The countersteering can of worms

Eric and Geoffrey are asking some tough questions regarding Countersteering a cross bike (or any bike)?

They want to know whether a gyroscopic force exists in countersteering, how bikes differ from motos, and how they can use all this mumbo jumbo to go faster.

Eric and Geoffrey’s comments

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Eric Says November 18, 2010 @ 9:58 am

A fine point that I’ve been wondering about related to countersteering. To turn a bike we’re told to push the inside grip into the turn. The result is that the bike leans and we start turning. But is this action a result of gyroscopic forces (like in the above diagram) or is it simply that the bike is light and we can directly lean it by moving the inside grip towards the ground? And are both of these actions “countersteering”?

I can very easily feel this “push left to go left” effect on a motorcycle. Push the left grip forward and the bike leans left. Push it more and the bike leans further. On a bicycle, it feels noticeably different even at high speed, no doubt because of the difference in mass/inertia between the two machines. In which case, at what point do the dynamics of the situation transition from “bicycle” to “motorcycle”?

And, more importantly, how can I use all of this to go faster?

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Geoffrey Says November 18, 2010 @ 2:24 pm

Actually, it isn’t gyroscopic effects. If you hold a bicycle still, and turn the handlebars, the bike will lean. It’s simply a mechanical thing, based on the rake of the fork.

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Eric Says November 18, 2010 @ 2:31 pm

Agreed. I was trying to be consistent with the terminology of the original post, but you’re right, you can hold the bike stationary and observe this mechanical response, so it’s not a gyroscopic thing. I do still wonder if there are two fundamentally different techniques on a bicycle. Turn the handlebars, bike leans. Or, lean the bike and the handlebars turn to match the lean angle.

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What I think

Can of worms!

Like I said in Countersteering a cross bike (or any bike)?, I rarely address countersteer because it balls people up.

Countersteering leans your bike in two ways:

1) Say you want to turn right. If you steer left, your body keeps going straight, and the wheels go to the left. This creates a lean to the right.

2) When you bump the bars to the left, gyroscopic forces do indeed lay the bike over to the right. (Consider a dirt jumper laying his bike into a flat table.) This gyroscopic effect is most evident at high speeds with heavy wheels. It’s an essential part of cornering on a street moto that weighs a lot more than its rider. You can feel it on a mountain bike too. Get some speed and give the bars a little bump. You’ll feel the bike lean over immediately and powerfully — much more violently than the pure mechanical response. Try it.

Bike vs. moto

The faster you’re riding a bicycle, and the heavier its wheels, the more it handles like a moto. But keep in mind:

My Honda VFR weighed 500 pounds. My Enduro weighs 30.

The only way to flick that Honda (or the huge BMW tourer I rode around Italy) was with gyroscopic countersteer. With a much lighter bicycle, you can physically lean it below you.

How to go faster

On the bike, focus on pushing the inside grip down into the turn. That sets the bike’s lean angle quickly and precisely. The steering column corrects and — bam — you’re railing.

But consider this: If your shoulders are behind your handlebars, when you push the inside grip down you also push it forward. So you’re physically leaning the bike below you AND you’re getting some countersteer.

In the real world, I think these forces get all tangled up. Concentrate on setting angles deliberately and precisely. You will corner better — and go faster.

CAN OF WORMS!

— Lee

Know more. Have more fun!

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