I've loaded a 294km tcx file on a 510 for a trip that starts Thursday - and I simply don't trust the bugger even though the 510 says it's ready to go-go.
Back from Sweden now - The profecy obliged - 510 stopped giving turn warnings (visual and audible) after 90km ridden of the 294km tcx file.
Back from Sweden now - The profecy obliged - 510 stopped giving turn warnings (visual and audible) after 90km ridden of the 294km tcx file.