Jet thruster motorcycle

BowlOfRed

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BowlOfRed
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Bosch has a system that uses thrusters near the bottom of the motorcycle to blast it out of a skid. https://www.engadget.com/2018/05/18/bosch-jet-thruster-motorcycle-slide-recovery/

Even though it's mounted low, it still seems like the lever arm it has isn't very large. I suppose it's fine for someone tooling around the town that isn't leaning over much.

I wonder if someone will hack the control system to try and fire their machine into another lane on command.
 
BowlOfRed said:
Even though it's mounted low, it still seems like the lever arm it has isn't very large.
Click to expand...

Even though it's mounted low? You are confused. The lever arm doesn't extend from the road up to the jets, the lever arm extends DOWN from the center of gravity to the jets. The relevant torque here is about the center of mass, not the contact point with the road. The lower the jets, the longer the lever arm.
 
Why would it need a large lever arm? All it needs to do is push back more or less through the center of mass against the direction of momentum.

Typical tire grips typical road at typical turning radius and traveling speed. If you exceed the physical limits of that arrangent, the tire breaks free and you start skidding. Once you've figured out the parameters for that outcome, all you need to do is provide a blast of counter-thrust sufficient to prevent the skid. You probably just need to buy the driver a brief moment of extra time to get back within tolerances.

ETA: Or what Zig said.
 
BowlOfRed said:
Bosch has a system that uses thrusters near the bottom of the motorcycle to blast it out of a skid. https://www.engadget.com/2018/05/18/bosch-jet-thruster-motorcycle-slide-recovery/

Even though it's mounted low, it still seems like the lever arm it has isn't very large. I suppose it's fine for someone tooling around the town that isn't leaning over much.

I wonder if someone will hack the control system to try and fire their machine into another lane on command.
Click to expand...

So it's just a safety/recovery system? I'm disappointed. I was picturing a motorcycle with jet thrusters as the primary power source. If it's done right, you wouldn't have to worry about wheelies or traction limit.
 
Ziggurat said:
Even though it's mounted low? You are confused. The lever arm doesn't extend from the road up to the jets, the lever arm extends DOWN from the center of gravity to the jets. The relevant torque here is about the center of mass, not the contact point with the road. The lower the jets, the longer the lever arm.
Click to expand...

As I understand it, this operates after the tires have lost their grip on the road. Low is exactly where it needs to be mounted.
 
I meant to say that to my eye, although it was as low on the body as it could be, that didn't seem to be all that far below COM. There's not much room for a long lever on a short bike.
 
Looks like the training wheels in the video offer the cheapest and safest option for stability ;) What happens when that jet thingy fires a foreign object into another motorists face? It would also be a bummer if the jet misfired while not turning and made the rider crash.

Interesting though. I wonder if having an exposed jet like that would be legal? It must put out a lot of power. Seems hazardous.
 
It looks dangerous to me. If a bike starts to slide away in a turn there are already ways to recover if you are a half decent rider.
If you can't recover you push away and slide. 'Lowsiders' are not too dangerous.
Having a bike pushed upright in the middle of a curve would be far more dangerous.
You are either going to run wide and leave the road on the opposite side or go right in to the path of an oncoming vehicle. Even worse your potential lowsider could become a 'highsider' and you are going to be flipped off the bike in a far more painful way.
 
If the bike is sliding then abruptly stopping the slide is going to push the bike upright.
Controlling a rear wheel slide in one of the conventional ways sits the bike up and can be tricky, that's when you have initiated it and are ready for it.

I am sure it's a clever bit of engineering but like the electronic riding aids already available they are resulting in over confident riders who haven't larned to control a bike correctly.
I know riders who have just come to bikes in the last few years who can't brake without anti lock and rely on switchable engine management modes for riding in the wet etc. They use the gadgets in place of riding skill. You can tell who they are when you follow them or see them at a track day. You can ride rings around them.

From this year the Euro NCAP 4 construction regs have made ABS compulsory on new bikes.
 
What side of the bike are you pushing on? Against the skid or into the skid?

Have you given any thought at all, to how to hold a bike in a turn when it's losing traction?
 
theprestige said:
What side of the bike are you pushing on? Against the skid or into the skid?

Have you given any thought at all, to how to hold a bike in a turn when it's losing traction?
Click to expand...

Yes there are several techniques for doing it.
It depends which wheel is starting to slide, front or rear and how the suspension is loaded up.
training videos are available on Youtube that can give you a far better idea than I could in writing, you just need to be sensitive to the bike and confident in your throttle control and brakes.
When you are setting up for some corners you deliberately get the rear wheel in to a slide, or even both wheels if you are good enough (Watch MotoGP or Superbikes) Track Days at Croft (My local circuit) need a controlled slide out of the hairpin to get away quickly.
 
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