What motor for 400lbs

[duivendyk]

Yes he needs the oompf all right,the question is ,does it have enough weight on the drivewheel with the requisite reduction, to handle the torque required.Only an experienced motorcyclist should ride one of these contraptions anyway I think.

 

[Junster]

I'm a N00b but couldn't he use a 80cc HT with a sbp shift kit? A Mountain bike frame with a 7 speed rear should give him a wide enough range to climb and still get 20+ on the flat and level. Or am I mistaken?

 

[loquin]

From a different post that jawnn has made, I believe he's riding a trike, with a cargo-box.

 

[macarollo]

I'm a N00b but couldn't he use a 80cc HT with a sbp shift kit? A Mountain bike frame with a 7 speed rear should give him a wide enough range to climb and still get 20+ on the flat and level. Or am I mistaken?

If you don't mind going very slow, I would think using the lowest gear could get you up the hill.

With my 80CC HT kit (no SBP shift kit) the top speed going up hill was about 20-25mph... I had to assist the engine if I were to go any faster. I am not sure of the grade of the hill though. I weigh 180 pounds though... If I were to weigh 400lbs I doubt I could go 20mph with stock gearing. I would guess maybe 15mph.

If you were to use a lower gear it could make it up the hill, but at 8-10mph maybe.

 

[duivendyk]

You can figure out that with the available torque from that kind of HT you can do about 8-10 mph on such an incline,you need gears or at least twice the displacement,preferably both.

 

[loquin]

again, jawnn has said in a different post, that he's trying to motorize a recumbent trike. You can't frame mount it - it would have to be a rack mount.

 

[duivendyk]

Someone recently showed pics. of a trike with a NV hub in the drive train (not on the rear axle),it looked like a 50cc? Honda or Honda clone,that might do the job.If he needs a max reduction of 50 that would mean 50/2=25 in the rest of the drive,the minimum would be 25/1.75=14.3 or a speed of 31 mph at 6k rpm and 31/3.5= 9mph minimum speed.
The trick is to come up with the remaining 25:1 reduction,that means or two 5:1's in cascade, which would be hard to do with chains,or an engine gearbox plus two chains, then something like around a 6:1 chain reduction would do the job, which is doable.The NV plays jack shaft.Rather messy though