I had the same question. I have that bike and just love it, however, it has a tendency to have aharmonic resonance (vibration) above 105 Kph. The sprocket sizes that I had were 15 tooth front and 50 tooth rear. I looked everywhere for the answer to this and when I checkedWWW.BIKEBANDIT.COM it stated that my stock sprocket sizes were 15 tooth front and 45 tooth rear, so I have ordered a new rear sprocket to see how that works. Bikebandit is an incredible parts site both OEM and after market. The parts blowups are very helpful and answer a lot of questions about how too reassemble something. The upside of the 50 tooth is very good acceleration for the engine size and surprises most people with bigger engines than mine. I am sure that the 45 tooth will reduce that acceleration a lot, but since I do mostly highway driving, maybe it will will help with the vibration. Hope this helps.
The chain is size 530, and the stock gearing is 15/45, meaning that the front sprocket has 15 teeth and the rear sprocket has 45 teeth.
15 and 45
I think 17/42 is stock
45 tooth rear
chain: 525 , sprockets: 16/43
14t on front. 40t on back
17 tooth front, 42 tooth rear, 110 link chain, size 530
13t driver goes on a 33t sprocket
Sprocket size will b 16T & 39
Usually the sprocket is an inseparable part of the freewheel, and the size of the freewheel is determined by the hub.
The recommended size of the chain to use with a small sprocket is typically a smaller chain size to ensure proper fit and function.
It uses a 47 tooth sprocket.