Q:

Bike Shorts, Do you wear things under/over them?

So I am going on a 200mi ride (over 3 days) soon. I was at the bike store getting my bike a once-over before I go, and I was told by the bike specialist, that I would really want to consider buying some bike shorts (the tight spandex kind) with padding. While that is fine, and I am going to take his advice, I dont know anything about wearing said bike shorts.
Do you wear underwear with them? Can I wear shorts over them? Do I really need them?

A:

Do you wear underwear with them? Can I wear shorts over them? 

Absolutely not. Nothing over or under, just the bike shorts.

Do I really need them?

For 200 miles? Hell yeah. Your ass will thank you.

A:

Yikes. 200 miles, just like that? Have you been training for it at all? I'm not talking about the endurance aspect -- I'm assuming you're in good enough shape to even consider it -- I'm talking about the physical act of your rear end being on a bike seat for 15-20 hours.
Yes, you need the bike shorts, 'taint no question about it. You also need to be ready for the very strong possibility that all your below-the-waist parts will be very angry at you. From the chafing, to the weight of your body on those parts for many, many hours... especially if you're a guy, they way your seat feels after an hour or two may be nothing compared to hour 12.
Don't wear anything over or under, but for that long a ride (especially if I'm gonna be sweaty) I like to shake a good healthy dose of Gold Bond down there to keep too much sweat from getting trapped. Please note that the experience of Gold Bond on your privates isn't something you dive right into the first time. Try a tiny bit first to make sure you don't have a bad reaction.
Seriously consider buying Chamois Buttr (your bike shop probably has some) and applying it liberally inside the shorts before putting them on, to reduce friction.
And most importantly, if at all possible, take as many long rides in these bike shorts as possible before your 200 mile multi-day trip.

