RWC Group, a truck and bus dealer representing IC Bus in Arizona, Washington, and Alaska, was an early proponent for LiquidSpring suspension technology on school buses. Tom Hartman, general manager for bus sales at RWC, said that districts, charter schools, and private schools are becoming increasingly sensitive to bus vibrations affecting children with special needs.
This concern led to RWC testing LiquidSpring suspensions in 2019, and Hartman said the ride was exceptional.
“We have received a lot of good feedback from school districts,” he confirmed. “After we sold the bus to a school on a Native-American reservation here in Arizona – where the roads can be very rough for school buses – they tell us that they love it. The ride is better, and the driver can make adjustments based on the road they’re driving over.”
“We like to say that it provides a ‘luxury car’ ride with ‘sports car’ handling, but in a bus.”
-David Nagreski, Director of Advanced Engineering, LiquidSpring
RWC has ordered five LiquidSpring-equipped buses by IC, and Hartman said he plans to order another demo bus now that the effects of COVID-19 on the industry are beginning to subside.
“I am excited to order another demo and start promoting it again,” he said. “I believe these are suspensions which we will continue to utilize for more school districts going forward.”
Because many districts are not authorized to purchase aftermarket components or parts, the suspension is installed at a Navistar Mod Center prior to leaving factory production. Navistar has recently completed their “B-Letter” to better explain the advantages of LiquidSpring to their dealers, and make the purchase of a LiquidSpring suspension system more simple for districts and contractors.
“We produce an active suspension system that utilizes a compressible fluid as the spring element,” said David Nagreski, director of advanced engineering for LiquidSpring. “By varying the amount of fluid that is engaged, we can change the spring rate and pulse between two ride types – softer than standard or stiffer if the route requires more control. We like to say that it provides a ‘luxury car’ ride with ‘sports car’ handling, but in a bus.”
The system differs from leaf-spring suspensions, where Nagreski said buses sacrifice ride in favor of handling, and air suspensions which he said offer a smoother ride but handle more poorly.
“The idea behind the LiquidSpring suspension is to only provide roll stiffness when it is needed,” he said.
“We have found that this suspension technology reduces 45 percent of vibrations from road to bus,” said Travis Ward, head of national bus sales at LiquidSpring. “Many maintenance issues – such as air conditioning, body panels, airbags, compressors, dryers, moisture separators, and more – are no longer a problem because of vibration reduction.”
While this technology represents a slightly higher price point than leaf-spring and air-ride suspensions, Nagreski said the system is comparable to an air-ride in terms of maintenance intervals. However, unlike an air-ride suspension, the CLASS suspension has no air bags or lines which need to be monitored. The suspension’s hydraulic systems should be monitored, but no refills or system replacements are required in a vehicle’s lifetime.
“School bus drivers, students, and aides are the biggest beneficiaries of the technology,” Ward said. Drivers will experience less fatigue and a safer drive, while students are more secure in their seats while traveling on bumpy roads or cornering.
“For many special-needs students and aides, it is so important to have a smooth ride,” Ward continued. “It can make a night-and-day difference, not only for them but for drivers as well.”
The increased prevalence of EV-based buses will also likely have a large impact on LiquidSpring’s presence in the school bus industry as an agreement with Lion Electric is already in place, and there will likely be many more to come.
“All-electric buses have huge power consumption,” said Ward. “A LiquidSpring suspension does not have a huge power draw opposed to a compressor-driven system. That can make a huge difference in battery power and longevity for districts.”
Learn more about LiquidSpring’s revolutionary active suspension technology.