Steering stem offsets

[koolio]

I know a little about rake and trail etc. am I right in assuming the less steering stem offset you have the more stable the bike is? Therefore offroad bikes have lots of steering stem offset and sports bikes have a small steering stem offset?

For example I note the Fireblade has very little steering stem offset.

https://img.auctiva.com/imgdata/3/3/6/4/3/2/webimg/627269898_o.jpg?nc=365

[G]

Here's a CCM yoke to fit WP forks (well, actually it's been machined to fit a C90 )

https://dl.dropboxusercontent.com/u/18968307/pics/c90ccm/2.JPG

Not too different.

However, what you will find is that the wheel is located forward of the centre of the forks there, while on a similar supermoto version it's often mounted in line (that's the case with the 690 enduro and SMC, that otherwise are very similar.)

https://www.yamaha-motor.eu/designcafe/en/about-design/technology/index.aspx?view=article&id=442629&page=2

[kestrel]

You can't judge a bike's stability by looking at fork offset alone, you have to examine the front end geometry as a whole, particularly the rake angle.
Reducing fork offset increases trail which gives greater straight line stability but slower steering. Reducing the rake angle will decrease the trail, giving quicker steering at the cost of straight line stability, it's very much a trade off.
As you can see, rake angle and fork offset changes both affect the trail value and ultimately the handling characteristics of the bike.
Wheel spindle position relative to the fork leg centreline also affects trail, which is why you often see bikes with the axle in front of or behind the forks.
Sketch a few front ends out with different offsets and rake angles, project the steering stem axis and drop perpendiculars from the wheel spindles and see how varying either value affects the trail.
____________________
Isle of Man.........Road Racing Capital Of The World

[koolio]

Yea I get it now, for some reason I thought that having a larger offset increases trail, clearly the opposite.