WTF has howstuffworks.com been smoking???

[TwoSeven]

yip - all the time.
still works the same way as I said - just more enjoyable

[vtec]

Ever ridden a bike on square tyres (sidecar tyres,car tyres)? Countersteering still works.....

Only if you've already got oversteer.. Stop trying to confuse them. :P

[skidMark]

this is entertaining to watch the cogs go round

[SPORK]

LooooooooooooooooooooL markaucjkland

[Motu]

yip - all the time.
still works the same way as I said - just more enjoyable

Never said it was fun! I know about the cone effect...people easily get confused on how a bike works because there are several forces at work - and the best part is,you don't even have to know! It just works,ask any 5 year old - it's just magic.

[FROSTY:Me]

yooz guys is awl wrong.bikez go round cornaz cos the bike gods let them.
sometimes you piss off the bike gods so you fallz off--so says baby bikie

IMHOcounter steering works cos you have 2 bloody great big gyroscopes
one spinning at each end of your bike -
but hey I know nuffing

[TwoSeven]

I dont think the gyroscopic effect of the wheels has much at all to do with the actual turning of the bike. But I am still working this problem out, so it may well do.

As I see it a wheel that is run as a castor (like a shopping trolly) will try and center itself if its moved forward. The angle of the castor dictates how much force it will use to try and center itself.

So according to this theory to get the bike to lean over, you need to overcome that castor effect. This is done by pushing the bar away from you to create a negative slip angle. Then the wheel will trip up over itself and fall over.

The force required to push the bars varies depending on the castor angle at the time you push it. Consider the following.

Given a Honda CBR600 with a castor angle of 25 degrees and a fork offset of 41.3062mm, running a 110/70-17 tire the trail will be 91mm.

If you change that tire to a 120/70-17 which will increase the height by 7mm roughly speaking you will end up with a new trail of 94.3mm an increase of approx 3mm (roughly 3%).

The effect is that you should notice that the bars are harder to turn.

What I am trying to figure out at the moment is how much the castor angle changes when the tire is at different angles and at different heights/pressures.

[Motu]

My brother had a chop with a homemade springer front end (the only way to have one was to make it in those days) It was well made and really looked the part,a big long rocker to give it that stretched out look.That put the front wheel contact point well forward of the steering axis - we measured it at eight inches negative trail!

I rode it often,and never noticed a problem,it was stable and still countersteered!

[Skyryder]

The best advice on steering: look where you're going and you will go there.

Skyryder

[TwoSeven]

As i understand things there are only two ways you can get a negative trail 1) point the forks backwards or 2) dont mount the wheel to the forks.

Also, a negative trail would force the wheel to turn around until it was postive again - either that, or the bike is being driven in reverse

[Ixion]

I think girder forks could have negative trail (not that one would want it) ??
Um, maybe leading link forks too ???

[Motu]

Girder forks often had optional links to reduce trail for sidecar use.Springer forks use a lower rocker,same as a C50 - the rocker on my brothers bike was about a foot long,this moved the wheel contact point ahead of the steering axis.Other forces came into play to make it riderble.