I would tend to disagree with cutting "all models" to 10.5 inch track. For those that prefer a narrower track, the SX is available and the narrow track (and shaped paddle profile) fits it's intent and personality better. A 12.5" wide track fits the ST and LT intent better. Giving up 2" of width is giving up a lot of floatation and would require a lot more spin to keep the same forward momentum and float. Many of us want more floatation and not less.
Losing even an inch off the full length of a track adds up way faster than adding or removing overall length. Look at the surface area differences between a 15" wide and 16" wide snowmobile track of the same lengths. Granted those are longer overall, but removing 2" of width off these snowbike tracks would be a fair percentage of removed footprint which would need to be countered with even longer long tracks. My personal preference would definitely be to keep the 12.5" width rather than needing to go even longer with the track to make up the loss of floatation because then one would have to deal with the issues inherent to going longer and longer.
Freeing up track speed and hp by sacraficing floatation seems counter to the intent of the ST and LT kits in my opinion. Keeping the SX, and perhaps expand that line, for those what want narrower tracks, but keep the 12.5" wide for the ST and LT since they are targeted for deep powder and in powder the tip in difference between the 10.5 and 12.5 is likely an insignificant improvement compared to what we'd lose (floatation). Just adding my opinion to the mix, but then I have not ridden an SX so don't have any first hand knowledge.
It probably largely depends on ones riding style and on the type of snow you ride. The deep powder regions may lean towards wanting to keep the 12.5" plus get even longer, for more flotation, and longer paddles vs. the wetter snow regions, spring riding, and/or those that spend more time on tracks or trails leaning towards a 10" track. So nice that we already have the SX targeting those condistions and the ST/LT for the deeper, softer conditions.
