Why wear the lycra in the first place? A pair of sweat pants or looser fitting hiking pants or shorts should work fine as would nearly any trousers, if you use an ankle band to keep them out of the chain. I've ridden 50 milers in sweat pants or plain old cheap loose fitting gym shorts and wicking undies. I don't want to be seen wearing lycra, its down right offensive to subject others to that, especially if one does not have rock hard abs. I did this once back in the day when wool shorts with real leather chamois were the only cycling shorts available. A gal asked me if I wore underwear with them , I said no, she said," maybe you better start". Lets face it, unless its 85 degrees and you are riding more than about 30 miles and trying to set a personal speed record, you don't need to wear skin tight stretchy pants for fun!