OK, assume that either the 14" or 15" wheels will
be of the same make/model (i.e. 72 spoke wires
5.5" wide) and the tires will be the same
make/model, (i.e. both 185/60 series).
I'm not sure I agree with your assessment of turn
in. I think the smaller diameter wheel/tire combo
will exhibit faster turn-in, though it might not
have as much grip once the car starts turning.
Please correct me if I'm wrong, I may have the
incorrect assumption.
You did raise some good questions though, this is
absolutely the kind of discussion I'm looking for.
Rick Morrison wrote:
>
> On Fri, 27 Feb 1998 09:54:40 -0800 Andy Ramm <aramm@concentric.net>
> writes:
> >I'm weighing the plusses and minuses of 14" vs.
> >15" wheels for my MGB. I have some pros and cons
> >but am wondering if any listers have some
> >definitive answers based on experience. Here
> >goes:
> >
> >14" Advantages
> >Lower cost for both rims and tires
> >Look more appropriate in the wheel wells
> >Lower unsprung weight
> Not neccessarily so. Too much depends on the particular wheel/tire
> combo. Alloy wheels with low profile tires would probably LOWER the
> unsprung weight, vs. Rosytles and 75 series tires.
>
> >Faster turn-in
> Only if you increase the overall diameter of the tire
>
> >Maintains proper scrub radius
> See above
>
> >Less prone to rub (?)
> Rubbing will be a function of wheel offset (if any), tire width and tire
> diameter. All are variable.
> >Less WW flex
> Assuming both are 60 spoke wheels. 15 " WW are availible in 72 spoke
> designs. Less flex than 60 spoke wheels.
>
> >15" Advantages
> >Higher overall gearing
> >Slightly larger contact patch (a little more grip)
> >Lower rotational speed in corners (also a little
> >more grip)
> All the above assume that the particular tire is increased in diameter,
> but has the same aspect ratio and nominal width.
> With the proper inflation (which will vary with the tire construction
> and size) the total area of the contact patch on a given car will remain
> the same. The Shape of the patch will change. for example, the contact
> area shape on a standard 155 x 14 tire is long and narrow. With a modern
> low profile tire, say a 185/60 x 14 the contact patch shape is short and
> wide. But the total area of the tire contact patch is the same.
> Higher gearing and lower rotational speeds are purely a function of the
> over all diameter of the tire. Properly sized, the 15" tire can have the
> same OD as the 14"
> Ie. a 155 x 14 tire has an overall diameter of about 23.53". A 205/50
> x15 tire has an OD of 23.07" almost 1/2" SMALLER.
> I think I just made a simple question complicated. But as in so much
> else, there ain't not simple answers. Just more questions!
>
> Rick Morrison
> 72 MGBGT
> 74 Midget
>
> >Look cool inside wheel wells
> >
> >These are just suppositions. Can anyone give me
> >some useful feedback on the subject?
> >
> >Thanks,
> >
> >Andy
> >
> >--
> >
> >
> >
> >
> >Andy Ramm
> >A silver face in a tweed world.
> >Remove obvious spam filter from email address when
> >replying.
> >"What we play is the blues, straight from the
> >delta, and I believe we'll make it on that," B.B.
> >King
> >
> >
> >By US Code Title 47, Sec.227(a)(2)(B),
> >Sec.227(b)(1)(C) and Sec.227(b)(3)(C), it is
> >unlawful to send any unsolicited advertisement to
> >this equipment. A violation of the aforementioned
> >Section is punishable by action to recover actual
> >monetary loss, or $500, whichever is greater, for
> >each violation.
> >
>
> _____________________________________________________________________
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--
Andy Ramm
A silver face in a tweed world.
Remove obvious spam filter from email address when
replying.
"What we play is the blues, straight from the
delta, and I believe we'll make it on that," B.B.
King
By US Code Title 47, Sec.227(a)(2)(B),
Sec.227(b)(1)(C) and Sec.227(b)(3)(C), it is
unlawful to send any unsolicited advertisement to
this equipment. A violation of the aforementioned
Section is punishable by action to recover actual
monetary loss, or $500, whichever is greater, for
each violation.
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