Rear brake use?

[p.dath]

Clarify my understanding please people. Considering only chain driven road orientated motorcycles.

Front brake obviously makes the front dive.

Does rolling on the gas cause the rear to rise or fall? My understanding is that the rear end rises, as the swing arm connects above the wheels centre of gravity (on most motorbikes) to the chassis (effectively sloping upwards), and a sudden burst of force "forward" would push the swing arm. And since the swing arm is already pointing upwards, the force goes in that direction.

Does the rear brake cause the rear to rise or fall? I would expect the answer to be the opposite of the above answer - fall. Similar reason I would have thought. The rear brake/tyre is now effectively "pulling" on the swing arm down.

[ducatilover]

When it works, use it to bring those awesome wheelies down (which a neither big, nor clever)

This, in effect, pulls the bitches.

[bogan]

Clarify my understanding please people. Considering only chain driven road orientated motorcycles.

Front brake obviously makes the front dive.

Does rolling on the gas cause the rear to rise or fall? My understanding is that the rear end rises, as the swing arm connects above the wheels centre of gravity (on most motorbikes) to the chassis (effectively sloping upwards), and a sudden burst of force "forward" would push the swing arm. And since the swing arm is already pointing upwards, the force goes in that direction.

Does the rear brake cause the rear to rise or fall? I would expect the answer to be the opposite of the above answer - fall. Similar reason I would have thought. The rear brake/tyre is now effectively "pulling" on the swing arm down.

Yup, rise under accel, fall under braking. But it is essentially due to the reaction torque from the wheel being applied to the swingarm, wheel goes CCW under accel, SA wants to go CW.

[Deano]

Yup, rise under accel, fall under braking. But it is essentially due to the reaction torque from the wheel being applied to the swingarm, wheel goes CCW under accel, SA wants to go CW.

It squats initially under acceleration though doesn't it ?

"When you get on the gas exiting a turn, that acceleration results in weight transferring to the rear wheel, commonly called squat.

Read more: http://www.sportrider.com/tech/146_0404_motorcycle_traction_geometry/index.html#ixzz1eOO0XshS"

[ducatilover]

It squats initially under acceleration though doesn't it ?

"When you get on the gas exiting a turn, that acceleration results in weight transferring to the rear wheel, commonly called squat.

Read more: http://www.sportrider.com/tech/146_0404_motorcycle_traction_geometry/index.html#ixzz1eOO0XshS"

I'm sure Keith Code says the rear tends to rise under acceleration, but the front rises more, hence the squat.

[bogan]

It squats initially under acceleration though doesn't it ?

"When you get on the gas exiting a turn, that acceleration results in weight transferring to the rear wheel, commonly called squat.

Read more: http://www.sportrider.com/tech/146_0404_motorcycle_traction_geometry/index.html#ixzz1eOO0XshS"

Interesting article! (even if I did have to open it in IE to get scroll bars back)

Looks like what I was talking about was the main bit of anti-squat, p.dath was referring to a minor effect, in my case it more often comes up, but I'm a lightweight, so weight transfer might be less than most.

[Gremlin]

Front brake obviously makes the front dive.

Actually... not necessarily. It's only due to the conventional suspension most bikes run, that the front dives. While my BMW is a shaft drive (re the chain line) it has nothing to do with the suspension. Two forks plus an extra spring, and the BMW doesn't dive under brakes.

[onearmedbandit]

Actually... not necessarily. It's only due to the conventional suspension most bikes run, that the front dives. While my BMW is a shaft drive (re the chain line) it has nothing to do with the suspension. Two forks plus an extra spring, and the BMW doesn't dive under brakes.

That's the telelever system though. It's like saying make sure the two chain adjusters are adjusted correctly, and someone then saying that's not necessarily true, as my bike runs a single sided swingarm.

[Gremlin]

That's the telelever system though. It's like saying make sure the two chain adjusters are adjusted correctly, and someone then saying that's not necessarily true, as my bike runs a single sided swingarm.

Sure... I'm just saying that making a sweeping statement like that isn't accurate when this thread seems to be rather particular

[p.dath]

It squats initially under acceleration though doesn't it ?

"When you get on the gas exiting a turn, that acceleration results in weight transferring to the rear wheel, commonly called squat.

Read more: http://www.sportrider.com/tech/146_0404_motorcycle_traction_geometry/index.html#ixzz1eOO0XshS"

If I understand correctly, that would also be correct. Acceleration would transfer weight to the back wheel, while also resulting in the rear end of the bike rising.


Also found this quote in the same article:

Because the swingarm is at an angle to the ground, a portion of that forward thrust acts to lift the back of the bike

Read more: http://www.sportrider.com/tech/146_0...#ixzz1eP3O4ZXJ

[Drew]

Also, if the rear suspension is compressed whilst leaned over in a turn when you get on the gas, the chain might actually try and make the rear of the bike fall. If the swing arm is already on an upward angle relative to the chain.

It's all well and good to get this technical about what he bike is doing when you ride it, but it rarely helps anyone ride better. Infact I submit the opposite to be the case. There are a load of people out there who try to practice counter steering for fuck sakes, it is not something that needs to be thought about at all! The enemy of smooth controlled riding, is quite often thinking about what you're doing.

[Gremlin]

Except that for some, some stuff doesn't come naturally, and have to read it, put it into practise, read a little more, and so on. Then it starts to fall into place.

For some (myself included), riding is natural, and therefore, just getting on and doing it, suffices.

[slofox]

There are a load of people out there who try to practice counter steering for fuck sakes, it is not something that needs to be thought about at all!

+1 on that. Think about it and you may well fuck it up.

When I was a kid I practically lived on a pushbike. All that countersteering etc etc etc just got acquired through a gazillion hours on a pushie.

It may be that kids who didn't have the pushbike experience have not acquired that kind of ingrained body stuff that goes into riding on two wheels.

[p.dath]

There are a load of people out there who try to practice counter steering for fuck sakes, it is not something that needs to be thought about at all! The enemy of smooth controlled riding, is quite often thinking about what you're doing.

And how do you propose to learn how to do something you don't know how to do? You learn and practice.

I can counter-steer quite deliberately, when I choose to (that means I have thought about it and decided I need to).

It would be far worse needing to be able to counter-steer, needing the reactions to kick in because you can't think how to do it, and then have an epic fail.


However I do agree with your second statement. You only have so much attention, and you don't want to be devoting a lot of it to basic riding skills. You simply need to be able to decide what to do, usually well in advance of actually needing to do it, and then let it happen.

[Drew]

And how do you propose to learn how to do something you don't know how to do? You learn and practice.

I can counter-steer quite deliberately, when I choose to (that means I have thought about it and decided I need to).

It would be far worse needing to be able to counter-steer, needing the reactions to kick in because you can't think how to do it, and then have an epic fail.

I cannot even begin to be bothered to have this argument again.

Anyone who thinks that they must consciously apply the pressure to the inside bar to get a bike to turn in that direction should stick with walking I think.

Just my opinion, you won't change it no matter what you say, don't try.