what happens to the velocity of a purely rolling cylinder immediately on climbing an inclined plane of angle A?

if it is a rough incline the velocity of the centre of mass of the cylinder will increase...due to frictional impulse which will act along the incline upward. because immediately after climbing the momentum perpendicular to the incline will be resisted and hence the velocity of the c.o.m will be the component along the incline  only which is less than initial velocity of c.o.m i.e rω but  "rω" does not change therefore there will be backwad slipping then immediately the friction will come into action whose function is to prevent relative slipping......and it act upalong the plane