In a side-by-side test recently performed by the North Central Regional Transit District (NCRTD) in New Mexico, a bus equipped with a LiquidSpring suspension system outperformed a comparatively upgraded vehicle in unplanned maintenance costs by better than 100%.
Who Are We Talking About?
Over the last two years the NCRTD in the Sante Fe region has been running a side-by-side comparison between two aftermarket suspension products; one of which is known across the transit and most light to medium duty industries as an acceptable remedy to ride issues. The other is an incredibly unique application that has largely built its credibility in the ambulance and off-highway mining markets over the last 10-plus years. That second company is Lafayette, IN-based LiquidSpring LLC, which has recently begun to make headway with its product lines designed for transit and shuttle buses.
LiquidSpring refers to its technology as CLASS, which stands for “Compressible Liquid Adaptive Suspension System” and is a direct and simple way to describe the core principle of their smart suspension offering. By simultaneously sensing for and responding to driving inputs, including speed, steering, road conditions, and payload distribution, LiquidSpring’s active process instantaneously responds to provide optimal ride quality in concert with the most responsive handling on the road.
What Exactly Happened?
While the benefits of a LiquidSpring system can be instantly felt by both the driver and passengers alike, there was of course a need to quantify the long-term comparative value over more traditional suspension upgrades. While NCRTD has reported buses in their fleet with a CLASS system have recorded over 125,000 miles in over three years of use with zero suspension related issues, they needed a more definitive test to assess the comparative value.
In order to remove any relative barriers, this field test, run by NCRTD, featured two buses that ran mirrored routes in the opposite direction. Each bus was managed in identical fashion with respect to the necessary preventive maintenance, and the cost that was evaluated was for “unplanned” maintenance items such as brakes, tires, and the tightening of equipment loosened by road vibrations.
The result? After two years and nearly 60,000 miles on each bus, the bus outfitted with LiquidSpring cost $0.023 per mile in unplanned maintenance while the bus with the more “traditional” upgrade cost $0.053 per mile, which means the maintenance cost of a CLASS equipped bus is 57% lower than a “comparatively” upgraded vehicle.
Why Is this Important?
Any driver can tell you that fighting feedback from road conditions is one of the biggest annoyances of their daily life, and any maintenance professional can tell you that vibrations caused by road conditions lead to a large percentage of long-term and recurring costs as equipment is repetitively put under undue stress. Furthermore, beyond merely the maintenance costs, the lifetime of the bus itself is assumed to be negatively impacted, although at this time that estimate has not been identified.
How Is This Relevant to Me?
Fleet costs? Vehicle life expectancy? Operational forecasting? Driver satisfaction? Rider appreciation? If any of these metrics are measured or observed by your agency or company, then the suspension system your buses ride on should matter to you deeply. With funds being made available for public transit in the latest COVID relief plan, now is as good a time as any to reassess the strength of your fleet as we move into a new era of transit.