| Author | Message | ||
     Flyboy |
can someone tell me what size sprockets i need to match the stock pulley ration on a xb12r? Thanks | ||
| Playhard |
On an 09 the stock belt final drive ratio is 2.41 so I run a 21F 50R, which is a 2.38 ratio. That setup has worked great for me at Jennings GP and Carolina Motorsports park. a 22R 53R combo would be closer to stock, a 2.40 ratio, and give you more swingarm clearance. On earlier model bikes the primary gearing is a bit different so that can also effect final drive gearing. I found out that the hardway at Daytona. Fellow racer told me to run a 22F 42R, which worked great on his 04. Well on my 09, I never got out of 4th. Gear. Ended up running a 21F 44R. | ||
| Flyboy |
thanks, I'm trying to find a baseline to run with...on my 06 the stock gearing at my home track works great...so I want to make sure I have some sprockets close to stock to start with. | ||
| Slaughter |
ALL sportbikes are geared too high for virtually any race track. (just something to keep in mind) IF you are riding street and track, no worries since acceleration out of corners isn't going to be a really big deal... HOWEVER, if your emphasis is more track than street with lower lap times, you really DO need to gear down. True for GSXR, R1, R6, XB, 1125, 749/848/1098 Ducks. They are ALL geared too tallwith "stock" gearing. You really need to be geared for just a couple hundred RPM short of your rev limit at the fasted point on the track. Unused RPM means wasted HP. (Message edited by slaughter on May 01, 2010) | ||
| Flyboy |
I agree with you for the most part. At my home track I gear a little different, almost opposite, I gear for the best drive out of the slowest corner...which has worked well for me over the years when I was racing R1's and Gsxr1000's. Last year I picked up a 06 12R and was pretty surprised to find the stock gearing working almost perfectly, (unless the previous owner changed to 9r primary...I don't know havnt checked). This year I picked up another XB trackbike with chain drive....and just trying to figure out what's going to be close to start with. The problem with gearing for the fastest spot on my home track is you end up having to shift too much in the infield and actually hurting the flow and drive out of those sections, so I gear for the torque through those sections, and you end up with taller gearing than you would think for the track...but it works and I found on the XB stock worked pretty well...maybe it's because I'm not used to running a twin yet, but we'll find out this year. | ||
| Slaughter |
Sorry - couldn't help with gearing since all the guys I know have already dropped down a bit for Willow (a known high speed track) My XB is a punched-out XB9 (1169cc) - so my gearing isn't XB9, not XB12 I got what you're saying about what you're used to. (sometimes I come off preach-y) | ||
| Lucas70374 |
does anyone use pmfr sprockets. i was told my hdfr to use then and the 6 bolt holes dont line up about 1/2 inch off | ||
| Flyboy |
Hey no worries Slaughter, I do appreciate the help though and like I said I agree with you. Even when I raced Brainerd we were geared down from stock. (fun track) I'm just trying to figure out what the stock pulley converts to in sprockets so I can figure out where to go from there. I want to make sure I have some choices...especially for when I go to other tracks. |
