Originally Posted by
jonwvara
No one rides around in the big-big on purpose, but even smart people make mistakes sometimes. If you shift onto the big-big without meaning to and the chain is too short, you're going to break something, and maybe hurt yourself. A slack chain in the low-low combinations is not ideal, but it's not really a safety issue. I cheat that way all the time, but learned the hard way about making sure the chain can handle the big-big. Even though, you know, you're never going to use the big-big. Except maybe that one time.
+1 on this. I did a new build and did the chain a bit too small and too late to get another chain, but was excited to try the build.... so I went out knowing big/big did not work and was sure I would not go there.
Sure enough end of ride on a MUP and had to deal with uphill and combo of clueless adult, kid, animal and oncoming idiot on an electric fat tire bike, and slammed it into big/big without thinking.
Immediate stop, but was going so slow I was able to reach out, and grab lean on a fence and clipout. at speed it would not have been pretty