Freestyle Track swap?

[polemite.productions]

anyone here ever upgrade the 136x1.25 track on a freestyle backcountry 550? i'd like to give my kid some deeper lugs, but don't want to spend a whole lot, or make it a major project.
144 would be nice, but i'm not sure i want to dive into a rail extension/tunnel extension. and would that require gearing too?
sure seems tough to find a 136x16x2 track. if i remember right, a 141x15 will go on there without a rail extension, but if someone could confirm, that would be awesome.
anyone know if there are drivers available for the freestyle, that would make the newer 137 tracks an option?

 

[xring60]

We can make you drivers for any track pitch/drive shaft configuration.

Andy
Avid Products

 

[the fix-it guy]

We replaced a 121 with a 144 with skid extension and geared it down, was an awesome sled. If your going to do it bite the bullet.