klaus gerhard wrote: Are the wheels of your bike both 19"? On my swingarm square the back wheel was 18" in the first place resulting a very limited ground clearance when cornering. When I changed to 19" in the back it was perfect.
That's interesting, Klaus.
The tyres on the blue bike appear to be Avon Roadriders. According to the Avon website, a 90/90-19 has an overall diameter of 647 mm, whereas a 4.00-19 has an o.d. of 671 mm. (Both unladen, presumably)
I have a Huntmaster-framed Square Four with a WM3 rear rim and Dunlop K70 tyre, which also measures 671 mm overall diameter.
It looks from Avon's figures that I wouldn't gain any ground clearance by changing to a 19" rear wheel/tyre (but I must admit I am contemplating some rear shocks 1/2" longer than standard