My tires are 23mm. It could have been my spokes, I am not sure. I have broken a spoke in the rear wheel, so it is possible. The reason I know the frame flex's more is when I have the bike on the trainer. It moves much more in the bottom bracket area than my Six13 does. I can look down when pedaling and see it.Friction_Shifter said:rear tire rubbing on chainstays
what thickness tire? (25mm or less?)
perhaps all your spokes need tightening?
perhaps tighten quick release tighter?
is this something that is known to happen with flexible frames? first time I've heard of it but I've been out of the loop for quite some years.