Supposed to meet up with some guys for a long ride tomorrow. I do not have a way of contacting them beforehand, and never ridden with them before. They are a bunch of triathletes. Anyway, should I bring my tri bike or road bike? I imagine group will be 5-6 at most. I like my tri bike better, as I do 95% of my training on it, but will bring my road bike if necessary if that is the appropriate etiquette. I do not know what bikes they will bring.
All depends…do you know them? Do they normally ride TT bikes? If they are triathletes, then my guess is they’ll be on tri bikes. I’d take my tri bike and stay off the aerobars if they are riding road bikes. If they are on road bikes you can explain that you figured being tri guys they’d be on TT bikes and next time you’ll take your road bike. Its not really that big a deal, especially being triathletes.
If they are triathletes and you do 95% of your training on your tri bike, I’d bring it, especially this time of year when most triathletes are spending most of their time on their tri bikes vs. their road bikes.
I’ll play devils advocate. you can never go wrong showing up with your road bike. If they are on tri bikes it matters not. If they are all on road bikes then you chose well and will immediately be more accepted then if you have aerobars. Plus road bikes are easier to paceline with.
Scarey thought - a large group of triathletes group riding together on tri bikes!
Depends who they are. If they’re serious group riders they’ll be on road bikes.
More than a third of our roadie group do triathletes. Not everybody has a tri bike, but of those that do, we always bring our road bikes for group rides.
“More than a third of our roadie group do triathletes.”
From what I’ve seen, women who do triathlons are way hotter than
women roadies, so your friends probably have good taste.
More than a third of our roadie group do triathletes.
Nothing really to add - road bike is a safe bet as others have mentioned but figured the quote was worth repeating 
Shane