| Author |
Message |
Johnny (63.159.193.82)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, November 30, 2002 - 3:49 pm: | |
I just saw these on a RIPTA transit (looked like a Grumman/Flxible 40'er, in desperate need of a DD mechanic, FWIW). They were Goodyear Metro Milers, B305/85R22.5, & had "MAX SPEED 55MPH" stamped on the sidewalls. Is this a simple case of using the cheapest crappy tires available, or are these built specifically for city transits, most of which simply will not go faster than 55-60MPH? |
Doug (204.182.81.207)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, November 30, 2002 - 4:19 pm: | |
No, they are not the cheapest crappy tire. Transit tires are a special duty tire built for transit applications. They have very heavy sidewalls to prevent damage from curbs and many even have wear indicators that measure sidewall wear. The tread area also is typically heavier that a conventional truck tire.
Because the tire has such heavy construction, it does not dissipate heat as well. The faster you drive a vehicle the shorter the cooling cycle is for the tires. At speeds above the rated speed the tire can overheat and come apart.
Other factors that can influence the tire temperature are ambient outside temperature and loading. The tire is designed to cool sufficiently fully loaded at 100+ degree temps, driving at or below the rated speed.
Doug |
Johnny (63.159.193.82)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, November 30, 2002 - 4:43 pm: | |
Ahhhh, I see--and judging by the right-rear outer dual's sidewall, they're a good idea.
Would that size be approx. equal to an 11R22.5? |
Doug (204.182.81.207)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, November 30, 2002 - 8:56 pm: | |
That?s correct the right rear takes worse beating the right front also tends to wear due to rubbing the curb during passenger stops. In our fleet we rotate tires for sidewall wear as well as tread wear.
If I remember correctly B305/85R22.5 are the same size as a 12/R22.5
Doug |
Doug (204.182.81.207)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, December 02, 2002 - 7:48 pm: | |
I checked today:
B305/85R22.5 are the same size as a 12.5/R22.5
Doug |