Showing posts with label Keith Code. Show all posts
Showing posts with label Keith Code. Show all posts

Tuesday 26 August 2014

Keith Code's Twist of the Wrist

A must read if you're serious about
understanding motorcycle dynamics
Reading Keith Code's Twist of the Wrist 2 on Kindle last night and came across this!  The part I'm in right now goes over how motorcycles tend to be self correcting (unlike cars).

When I bike starts to slide at the back it pushes the front wheel in the direction you want to go (unlike a car that pivots on the front wheels and requires you to counter steer into a slide).

The worst thing you can do on a bike is attempt to force a counter steer into the handlebars.  When you do this you're creating huge torsional pressure between the front and back of the bike.  The bike resolves this by snapping back violently, launching the rider over the high side of the bike leaned into a corner.

Code keeps drilling in the point that the bike wants to self correct.  If you're loose, relaxed and gentle with the controls the bike will bring itself back into alignment, even if the back wheel is sliding.

Even backing off the throttle suddenly on a rear wheel slide can cause a high side (you suddenly dump all the bike's weight onto the front wheel causing it to snap back).  It might seem counter-intuitive, but in a slide maintaining throttle and letting the bike sort itself out will resolve most slides.  It's a rider's involuntary reaction due to fear and a lack of understanding of how motorcycle dynamics work that result in most corner related crashes.

I've been making a point of practicing throttle control in corners, using lower approach speeds but rolling the throttle on with a light hand as early as possible to balance the weight of the bike 60/40 over the back wheel.  I'm amazed at how settled in a corner the Ninja is now.

Motorcycle dynamics are a completely different beast from car dynamics.

Monday 18 August 2014

Twist of the Throttle

The cornering bible... 
I'm currently reading Keith Code's Twist of the Wrist.  I've been looking for an intelligent description of motorcycle operation that accurately explains the dynamics of two wheeled riding (which differs significantly from three and four wheeled operation).

I listened to an interview with a senior Honda engineer (I can't remember where) and he said that after World War 2 the engineers that couldn't go into aviation (because of the U.S. embargo that prevented a Japanese aviation industry from re-inventing Zeroes) went into motorcycle engineering because the dynamics are similar (motorcycles work in 3 dimensions like airplanes).  Victory in World War 2 meant the end of allied motorcycling manufacturing as they knew it... an irony of victory, but I digress.


The Ninja takes a breather at Higher Ground, the lovely
coffee shop at the top of the Forks of the Credit in Belfountain.
Professor Code's book explains the dynamics of motorcycle riding in better detail than anything else I've found.  The video explains the psychology and physics of riding and dismisses many of the misconceptions.  

I spent this afternoon riding over to one of the few curvy roads in the farming desert I live in to practice my throttle control and make a conscious assessment of my fear reactions to riding.  I'm determined to get rid of the 'chicken strips' on my tyres.  I got down to my peg feelers on a couple of the long corners, finally.

The distance between driving a multi-wheeled vehicle (which I've got a lot of experience on) and two wheeled vehicles is massive.  You have to fight a lot of habit and psychology to give the bike what it needs to corner well; the dynamics are completely different and counter-intuitive if you're overly four wheel focused.  Even the process of approaching and exiting a corner is much more complex on the multi-axis two wheeled conveyance.  Driving and riding are two very different processes, and I'm frankly enjoying the complexity of the simplicity of two wheels by comparison.

Reading/watching Twist of the Wrist should be a requirement for anyone wanting to take on motorbiking, it'll make you aware of the mechanics of riding.  

I really need a track day, not for the speed but for the ability to focus on process without worrying if the person coming the other way is texting.