What do front hub motors weigh??

[Donny G]

I was playing with idea of 2WD electric bike, using hub motors. I even contacted Crystalite for prices, but dropped the idea because of money shortage...

I've got a pair of crystalyte 406/408 two speed hub motors collecting dust
these are dual winding motors suitable for high voltage at 60v they pushed my heavy 26" wheeled schwinns to 34 mph @ 40Amps at 72 volts they would
seriously haul Balls

 

[vanilla ice]

I don't think a .6 horsepower 16 pound hub motor would do a darn thing in sand. Depending on the bike there's anywhere from 20 to 100 horsepower to the rear wheel. What's half a HP going to do?

Have fun and good luck!

You could be right, I'm not sure. The ohlins Yamaha setup only transfers a small percentage of the WR450's power to the front. IIRC ~10- 15%. Thats what makes me optimistic something like an electric motor can work. Those things make like 50hp, so figure 5hp to the front may be enough.

And by work I mean slightly improve handling characteristics, not aid in acceleration. After all this is hugely inefficient- transferring power from an internal combustion engine to electricity, and back into motion through an electric motor. But it could be worthwhile depending on the effect on handling. The ohlins hydraulic setup is likely just as inefficient.

Who knows maybe mimicking the ohlins setup with a couple of industrial small hydraulic pumps would work too. IMO that would be more difficult for a shade tree type though.

You're saying 0.6hp, but there are much more powerful hub motors available. Heck I'm running my currie motor at over 1200watts and its a cheap little tiny bugger. And then theres always fork mounting a motor if a hub motor cant cut it.

It would be interesting to see what kind of heat would be generated. You've got to remember the ICE is still powering the rear wheel also. That should reduce the current draw somewhat.

I'll probably just stick to bicycles for now. I'm sure somebody will try this fwd thing on a ICE motorcycle sooner or later. From the rave reviews 2wd motorcycles have been getting I'd say its worth a shot. And as time passes the tech gets better, motors get lighter and more powerful. I'll return to this thread in five years and see if I was wrong.

 

[RLK]

The next question might be...

Why don't racing snowmobiles have powered front treads where all the best currently winning race sleds have skis?

The physics are similar. Any good sand rider will tell you, "Keep the front end light" while making a twisting throttle motion with his/her right hand.

Keep the front wheel light.

Edit: A seperate part of the lesson I took from the Pro rider was about bike setup. I ended up buying high rise ATV handlebars that brought my controls exactly to belt height when standing on the pegs. That alone made technical riding of the bike over sand and rocks and mud and all other challenging terrain a billion times easier. Still, its all about weighting the footpegs.

 

[DougC]

Before I was born, my mother's family had a Rokon 2WD motorcycle on their farm. I am told that you could be in the middle of midwestern-type woods and it would go anywhere you pointed it without much trouble. Riding across freshly-plowed fields was no big deal. Wasn't very fast (more like a giant minibike) and was rather expensive though.
~

 

[beast775]

e bike gas power

i liked the rokon i remember riding one mid seventies i beleve to long ago to remember!built a hybrid 43cc gas rear and 600 watt ehub front.i drove up a 20% gravel grade standing up and the ehub really pulled well, i drove up the same grade with just the ice motor and had to jump off at the top and push the rst of the way,but all the weight and mechanilcals on the hybrid would not be worth making for all day off roading,i have video of the said gravel grade but am losing interest as i type.115 lb bike vs 48 lb bike id rather push for 5 seconds compared to all the madness from a hybrid gas back electric front,did not compare to me.

 

[billvon]

You're saying 0.6hp, but there are much more powerful hub motors available.

He may be quoting average power. That's one problem comparing motors; gas engines are rated at peak power and electric motors rated at average. I have a Crystalyte 5304 that I can run at over 5kW (about 7hp) in short bursts. I think it's rated around 500 watts though.