Turn 8 and Turn 9 High-Speed Carcass Deflection
Willow Springs' famous Turn 8 is a flat-out, 130+ mph right-hander that subjects a motorcycle's rear tire to sustained lateral g-forces for over 4 continuous seconds. Under-inflated track pressures cause excessive carcass sidewall squirm, generating localized overheating and cold tear tearing along the medium-soft shoulder rubber.
Key Findings from 12 Shakedown Stints
- Setting rear cold pressure too low (e.g. 23 PSI cold on a street-construction tire) generated an uncontrollable 8 PSI hot gain, causing a convex crown profile and diminished lean angle grip.
- Starting at 28 PSI cold resulted in an optimal 33.5 PSI hot reading off the warmers, maintaining uniform tire footprint width across full apex transitions.