I dont notice much difference from a 129 to a 137 but I sure like the fact that the 137 has another set of Linq clips.    That alone is reason for me to go with the longer track.  

And pull start a 2 stroke if equipped with pull cord

2 stroke or 4 stroke?   Front end weight makes a difference.  FWIW. Had a 146 Pantera 7000 and the "flickability" between it and a 137 ZR9000/7000 are marginal. Ride was good with both, probably a bit better with the Pantera. The Pantera did push more in the corners tho, even with the 2up seat and bags off. Added note, my wife preferred driving the Pantera than the ZR7000iACT she has now.    Can't compare to a newer 2 stroke as I have no experience on them. I still miss my old Sabercat 700. Worked great everywhere. Bonus is you can actually pick up a 2 stroke if it gets stuck.😉      

If anything I would tip toe into at 137 - think 129 to 146 may be too much and could prove to not be to my liking. I am a guy who likes very little change - and usually am quite comfortable sticking with what I know works and what I know I like. Going to a 137 would be a huge thing for me mentally

OTB This goes for volunteers as well. Personally, I spent more than $1200 in fuel in my truck hauling my ATV and sled doing trail work last season (plus fuel/repairs in my atv/sled/chainsaw). Yes, it was extreme due to the 2025 ice storm. Would be well over $1600 with today's gas prices. (How about a free trail permit!😉) These costs don't show up in the OFSC budget ledger.  I imagine we may see a decrease in volunteer activity this year due to fuel costs. Many of our volunteers aren't high end people(me included) but do it for the love of sledding. The juice may not be worth the squeeze anymore to some people. Hope not. Time will tell. JMO.   Also OTB, this will again limit the amount of new or younger people that will join the sledding utopia.