Quote Originally Posted by Catrin View Post
I am currently debating this very thing - in the process of getting accessories for my Gunnar. I COULD say that I can just change seat-bag when I move from one bike to the other - but that will grow old. I know me
I used to have a seat bag for each bike...then I got too many bikes Now it's a seat bag for each wheel size...the road bikes share a bag, the 29er and the 26" mountain bike each get their own. The commuter's stuff goes in the panniers.

I carry a small multi-tool on the roadies...with 3, 4, 5, 6 mm allen keys, and a Phillips screwdriver. I don't really sweat the brand...as long as it's small and has what I need, it's all good. I also keep a spoke wrench in the seat bag, in addition to tire stuff. I stopped carrying a chain tool on the go-fast bikes several years ago (although the MTBs and commuter each have one.)