Advice on how to convert my KMX recumbent trike

[Monkreadusuk]

Good evening,

I'm looking for some advice on how to convert my KMX trike to electric. I'm after something to assist with me 20 mile commute that includes a couple of hills. Looking for pedal assist and the option to increase my speed when using off-road.

Would a rear hub be better for the trike as it would allow me to keep the 3 rings on the front for assisting with hills etc?

Any advice gratefully received.

Many thanks

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[Deleted member 4366]

You don't need three rings on the front for hills when you have a motor.

Whatever system you use has advantages and disadvantages, which makes it an even choice for your application. If I were converting one, I think I'd go for a crank or chain drive to take advantage of the greater speed range.

 

[anotherkiwi]

Hi,

I have been kicking the theory around for quite some time, here are a few random thoughts:

- after discovering the stress that goes through a 26" trike rear wheel in corners a stock Chinese made wheel won't last long in my opinion
- trikes go fast enough already on the flat so a vanilla 25 km/h pedelec hub motor for help on hills and starting off is a choice that has its merits
- if you want to go faster de-restricted or faster up hills the crank drive wins

I have both types of motor and almost dropped the hub motor in a couple of times but what held me back was the gearing. The road I ride most often requires correct gearing to get me home in case of battery failure and 26:32 is too high a gear for the last hill so the freewheel motor won't do... maybe on a 20" rear wheel trike?

In my neck of the woods I need two chainrings, one for going up and the other for coming back down. I have opted for 48-32 which is a reasonable compromise for my age (having problems pulling 48:11 these days... ). That means climbing at cadence in 32:15 is about 25 km/h cutoff speed and 48:11 spins out at over 60ish (I find I have pedal steer at over 55 km/h - lack of rider experience rather than steering issues).

I have an 11-40 wide range cassette which is OK so far but am looking at converting to 10 or 11 speed to get the extra 6-10 teeth on the back. This would probably be overkill for the UK but I have an ongoing love affair with Navarra which I tend to explore randomly and they can throw >15% "hills" into the mix

Conclusion:

- I would love a rear hub motor such as the tiny light weight Xiongda just for climbing at reasonable speed
- I am going for a GSM mid drive powered trike to profit from the gearing options it provides for "hors catégorie" climbing conditions

 

[Deleted member 4366]

Forum member twinkle and her friends have built several trikes with different hub-motors, and one or two of her crew have crank-motors. Send her a PM and ask for her comments.