12R 22.5 in metric?

[jjrbus]

Is there a metric equivlent to the 12R 22.5?

[Sojourner]

http://www.bridgestone.com.au/tyres/products/truck/trucknbus/chart.asp

FWIW

Sojourn for Christ, Jerry

[tekebird]

no direct conversion.......new coaches use 315/80/22.5 which is a bit larger than a 12r22.5 IIRC

[TomC]

315/80R-22.5 is the metric version of the 12R-22.5.  It is a superior tire with versions made that can support up to 10,000lb per tire!  Good Luck, TomC

[RJ]

Just make sure that the tire you're looking at is rated for highway speeds (75 mph).

There are some this size that are intended for transit bus use, and have a low speed rating (50 - 55 mph).  Harsher ride, too, due to the heftier design.  (Transit drivers think the curb is part of the braking system, thus the need for the heavy sidewalls.)

FWIW & HTH. . .

[jjrbus]

The curb is not part of the brakeing system? What are they there for then?

[Runcutter]

In transit service, curbs also help greatly with steering the fronts.  Running over them with the rears, on right turns, makes sure passengers won't sleep beyond their stop - tough to sleep when you're holding on with both hands.

Several transit systems I've worked with have had a curbed/destroyed tire on display near the drivers' room - with a sign indicating the cost of the lost mileage on that tire (leased tires).  Thought of this expense is even more important for us, since we'er buying our own tires.

I"m in the market for six new tires (due to age-related weathercracking) for the 4107 - Gulp!  Thanks for the original question, since I have to decide weather to replace the current tires in kind (12R 22.5), go to compatible metric, go new fronts - Bandag rears, go with easier-to-find size, etc. (Russ, any suggestions?)  Thanks again for the question and answers.   

Arthur Gaudet  Carrollton, TX

[tekebird]

315 is close to a 12r22.5 but they are wider at least the ones I speced out when shopping tires a month ago

[TomC]

315÷25.4=12.40".  The 315 is almost identical to the 12R in height.  In the Michelin book, they are only off by 1rpm to each other.  Good luck, TomC

[NewbeeMC9]

I didn't see 24.5 sizes    Are they getting phased out/hareder to find or are the still out there in the trucking world?  Min are all 11R24.5

[belfert]

I didn't have much problem finding 11R24.5 tires for my bus.  12R24.5s would have been much harder to find.

My bus is Mexican made so it had metric tires originally.  It had 11R24.5s on it so I put 11R24.5s back on it.  I noticed later that the tire size was actually supposed to be metric.  I don't know if the rims had been changed or not.

Brian Elfert

[tekebird]

no the 315/ (80) I think is about the same Diameter as the Non Metric eqiv in 22.5 or 24.5.  However is .5 inch or more wider if I recall