Yeah, and not just a slight decrease in trail. 13mm is a big difference. Most would find the steering to be too twitchy. OP, I wouldn't do it unless you plan on running really high volume plus tires that will put you close to 29'er size. We've seen big wheels run shorter offsets with other geo mods, but there's a reason we dont' see smaller wheels with longer offsets. If you're doing it because you can get a good deal on a 55mm offset fork, it's not worth it.The increased offset will decrease the "trail" - it should have the result of quickening your steering response. This could be good....or bad. Depends on how you like it.