How to stop during a hydroplane situation?

[flying_hun]

while traveling in a straight line, at between 65-80 mph, while raining on a road that seemed to be shedding water pretty well, no puddles. Riding along with a steady throttle...revs jump up-while bike slows down...rear starts to wobble...cut the throttle, and the rear bites again. It sometimes happens so fast I don't have time to cut the throttle, which is why it is eventually self correcting.

Not a hydrodynamics guy, but the front wheel will part the waters for the rear, but if the water is not thrown clear of the rear tire, since the front is skinnier, the rear will still have ride over it. There may be less water in the middle of the tire, but more on the outside. Just my guess.

Hydroplaning is the only explanation for the rear losing traction?

 

[monkeythumpa]

Hydroplaning is the only explanation for the rear losing traction?

I can't think of another reason the rear would lose traction in the conditions I mentioned. I have hydroplaned plenty, on purpose and by accident, on plenty of different vehicles. I know what it feels like.

 

[ST Guy]

It is based on it happening to me, three or four times in 11 years, while traveling in a straight line, at between 65-80 mph, while raining on a road that seemed to be shedding water pretty well, no puddles. Riding along with a steady throttle...revs jump up-while bike slows down...rear starts to wobble...cut the throttle, and the rear bites again. It sometimes happens so fast I don't have time to cut the throttle, which is why it is eventually self correcting.

Not a hydrodynamics guy, but the front wheel will part the waters for the rear, but if the water is not thrown clear of the rear tire, since the front is skinnier, the rear will still have ride over it. There may be less water in the middle of the tire, but more on the outside. Just my guess.

Probably depends upon how flat the rear is worn. In theory, the front should be parting a lot of water for the rear and the front will tend to hydroplane first. But there are a lot of variables like different sizes and profiles front and rear, the wear of the tire, and the design of the tread pattern front vs. rear.

 

[ST Guy]

HH, I think keeping a space cushion and staying loose is about all there is to be done, and it sounds like you did well. FWIW, I'm not convinced that a heavy bike is that big of an advantage. Besides, when things go all pear shaped, I'd rather be on a lighter bike.

A heavier bike most definately has an advantage, often a big one. If you look at the tire sizes being used on various size bikes, they are often the same size. For instance, you'll find 120/70's used on everything from small sport bikes to big sport tourers. Same profile, but with more weight, it takes more speed to hydroplane. Ligher bikes are usually at a disadvantage.

On thing that can be done is switch to sport touring rubber for the winter. They often have deeper grooves that are also designed for optimal displacement of water. And if you're worried about grip, the rubber compounds are forumlated more for wet and cold weather use. They're worlds better than sport rubber in the wet.

And if you're worried about dry grip.....don't. You'd have to be insane to exceed the grip of modern sport touring rubber on the street. There was an article some while back in City Bike, I believe where a group went on a ride to Northern Cal for a long weekend ride. Some of the purposely spooned sport touring rubber on their sport bikes and besides not needing to worry about wearing them out (which some of the sport tire shod bikes did), they reported the tires worked brilliantly and never showed a hint of losing grip during their spirited weekend jaunt.

 

[monkeythumpa]

I'm guessing the OP puts preserving human life higher up on the priority scale than a moto. God forbid you ever lay your bike down or are involved in an auto collision, and the first on scene has your attitude

No good deed goes unpunished. It is always the guy who gets out to help that is killed, not the guy who started the chain of events.

Besides, it would have to be one special dude/ette that is worth sacrificing my bike for.

 

[ST Guy]

I thought the question was how to stop, while most people seemed to reply to how to ride thru it. DataDan's answer makes sense - it's the speed that "float/hdroplane" the tires over water - reduce the speed to reduce/stop hydroplaning. The more you gas it, the more the front will unweight and float/hydroplane, but here we want to the weight the front (by rolling off the throttle) to have it sink down, right?

Right. Simply roll off the thottle and ride it out. When you have traction again, you'll know it and you can gently apply brakes. Or madly apply brakes if you have ABS.

 

[monkeythumpa]

Probably depends upon how flat the rear is worn. In theory, the front should be parting a lot of water for the rear and the front will tend to hydroplane first. But there are a lot of variables like different sizes and profiles front and rear, the wear of the tire, and the design of the tread pattern front vs. rear.

