My steed and I set forth at 4am yesterday for a 200km Brevet going east from Seoul known to include every single hill in the area. In preparation I had my 53-39 Chainrings and an 11-34 on the back. Works well for climbs up to 15% or so. We set forth at 6am and made good progress to the first hill in an hour twenty minutes. All is good, I'm on track to finishing sub 10 hours then. just before 4 big hills my chainring bolts work loose and derailler turns the 39t chain ring into a pretzel. Fortunately I had two chain ring bolts left. Using my multitool(s) I let the dead ring just hang loose and fastened the 53t as best I could.

We then found a tool shop and used these


To make this


Then proceeded to climb another 1500m of hills on a 53-28 as the lowest (the lowest workable combo since the 34 only works on the 39). Admit I walked quite a few of them, its horrible climbing on that ratio. Got back in 11 hours 24 minutes and gained these


A fine hat for my eldest it is too. An adventure to be sure. I didn't get my sub ten hours but I did finish with time in the bank and the weather was great. Garmin flawlessly did its job. Now my poor roadie needs some tlc before she can travel with me again...