JDN

I think you are riight about that tire not being directional. It would depend on the water dispersion tread more than the handling tread, wouldn't it.

NickP

Sorry what is so special about pulling and turning the tire? Any tire place that does run flats can do this??? Sorry for being lame, but what am I missing?

Rudy

There's probably more reasons than this, but for sure, due to the relatively small sidewall as well as the increased sidewall stiffness of a run-flat, many tire shops aren't able to mount these types of tires without damaging either the wheel or the tire (or both, I guess).

Some tire machines turn the wheel and have a fixed arm, others keep the wheel fixed and have a moveable arm, some arms have little wheels on them to prevent damage to alloy wheels, etc. The more expensive machines can do the job with no damage but of course the technician needs to be experienced on the task as well.

Since these fancy machines are pretty expensive, not many places have them yet.

JDN

Pulling and turning would reverse handling tread by putting it on the inside. For maximum handling, I believe that tread is designed to be on the outside as the manufacturer has labeled the tire.

Conversely, I believe the water tread (my nomenclature ) is directional for displacing the max amount of water, albeit, different in direction than I would have expected. It looks to me as though it is designed to move the water forwqard, diametrically opposite to the direction of travel. I would have thought it would have been more efficient to move the water to the rear than forward. But I are (sic) not an engineer.

NickP

BTW: I just had 4 new run flats put on my Z4 yesterday (I was at aprox 20K miles on all 4), by conicedence this was the week I was to change them anyway, I sped this up as I had a flat Monday AM

The shop I went to was referred to by my dealer. All 4 replacements were in stock and I watched the installer as he worked. He correctly did all the sets as "outsides", was CAREFUL when he was pulling the old tires off the rim and putting the new ones on. Not a single bit of damage either side of the rim...

BMW530

I thought there was a "special" or "different" way to fit a run flat tyre. When I had a puncture a week after I got my car. I returned to my dealer to try and get it repaired. Unfortunately the main technician was off sick. His assistant was not too confident in changing and repairing the tyre, they they had to take it a specialist to get it done. From that I guess there was a different way of fitting a run flat tyre due to the stiffer side walls.