everyone must already know that there is only a 5-6% difference in mounted tire diameter between the common 19 and 21 DS type tires, hardly seems a big enough variance to make a difference traversing varied terrain, especially on a DS bike, as opposed to a dedicated offroad moto.
the section width of the same tires is a different story, with the variance being over 20%.
so it's unlikely the diameter that accounts for handling reports in mud, sand, etc., the argument comes down to running skinny versus not so skinny.
i like the 19 for running both paved and gravel, does well on both.
Canada/Alaska, 2009; Eastern Canada, 2010; TAT, CDR, FTR, Yukon, 2011; Travels With jdrocks, 2012; jdrocks Rides CO to AK 2013; jdrocks Rides West TX, NM, AZ, UT, CO 2014
V649HP BIKE BUILD