If a spoke breaks during a ride, a spoke wrench will only do you good if you've also got an extra spoke. And that's assuming it's not a rear drive-side spoke, which is under more stress than any other and might require a chainwhip and cassette lockring tool and wrench to get to it. Where does it end? Should we also bring extra brake and shifter cables--how about cable cutters and end caps? That'll fit in a jersey pocket just fine.

These tools are great for DIY repair and maintenance, but keep 'em at home. Make sure your bike is good to go before the ride and the only thing you should really expect are flats. I carry an extra tube, patch kit, tire levers, a pump, and mini-tool on every ride (and some would even say that is overdoing it). But unless I'm touring hundreds of miles away from home, there's no need to carry all the extra just-in case tools.

Edit: Okay, something like this would be acceptable: http://www.performancebike.com/shop/...tegory_ID=4217