I have recently switched from a Stronglight crank to a Miche Primato. The R/H side, the chainset, has been fine and a lot 'rounder' than the Stronglight which results in a more even chain tension. When I installed the L/H crank it was extremely close to the bottom bracket shell although it didn't seem to be touching, I did a couple of rides with it, including a 200km and then noticed it was loose. The bolt remained tight and it looked like it had gone too far onto the bottom bracket square taper so that the bolt was just tightening against the end of the bottom bracket. I have since fitted the stronglight L/H crank, which fits fine, but I find it slightly annoying that I have mismatched cranks.
Although I've not removed the bottom bracket I'm sure it's a Shimano 107mm UN (something). I did wonder if I should fit a Miche bottom bracket but this feels a bit of a punt and it looks like I'd also need to buy a Campag tool to fit it which is an added cost.
Any thoughts?