I tend to overpack so I don't need to make the call of shame. So I like the
Serfas Speed Bags. I swap one in medium size with the expanding pouch between my hybrid and road bike. After using one for several weeks I may get a larger bag for the hybrid and dedicate the Serfas to the road bike.
The Speed Bag isn't the most streamlined looking but I doubt the aero characteristics matter under the saddle and behind our bodies.
What I like about the medium LT-2 Speed Bag:
- Holds its shape with plastic inserts in top and bottom and fairly stiff lid, unlike some floppier saddle bags (notably the Jandd mountain bag, which I may get for the hybrid).
- Organization niches: inside pouches, elastic retainer strap and snap strap for keys, ID, those Lezyne glueless patch kits in little envelopes, etc. Much easier to find stuff at night.
- Reflective trim.
- Double zipper -- helps when closing lid over bulky stuff like my Topeak RaceRocket HP, which fits but barely.
- Three attachment points: two Velcro straps on the saddle rails, one on the seat post. Very secure, even when heavily loaded.
- Loop for taillight. For a few weeks I just clipped my Cygolite Hotshot to the loop. Now I use the Cygolite mount on the seat tube just between the seat stays and under the saddle bag.
- Expandable via zippered floor.
- There are a couple more accessory loops I haven't found a use for. In a pinch they could be used for additional straps to secure the bag to the saddle.
What I'm meh about, although I don't dislike anything about the Speed Bag:
- The two Velcro straps that go over the saddle rails must be threaded from the inside-out, then tucked up under the saddle. Even with my long, thin fingers it's awkward. But once it's done it holds. If I didn't switch the bag between two bikes it wouldn't be an issue.
- It's difficult to snug up enough to eliminate any swaying. So it won't suit folks who want to maximize every possible efficiency. They'd prefer a rigid, fixed clamshell container like the Aeroclam or Lezyne Pod.
On my road bike for relatively faster, shorter rides, I'll zip the expandable pouch shut, and just carry:
- Spare tube
- Lezyne glueless patches in a small, flat plastic envelope in the lid pouch
- Multi-tool, levers and blue paper shop towel in a ziplock bag
- Minimal first aid kit tucked into inner side pouch with a few ibuprofen, antihistamine, asthma pills (ephedrine, expectorant and cough suppressant -- true rescue inhalers no longer exist and some asthmatics still respond only to ephedrine as a bronchodilator), wet wipes with sunscreen and bug repellent; glucose tabs and NUUN tablets or DripDrop sealed pouches of powdered electrolyte supplements.
- Small wallet
- Keys clipped to the keyholder strap inside the lid.
On the hybrid for longer casual rides I'll open up the expandable pouch and add:
- USB battery and cords for recharging my doodads
- The larger tube for my 700x42 tires
- Kind bar
- Extra first aid stuff including bandaids, small clotting pads, tape, etc.
I'll probably get a larger saddle bag for the hybrid to hold a larger first aid kit, more tools, etc.
*****
A bit of O.T digression...
The small clotting pad in a first aid kit may not seem like a big deal but I've found some otherwise calm folks who don't complain about pain from crash injuries freak out over bleeding that won't stop easily. The clotting pad is mostly a placebo that helps minimize emotional shock. When people don't see their own blood they tend to be calmer. A notably example is boxer Manny Pacquiao, a genuinely tough guy who rebounds well from being stunned and even knocked out, but has a phobia about his own blood. A small clotting pad takes up little room and can be handy for leaky cuts -- especially on the face -- nose bleeds, etc.