I have a Norco with shimano drivetrain with wolftooth 49t rear cog and wolftooth 32t chainring. And never got the right chain line for my big 49t rear cog. Too much of an angle from my chain ring. So I purchased a 3mm spacers for the chainring. Unfortunately the bolts aren’t long enough. So I finally bought these. Why i waited for so long, i dont know. But now my chain line is around 48-49mm. Right where it should be. If you have chain line problems. Spacers and these bolts will help.