The common things to ride on the back of a 22 tooth chain ring is an 18 tooth freewheel or freehub with 17, 18 or 19 tooth sprocket or cassette.The norm for 18 tooth front is a 13, 14 or 15 rear sprocket on a freehub. With 22 front 17, 18, 19 back there is chain wrapped around more cogs than with an 18front 13,14,15back sprocket so it is much less likely to skip and spreads gear wear alot. If you want a harder gear, beacause the bike's gear feels too light to pedal to hop far, all it needs is to reduce your rear sprocket by one or two teeth. Or: Your cog might be too small on the back and stopping you pedalling as much gear because it feels to heavy. This would mean you need to add one or two teeth on the back sprocket. You maight need to change your chain length too. Ben
