DIY EBike for an M.E Sufferer

[jerrysimon]

Well this is a new project for me

I am not sure if you are aware but my eldest (24 year old) daughter suffers from M.E.

She recently moved back home and has been really taken with my EBrompton which she thinks would get her more mobile to attend clinics, visit the boy friend etc. She finds it really difficult to get out i.e taking buses etc which usually means I have to ferry her around places in the car. She is keen for me to build her an EBike which would both help her get a little exercise, whilst being able to use assistance when required.

I have quite a few spare bits and pieces and this is what I plan to use

1. Generic 17" frame 26" wheel MTB with front suspension forks.
2. 36v 190 RPM Tongxin front wheel motor hub.
3. Tongxin Controller and thumb throttle.
4. A123 36v 2.3Ah DIY battery pack.

I don't have any cutout breaks and if someone has a one that they could sell me that would be good ? One should be sufficient.

As you know I am more familiar with small wheeled bike conversions. Is the 190RPM motor the right fit for a 26" wheel bike ? What will be its max speed and how do you work that out anyway ?

Initially I was planning to just do it throttle control only (like my EBrompton) though not sure if pedelec would be better for an M.E sufferer ?

I will do some pics of the project as I have a few questions about the controller I am using, as some of the throttle wires don't match up color wise. On a hall throttle are there two or three actual connections ? My spare throttles have four or five wires but they are the ones with light indicators so some of the connections are no doubt for those. I will do some pics later.

Again being in Cambridge the battery should be sufficient for up to 10 miles, plus as she will be locking the bike up in the city I want it to look well used and pretty stealth in terms of being an EBike.

Regards

Jerry

 

[flecc]

As you know I am more familiar with small wheeled bike conversions. Is the 190RPM motor the right fit for a 26" wheel bike ? What will be its max speed and how do you work that out anyway ?

14.7mph. The step by step self-explanatory way:

The RPM of 190, times 26", times Pi (3.14) to give the wheel circumference, times 60 minutes to bring it to per hour, divided 36 to turn inches to yards and then divided by 1760 to turn yards into miles per hour.

 

[jerrysimon]

Thanks flecc,

Looks like it will be perfect and within the law

Initially I was going to put it in a 20" wheeled bike which I thought would be too slow and using that calc would only give her 11.3 mph


Regards

Jerry

 

[Pedalo]

Jerry,

I have a spare brake lever you can have for free. I doubt I'll ever need it. You might need to PM your address as I don't think I still have it and you might need to wait 2/3 weeks as I wont get a chance to post it until then.

Yes a hall throttle has 3 connections, +5V, Ground and the hall output voltage which will be somewhere between 0 and 5V.
If your throttle has lights, they are usually to show the state of the battery so would take 48V, 36V or 24V depending on the spec of the throttle.

I look forward to reading about the project!

 

[jerrysimon]

Thanks for the throttle info Pedalo,

Very kind of you re the brake. I will PM you.

There is no rush as I can fit the lever later. I intend to have a cutout switch fitted as well. I just like the idea of a cutout brake for extra safety.

Regards

Jerry

 

[vhfman]

I empathize with your daughter as I have ME /CFS, it is a very debilitating illness and getting mobility is a great boost, so I hope the bike build goes well. Personally I prefer throttle control so I can, when needed give the legs a rest and still keep going with the motor.

Most Hall Effect throttles require 3 wires. A +5V, 0v( ground), and the signal(~1-4.5v) out of the hall effect device to the controller. The other wires are often for LED displays and ON/OFF switches. But as to the wire colours used, it seems to depend on the controller/throttle manufacture.

Jerry to work out the speed of the bike with any wheels size you just multiply the motor RPM by wheel circumference multiplied by 60 all divided by unites in a mile. To get MPH I convert the wheel unites into feet because I know that there are 5280 feet in a mile; so 26/12 X Pi to get wheel circumference in feet = 6.8, and for 190 RPM motor the formula is:
6.8x190x60 / 5280 = 14.68 MPH.

Just posted a bit slow to find your question was all ready answered, as I got called away to the phone while I was writing my reply.

Chris

 

[jerrysimon]

Damn I just did a long reply to you Chris but lost it!

Hit the "repy to thread" button instead of post quick reply after I had typed it

Anyway thanks for yur reply and interesting to note your comment about the throttle option.

I will type the longer reply later which gives some history to her condition.

