Maybe I'm missing something, but it says the Polaris 850 had a 163x2.6, which would mean the standard quickdrive setup: 22/43 gearing. The Summit has 21/53 gearing, albeit with a bigger driver. Taking that into account, I'm still coming up with a 18% lower gear for the Doo. The chaincase sleds are also at a gearing disadvantage: same driver diameter as the Doo, but 19/44 gearing comes out to 2.31:1 ratio, compared to 2.52:1. Would love to ride the Doo turbo and a '21 Khaos with QD2 back to back, but I'll be doing well just to get in another ride or two at this point!