Just wondering if the switchback or 121 has more steam up top. This would be 08 vs. 08. I thought the previous SB had more, but I'm not sure if the coupled 136" is the same. Anybody know for sure?

I've seen 102 on the speedo of my switchback but I also saw the 600 121 right next to me and maybe a little faster. Just lucky I spent a bunch more on a Dragon with 100cc more

Out of the box the 121 will be notably faster based on stock gearing comparison alone...simple math. Switchbacks are geared very low and not set up as top speed sleds at all...but with some simple gearing and clutching mods, most certainly they can be made much faster...if that is your goal.

But apples to apples, a 121 will always have the edge on hardpack and ice (less rotating mass and track air resistance), and a 136 might have a notable speed edge in soft and deep snow (more traction and better flotation).

As always, setup is everything.

......hope this doesn't include 2005 switchbacks. Mine will go all of 120mph (on the speedo) And I have the 144 track.

LOL @ 120mph.

Throw a GPS in your pocket and go for a ride. I'll bet the farm it's at least 10mph high on the speedo.