Yeah that too
I was going to ask how much tread does each set have
tyres with bugger all tread will be very heavy to turn
new tyres are much easier

the width doesn't seem to make a very noticable difference
I had a Hilux with 31/10.5/15 tyres with good tread, on being taken away
I changed to a set of 700R/16 with no tread, I could hardly turn the
wheel with the skinnys on

Kev

Different. About a good 1.5 to 2" difference in offset on each rim.
Track width increases roughly 3 to 3.5". [I'm pretty rough with a tape
measure.]

Had two replies on a subey mailing list:

I must say that is quite baffling. but, my only answer could be that the
stance of the brat with the 23' wheels has more wieght on the little
tires and a more narrow stance, making it more top heavy to the tires so
to speak. with the larger tires coming in at 27'' it could be the tires
are wider thus making a wider stance and distributing the wieght more
evenly on the 23' tire and not centralizing on such a narrow tire
causing the axle and struts to take more of wieght over its "narrow, top
heavy stance". by the tires ( the 27s I mean) taking more wieght it
takes the wieght off the axle, half shaft, struts etc. causing as you
mentioned   " less friction" and allows your tires to move more free. oh
by the way how large are the rims on your BRAT. I was thinking of
putting after market rims on it and was wondering how large you were
able to go. I am assuming they are 17' rims. hope this answers the
question you had. majoring in physics helps a little.

--

Just off the top of my head, I would speculate a few things actually
contribute to the different feeling of the steering between the
different tire sizes.  First, the larger diameter tires have more
mechanical leverage - kind of like a longer wrench compared to a
shorter one.  So, once they are rolling, turning them becomes easier.
It is similar to the principle involved in rolling a styrofoam cup
along; it always turns in the direction of the small end as the
larger end rolls easier and travels further.
The weight of the vehicle and tire inflation determine tire contact
patch more than does tire size.  However, the different tire may
change the shape of that patch, from wider and shorter to narrower
and longer, thereby changing the steering effort.
Also, the different wheel offset, to accomodate three extra inches of
width, may have changed the steering geometry somewhat, altering the
steering feel.
And obviously, differing tire compounds, tire construction, and tread
patterns can greatly effect steering effort.