Originally Posted by
HillRider
That's pretty much the best approach. You are trying to turn a sports car into a station wagon and it won't work well.
FBinNY's technique for obtaining more clearance will work with track dropouts since they have a lot of slot length to allow chain chain tension adjustment so giving up a little is no big deal. Most vertical dropouts are just deep enough to enclose the axle and shimming them on top can leave part of it unsupported. Not a good thing to have.
Most dropouts have enough slot depth in comparison to the locknut face diameter to allow 2mm shimming with zero overhang at the bottom. It's certainly something to check, but as long as any overhang is marginal or less, and the front of the axle at 3 o'clock is square to a vertical surface so that the chain cannot pull it forward, gravity will work with you to keep everything in place.
Yes, getting the appropriate bike for any type of riding always makes sense and is usually better than having to modify. But it isn't always practical. If starting fresh, buying right is the only smart way to go, but if one already has a bike, and doesn't wish to shell out for another, sometimes a bit of creative DIY allows expanded utility. If "go buy new" was always the advice we wouldn't need a forum, there's thousands of shops willing to give that advice, and be first in line to fulfill the need.