I have a couple of post bags I purchased a few months back. A frame bag and a handlebar bag They are not overly big, and I really like them. So much, that I leave them on my bike all the time. Folks have told me that they cause drag and probably are slowing me down. I'm a slow rider anyways. But I'm curious, do they actually slow you down?
Another consideration is a full frame bag might make your bike more sensitive to crosswinds. I don't notice that with my Banjo Brothers Medium bag (side area about 50 sq in).
I'm not sure what to say here on faster. I need an amount of carry capacity to address the items needed to survive a true gravel/adventure/everywhere type ride. I recently road with a dude easily worth about $5000-$7000+ more on the hoof than me via his titanium, plastic wheels, electronics and what he was wearing. Without knowing how to handle a bike I kicked his butt on actual gravel, and without carrying same tools and amount of water I suppose that would be a speed advantage too.
I don't analyze rides a lot but with similar bikes one does have a big seat bag and frame bag the other doesn't have. 12 - 30 mi loops near home are always about the same time regardless of the setups.
No scientific proof to back up anything I'm about to say to take it with a grain of salt.
I can't imagine it 'not' slowing one down as it's more wind resistance. I have a homemade feed bag I take on every ride. I don't care if it slows me down. It gives me a secure place for my phone and anything else I want to put in there. On the MTB, I have a homemade frame bag for my water bladder and other goodies. They make the ride more enjoyable.
I've reached an age that I'm out there to enjoy life, have fun, get away from electronics for a bit, and get some exercise so speed isn't a big concern for me anymore. It used to be but if I want speed and Strava PRs, I'll hop on the roadie for that. It's funny, I was a hugely competitive person until I did an IM. After that, it's all about having fun. I on longer have to prove myself. I wish I would have been more like that in my younger years.
Yeah, I don't care about my speed. I've turned into a recreational rider, where I ride to see the sites. I still ride for fitness though. So all my old cycling buddies will make cracks on all the stuff I carry. I was on a ride yesterday, where I saw a pace line go by at a high rate of speed. There were a couple folks I knew in it. I thought, I used to do that, and it was fun. But I no longer want to do the workouts that it takes to do that
