Quote:
Originally Posted by 135
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I fitted one of these used slicks to an 18x9 and 18x10 wheel to get some further section widths and ODs for fitment data: - 18x9, 266mm, 651mm OD - should have been 278mm/9" - actual is 12mm less!!!
- 18x10, 281mm, 647mm OD - should have been 288mm/10" - actual is 7mm less!!!
And calculated values based on 9" and 10" measurements: - 18x9.5, ~274mm, ~649mm OD - should have been 283mm/9.5" - actual is ~9mm less!!!
So, either, the used slick had shrunk and its section width was less than expected on narrower wheels, OR, the slick is substantially narrower when fitted to much narrower wheels relative to the 11" measured wheel. |
An update to my post above...
I have just fitted some Michelin N2# 27/65/18 scrubs to 9.5" and 10" wide wheels.
The 10" fitment resulted in the same 281mm section width. The sidewalls are practically flush with the wheel's flange.
A 10" wide wheel is measured to the bead seats inside the wheel's flanges and the wheel is actually ~11" (279mm) wide to the outside of the flanges, which is what is measured to and what can potentially contact on suspension, or bodywork, if the tyre is undersized/stretched for the wheel - see my previous post for more discussion on this topic).
The 9.5" fitment resulted in a 273mm section width, which is only a minimal 1mm difference to my previously calculated value (based on the section widths of scrubs fitted to 9" and 10" wide wheels).
Actually, I rounded up my previous calculated value of 273.5mm to 274mm, so there really wasn't anything in it between the actual and calculated values.
So these are the second set of Michelin N2# scrubs that measure less than expected based on Michelin's advertised section width (both 2015 and 2017-2020).
The tread width of the Michelin N2# 27/65/18 is 252mm (2015) or 263mm (2017-2020), which seems quite narrow for such a wide section width (298mm in 2015, 295mm in 2017-2020) but, while it might be more commonplace with slicks, is more reasonable when in context of fitment to 9.5" and 10" wide wheels, tending to a more square-shouldered tyre, particular on a 9.5" wide wheel.
Interestingly, the tread width was 270mm in 2008 and 274mm in 2013, so it looks like Michelin has changed the specification on their slicks, as they would have through development over the years.
Note, Michelin (2019,2020) states the
nominal wheel width for the N2# 27/65/18 is 11" +/-0.5".
Also, these scrubs weighed 9.8 kg (21.6 lbs).