I have had my latest commuter bike, a ribble audax/winter bike with a set of fulcrum 7 wheels since Nov 2012. Fantastic commuter which has been hammered through 2 winters and heading into a third. Approx mileage at present is 5000-6000. I have been through 3 chains and a cassette through general wear and do all my own maintenance.

My question is how do I tell when the wheel rims are worn to the point they need replacing? I can still see a wear marker which is just visible. Would I feel a pulsing through the brake lever if the rim is on the way out or is this too late? My commute takes me down a large hill on my way home which can see me braking from speeds of up to 40mph to zero for some lights at the bottom. Really don't fancy a failure!