I used to put down a layer of tegaderm under my minimed sof-sets, because I was allergic to the adhesive. since switching to the Animas insets, I haven't had a problem, thankfully. I'm not on a CGMS (yet! really want one though.) but Gillian's suggestion is a good one.

I did 42 miles on Saturday with a 40% reduction and ate breakfast and bolused about 80% of that. I was 87 at the midpoint of the ride. I had a gel pack, and that helped keep me steady in the second half, but I was still 87 after the ride and falling. So, I kept it at -20% for a few hours and had lunch with protein to help keep my blood sugar up.

I'm doing a 60 mile charity ride Saturday, thinking I'm going to try -50% since I know this will be harder since it's long and I'm riding with fast people. I'm also going to keep some energy gel chews on me to eat at the rest stops at 20 and 40 miles. You might try some sort of carb/protein bar (clif bar or clif block are my favorites, but there are others) at mid-ride to help keep your sugar up, plus something short acting like the gel or gatorade to treat the low.

Ruby- do you start your basal decrease an hour before you go out? It needs time to actually reduce the insulin in your system. When I go out in the morning, I'll bolus for my breakfast (usually 80% or so) wait 15 minutes, eat breakfast, and reduce my basal before I go get ready to ride.

Beth