Always Hook A Thumb - While it's important to relax your body for comfort and control, don't mistake relaxation for a lackadaisical approach to safety. Be sure to keep a controlled grip on the handlebars at all time, especially as roads and trails get rougher. This doesn't mean hanging on with a vise-like death grip. Just hold snuggly and remember this important rule: Always keep at least one thumb hooked beneath the handlebars. As long as there's a thumb beneath the handlebars, your hands can't slip off and you'll be safe.