I don't know anything but riding in groups (besides as a kid)... but wouldn't you rather ride with those nicer bikes and remind them how your cheap bike can hang just as good? :)
I did this for a while, actually. I could keep up with everyone except the hardcore racer-wannabes. After a while, I just got tired of it. If they invited me to a ride again, I'd probably do it, but more often than not, I'd ride to the start point by myself (6 miles) then do 35-ish miles with them, then ride another 6 home. It started eating into my free time on Saturdays, since I was already getting ride time during the week to/from work.
I still chat with some of those folks, but when they start spewing over some new carbon thing, I just roll my eyes and sigh.
(EDIT) A lot of it had to do with them talking about nothing except expensive toys... I guess you could say my lifestyle wasn't compatible with theirs. Either they'd ride too fast to talk, or they'd talk about stuff I didn't care about.
Yeah, so I used to do races - I was running, worked my way up to 1/2 marathons, got injured, learned to swim, switched to sprint triathlons.
They were fun, but expensive. A half marathon is $90-$120. The triathlon was $120, plus the $250 (now more than that) training group fee, plus I had to buy a wetsuit and tri shorts...
I did two sprint triathlons total (before I had the second kid, and I haven't been able to get into the wetsuit yet, so...plus there's that $300 training fee + $120 tri fee). Before the second one my friend REALLY tried to get me to replace my hybrid bike with slicks (that I rode 10 miles to work 1-2x a week) with an actual road bike. In fact, they gave away a road bike that was donated, drew a name, but the kicker was that it was for people 5'4" and taller. And I'm not.
I simply said "yeah, I'm not that fast. But I'm a slow swimmer - 2nd to last out of the water, and I run a 10 minute mile. The bike part of the race is 6 miles long, I don't think a new bike is going to help shave off a ton of time from my 1 hour and 4 minute sprint triathlon."
I'm still into fitness. I have a gym membership and a bunch of workout DVDs to use at home on my hubby's gym days, etc. But I can't justify replacing a perfectly good bike. Even if only 7 of the 21 gears still work.