Are doing jumps with a Hub Motor safe?

[EdwardNY]

I have a yescomusa kit in the mail to me now so hopefully next week I will have my bike up and running. I have been recommended that I should not do jumps with a hub motor motor. I also have read here that if you do jumps to just let off the throttle when you land.

I have a full suspension mountain bike that I have done plenty of jumps with, only as high as three feet max. I was wondering if this will still be possible when I install my hub motor? Are there any issues with doing this and what can I damage?

Do I have to drive the bike much easier with a hubmotor?

 

[Philistine]

Direct drive hub motors are fine to jump (well, their limitation is the strength of the spokes and the rim, obviously the weight of the motor is harsher than a normal hub. But geared hubmotors are a bit more fragile, because if you jump (particularly under throttle as you say - or land under throttle at least), you can strip or damage the teeth on the planetary gears. Having said that, go check out the Phasor cycles sale thread for what people do do with geared motors and seem to get away with it (he is jumping with a BMC/MAC). Is a Yescomusa a geared motor? There are lots of guys on here who jump with geared hubmotors and seem to be fine. If it is a geared motor, then you can always replace the gears anyway. If it is a direct drive motor then it is just common sense as to the damage to the spokes and rim.

 

[amberwolf]

The only potential issue I see with a DD motor is if the magnets aren't glued down properly (or at all); you could end up with a magnet jammed between stator and other magnets, suddenly stopping the wheel.

If it's a rear wheel you'll probably just skid out, but if its' a front, well....it depends on what you are doing at that moment how bad it would be.

 

[dogman dan]

To the extent that I still have the balls for it, I jump a direct drive hubmotor all the time. I wouldn't call em hucks by a long shot, certainly nothing compared to the jumps I once took when the landings would be bottomless powder snow. But If I hit a small bump and fly a yard or two it's no more damaging to the motor or the wheel than riding along through softball size rocks is. I don't hesitate to ride off a curb at 20 mph for example. Riding up a curb, I'll slow down.

Same hazards as abusing a regular bike wheel, you might hear the spokes squeal some, might pinch flat a tube, might pull spokes right out of the rim if you run too much spoke tension. Even crappy full suspension helps a ton. If you have rocky trails, or the landings are flat you likely will eventually damage a rim with a hardtail.

It's a possiblility that the flange on the hub could crack, but I've had no problems with that riding full suspension in dirt. I have rode trails rough enough to loosen all the hub cover bolts though.

 

[The fingers]

The more fun it is, the less safe it is. 8)

 

[kfong]

I'm doing 2-3 ft jump quite often on the BMC in the trails. I just let go of the throttle while landing. I run a full suspension with Fox rp23 for the rear. Motor so far has been dead reliable. I wouldn't do it with a fixed suspension bike. I've had to replace two spokes this year.

 

[dogman dan]

Makes sense. Even with a dd motor, It might be best to land with throttle off. Now that I stop to think about it, that's how I ride. By the time I'm airborne, I'll be backing off anyway.

 

[cal3thousand]

The more fun it is, the less safe it is. 8)

Is that why I'm having so much fun on these LA streets? :wink:

 

[EdwardNY]

Makes sense. Even with a dd motor, It might be best to land with throttle off. Now that I stop to think about it, that's how I ride. By the time I'm airborne, I'll be backing off anyway.

What about riding off of curbs, do you let off the throttle?

 

[EdwardNY]

Makes sense. Even with a dd motor, It might be best to land with throttle off. Now that I stop to think about it, that's how I ride. By the time I'm airborne, I'll be backing off anyway.

What about riding off of curbs, do you let off the throttle?

 

[dogman dan]

Yeah, now that I think about it. Top speed of that bike is 25, so that's fast enough for me to fly off a sidewalk, or from the dirt to the street. I'd likely be wanting to apply throttle back later, after I make a turn when I land, or something like that.

It's not that I thought about it or anything, I think I just am off throttle because I don't need any at that moment.

 

[kfong]

Makes sense. Even with a dd motor, It might be best to land with throttle off. Now that I stop to think about it, that's how I ride. By the time I'm airborne, I'll be backing off anyway.

What about riding off of curbs, do you let off the throttle?

If I'm jumping, I usually have enough air time to let off on the throttle. If not then I'm probably on full or partial throttle and moving pretty hard through the trails. I have a spare BMC motor and have yet to swap them due to any break downs. I ride my ebike just like I would ride a mountain bike in the trails. The BMC motor has been a very rugged and reliable setup at moderate power levels. If you intend to push the motor over 2000 watts, you only have yourself to blame.