You chain couldn't fall off before you left on your commute? We need to develop a smart chain
My new chain arrived in the mail the afternoon my old chain broke. Of course I was 3/4 up a steep hill standing in 1st gear. I did the 150 rpm thing followed by the timber thing ... At the last tenth second my foot pulled free of the SPDs and spared me a few bruises. I was able to push/coast the remaining mile or so to pick up my wifes van.