Moulton Midi conversion?

[frazzled]

Hey all

Been thinking of converting a 70's Moulton Midi to an e-bike.

It might sound silly, but while I'm usually content with my other bikes, I have a medical condition which causes bouts of severe lack of energy and strength. An e-bike would at least help me get to the shops.

I did have an electric bike for two years, but it got stolen. So I have experience with them, but not with conversions.

Looking online, most of the kits seem to be aimed at bikes with much larger wheels.

Any advice on kits for old bikes with small wheels? I realise it would probably be cheaper to simply buy a new e-bike, but this would make for a fun and unusual project.

I'd not be doing any serious mileage, only local.

Cheers!

 

[dicko]

Cytronex do an e-bike conversion for Bromptons with 16 inch wheels. If your Moulton has 16 inch wheels and the fork arms are the same as a Brompton apart then their kit will probably fit.
Cytronex is in Winchester and are very helpful British company. Good luck 🤞

 

[cheys03]

I have experience doing an ebike conversion for a Moulton Mk3 using Brompton 349 16” wheels. This conversion used an Outrider (aka Tongxin) motor, 100mm spacing and 328rpm@ 36v if memory serves to get the full 15.5mph UK legal max speed. The main consideration with small wheeled ebikes is the high motor rpm (and controller electronic rpm if Sensorless) to get the speed.
The benefit is that acceleration is normally quicker than with bigger wheels.

It will be like any other conversion, just make sure the motor axle width/length fits the forks or rear triangle and the motor is capable of higher rpm at your chosen battery voltage - about 328rpm at 36v nominal and say 240-260rpm at 48v nominal.

Sounds like a cracking project, good luck!

 

[Pale Rider]

ARCC specialise in Moultons, although their conversions appear ludicrously expensive for what you get.

Not really aimed at diy, but business is business, so no harm in giving them a ring.

https://www.arccbikes.com/products/moulton-tsr-electric-conversion

 

[figbat]

Swytch claim their kit works on any wheel size.

 

[frazzled]

Thanks for your replies guys, really appreciated.

The Moulton was given to me last year but I had no idea what to do with it! So it's been in storage since but I'd love to get it back on the road over summer.

It does need some light restoration and repair, but no more than a weekends work.

That'll give me time to ponder on the best e-bike solution. Still got the 48v battery from my stolen bike, so maybe that can be re-purposed.

The Moulton does likely have 16" wheels, but will check when I get it out of storage in the next day or two.

Again, thank you.

 

[raleighnut]

Best thing to do with a Moulton is throw it in a skip, I had a ride on one in 1974 (It belonged to Bill Moores' big sister) I didn't think anything could be worse than a Raleigh 'Chopper' but the Moulton proved that to be untrue. Not too bad in a straight line but the slightest attempt to go round a corner sent it into a shivering mess at anything above walking speed, in fact the best way to go round a bend was to get off and walk.
The combination of rubber mounted handlebars a a rudimentary rear (again rubber mounted) rear 'suspension' meant it was like riding a wet dishcloth on jelly but at least it didn't have the 'chopper' castration gear shift lever.
By all means fit an electric kit on one and if you send me an address I'll send some flowers to the ward you're in.

 

[CXRAndy]

im buying one of these again for second conversion

https://www.electrifybike.com/products/tsdz2-osf-upgrade-motor-kit-250-750w?F1=Universal Thumb&F3=860C Color Display for TSDZ2 OSF

I did my wife's bike back in 2019 and its still doing very well. I bought the battery from Chinese website, which I've found the older email order so have ordered more

 

[frazzled]

Thanks CXRAndy, I'll take a look at that.

raleighnut - Colourful and amusing description, but I think you had a bad apple. They are limited, but fine for pottering around town.

 

[rogerzilla]

A Midi should go in the skip - no front suspension, and the wheels are too small (it's Raleigh's ultra-cheapened Mini). Most other Moultons have the potential to be decent bikes.

 

[bonzobanana]

I feel that going with the Moulton/Raleigh bike is going to cause a few issues. You can get bikes off freecycle or just a few pounds or less on facebook marketplace. You can choose a bike ideal for an ebike conversion which I would say is a steel mountain bike without suspension. Starting with a more standard bike means the kit price will be much cheaper and easier to get. The fact you already have a 48V battery and presumably the charger means all you need is a 48V kit. Your existing medical issues makes it sound like a throttle would be ideal which is perfectly legal on a ebike kit. The Moulton is fairly lightly constructed and probably not ideal for extra stresses of a ebike kit. You want a bike that is a little overbuilt like a rigid steel mountain bike.

 

[CXRAndy]

I came across this article
https://www.cyclingweekly.com/revie...-tsdz2-mid-drive-e-bike-conversion-kit-review

The positives are spot on but the negatives are not like they describe. Straight forward to fit (if you're practical).

The standard motor is excellent, but if you get the one with Open Firmware, the motor becomes even better. You can alter voltage for different batteries, add more levels of assistance, set different cut off speeds. Also the motor is tuned better for greater range. My wife can get a comfortable 50 miles from her 740Whr battery.

 

[frazzled]

bonzobanana, you are pretty much spot on with everything there. I understand there are more suitable bikes for conversion, but this is just a fun project. It won't see much use, except for the days when I need assistance. Got a mate who has some motor parts, so if my old battery can be fitted, we might be able to do this at very little cost.

CXRAndy, thanks for the link. Interesting read. Think I need to learn a little more about conversions before going ahead, but I do have the technical skills.

Regarding thowing it in a skip... Well, it's been in our family since new. It's almost as old as me and I'd like to see it put to use. Not by any means the best ride ever but - as said - range isn't an issue as I'll only be riding local, and I only weigh 60kg which probably makes the little bike more suitable.