube battery makes a nice installation. there's loads to choose from. best bang for buck at the moment is the Yospower kits from Ebay seller Yspower something or other. he also sells them on Aliexpress. he has a warehouse in Germany, so no duty.

 

[Benjahmin]

A small frame does limit your battery choice. Bottle batteries need space to get them on and off the cradle.
There is a company called Bga reworking who can make bespoke batteries. Having one made to fit a frame bag might be an alternative. Can get frame bags made here:
https://www.alpkit.com/products/stingray
Another route may be to buy a soft case battery and carry it in a pannier. Lowers the centre of gravity but does put it off centre.

The cube you tried will be a torque sensor control system and needs rider effort to get motor assist, so not suitable I'd say.
A hub motor kit will come with a cadence sensor, this requires the rider to merely rotate the pedals (no effort involved) to get assist. It will also have a throttle to fit.
Front hubs can produce some tricky handling characteristics at low speed manouvres or on loose/slimey surfaces on steep hills. OK if you're an accomplished rider but not for the nervy.

 

[shiftspark]

@d8veh I cannot find the yospower on ebay as they are no longer a user, also not keen on the aliexpress web site , is it a chinese ebay site ?
In other news I have been to decathlon and found 2 bikes that should be suitable a mountain bike and a hybrid which I prefer as its lighter than the mountain bike and lots of room for a battery.
I have emailed details over to @Woosh to see what they recommend but i will fit a rear wheel conversion and bottle mount battery.
Thanks

 

[Woosh]

is your bike the Rockrider 520?

 

[shiftspark]

Hi
Yes I am I've just seen you email but I am on my phone so will have a look later.

 

[Deleted member 4366]

@d8veh I cannot find the yospower on ebay as they are no longer a user, also not keen on the aliexpress web site , is it a chinese ebay site ?
In other news I have been to decathlon and found 2 bikes that should be suitable a mountain bike and a hybrid which I prefer as its lighter than the mountain bike and lots of room for a battery.
I have emailed details over to @Woosh to see what they recommend but i will fit a rear wheel conversion and bottle mount battery.
Thanks

https://www.ebay.co.uk/itm/36V350W-26-Rear-Motor-with-Cassette-Electric-bicycle-Conversion-kit/222254726342?epid=1785746085&hash=item33bf69fcc6:g:C3IAAOSwdTJaXvku

Search his store for other items. If your bike is 8spd or more, you need a cassette motor, like the one in the above link, otherwise you use a freewheel motor, which is a bit cheaper.

Freewheel motor kit:
https://www.ebay.co.uk/itm/36V350W-Electrical-bicycle-E-bike-Hub-Motor-Conversion-kit-Rear-wheel-26/222254716621?hash=item33bf69d6cd:g:byUAAOSwQwZaXvGL

 

[Nealh]

Links for Yosepower hubs in Yosepower thread just use the search button.
Aliexpress are awesome.

 

[shiftspark]

Is this one ok ?
https://www.ebay.co.uk/itm/27-5-250W-eBike-Rear-Conversion-Kit-With-36v-13ah-Battery-UK-Hand-Built-Wheel/302660250453?hash=item4677f4eb55:m:mxIOv_3DomdlBPx5tRfDj1A @d8veh thanks

 

[Nealh]

Is this one ok ?
https://www.ebay.co.uk/itm/27-5-250W-eBike-Rear-Conversion-Kit-With-36v-13ah-Battery-UK-Hand-Built-Wheel/302660250453?hash=item4677f4eb55:m:mxIOv_3DomdlBPx5tRfDj1A @d8veh thanks

No .
Although it says 250w the pic is of a heavy and fast wound 1kw D/D hub motor, ideally suited for fast 20+ mph and pretty useless at slow speed and will have poor climbing ability unless you throw a lot of amps at it which means a high spec battery.
The 13ah battery is poor for a power kit and will have Samung 26F mediocre cells (probably), ideally for a low power kit with 12a controller, anymore then 12a and it won't be much good after 18/24 months.

 

[shiftspark]

Good job I checked here as I was going to get it ! cheers.
Can you recommend anything then as Woosh have no 27.5 in stock until summer either.

 

[Nealh]

http://www.pedelecs.co.uk/forum/threads/yosepower-hub-kits.30061/
Post #5
Both sellers sell the same kit and are based in the same city, if you look carefully one of the sellers give motor rpm speed on some of the kits and kits come in various wheel sizes which are already dished to sit centrally in the D/O's.

Also d8veh has linked above as well.

 

[shiftspark]

Hi
My bad, I found 27.5 on the 2nd link just worried as its 350w not 250w, if it was for me i'd have 1000w but just concerned as its for my son and don't want him going over 15 mph or will it not ?
cheers

 

[Nealh]

All kits will go over 15.5mph the setting for restriction is within the lcd, make sure it is set to 25 - 28km/h and don't let him see how you do it. But if he is clever enough he may well eventually find out how to.

The hubs have a 350w label which can be peeled off though there is a 350w engraving on the side case hidden behind the cassette/freewheel.
A lot of these hubs are marketed as 350/500w because the yanks won't touch them otherwise so we seem to be stuck with them as marked.
The Aikema sxhc128 is 500w yet the same hub in a Wisper is 250w.

 

[shiftspark]

Thanks just awaiting reply on which battery and carriage costs and were good to go.

 

[shiftspark]

Great it has taken that long to get back to me the wheel is now out of stock !
So is the any good
https://www.ebay.co.uk/itm/250W-Electric-E-Bike-Conversion-Kit-With-Battery-36v-Lithium-Front-Rear-Wheel/112349170215?epid=709218217&hash=item1a28884a27:m:mU-F1ryU9OfEy-HAbXpRjxw

 

[shiftspark]

I have bought the above package as the ones further up are all non stock for a while.
Bought it via the web site rather then eBay for £425. Kits arrives thursday so hopefully up and running over easter.
Thanks