Cornering

If you're doing it right the front wheel is in the air
and the back is sliding. It doesn't cause a front end washout.
I managed it once at Quarry Bends.
Or this could just be the ramblings of an old git in his dotage.

 

Apart from everything else, this is an opportunity to let the gyroscope
into the motorcycle turning debate again.
At greater speed the wheels gyroscopic effect gets greater, resisting
change to where their axle of rotation is pointing.

In the responses in this thread I miss some consideration of how
braking rear or front and acceleration affects steering geometry by
compressing or unloading the suspension. This can totally change how
the bike feels.

 

OH- wrote

I think you will find that this is because it so much a part of the
shaftie not countersteering thing that folks tend to forget that it does
have an effect on chain driven bikes as well, albeit a small one, and
they tend not to mention it in case there are any more unfortunate
incidents like there was the last time.

 

It was somewhere around Barstow, on the edge of the desert, when the

Pixies little feet.

--

Dave

GS 850 x2 / SE 6a
SbS#6 DIAABTCOD#16 APOSTLE#6 FUB#3
FUB KotL OSOS#12? UKRMMA#19 COSOC#10

 

I will make it this weekend's mission to prove him wrong.

 

Bike physics is always hard to analyse - well I think so. From my
experience...

When the bike is decelerating, especially braking, it requires more steering
input (countersteering that is) to get it to lean over. I dunno why cos when
the forks are compressed the rake angle of the forks is steeper so it should
turn faster but it doesnt.

Racers turn into corners hard on the brakes which I'd say is why most want
the bikes to turn so quickly. I tend to turn into most corners on the road
with the brakes on, out of habit. I'm just used to pushing hard on the
inside bar so therefore dont ever feel like its going to run wide.

 

I was just saying that turning/leaning into a corner is how we compensate
for the centrifugal effect pushing us out.

 

porl: I lost the back and it still fucking hurt.

 

Let's all make a pact never to talk about it again.

 

Until they ran out of revs :-o

 

You don't need to whack the throttle open, just give it a little bit
to maintain your speed as you'll actually slow a bit as you corner. It
will also set the suspension and transfer some weight to the rear
tire.

If you've overcooked it, well then you better have some ground
clearance and traction to lean it in more or your going to make nice
bike-shaped holes in the hedges.


--

John
Apple Valley, MN
'02 FZ1
'73 RD350

 

Is that in rideable condition?

--

jeremy
['75 RD250A ] | ['02 Fazer 600 in blue]
____________________________________________
jeremy dot ovenden at hazelweb dot co dot uk

 

Wot, the mosquito fogger? Yessir. And I will get you pictures some
time this millenium! I've actually procured a genyoowine Yamaha seat
cover[1] for it so piccies won't be along until at least that gets
redone.

[1] It currently has a huge rip in one side that is adorned with what
looks like cigarette burns. Utterly ratty.

--

John
Apple Valley, MN
'02 FZ1
'73 RD350

 

Imagine looking at the front of the bike when it's leant to the left,
then with it upright, and finally with it leant to the right. What
happens to the height of the headstock as you transition from leaning
one way to leaning the other? It rises.

So when you're braking and there's more weight transferred to the front
of the bike there is more steering input required as it's actually
harder to get the headstock (and the rest of the front half of the
bike) to rise. In effect you're trying to push against more of the
weight of bike + rider than when you're hard on the gas.

 

Are you sure? Surely the centripetal forces act on the bike tyres and
the forces on the rider are straight down through the seat towards the
straight line between the contact patches (all the time you're
cornering at constant speed anyway).

 

... also, if there were a centripetal force pushing the rider outwards
(which you think you're leaning against), would this not also act on
the bike and tend to straighten it out (reduce the bike's lean angle)?

 

I said centrifugal not centripetal. The centrifugal force is what enables
wall of death riders to stick to the walls.

 

What does it fucking matter?

Why don't the cunts that don't understand just go and ride and work it
out? It's not fucking difficult.

 

ITYM the imaginary force we refer to as centrifugal is what sticks them
to the walls.

Actually (as I am sure you well know young Porl) the bike is trying to
go ever higher and tiny sprinklings of fairy dust cause it to slide
back down.

 

Almost.
The centripetal force is proportional to the square of the velocity,
implying that a doubling of speed will require four times the
centripetal force to keep the motion in a circle. If the centripetal
force must be provided by friction alone on a curve, an increase in
speed could lead to an unexpected skid if friction is insufficient.

Joe
Chinese takeaway to reply