Well its what ever rear sprocket is sold for the grubee 6 bolt hub axle flange. I cant really find a spec on it and I sadly left my caliper at work so I cant measure it right now.
http://www.bicycle-engines.com/6-Bolt-Rear-Sprocket-for-disc-brake-set-up-Larger-Diameter.html
These are the sprockets, I got the 44T one from Grubee but need to buy the 36T one from Bicycle-Engine to see if it will work better for me.
http://www.bicycle-engines.com/6-Bolt-Rear-Sprocket-for-disc-brake-set-up-Larger-Diameter.html
These are the sprockets, I got the 44T one from Grubee but need to buy the 36T one from Bicycle-Engine to see if it will work better for me.