Old tricycle build. Looking for advice. Mac motor?

ihategeeks

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Mar 26, 2013
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I'm looking to turn this old granny trike into an etrike.
24 inch wheels.
Got it for cheap and it has nice steel 100mm front forks to work with so I figured it would be an easy project. (bright don't kill me yellow)
Most of my driving around town is flat, but I still want good pulling power as I intend to cart a kid behind, or even a trailer at some point.

Questions!
Is a 12TMAC the best motor for this application?
Speed is no issue, trikes can't go fast. But will it be too much torque for a front wheel and just spin the tire?

I would potentially like to dump big amps into it , can the mac handle that?
The 9C I have starts melting things when I go over 25 amps on the controller.
I ideally want to get a 30 amp controller.

I saw a video of a lunacycle pulling a car, and while I'm not that ambitious, I would really like to be able to haul a utility trailer loaded up with wood, mulch, (stones if possible), am I asking too much from a front wheel setup?


if anyone has recommendations for trailer receivers for tricycles I would appreciate that too :mrgreen:


Any input is welcome!
 
Where are you located ?

BTW, I have a 6 T mac , laced up to a 27.4 inch wheel, I do not need to run 30 amps through it unless I want to go fast, which I do often on that bike . It handles 30 amps and even up to 35 amps for very short bursts. I have nearly 3,000 Km's on it at the present time ( I have my C.A. set to record Kph and Km's since my Garmin records in Miles ), and the motor is still running strong.


So you see , with a 24 inch wheel you can use any Turn number of Mac Motor you want and still go up 6 % grades easily. Mine goes up 4-5% grades very easily.
I have a brand new Mac Front Hub motor laced up to a 24 inch rim that I have been wondering what to put it on, it is still new, I was going to convert a 24 inch BMX bike for a easy to make , simple , kick ass light weight around town e-bike that all the young punks would drool over ... but I have many other projects in the works that need to be done first , so I could sell it if you decide to go for a simple low speed front drive system .
 
To get traction from a wheel, you have to have weight on it in proportion to how much traction you want. If you want strong acceleration and towing from a trike like that, you should probably power the rear wheels. That way you have at least your own body weight to provide tire adhesion with.

Most granny trikes have one-wheel drive, with the other rear wheel free-spinning on its axle. That gives you another kind of traction problem when you turn towards the powered wheel and the weight shifts to the outside rear wheel.

In tackling this same sort of problem with pedicab trikes, I chose to design a system with the big 2-4kW Cyclone gearmotor driving a differential, rather than trying to use a front hub motor. Instead of a differential, you could drive the trike's axle directly and put the power through its one driven wheel-- or if it has separate half axles, you could drive the idle side with a motor and the other side with pedals. Or you could get a differential axle if your trike is able to accept its diameter.

I will point out that having over 1500W motor power on a trike that becomes treacherous over about 12mph is both unnecessary and unhelpful. If you use enough gear reduction to stay at safe speeds, you wind up with so much torque that you'll exceed the practical capacity of the components. I think using the 12T MAC motor is a good idea, but feeding it 30A or more is likely to break stuff and wear things out without giving you useful advantages in return. Granny trikes are not strong and they're not designed to cope with much pedal power, let alone superhuman amounts of motor power.
 
FWIW, I started out with something rather like that (Delta Tripper) before I tore it apart and built SB Cruiser out of it.

if you're ambitious, and can weld, I'd recommend looking at my SB Cruiser and Raine Trike threads, for some ideas on various parts of your project.

I'm not sure how much power that (presumably) live-axle and drivetrain will take, but a middrive to the rear thru the chain would be one way to get power to both rear wheels.

Front wheel drive can work, but rear wheel drive works much better with the cargo weight and stuff. Especially with a trailer, which cna push down on the rear end and lift up the front, taking away your traction, whcih will *also* take away your steering if the motor causes the tire to skid because of the lost traction (which is less likely to happen if that wheel is not powered at the time).


Hubmotors are only an option in the rear if you do some hefty modifications adn don't want a pedal drivetrain, or do more modifications to run that to the front wheel instead. It'd be possible to add hubmotor mounts to the rear of the live axle outputs, and put sprockets on the ends of the live axle, instead of wheel hubs, then run chains from those sprockets to sprockets bolted to the hubmotors inboard sides.

If you did something like this, you could actually put the hubmotor axle mounts *above* the live axle, and drop the cargo basket or deck down several inches, yet still keep the same wheel size, and gain the lower COG and better cornering of the lower deck, while keeping the better ride quality of the larger wheels.

That's sort of how the Raine Trike is setup, except I'm only driving one side with the pedals.

SB Cruiser has smaller rear wheels, which have a harsher ride over bumpy roads than the bigger wheels would.

But it is all low-slung weight so it corners well at speed, and the twin hubmotors let me haul things like a piano, almost 600lbs of dog food, couple of St Bernards, etc. ;)
 
I have hauled all sort of items around with this combination,
Simple / Cheap, and lots of low speed torque, ( no hill climbing )

https://www.google.com/search?q=razor+ecosmart+metro+electric+scooter&oq=Razor+Ecos&aqs=chrome.0.0j69i57j0l4.5585j0j7&sourceid=chrome&ie=UTF-8

https://www.rei.com/product/896409/burley-steel-hitch

And a kids trailer that I took the fabric off and made into a flat bed trailer .



ihategeeks said:
I would really like to be able to haul a utility trailer loaded up with wood, mulch, (stones if possible), am I asking too much from a front wheel setup?


if anyone has recommendations for trailer receivers for tricycles I would appreciate that too :mrgreen:


Any input is welcome!
 
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