I just picked up a project bike and I was looking for tires and was
having some trouble finding ones that would fit. Will a 100/90 18
tire fit on a 3.25 18 front rim safely and also a 110/90 18 tire fit
a 3.5 18 rear rim? Thanks for any help with this.
Scott

On 6/28/2011 7:44 PM, Scott wrote:
> I just picked up a project bike and I was looking for tires and was
> having some trouble finding ones that would fit. Will a 100/90 18
> tire fit on a 3.25 18 front rim safely and also a 110/90 18 tire fit
> a 3.5 18 rear rim? Thanks for any help with this.
> Scott

I am posting a chart that I found in an old edition of the Dennis Kirk
Street Bike catalog. They no longer print this chart in the catalog,
perhaps for liability reasons. Please take note of the fact that tire
sizes are approximate. Even tires of the same nominal size from one
manufacturer, but of different models, may not have the same
dimensions, so I would not expect that tires from different
manufacturers would adhere to a strict size relationship.

Do you really mean you have a 3.25" wide front rim, or as I suspect,
you have a front rim that had a 3.25" sized tire on it? Check out
the chart to see what I mean. My guess is you have a front rim that
is either 1.85 or 2.15 inches wide which is the correct size for a
3.25" size tire. If it's a 2.15 width rim it will fit a 100 mm wide
tire but it still might not be the right tire for your bike. Same
comments apply for your rear tire/rim question.

--------------------------------------------------------------------

(This chart was taken from the 1994 Dennis Kirk Street Bike catalog)
TIRE WIDTH EQUIVALENT CHART

The table below illustrates the relationship between different tire
size systems. Use it to compare the various widths and determine
possible replacement sizes. Since motorcycle tires are manufactured all
around the world using different size designations, we cannot imply
exact interchangeability.

PERMISSIBLE STANDARD LOW PROFlLE ALPHA-
RIM WIDTHS METRIC INCH INCH NUMERIC
1.60, 1.85 70 2.75 - MG
1.60, 1.85 80 3.00 3.60 MH
1.85, 2.15 90 3.25 3.60 MJ
1.85, 2.15 90 3.50 4.10 ML
2.15, 2.50 100 3.75 4.10 MM
2.15, 2.50, 2.75 110 4.00 4.60 MN
2.15, 2.50, 2.75 110 4.25 4.25/85 MP
2.15, 2.50, 2.75 120 4.50 4.25/85 MR
2.15, 2.50, 2.75 120 4.75 5.10 MS
2.50, 2.75, 3.00 130 5.00 5.10 MT
2.75, 3.00, 3.50 140 5.50 - MU
3.00, 3.50 150 6.00 - MV
3.00, 3.50, 4.00 160 - - -

Scott <(E-Mail Removed)> wrote:

> I just picked up a project bike and I was looking for tires and was
> having some trouble finding ones that would fit. Will a 100/90 18
> tire fit on a 3.25 18 front rim safely and also a 110/90 18 tire fit
> a 3.5 18 rear rim? Thanks for any help with this.
> Scott

I've got a 400 Four which, as you probably know, runs the same wheels.
Your sizes are up on the recommended fitment, but do fit, because I've
seen bikes wearing them. Not sure what effect thay'll have on steering,
though.


--
BMW K1100LT Ducati 750SS Kawasaki GPz750 Honda CB400F
Triumph Street Triple Suzuki TS250ERx2 GN250.
Higgler Supreme
chateau dot murray at idnet dot com

Thanks for the replys...Looks like I have some more reading to do
before I buy any tires.
Scott