Originally Posted by
63rickert
NO. We have seen this movie before. We have seen this movie before way too many times. The following is not a theoretical concern. This happens.
Shift to the large/large combination with a short chain and the derailleur is bent, twisted, sheared off. If you're lucky. Frame damage is likely as well. Crashing is not automatic but very likely. ALWAYS have enough chain for large/large. You cannot count on remembering. Recipe for failure.
I concur. The one time i rode...knowing I had too short a chain and being sure i would never do big/big.......of course i did.....some one on a trail jumps in front of me on an uphill and I think i have 2 more left, not 1....fortunately it was slow, i realized it the second I did it and stopped....did a monty python slow leaning fall...and all that was hurt was my ego.
fwiw I am a big fan of small/small sizing I have used this method with great success with both modern 105 5800 and vintage (dura ace 12/28 and 39/52 front)