North Auckland Street Skills - NASS

**p.dath** · 16th February 2010, 13:33

Originally Posted by R Sole

PS d.path are you going to be at the riding class on Wednesday? It would be cool to meet you eventually.

I need to get a pink slip first...but its all in the interests of safety so its essential right!!?

I should be there, unless a whole pile of parts turn up for my bike, then I'll be busy in my garage.

**Big Dog** · 16th February 2010, 19:45

Originally Posted by R Sole

I have to say that while I learnt from riding around the cones on the one night I went, I did not feel like there was enough instruction on the theoretically correct way of doing things, and why.

Anybody elese think this too? If it is actually stated upfront, so we know what to look for and what we should be doing, it makes us learn (or at least exchange info and techniques) a lot faster than screwing around for ages before the light goes on.

I try to keep instruction to a minimum as I am told I am too wordy and judging from the faces of the attendees if I explained any further most would go to sleeep on the spot.
I am however available after to discuss in greater detail with those who wish to.

**Big Dog** · 16th February 2010, 19:54

Originally Posted by R Sole

Actually my original question had nothing to do with CS. I just wanted to know why you tend to have highsides from a loss of traction if you chop the throttle mid corner. Throttle control is all important mid corner- I want to know why - the fizziks of it.

A highside is ususally the result of catastrophicly regaining traction.
You lose the traction.
You regain it in a sudden manner whilst your forward motion no longer exceeds your lateral trajectory.
This results in an uprighting of your bike so sudden you now exceed grafiy in your motion.

The less likely and far easier to arrest if you catch it in time is when you have not in fact lost traction, but rather your grip and sideways motion rotate your bike violently along the lateral axis resulting in a catapult..

**R-Soul** · 17th February 2010, 13:05

Originally Posted by p.dath

I should be there, unless a whole pile of parts turn up for my bike, then I'll be busy in my garage.

Pink slip denied!! Its bulk shopping day, and I am babysitter for the night...
ah well... next week!

**R-Soul** · 17th February 2010, 13:07

Originally Posted by Big Dog

I try to keep instruction to a minimum as I am told I am too wordy and judging from the faces of the attendees if I explained any further most would go to sleeep on the spot.
I am however available after to discuss in greater detail with those who wish to.

I think I did end up talkingto you since you were talking o others, but I think what was frustrating was not knowing who the person to speak to was? This was not pointed out early.

**R-Soul** · 17th February 2010, 13:08

Originally Posted by Big Dog

A highside is ususally the result of catastrophicly regaining traction.
You lose the traction.
You regain it in a sudden manner whilst your forward motion no longer exceeds your lateral trajectory.
This results in an uprighting of your bike so sudden you now exceed grafiy in your motion.

The less likely and far easier to arrest if you catch it in time is when you have not in fact lost traction, but rather your grip and sideways motion rotate your bike violently along the lateral axis resulting in a catapult..

Thanks for that- but I know what a high side is - now I want to know why chopping throttle suddenly in a corner results in one.

**BoristheBiter** · 17th February 2010, 13:11

Originally Posted by R Sole

Thanks for that- but I know what a high side is - now I want to know why chopping throttle suddenly in a corner results in one.

in very simple terms, when you chop the throttle off the bike stops you dont.

**Big Dog** · 17th February 2010, 16:58

Originally Posted by BoristheBiter

in very simple terms, when you chop the throttle off the bike stops you dont.

Resulting in your lateral inertia exceeding your longitudinal inertia. Like a catapult.

**Big Dog** · 17th February 2010, 16:58

Originally Posted by BoristheBiter

in very simple terms, when you chop the throttle off the bike stops you dont.

Resulting in your lateral inertia exceeding your longitudinal inertia. Like a catapult.

**fizbin** · 17th February 2010, 18:30

or this can be displayed by
[youtube]66ZtZ8m63qY&feature=related[/youtube]

**Badger8** · 17th February 2010, 19:57

Originally Posted by R Sole

Actually my original question had nothing to do with CS. I just wanted to know why you tend to have highsides from a loss of traction if you chop the throttle mid corner. Throttle control is all important mid corner- I want to know why - the fizziks of it.

You are mid corner, gently rolling on the throttle. Bike is settled, slight throttle helping keep the suspension taught, contact patch at the rear loaded up, not too much on the (smaller) contact patch at the front.
Chop the throttle, rear lifts, suddenly you have a lot more load pushing down the line of the forks (so outward at an angle to the ground) on a smaller (relative to the rear) contact patch. Static coefficient of friction is overcome reulting in one of two things.
option less pain: Lowside. Front washes away, bike lays down, you go slippity slide.
option more pain: highside. Front tire, now unloaded of some of this force as the suspension pushes out now front contact patch is moving sideways, finds eough grip and grabs. Static coefficient of friction is higher than kinetic, grips hard, throws you over like a catapult. Ouchies.

That do it for ya?

**fizbin** · 17th February 2010, 20:38

Or as someone so eloquently put it:
FAIL

**TOTO** · 17th February 2010, 21:17

Originally Posted by fizbin

or this can be displayed by
[youtube]66ZtZ8m63qY&feature=related[/youtube]

looks to me that he had not actually exercised prior to attempting this. Hence resulting in him opening the throttle on the 1000cc sports too much, which resulted in him loosing traction on the back wheel, then shutting it completely and then as Matt said, he catastrophically regains traction, resulting in a catapult type motion. If the rider had taken his time in the car park , and slowly built his confidence in riding the bike progressively lower and with the right body position, this would have not happened. It is all about practice and the car park is the best and the safest place to do it.

Nice noght peeps, hope to catch you all next week. Hope you all getting down to paeroa to watch the racing this sunday. It will be a minter.

Be safe