Bombar's Beemers offers sprockets from world class manufacturer, Sprocket Specialists. These American made sprockets are excellent. 
We can supply you with chain from Dyna Chains to enjoy with your sprockets. Available in lengths made to order in 520, 525, and 530 sizes. 
A typical F650 chain with front and rear sprocket setup is $259 - Way better than OEM!!!
Call us for full details 919-450-7450