I ordered a front, rear sprocket and D.I.D. o-ring chain for my TW from the Lytle racing group. I wanted the 15/50 combination and was having a little trouble being confident that I was ordering the correct items from their website. I called them and they were very helpful placing the order over phone. They had to special order the front sprocket, but even so I received the complete order in 3 days. BTW, if anyone wonders what the total cost for all three items and shipping, I paid $124.60.