Is it necessary to remove the whole wheel/ disc/ caliper assembly to change a tire or inner tube. I am embarassed to admit that in spite of having co-owned a G109b in England for 15 years I have never had the spat off to see if the wheel rim is in halves which can be split to change the tyre. If it can be split, does anyone know what the tightening torque for the bolts should be. John Chapman Plymouth UK.