What motor for 400lbs

jawnn

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What size of motor do I need for moving 400 lbs up a 14 percent grade?

Examples would be good to see.
 
On the hills, torque is more important than HP...

14% is 8 degrees.

You need 56 pounds of 'thrust' to maintain a steady speed at an 8 degree grade pushing 400 pounds. On a 26 inch diameter tire, that works out to 61 foot-pounds (60.67...)

Assuming zero losses in your gearing , with a 20:1 gear ratio, the engine must therefore be able to provide 3 foot-pounds of torque.

So, whatever engine you get, with fixed gearing, divide 60.67 time the total drive ratio to calculate the absolute minimum engine torque.

But, if you design a CVT based setup, you could make this work. If the total ratio was 18 to 1, a 2.5:1 CVT reduction at hi load conditions would make the effective gear ratio about 45 to 1.

and, going up hill, dividing 60.67 by 45 yields 1.3 foot pounds. (there are more losses with a CVT though, so you should count on about 1.7 foot pounds engine torque, at a minimum.)

For reference:

The Honda GXH50 is 2.5HP, 2.2 ft-lb max
The Honda GX35 is 1.3 HP, 1.4 ft-lb max
Mitsubishi TLE43 is 2.2 HP, 1.6 ft-lb max
 
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If you are healthy enough to pedal a 21-speed bicycle, then a Honda x50 or 2.2hp Mitsubishi engine with 1.125" roller or corresponding gear ratio should be able to ASSIST you up the hill.

If you're not healthy or skilled enough to pedal uphill then you need a motorcycle.
 
Thats just the engine , There is also the issue of the correct Bike.
Got to get them both right !!!
 
You will need stronger rims. If you get a 24-inch wheel bicycle, you can get plastic BMX wheels for it, and they are tough! I have one of those plastic 24's on the rear of my bike, even though it's a 26-inch bike, because I kept breaking spokes often on my dirt road.

Also, you may need low gearing and sacrifice speed for torque. You could also look around for a bigger engine. My bro's 2.5HP (79cc) trailer can a 300lb person, with cargo on the trailer. If you demand more power for hills, the best option is a 6.5HP Honda Clone engine. I can take any hill with mine.
 
I don't think a 50cc or smaller engine is going to cut it, you need at least a 50:1 reduction,which means doing 8mph going up that grade at 5.5k rpm (max torque) so you wont be able to do much over 10 mph without a gearbox or a CVT.So it's a CVT and/or a larger engine (100cc plus), preferably both
 
What size of motor do I need for moving 400 lbs up a 14 percent grade?

Examples would be good to see.

Nothing seen on this site would be what you need. I think you might want to go the way of an actual motorcycle. 14% grade is quite steep and if you plan on going down as well, you'll need something with substantial brakes.
 
Admittedly,it presents problems,I live in a place with 10% grades and manage to get up&down with a Mitsu/Staton/NuVinci setup (pricey).Even with that wide 3.5 ratio range my top speed is only around 25 mph.I cruise at around 18-20.You need the best brakes you can get.Brake fade can be dangerous on long steep descents!!.
 
not to be discouraged

be glad to take a guess here

3 hp or aprox 47cc

ride that thing sideways

not to be discouraged
with a little studying I think that you will find just what you need

when I owned a bicycle shop years ago
we sold a few bikes to ones close to your weight

and now days we have many experts making
things such as heavy duty wheels

a nice strong frame
aprox 50cc Japanese engine
direct chain drive
with some low gearing

should put you close -- I would think ???

ride that thing sideways
 
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