Other than for sentimental reason or just for the heck of owning a set, the widetrac knuckles are nothing but an aluminum version of the stock knuckles with bigger bearings. I'd rather have the racerx knuckles than those.
Castle Neu 1520 on 6S LiPo Powered Gmaxx (Nitro Killer)
Predator with OS .21TM
Supermaxx with Mach .26
Revo with OS .18TZ
Kyosho ST-RR Conversion
Ofna CR with Tekin ESC/Motor (2)
This is true... If you want to run bigger bearings, I am sure if you find a set of knuckles with enough meat on them, you can always mill out
the bearing seats to 15mm or 16mm and drop bigger bearings in. Another opting is to get some RPMs... I think they use 15mm bearings.