They have stoma guards, which protect your stoma from injury. In fact, Matt (a.k.a. awesomeame) just posted a thread on here that says he has one for sale on Ebay! His topic is "stoma gard", and he said you can find it on Ebay, if you do a search for "stoma gard". He's from Canada, so maybe that's the way they spell it up there.
When it comes to cycling, you shouldn't have any problems at all. I do a one-hour aerobics class twice a week and sweat a lot, and my wafer stays on just fine. I would recommend that you start out slow and build up your stamina, since you're only 2 months post-op.
Dx'd Crohn's in '99 at 28. Proctocolectomy and ileostomy in '06.
Disease-free, medicine-free, and very thankful to be healthy again :)