Cheap kit for "full electric" conversion (for foot injured wife)

[MarmiteOnToast]

Hi

Sadly wife has a foot injury which is preventing her pedalling and riding, as well as standing, walking, running, driving, working etc. Cue a rather p*d off wife, virtually housebound for 2m so far (from almost daily running, walking, biking etc...) She is self employed, so no income, so need to be careful on budget
Hopefully short term (1m)

Anyway, for a short term thing, thinking we can convert her Specialized Myka Elite to a thumb throttle ebike. But know zilch about these things. But looking at ebay rear hub conversions (£120) + battery/charger (£220?) + bits - so £400 ish.

Requirement would be 100% thumb throttle, no pedalling (yes, I get this is illegal in UK - its either this or a mobility scooter....)

Top speed 10-12mph is fine

Distance - ideally 15-20 miles, reasonably flat (e.g. canal paths)

Are the ebay kits suitable for this type of thing? Is 100% electric with no pedalling possible? If so, what AH batter for 20 miles max (pretty flat)

(Should add, most journeys would be <10m - e.g. to pub or shop)

Thanks for any advice and ebay or other links etc that may match this requirement

Alternatives welcome! (Even some form of adult "follow me" bracket!)

 

[Woosh]

is your bike like this one?

If it is, it's not going to be cheap to convert for throttle only.

 

[MarmiteOnToast]

is your bike like this one?

If it is, it's not going to be cheap to convert for throttle only.

No, slightly different - more space in the frame (currently has 2x bottle cages that take 600ml bottles each)
What problems are envisaged?

 

[Woosh]

What problems are envisaged?

you need a large margin to make sure that your wife can get home without pedalling, ever. That usually means either a powerful rear geared hub drive like this one:
http://wooshbikes.co.uk/cart/#/product/uid-188-swx02-48v12ah/bafang-swx02-48v-250w-rear-hub-kit-with-48v-12ah-battery
and plenty of battery or a Bafang BBS kit, again with a good battery.
Cut a piece of cardboard, 36cm x 10cm, to see if the battery would go inside the triangle. If it does, the installation will be simpler. If not, you would need a rack battery which will make the bike much more difficult for your wife to get on and off it because the bike is not a low step.

 

[MarmiteOnToast]

The wife would only be using it for a month (touching wood) - and I'd always be with her. Not worried about it running out of puff - it'll only be around here and I'd go and get the car if needed. Its literally a temporary thing to get her out of the house. She has full mobility and can still get her leg over anything (so to speak )
We have a topeak rack we could use to mount any batteries if needed.

Will check out the link and site - thanks - not one I'd found. Assume its your site based on your username?

Looking around, 250w sounds like its powerful enough for her desired use, and the distance of, say, 20 miles max (10-12mph, flat, 100% elec power) needs what size battery? Is there a rule of thumb?

 

[Woosh]

It's very easy to be seduced by an electric bike.
Suddenly, 50 mile rides are very doable.
Once you have converted your wife's bike, you may want one for yourself.

Post the link to what you want to get, people will chip in with their experience.

 

[MarmiteOnToast]

You are possibly right but our usual week would be a few bike rides, a few runs, a few long walks. We're always out and about. hence a "minor" foot injury which has left her housebound for 2mths isn't great for her mental wellbeing, and with the exception of a wheelchair or mobility scooter this is the only way I can see of getting her out of the house.
We've recently done 1000 mile bike rides - and are 100% enjoying human power.
eBikes may be great but not on our agenda until we need them - sadly she does at the moment but won't be something she'd want to retain after.
Hence wanting to do cheap and cheerful for now.
When the time is right and we're old and knackered (she is getting there already) we'll invest properly - but for now, quick win needed and a cheap n cheerful price (and accept it may not last!)
Was looking at boggo cheapo
kit: https://www.ebay.co.uk/itm/Voilamart-36V-500W-Electric-Bicycle-Ebike-Kit-Cycling-Hub-Motor-Rear-Wheel-26/223507253986
battery : 36v 10AH: https://www.ebay.co.uk/itm/36V-10Ah-500W-Downtube-Lithium-Li-ion-Battery-Pack-E-Bike-Electric-Bicycle-Motor/383150878214

 

[Woosh]

don't go for that motor wheel. It's a direct drive motor, weighing a ton, suitable for 20mph-30mph so not good (and illegal) for trundling about on public roads and cycle tracks.

We've recently done 1000 mile bike rides - and are 100% enjoying human power.

Your profile would be ideal for a lightweight kit like the 1.9kg Aikema 13.0

http://wooshbikes.co.uk/cart/#/product/uid-121-85sx-13ah/akm13085sx-rear-hub-kit-with-13ah-battery

Don't buy that battery either. You need a battery and charger. Chinese cells are usually not trusted. Pay a little bit more and get a battery made with Samsung, Sony, LG or Panasonic cells.

 

[sjpt]

Doing a cheap conversion isn't going to be that cheap, and not a long term value for money either. Is there anywhere nearby that rents them? Renting by the day is often very expensive, but as its out of season they may be happy to do a special deal for a months rental.

p.s. Woosh isn't trying to wind you up and press for a sale ... he really is being helpful.
p.p.s When my wife had a bad foot injury (crushed under slipping horse) she was lucky that the local Shopmobility (Winchester) would rent her a mobility scooter to keep at home for very little (£2 a day if I remember) which was really excellent for her. She couldn't have ridden an ebike over that time. I think ours have changed the rules now so it wouldn't be possible any more, but it may be worth checking your local one.

