The digital pressure gauge is very precise, measuring pressures up to 11 bar and is suitable for both Auto and Presta valves. It will also function with Schwalbe’s ‘classic’ bicycle valve. Tip: Test tire pressures at least once per month with a pressure gauge. Testing by thumb is completely unreliable as with just half of the required pressure the tire will feel hard. Insufficient air pressure is the most common bicycle problem that results in dramatically increased rolling resistance and premature tire wear.