new bike - why am I exhausted?

I've been riding 6 days a week for 5 months now, anywhere from 10 - 20 miles per day, putting my ALL into it, or so I thought. I was riding a 7 speed commuter bike and wanted to see if I was going to keep this up before spending the $$ on a better bike. Well, I'm addicted and after 3 weeks of serious shopping and test riding I found the perfect bike for me - fits like a comfortable shoe, and rides like a dream. Trek 7.6 FX WSD. My first ride was day before yesterday. I did my usual route and must have said OMG! about 187 times as I glided through my 20 miles. When I got home I was floored to see I had cut 20 minutes!!! off my time, but boy was I beat. I don't get it!! The same thing happened yesterday and today I'm just resting because I'm exhausted! I realize I am in a more bent-over position, and I can actually feel muscles being used that weren't being used on the commuter bike - is that it?? I am pretty sore today. I'm drinking and eating and doing all those other things you're supposed to do. Here I thought I was in pretty good shape after 5 months of riding - but obviously not. Should I take it easy on riding for a few weeks? Like only go 10 miles or so? :confused:

I have the 7.3 fx, I'm guessing it's similar to yours. I felt some different muscles being used at first too. The outer thigh area (saddle bags that I no longer have!) was being used more than on my previous bike. Maybe your time sped up because of you working harder, being psyched about the new bike. I like mine a heck of a lot!

You are in pretty good shape I'm sure, after all the riding you've been doing. You're just using different muscles on the new bike. And it sounds like maybe you got a little carried away with your newfound speed too :D - nothing wrong with that! Just make sure you take a day of active rest (short easy ride, walking, yoga, etc.) once or twice a week to let your body build those new muscles.

You are doing great! :D
Your body will take a month or two to really settle into the new bike and adapt the new muscle positions. It took me about 250 miles before I felt really comfy on my new bike- and my two bikes are more similar to each other than your two bikes. Rather than try to start tweaking anything on your new bike, allow some time for your body to tweak itself into the new positions. :) It's like a new pair of good leather shoes.
Don't worry- it'll all fall into place.
Congratulations on your new bike!

Well, I started this thread last week because I was exhausted after every ride - I had just transitioned from a commuter bike to a hybrid. Took your advice and laid off a day. Much better energy the next day. Yesterday, I was literally just turning around and the bike just shot out from under me. I wasn't even pedaling I don't think. Who remembers. My head smacked the pavement (cracked the helmet) and because it all happened so fast I must have landed on my ribcage - didn't have time to put my arm out or anything.
Spent 3 hours in the emergency room, nothing's broke - just bruised. Big red spot on my left forehead this morning and ribcage is extremely sore. Guess I'll get some rest now eh. No damage to the bike really. Mirror shattered, that's about it. What I'd like to know is WHAT HAPPENED??! :eek:It happened so fast I can't even describe it better. It just shot out from under me. It had been raining but the pavement sure looked dry. My husband thinks it might have been oil film on the road? I sure didn't see anything. I almost lost the bike in a flippin' crack in the road the other day too. So, okay - obviously I can't ride this bike the way I was riding my fat tired commuter. A friend told me you have to take cracks at an angle:confused: - can't do it head on like I did with the fatties. Is there a book, an article, or something on how to ride a road bike and not kill yourself. I want to get back on this horse - not be afraid of it. Thanks!