 

[MarmiteOnToast]

I'm sure anywhere that rents them will be legal pedal assist, but for sure its worth an ask - will pop into LBS.
I'm not worried about legalities, and neither would you be seeing your OH getting more depressed by the day. After seeing d*cks on youtube I understand why the law is necessary. But there is no practical alternative for us except a mobility scooter (or a cheap tandem with independent pedals)
I appreciate and heed the advice - and indeed believe the advice to be good. It will be read and studied but also needs to be taken in context - eg I want something to work for a month maybe 2 then it'll be put in the shed and not used until next injury. Doubling cost for "better" isn't viable - bearing in mind self employed not working means less play money. If something can work for £350 (e.g. £300 as linked including charger + any odds n sods) and is good enough that is great and the point of this question.
Spending £600 on a better system is sensible for most who want to use it - but puts the short term usage costs up quite a bit! (In my scenario, do I really care the motor is weighing a tonne when it'll be used for a month, on the flat, on full elec (illegally but at slow lady cycling speeds in sensible places)? Nope. But for most, yes its a factor. Do I care the battery is chinese? Nope - UK supplier, ebay/paypal 30d returns, and that'll cover most of the anticipated usage

*NOT* dissing or ignoring the comments, they are all valid and apprecaited - thanks

 

[Woosh]

how about buying a second hand e-bike for your wife and sell it when she no longer needs it?

 

[Kwozzymodo]

whereabouts are you based?

 

[MarmiteOnToast]

quiet village in sunny wiltshire, on the flat, easy access to canal and wide bridleways and barely used country lanes.

 

[Benjahmin]

Problem with the direct drive motor that you linked is that it will not want to go at the speeds you've mentioned. These generally work better at higher speeds (18-20mph+), so may be a bit leary on tow paths. At lower speeds they heat up (wasting battery capacity) and growl. That's why you're being pointed towards a geared hub.
Have you looked in the classified section of the forum?

 

[MarmiteOnToast]

Hi
Yep, I've been searching here as well as asking and seeing the experts comments on other threads. I'm now changing tack to 250w front hub - which is geared (not DD) and a smaller motor which is less chance of getting in the way of brake calipers. Also not touching any other mechanics so easily reversable to be resold on the 'bay in a month (hopefully)
I'm 100% in agreement its not a great answer but will meet needs that are stupidly basic.
Had I not asked here, I'd have bought the DD and that'd have been wrong - so thanks a mill.
Not seen classifieds on here, will check

 

[gw8izr]

I know you said she cannot pedal and needs throttle but I presume she can get to the bike and basically sit on it so she must be able to support some weight on her legs? Can she spin the pedals without actually putting pressure on them? As that might open up a few opportunities.

 

[MarmiteOnToast]

I know you said she cannot pedal and needs throttle but I presume she can get to the bike and basically sit on it so she must be able to support some weight on her legs? Can she spin the pedals without actually putting pressure on them? As that might open up a few opportunities.

Thanks for asking.
Yes. She can walk around the house and up stairs, but just not frequently. If she walked 100m she'd be in pain. Yesterday was quite bad, but a few days ago walked maybe 1km in a couple of hours which probably caused it to go worse.
So yeah, she is "mobile" and better than a lot of people, but still housebound because of it. Doing a 10km loop (country lane, canal) would be the most outdoor she has done for ages. (Its basically a fkd tendon in the foot, trivial medically, just huge impact to her life). Don't get me wrong, 100000001 people would swap their ailments with her tomorrow! And most normal people wouldn't mind - but....

 

[gw8izr]

Some of the mid drive kits allow you to zoom along the road by just turning the pedals rather than peddling, it might feel a bit more like actually cycling which psychologically might be better than just using the bike as a scooter. I was just wondering if that might be a better approach. It might be good physiotherapy to help with recovery of the tendon damage when things move along as they inevitably will.

I’ve just fitted a mid-drive to my bike But it is the type that needs pedalling harder to make it go faster or up hill which wouldn’t suit her needs.

To be honest once she has the electric motor on the bike I bet she doesn’t want to take it off. They are just great fun

 

[sjpt]

As mentioned above, the ones that use just turning the pedals are the cadence sensor ones as opposed to the torque sensors. Cadence sensors are more common with hub motors and torque sensors with mid-drive, but all combinations are available.

 

[MarmiteOnToast]

Hi guys
I ordered and now have my hands on a 36v 250w front wheel kit (geared brushless) and 10Ah battery.
About 0.0001mm clearance for the battery for it to fit and enable removal, slight mod of cage needed to connect to bottle bolts.
Front wheel is tight in the front axle. But can fit - problem I have is the nuts for the axle conflict with the fork - doh. Also the front disk screws hit the fork. The wheel assembly hits the hydraulic caliper (as expected) so the mechanical one due tomorrow.

That said, the bench test of the items work "perfectly" on the bench, the throttle is gentle enough and easy to control, and everything seems to work as is.

Need to add an M12 washer on the axle to allow the brake disk bolts to clear the fork, and probably a few M12 washers on the external side of the axle so the nut an go on without touching the fork.

Just got to figure how to get the nut over the connector to get a washer on lol - I'm sure the cables come out of the connection block.

For the price paid I'm surprised how solid it all looks and feels - time will tell how it works. But wife appreciative and will pay me back in kind!

(Even with new brakes and bits, it'll be sub £300 all in. I 100% accept its not as good as other kits, but not bothered for now!)

Will report back once tested....