So yesterday I bought a P30 chain guide at one of the not so local stores in San Diego county. I went to go install it this morning and what do you know the chain ring bolts on my stock crankset are not long enough to accommodate the bash guard and the new e13 guide ring. This is after one of the mechanics said I would be fine with the stock crankset bolts... This is my first experience with a bash guard so I was unsure of the extra Parts needed.

My question is what size crank bolts would I need to have perfect fit? I know E13 makes a 15mm pair for use with their bash guards, would that work on my set up? I am a amateur mechanic and its frustrating when you go to a lbs and the employees or mechanics make you look like Einstein sometimes.... Just had to vent