I have a Shimano 6500 gruppo laying around doing nothing. I also have a hybrid I could use as a bad-weather road bike. The group lacks shifters and I don't fancy using STIs on a flat bar anyway. Will Shimano 9-speed MTB parts work with the 6500 derailleurs?
Now, I know that some of you think that anything will work with anything else, but I'd prefer to hear from people that have actually done it and lived.