I posted this to the Commuting forum, but you folks might be able to help too.
Yesterday morning I had a little accident on the mile ride to the train station from Neil F.'s house. I was in a hurry and apparently didn't fasten a pannier strap securely, or I struck it so hard with my heel that it came loose, or the load - cable and U locks for a lunch stop in downtown Manhattan - swayed too much. Regardless of why, the left pannier came undone at 18 MPH and was sucked into the rear wheel. I skidded to a stop. I remained upright, leaving a long skinny skid mark on Central Avenue. A preliminary account of the damage included nine spokes knocked out or broken, I don't know how many others loosened or otherwise damaged, the rear wheel seriously out of true, the rear tire shredded, holes in the left pannier, bent derailuer hanger, and the rear brakes knocked out of alignment. Other than the shock and some upper body weakness caused by my having to carry the bike a mile, I was OK.
The total cost to get me on the road again was 183 dollars: - new 32 spoke rear wheel, new tire, new derailuer hanger, and labor. The only part of the two month old hand-built wheel that could be saved was the hub, which they gave me to sell on Ebay. I was lucky Highland Park Cyclery was open, and my thanks to them for doing emergency work to fix the bike. Since I'd traveled 100 miles by bike and train, I would have been stranded otherwise.
My question is, how can I avoid such a problem happening in the future? I don't want to have to replace rear wheels regularly. The bike is a Trek 7.5 fx, with a Blackburne rack and Trek 'grocery sack' panniers. I'm 6'1", 265 pounds and falling, with size 13 feet. I don't use clipless pedals or straps, but platform pedals.