Regards

Jerry

 

[flecc]

Damn I just did a long reply to you Chris but lost it!

Hit the "reply to thread" button instead of post quick reply after I had typed it

So it's not just me.

 

[jerrysimon]

So it's not just me.

Yes flecc I have done it a few times now on this new format.

Regards

Jerry

 

[jerrysimon]

Ok things have moved on so I will update some pics.

Donor bike with front wheel removed - A generic womans ATB with front suspension. Quite old and a little tatty but works fine. I chose this as she wants to ride it into the city and leave it locked up and this should help make it look less nickable

Motor - A spare 80mm 190RPM Tongxin like the ones I ordered and had to cut down. This was purchased off a poster here a while back and has been sat unused in my collection a few months. Fortunately the narrower motor was perfect because of the fork profile. The existing spacers were machined down so that the hub sits centrally in the forks.

Parts ready to build wheel. Spokes were purchased from SJS and length calculated for a 2 cross pattern. Building the wheel was a little different than my 16" wheels which I have learnt on, mainly the initial lacing when rotating the hub and weaving the spokes. Tensioning up and truing was easy having learnt the technique on my smaller wheels.

Regards

Jerry

 

[jerrysimon]

Completed wheel fitted with nice comfy Big Apple tyre

Inital fit for a test ride which went well. It was slightly faster by about +2 mph about 16-17mph than my EBrompton. Although the caculations said around 15mph I am guessing this is because of the large Big Apple tyre ?

PS I notice with this new forum you can't edit older posts like you could with the previous forum

Regards

Jerry

 

[jerrysimon]

Completed bike.

As always the controls, battery positioning and wire tidy up always takes the time. The bike has :

1. Throttle control
2. Cutout break (Many thanks to who sent me a spare one he had free!)
3. Battery (fused with switch see below) in rear removable pannier.

Many of the parts are spare ones that I had lying around from previous purchases including this second hand original Tongxin controller that comes in a nice metal waterproof housing. Attached with a jubilee clip and wrapped in waterproof tape.

Cockpit controls

That is a basket mount which initially was going to carry the battery but when put in there it was all too heavy and the front wheel became unmanagable.

Regards

Jerry

 

[jerrysimon]

My DIY batter is well known already (see here) and as I had a spare second one I was going to use it as is for my daughters bike. However I was unhappy with the connectors. Whilst fine for me and my EBrompton I wanted something more fool proof and neater for my daughter.

So I came up with this.

Regards

Jerry

 

[jerrysimon]

Here are some final pics of the battery and how I installed it inside a tupperwear box with a seperate switch and connector (Speakon 2 pole rated to 40amps) available form Maplin here.

Finally I had to make a seperate charger lead to enable her to charge it from my chargers with Deans connectors fitted.

Regards

Jerry

 

[fatts]

Hi Jerry,
I agree with vhfman keep throttle and pedalec my partner had M.E. for many years plus spells in a wheekchair and I aint the best wheelchair person lol. Another point my partner has inner ear problem which affects balance so she uses a tricycle more now dont know if that was due to M.E. or not
I have sent you a pm or will do in a min by the way
Fatts

 

[Cyclezee]

Hi Jerry,

Nice work as I would expect by someone with your skills. A bit late in the day as I have only just read your thread. I think you have one already, but I have spare set of brand new and unused brake levers with cut outs. I can post them to you free of charge.

They look like this

 

[jerrysimon]

Thanks John for another very kind offer, but I have fitted the one also kindly sent to me by Pedalo and it seems fine.

Regards

Jerry

 

[jerrysimon]

Hi Jerry,
I agree with vhfman keep throttle and pedalec my partner had M.E. for many years plus spells in a wheekchair and I aint the best wheelchair person lol. Another point my partner has inner ear problem which affects balance so she uses a tricycle more now dont know if that was due to M.E. or not
I have sent you a pm or will do in a min by the way
Fatts

Yes my daughter has been on two test rides and loves the bike. I am hoping it will make her more mobile and help increase her fitness/stamina. Re your PM she has had M.E. for about 3 years but two years ago attended the "Lightning Process" a CBT type course which worked wonders and got her up out of bed and back to University to complete her degree this time last year. Although now mobile she does still have slight lapses but definately on the mend.

She is now talking about doing a Masters.

Regards

Jerry

 

[TylerD]

A real labour of love Jerry, what a great bike , I hope your daughter travels many happy miles on it