CPSC made available another research report regarding ATV stability. This one, by contractor SEA, measured performance on groomed dirt. Like previous reports (PSL, 2/12/18), this document (bit.ly/2F6ruk3) does not make conclusions or recommendations. Rather it simply relates test results. Some highlights of those include:
- The tests compared 12 ATVs on groomed dirt versus asphalt. There was 0º rider lean with counterclockwise turn.
- SEA found "a mixed bag of correlation between the results from tests…on groomed dirt and on asphalt."
- In circle tests, four ATVs "remained understeering up to the tests' limits of 0.4g" on both surfaces. Five "transitioned to oversteer at higher lateral accelerations on groomed dirt." Three did so on asphalt.
- In J-turn tests, one vehicle did not experience two-wheel lift even at higher tests speeds. Seven had higher threshold Ay values on asphalt and two on groomed dirt. One had the same value on both surfaces.