Here are the tread patterns it happened on:
http://www.metzelermoto.com/web/cat...xml&menu_item=/products/catalog/sport_touring
http://www.metzelermoto.com/web/cat...rathon.xml&menu_item=/products/catalog/custom

I ride enough twisties to counteract the commute so my tires don't really get too squared off.

 

[ST Guy]

you forgot; "screaming"

1) roll off throttle to lower speed, 2) keep bike upright, 3) scream like a little girl

Of course, since I have abs I also get to: 4) grab a big handful of brake and enjoy the ride




(glad that went ok for you Gwynn... and for helping the cager )

I think I'd hesitate to grab a big handful of brake, regardless of ABS, if you're still hydroplaning. While the ABS will immediately sense the lack of traction, it might slow the wheels enough to cause some additional stability problems while hydroplaning. I've got to think that you want to keep the wheels spinning at all costs while hydroplaning.

The trick, of course, is to recognize when you're not hydroplaning anymore so you can apply the brakes.

 

[ST Guy]

Not to get too sciencey here, but a heavier bike will have bigger tires. And if the contact patches are loaded equally, the lighter and heavier bike will both hydroplane.

One thing you can do to improve the situation is inflate tires to the maximum. This may sound counterintuitive, but the effect is to concentrate loading in a smaller contact patch. Both Gary J and David Hough recommend this in their books.

Many bikes of very different weights use the same tire sizes. So, in most cases, the heavier bike definately has the advantage.

Raising the tire pressure is definately a good idea. Though one must keep in mind that overall maximum available traction will go down. But in wet weather, needing that extra bit of traction probably doesn't outweigh the reduced tendency for hydroplaning that higher pressure may provide.

Best thing, though, is to switch to sport touring rubber in the winter.

 

[NorCal Factory]

While many people said to go off throttle, I disagree. I think you should maintain the throttle or add a little more throttle while leaning back.

If you have ever ridden dirt bikes through long water puddles or really slippery mud sections at speed, you will know that adding throttle will help keep the bike straight (steering with power) and allow the front tire to still steer fairly well without full contact with the ground.

Another really good example of this is running down sand washes at high speed.

While the front end is wiggling, it still gets you pointed in the right direction rather than washing out. If you slow down below the plane speed, it tends to oscillate more and then auger in causing a crash.

Then after you get through that section, you slow down.

 

[louemc]

I have a sneaky hunch..the term Hydroplane is getting used too freely.

Wet pavement, has variables. A couple inches of standing water, and dips in the road, changing that to a foot of depth, that isn't seen under the thin lake...too even deeper...doesn't mean hydroplane, sure can mean slipping and sketchy feeling.

Hydroplane is total disconnect, tire up off the pavement, floated by water, no control, not even as solid as ice.

What does one hydroplane in?
Actually not seeing the water? Actually not saying "damn that's some water, I'm slowing to a crawl for this, and picking up to whatever I can handle, once I get in it and see how it is"?

I trust Happy Hornet to have described her situation accurately, and done it well...No way (not being there) can I say something wasn't done right, or that she placed herself in an unreasonable danger....because I wasn't there, seeing how it was going down.

I think it's safe to say it turned out fine...so...that's a good sign.

 

[ThumperX]

If you feel the need to stand on the freeway, while cars are spinning out of control I recommend that you park your bike 100 yards past the accident and get to a safe position (not on the freeway). Personally I would not have stopped unless the guy was on fire or something that NEEDED immediate correction.

The guy was trapped in the vehicle facing oncoming traffic. I value human life more than my motorcycle. As offensive as that may be to some that is who I am. Since the bike was stopped already, seemed OK to leave it where it was with turn signal flashing. If it got mowed down instead of the driver getting killed seemed like a worthwhile sacrifice.

 

[Gary856]

While many people said to go off throttle, I disagree. I think you should maintain the throttle or add a little more throttle while leaning back.

If you have ever ridden dirt bikes through long water puddles or really slippery mud sections at speed, you will know that adding throttle will help keep the bike straight (steering with power) and allow the front tire to still steer fairly well without full contact with the ground.

Another really good example of this is running down sand washes at high speed.

While the front end is wiggling, it still gets you pointed in the right direction rather than washing out. If you slow down below the plane speed, it tends to oscillate more and then auger in causing a crash.

