how fragile is the E ink phone? Is it one drop away from being a paperweight? I'd like to think that the big names that make the bicycle computers expect the head unit to be skidded across the pavement doing 20 mph+ at times & maybe accidentally stepped on/ran over... I haven't tested the durability out, but that would be my expectation. Whereas a phone.... I'd at least expect some water resistance, but falling off a bicycle going 20 mph... not expecting a good outcome.