Originally Posted by
merlinextraligh
The difference in weight between a small multi tool with a chain breaker and without is about an ounce. For example a Lezyne Carbon 10 is 80 grams, and a Carbon 5 is 44g. The 10 adds a chain breaker, multiple spoke wrenches, a torx bit, more size allen wrenches, as well as a chain breaker. (And it opens beer bottles)
It's rare to wreck a derailleur or break a chain on single road bike, but it does happen. Having a chain breaker is the difference between riding home SS and walking.
For me it's worth the 36 grams of insurance.
+1 on a Lezyne. I carry a stainless steel Lezyne that has a chain breaker. I have never broken a chain on a ride in all my years of riding, but I carry the multi-tool chain breaker and a KMC link for the peace of mind.