W
ith another school year well under- way and winter weather approaching, transportation directors and tire experts stress the importance of checking and
maintaining tires. This could be even more important for electric school buses, since the extra torque that elec- tric motors provide could cause faster tread wear due to heavy battery packs. Damaged or overly worn tires reduce fuel efficien- cy and increase costs. And they can cause serious accidents, like the tragic fatal crash in New York in September, where a faulty front tire reportedly caused a charter motorcoach carrying a high school band to plummet off an embankment. (The crash resulted in two adults being fatally killed and 40 students injured.) Electric school bus tires “are under different types of
stress and need specialized technology to help keep fleets moving efficiently,” commented Frank Incorvaia, manager of commercial strategic accounts for Goodyear North America. Meanwhile, Charles Faillace, the parts inventory
specialist for the School District of Philadelphia in Penn- sylvania added that, “The electric buses wear out the rear tires faster because the torque of the electric motor, they grab harder,” he said, noting it’s not a night and day difference, but something that he’s noticed. “If you see an electric bus needs a tire 10,000 miles before a diesel or gas bus, that’s one reason.” He noted that when ordering a school bus, the dis-
trict specifies a heavier duty 16-ply tire. However, the same tires are ordered for both an electric and diesel school bus. Shaun Uys, vice president of the U.S. commercial
vehicle tire division at Continental Tires North Amer- ica, added that tires must have a higher load index to withstand heavier batteries and charging technology in electric school buses. “Most of the truck and bus tire lines in Continental are already built to meet these require- ments,” Uys added. “A higher weight vehicle will cause for a longer braking distance and will cause more wear on the tire. It is vital that these tires also need to make sure they have low rolling resistance … defined as the amount of energy a tire uses over a defined distance.” Ken Martinez, transportation manager for Salt Lake
City School District in Utah, said he expects to see more wear in general and more uneven wear in particular on the tires his district’s 12 electric school buses use, though it is too early to tell for sure. He added he is keeping tabs on the situation, since the district hopes to have 75 of its 100 school buses electric by 2035. “I feel like there is going to be significantly more, or at least slightly more tire wear from the electric version,”
Charles Faillace, parts inventory specialist for the School District of Philadelphia in Pennsylavnia
Martinez said. “The electric school bus has almost three times the amount of torque. When the drivers are in a hurry and they really want to accelerate, they really accelerate.” At another district’s suggestion, Martinez began
investing in Michelin XD2 tires about seven years ago and reported they have been useful for both diesel and electric buses. They are slightly more expensive than standard tires, but they are “worth the money,” he said. Tire companies say that certain pre-existing and new
tires are especially appropriate for electric school buses. Goodyear, for example, offers RangeMax RSDEV, with advanced casing and tread compounds that offer ul- tra-low rolling resistance. “Tredlock Technology helps deliver even wear, increased traction, and a Three-Peak Mountain Snowflake (3PMSF) rating means traction in all weather conditions,” added Incorvaia. Bridgestone designed the R192E specifically for elec-
tric urban transit buses “to provide higher load capacity and improved rolling resistance for extended range,” said Jason Roanhouse, vice president of North American Bandag Operations for Bridgestone Mobility Solutions. “Bridgestone does not currently offer tires or patterns
specifically designed for electric school buses, as the additional load capacity has not been an issue,” Roan- house added. “However, other existing products like the Bridgestone R268 Ecopia and Firestone FS561A would meet the requirements for electric school buses, and both are [EPA] Smartway verified in providing excellent
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PHOTO COURTESY OF TAYLOR EKBATANI
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