Electric Bikes - Hub motors - weight limitations?

Has anyone seen mention of, or experienced any problems related to heavy loads on hub motors?

I am looking into using some sort of kit on my Xtracycle equipped Instigator. I am familiar with the Stoke Monkey but they are not currently available.

Looking at all the options, I am checking out the various hub motors like BionX, etc. and wondering if there are any issues with using them on a bike that potentially will weigh as much as 400lbs including bike, rider and cargo.

Has anyone bent axles or otherwise damaged hub motors by hauling too much weight?

Well, the good news is, that 400lbs isn't all sitting on just the one wheel. As you know, the Xtracycle shifts the rear wheel away from you which essentially brings your weight much farther onto the front wheel. My personal experience with Crystalyte is that their axles are *very* thick and durable. The thickness of the axle is probably about 40% more than that on my All-Mountain bike's wheels. Many of these motors are also built with 36 spoke design instead of 32. I've not had any problems with the Crystalyte 408 on my Xtracycle, mind you its situated in the front wheel and recieves less weight than the rear wheel. I can also tell you though, my rear wheel is only 32 spokes and hasn't had any troubles either. I wouldn't be worried too much, personally.

My personal opinion is that for current hub motors, something geared (i.e. very high torque) like Heinzmann would probably be the closest to the Stokemonkey experience you'll get. Many other motors like the BionX and Crystalyte are good motors, but they don't *haul* like Stokemonkey or Heinzmann does.

only problem i ran into was the rim. i replaced it with a double wall rim with steel eyelets now all get is the sound of the hubmotor not the pinging spokes. makes one hell of a solid wheel :)


cheers

I go with karma. I'm 80+ kilos, so when I ride back from the grocery store on my ebike with 2 full panniers and a backpack with a case of bottled water on the rack, I must be pushing 200 kilos. Slower starts, more difficult stops, and I'm using the hub more than normal (if you do this all the time think about putting two battery packs in parallel to improve your amp hours) but haven't had any trouble for now.