Electric trike conversion - advice needed please

[Jaunty]

Hi all.

I am slightly disabled and nowadays ride a recumbent trike. Its great - I can go slower and slower and even stop without becoming unstable and falling over - I can just stop and sit there and have a rest - I don't (and can't) put a foot down to hold me up at traffic lights. I have a really low bottom gear (11 gear inches) and creep up steep hills - sparrows and pedestrians may overtake me, but I get there.

However, I am getting older, as happens for some reason. And I now need some help climbing hills. I bought a second-hand Urban Mover UM44 over eBay to see if I could cope if I didn't have to pedal, but have found that my confidence to ride two wheels has completely gone. It is nicely engineered, and I am contemplating cannibalising it to fit its working bits to my Trice T.

I want to do my own pedalling on the level and down hill, and do not want to have any great electrical speed ability. What I need is good torque to help me climb hills at, say, 5-7 mph. It seems to me that if I fitted the hub motor from the UM 26" wheel to a 20" wheel for the rear of the trike, I would get the kind of torque I would need.

Before I start, I wondered whether anyone had done such a thing before (it seems unlikely that they haven't), and also whether I would be better to buy a conversion kit.

Your advice on both questions would be most welcome.

Thanks,

JT

 

[tongxinpete]

Could do with more info on the UM44 ie max speed (legal 15mph?) & what motor it uses.
If above is true, light load = 15mph, & poss max torque made @ around 12 mph as it stands in the 26'' wheel (would be a 190 rpm motor)

Now going to a 20'' wheel gives a 23% increase in 'torque' ie hill climb ability (& 23% lower speed) So now your motor will give max torque @ around 9.24 mph, this is a bit faster than the 5-7 mph you wanted BUT as it may contribute about half the effort you presently put in with your pedals shifting up 1 cog may be poss & needed to keep your pedal rpms the same, If you pedal happily on the flat unaided now, well this may be OK.

When lightly loaded the motor would now give about 11.5mph (maybe 12 mph as even in this role we have lightened its load)
I find the UM44 was sold by Halfords? they do not show many hard facts on it, so more info here would really help with the calcs. As to whether to strip this or buy a kit, well really depends on a) what you paid for it & could re sell it for. b) price of kit to buy instead. (you have this there & know it all works) where importing a kit off say ebay can be a bit of a gamble. Donor bike could be re sold with a normal wheel put in from the junkpile as just a bike, so a bit of money back there. Is it a front or rear motor? & what type of batts does it use? Also do you know the steepest hill you often climb eg 1 in 8, 1 in 6, or worse !! (this can be found with a spirit level, straight edge, & ruler, better done in feet than inches or cms as tiny imperfections in road can throw things out. Pete