As has been said above, tar is shite. All it can offer in the dry is a fairly good hold/ bite and some noise. The downsides are that: When it gets wet, it turns to oil, makes a mess. It has to be constantly re-applied.VERY tempremental, too little and it offers no real advantage, too much and it clogs the pads up, makes the rim horrible and the brake pads get stuck to the wheel when you brakeJust generally not worth the hassle.And now, i will do my usual of defending the rims from the evils of angle grinder, just buy some soft compound pads (i.e zoo's) and make sure that the rim stays clean. Matt