Is this a normal experience?

[RolliePollie]

My guess would be that this is pretty normal. Even if your new bike fits you, it seems to me that your body might take a little time to get used to the new position. Even though you've already got a bike and you're used to riding, the new bike is putting your body in new positions and probably using muscles in a different way. When I first got my bike, everything hurt while I was riding and after I was riding (and I was only riding 3-5 miles on a flat bike trail). But pretty soon, things stopped hurting so much. Hopefully this will be the case with you as well. Good luck and don't get discouraged!

[Zen]

I can't find that bike in a search
Did you go from upright to drop bars?

[pinkychique]

I bet the biggest thing is that you're just not used to riding. Riding made me really sore the first long rides I went on ( and riding a bunch of little ones has the same effect). I vividly remember lying on the couch wanting to die after my first 70 miler...so it's all about getting used to it.

The BIGGEST thing about your back: take the bike to a professional bike fitter to make sure it's the right measurements for you. I was lectured by my BF's dad (a doc) about how someone he knows rode a bike that didn't fit him and then ended up with a permanently messed up back.

Then make sure you do your core workouts! The core strength helps the back to do less work to hold you up in the saddle, so at the end of a ride you feel better. It makes a huge difference to have a strong core.

Keep on riding!!

Congrats on getting the bike not from Walmart!!