I understand the dirt bike technique when you have a thick layer (inches) of loose stuff and nothing solid underneath, so you'd gas it and surf over the top of the loose stuff. On a street bike on pavement, though, when people say "hydroplane" I think of a thin (small fraction of an inch) boundary-layer of water between the tire and a solid surface below, so as soon as you loose enough speed to allow the tires to fully expel the boundary-layer water and make full contact with solid pavement, you'd regain traction. Since it's the speed that caused hydroplaning in the first place, adding more speed doesn't seem right. Now if we're talking plunging into foot-deep standing water then I'd say replace the front tire with water-ski.

 

[planegray]

I think I'd hesitate to grab a big handful of brake, regardless of ABS, if you're still hydroplaning. .....

yeah, I was just playing with the "NO ABS " crowd

The only time I've ever given my soul over to god and the ABS was on 880 when EVERYthing went to shit and there was spinning cars and tire smoke all around me

 

[NorCal Factory]

I understand the dirt bike technique when you have a thick layer (inches) of loose stuff and nothing solid underneath, so you'd gas it and surf over the top of the loose stuff. On a street bike on pavement, though, when people say "hydroplane" I think of a thin (small fraction of an inch) boundary-layer of water between the tire and a solid surface below, so as soon as you loose enough speed to allow the tires to fully expel the boundary-layer water and make full contact with solid pavement, you'd regain traction. Since it's the speed that caused hydroplaning in the first place, adding more speed doesn't seem right. Now if we're talking plunging into foot-deep standing water then I'd say replace the front tire with water-ski.

I agree with what you are saying in some cases. It's all a matter of degree.

"When is doubt - gass it!" Really works.

 

[ST Guy]

yeah, I was just playing with the "NO ABS " crowd

The only time I've ever given my soul over to god and the ABS was on 880 when EVERYthing went to shit and there was spinning cars and tire smoke all around me

I see you're still here.

ABS....

 

[russ69]

The guy was trapped in the vehicle facing oncoming traffic. I value human life more than my motorcycle.

I wasn't concerned about the bike but I was concerned about the rider being the next victim of a car not being able to slow down. He had stopped in a very dangerous spot.

 

[ThumperX]

I wasn't concerned about the bike but I was concerned about the rider being the next victim of a car not being able to slow down. He had stopped in a very dangerous spot.

Ah, got it. No way I stood there, I hopped the guard rail and stood near but not between ready to leap down the ditch. I value my human life above just about anything
But, I wasn't going to leave that man alone. Stayed until CHP arrived, then got the hell out of that situation.

 

[louemc]

While many people said to go off throttle, I disagree. I think you should maintain the throttle or add a little more throttle while leaning back.

If you have ever ridden dirt bikes through long water puddles or really slippery mud sections at speed, you will know that adding throttle will help keep the bike straight (steering with power) and allow the front tire to still steer fairly well without full contact with the ground.

Another really good example of this is running down sand washes at high speed.

While the front end is wiggling, it still gets you pointed in the right direction rather than washing out. If you slow down below the plane speed, it tends to oscillate more and then auger in causing a crash.

Then after you get through that section, you slow down.

Good to hear the voice of a dirt/sand (and water there) point of view.

I was contemplating adding those...but...felt they would sidetrack the explanations. The Dirt/sand (and water there) is offering up in bike control skills/sensations, that the pavement rider is best taught with.

I find a difference in Dirt/Sand (and the water there), that doesn't apply on public road pavement though.

On Dirt/mud/Sand (and the water there)...speed, high speed, improves the situation. Dirt/Sand/Mud (speed throws the mud off the knobs, so they can bite), gets firmer (not having time to move), bike momentum carry's you over and through as a help.

Water is best done with the front wheel up, so the rider isn't swamped in the splash.

I couldn't think of a single thing to say to a pavement rider, that would be taken right, in that off road example. Only an off road rider/racer would know those things.

On pavement that is lubricated with water...You as a pavement rider, have to feel your traction limit. You are OK within that limit. Exceed it, and the message the bike is giving of exceeding it, and Bam it's bike down.

 

[MysterYvil]

Ah, got it. No way I stood there, I hopped the guard rail and stood near but not between ready to leap down the ditch. I value my human life above just about anything
But, I wasn't going to leave that man alone. Stayed until CHP arrived, then got the hell out of that situation.

I have absolutely no moto-hydroplaning advice, but my hat is off to you for your actions!