Originally Posted by
WizardOfBoz
First question is why I don't see more seat bags on road bikes?
Jersey pockets are enough for the short rides most people do and traditional seat bags are too small for long distance rides.
I always carry wallet, keys, and phone in mine. In my larger jerseys (XS LG standard fit) there's room left for a spare tube, wind shell, leg warmers, and four Clif bars.
OTOH, on long rides I also want more food, a spare tire, helmet light, gloves, thermal jersey, and thermal tights which need storage a small saddle bag can't provide so I use a rack-mounted trunk bag.
Here's my ideal seat bag: two compartments, one for tools and one for phone/wallet.
I upgraded to an Arkel, which combines a water-proof inner bag that mates to a holder mounted like a traditional saddle bag. It's big enough to carry two tubes for the rainy season (where flats are frequent and less time getting wet fixing one is better) plus two tire levers, Park dog-bone, chain tool, spoke wrench, long 6mm hex key, patch kit, two master links, left over chain, nitrile gloves, TiGr lock mechanism.
I also have a full-sized frame pump mounted next to my top tube that'll have me back on the road in 100 strokes without my T-rex cycling arms falling off.
The two compartments to give easy access to the phone/wallet without dropping tools on the ground.
It only has one compartment, but you access it vertically so nothing falls out.
Waterproof on the bottom so that when it rains the spray doesn't destroy phones and rust tools. Good quality, compatible with high-end road bike (Trek Domane Series Six). Ideally black. Could be red.
It's water proof. Arkel makes tough bags which could probably survive a grizzly bear attack. They're made in Canada not a sweat shop in an emerging country.