Stock front sprocket is 15 tooth.
Go to 16 tooth for less revs and less vibration on the highway (change is 6.7%).
Go to 14 tooth for quicker acceleration (change is 6.7%). Will rev more on the highway. Better if you have a tach. The new 6th gear will be halfway between the old 5th and 6th gears. (I had 14T for a while and mostly hated it.)
I got my 16T sprocket on ebay.
INSTALLATION – You need a torque wrench. You don’t need the rear wheel off the ground. Loosen the chain first. Torque values: Front sprocket 40.0 ft lbs … Front sprocket cover 9.0 lbs/ft.
Not usually needed for Rebel 500: You might need to leave off the metal part when you re-install the plastic sprocket cover. Rebel has a steel half moon plate that goes on with the plastic sprocket cover. For some people it hits the chain, so they have to leave it off and some people have no problem (or they use a grinder on it), so they can leave it on. My Rebel 300 front sprocket was wedged by it – I couldn’t even push the bike. It serves as a case guard in case the chain breaks, but that’s unlikely on a 300cc bike if the chain is well maintained. So I had to leave mine off.
Rebel500 