hey guys,

I just was wondering if someone could explain the physics of when a bike will highside vs. lowside? What are scenarios where highsides are very likely to occur, and what are the best tactics for avoiding them (including how to make sure it lowsides instead, if the situation gets that dire).

hey, since i got a high-side last week.

a high-side is when your rear end slides and catches again. This will must likely cause You to get airborn onboard your bike. And if you're lucky. You might catch the bike and get some kind of control and get out of it without a crash.. but must likely you will not because the force of a high-side when you're exceeding 50mph is just so huge there's really nothing much you can do than wait to hit the ground.

a low-side could be when you're going into a corner too hard, enough to lean over the edge of the tires. then you'll just slide off the track/street...

hey swedie, thanks for the explanation.

However, I guess I'm not so much interested in the physics after it occurs, but more BEFORE it occurs.

Generally will a rapid loss of traction on the wheels cause a lowside, and a more gradual loss will cause the slide which then causes the rear to regain traction and cause that horrible kick?

the lowside scenario was good, maybe thats what I'm looking for.. the more likely scenarios where a lowside or highside will play out...

a high-side will most likely occur when you don't have have full leaning and is about to get out of a corner with full throttle. If you loose traction there.. you might slide to the side too much and then it will kick back.

but it should just result in a black line on the road = pure powerslide :rock

if a low-side occurs it is probably because you're too hot into the corner and use the front brake too much to lower your speed.

http://www.msgroup.org/TIP001.html

that was a good link. The only bad part is they occupied most of their time talking about rear brake usage causing a highside, I'd rather they talk about highsides that are caused by not so newbiesh mistakes.
So if you are positive the bike will highside, get on the front brake which will cause a lowside instead.

of course since all of this can happen in tenths of a second, so I guess theres a good chance you won't have time to think about this at all...

A highside occurs when the rear tires spins up, slides out and catches traction when it's not in line with the front of the bike. When the rear catches traction, the bike wants to straighten itself and stand up right at the same time.

The only way to avoid a highside is by staying on the gas and standing the bike up. This will basically lead to a wiggle or an "off the seater," this is where your ass and legs get whipped around for a sec. but you don't crash. Most people instinctively shut the throttle and induce highsides.

As for turning them into lowsides: the only chance you have is mid corner. If you are cranked way over mid corner and the rear end breaks free and you feel you can't save it, just give it a bunch of throttle and the rear will come around and lowside.

Trying to grab the front brake if the rear slides out will defiantely lead to a high side. The moment you release the throttle, the rear will catch and highside you, well before you have even reached for the front brake.

Highsides, hitting coolant or oil or dirt are usually very difficult to avoid since the rear kicks out so fast and it will catch traction the moment it finds good road. Just stay on the gas, keep the rear spinning up and stand the bike up.

I once went into a down hill corner too hot in the wet on a road I did not know.... in the dry I would not have braked at all for that entry speed.... but in the wet I did and ended up giving it a big 2 finger pull on the brake lever. Damned fingers would not let go and my grip was so tight on the lever I could not get on the power either. I had no option but to try and turn the bike with full front brake still applied and with the back end still jumping side to side. It started to low side.... and just as it was leaving the road and before the bike had got all the way down on the low side, the back end hit a post and "high sided" me. Time to relax and bounce off the rocks and trees. Where did that river come from? That was close!

It is really annoying when the survival reaction kicks in and the conscious mind cant override the subconscious mind! :eek: I wont make that mistake again (hopefully). :no