No.

I'm all for the Boy Scout creedo "Be Prepared" but you have to draw the line somewhere; "Be Prepared" for what? Everything that might possibly occur on a ride? That's ludicrous. Or at least impractical.

Every ride I go on, regardless of length, I have a multitool, a tire lever, & a pair of new tubes (all in the saddlebag that's always on the bike), at least one full bottle of water, and a cellphone, ID, insurance card, credit card, & >$20 cash in my pocket.

For a long ride (>50 miles) I'll bring a PowerBar or some ShotBlocks too.

Because on nearly every ride I've ever gone on, I've needed most of the above. And the extremely few times I've needed the insurance card, well, it doesn't take up too much room so it's not too impractical or too ludicrous.

But anything more? I've never needed a chaintool, or a First Aid kit, or a snake/insect bite kit, or a Dremel Tool, or a rivet gun, or a shotgun, or a pair of jumper cables, or an inflatable air mattress, or three unreleased recordings of Crosby Stills & Nash fighting in the dressing room of the Fillmore East, or an enchilada wrapped in pickle sauce... so why would I bring those on a ride "just in case"?