Electric Motor Kit For Upright Trike

HMS_Dave

Active Member
Location
Midlands
Hello all, Can anybody recommend a legal ebike system for a tricycle? Im a heavy guy - https://www.cyclechat.net/threads/obese-rider.252199/ and i need something that is road legal and powerful enough to help when i struggle.

The idea behind the trike is to genuinely use it to replace a car in many cases so it will be functional and to lose weight and gain fitness. I think, if i stuck a 10000 watt motor on there from a ship winch it would struggle so my current research has lead me to a motor with as much torque as possible. Mid drive kits although more of a pain to fit than hub motors seem to hint at them having more torque but then the tricycle im looking at has a shimano nexus 7 internal hub gear so im worried about loading that with torque.

Does anybody have any suggestions can the shimano IHG do it? Is there a more torquey hub motor out there that im missing?

Thanks very much Ladies and Gents.
 
I think, if i stuck a 10000 watt motor on there from a ship winch it would struggle so my current research has lead me to a motor with as much torque as possible.
10000 Watt! At typical e bike voltage (36v) that would be 278 amps! Are you working for MI6 special projects? Or will it be a stunt trike for the next Jonny English film?

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HMS_Dave

HMS_Dave

Active Member
Location
Midlands
10000 Watt! At typical e bike voltage (36v) that would be 278 amps! Are you working for MI6 special projects? Or will it be a stunt trike for the next Jonny English film?
I wish, Just being facetious. Although i think id be more Robbie Coltrane than Daniel Craig in the spy world...
 

numbnuts

Legendary Member
Location
North Baddesley
I don't think a 250w motor is going to cut it to be honest and hills would be out of the question even with the lowest gearing.
Mine trike and all it's crap weights in at 42LB and I'm 170LB and on really steep hills 1 in 5 say I'm going up at 5-7 MPH and you can hear the motor labouring, if you tried it you may burn out the motor very quickly.
 

raleighnut

Guru
Location
On 3 Wheels
That BPM front wheel kit looks good, I've only got a 250w on my trike and it does 'labour' a bit on steeper hills, one thing though it only comes in 26" or 700c so you may need to fit a different fork, I had to but then the original fork ends were too thin to tighten the nut up due to the 'anti rotation' fitting on the axle.
 
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HMS_Dave

HMS_Dave

Active Member
Location
Midlands
Simplest conversion would be a front hub motor.

The BPM motor in this link is quite perky, some call it the Big Powerful Motor.

I've tried one in a push bike and it does pull well.

You won't know exactly what it will do for you unless you try it.

The retailer is UK based and has a good reputation.

Worth lifting the phone.

http://wooshbikes.co.uk/?hubkits
The BPM motor looks good but it is stated as NOT road legal on their website due to it being 350 watts and it is marked as such. I understand there are those that fit big motors and never get caught, but i have a sneaking suspicion the law is going to find a way to catch up with these folk in due course due to the anti-cycling lobby being very chirpy. I know that id probably need a big motor due to weight and im unlikely to break any speed limits but as disagreeable as it is, it is still illegal. Im just wondering if there is a 250w motor that is gearing for torque rather than speed as most seem to want you to get to that 15.5 mph limit as fast as possible but i don't very much care about that...
 

raleighnut

Guru
Location
On 3 Wheels
The BPM motor looks good but it is stated as NOT road legal on their website due to it being 350 watts and it is marked as such. I understand there are those that fit big motors and never get caught, but i have a sneaking suspicion the law is going to find a way to catch up with these folk in due course due to the anti-cycling lobby being very chirpy. I know that id probably need a big motor due to weight and im unlikely to break any speed limits but as disagreeable as it is, it is still illegal. Im just wondering if there is a 250w motor that is gearing for torque rather than speed as most seem to want you to get to that 15.5 mph limit as fast as possible but i don't very much care about that...
The XF 07 is 250w and looks similar to my 'cyclotricity' kit .
 
The BPM motor looks good but it is stated as NOT road legal on their website due to it being 350 watts and it is marked as such. I understand there are those that fit big motors and never get caught, but i have a sneaking suspicion the law is going to find a way to catch up with these folk in due course due to the anti-cycling lobby being very chirpy. I know that id probably need a big motor due to weight and im unlikely to break any speed limits but as disagreeable as it is, it is still illegal. Im just wondering if there is a 250w motor that is gearing for torque rather than speed as most seem to want you to get to that 15.5 mph limit as fast as possible but i don't very much care about that...
Staying on the right side of the law is not simple when it comes to power rating.

All motors - even nominally legal 250w ones - peak at about 600w when the controller demands full power.

That peaking is not really covered in the legislation.

The power cut-off is simpler, that must happen at 15.5mph, irrespective of the size of the motor.

Lots of 250w stickers online, there being no realistic way of checking a motor's power rating other than by looking at what, if anything, is marked on it.
 
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HMS_Dave

HMS_Dave

Active Member
Location
Midlands
Thanks for the replies everyone. I've been doing some research on the motor ratings and its amazing that they can even come up with a wattage as a limit. It seems the watt ratings of the motors are only what they are tested at that are guaranteed not to overheat and have little to do with power for most part. Different motors have different windings which affect RPM and so torque/power and batteries and controllers.... Obviously, if on the side of the motor it says 'POWERFUL 1000W MOTOR' the police are going to nab you, but in testing, every motor is going to for a short time at least breach 250w and onwards close to a 1000w in high stress situations for some legal motors... Im no expert so if im talking rubbish please correct me but that seems crazy to me given the stringent legislation involved...
 

voyager

E- tadpole Triker
The regs are 250w continuous Peak power can go above this for short periods,
It is the controller that limits the power not the motor . A 250w max power system would be worse than useless .

Most 36v controllers are rated at 250w but with a current limit set around 15a max current limit (fold back current ) so that makes 540w max power a normal everyday viable power output.
The 15mph +/- 10% limit is the only realistically testable part of the specification.

Regards Emma
 
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