D
duivendyk
Guest
Bicycle frames are NOT designed to cope with substantial vibration,least of all those made of strong but metal fatigue prone thin wall Cro-Mo tubing.The thick wall old fashioned mild steel frames stand up best.Rack mount systems tend to transmit less vibration to the frame (with proper mounting).Losing control&crashing can be very dangerous with traffic around.The saving grace is that the fatigue crack is usually not yet complete before it becomes apparent that something is amiss,But a frame can unexpectedly fail catastrophically when overstressed (braking a hard landing etc).Get some life&disability insurance.