exceeding recommended rim width

[Tmoose]

205-70-15 radial snow tires
Firestone's chart list rim width as 5 to 7 inch.
I got a good deal on alloy wheels, but they are 8 inch wide.
I'm going to use them anyhow.

Does anyone see Any problems aside from more difficult bead seating?

thanks

Dan T

 

[NormPeterson]

Slightly greater rate of shoulder wear if you maintain the same inflation pressure?

Less protection for the wheels against "curb rash" and pothole impacts?

Stiffer ride?


FWIW, I once ran a set of 185/70-13 tires on 7" wide wheels, which is also a combination that's 1" above the currently specified rim width range. Year round, with no unpleasant occurrences.


Norm

 

[evelrod]

I have 225-70-15 Goodyear "winter/SUV" on 8" rims on the rear of my 23T roadster. No problems. Even use only 20psi as the steel belted radial does not deform like an old bias tire tread would at high/low pressure.

Also we use 185-60-13 Hoosier radials (recommended 5 to 6 inch) on 7" alloy rims on the Lotus Cortina race car inflated at 30psi cold. No wear problems. 165-70-10 Yokohama AO32R's (recommended 4 to 5 inch) on 6" on the Mini, also at 30psi cold.

As indicated above, tires mounted on the wider rims than recommended still maintain proper wear/grip characteristics and pressure as would be expected from the narrower wheel. I attribute this, at least partly, to the VERY stiff tread belt.

Tire mfgr standards for wheel widths often/usually do not take into account what CAN be safely used but instead what is NORMALLY used.

Rod

 

[GregLocock]

I can't really see a problem there, although usually we only run half an inch over on rim width.

Cheers

Greg Locock

I rarely exceed 1.79 x 10^12 furlongs per fortnight

 

[cibachrome]

Probably gonna have a fender rub: either inner wheelhouse or wheel lip. If its not a friendly rub, you're going to cut the tire. Friendly rub, turn up the radio. Most likely when backing out of a ramped driveway or over a railroad crossing with 2 sets of tracks.

 

[CapriRacer]

One other issue not yet mentioned:

Bead unseating is easier if you exceed the allowable rim width range. This means that impacting a curb at an oblique angle carries a greater risk of the tire suddenly deflating.

 

[evelrod]

Yeah, technically you are correct...as far as it goes. However, you would need mitigating circumstances to get such a catastrophic "unseating", such as incorrect pressure, "crashing" into a curb or related obstruction in which case even a tire mounted on a narrower rim would unseat the bead.
One inch over std is just not a great risk for such a happening...low pressure and 2 or 3 inches, as in dune buggy use, maybe.

Also some of the rather stupid tire mountings I see occasionally on the local rice burner "stink bugs"...But that's another problem altogether.

Rod