I bought a 2008 Bailey that ran "WhipCity" out east and the gearing is 13-50 with no clue what gear he raced in, I believe he ran 2nd gear (2008 GSXR stock). My question is going to a longer track (3/8ths) should I just try 3rd? Also the car has a completely worn out set of chain tension blocks, can I lose the tensioner and blocks? Whould a 14-54 gear help me out to control chain whip? I appreciate any help I can get, thanks, Tom

Any guesses, my magic ball is not working. Ill buy a tach and try to figure it out....

I wouldn't think changing the sprockets would have any effect on whether or not you need a chain tensioner. You need to adjust your chain by changing the length of your radius rods, keeping the birdcages square by re-adjusting the torsion arm. Gearing changes should be mainly to fine-tune your drive ratio to the length of the track. Most guys I've talked to run in second. I can't help you with what you need for a 3/8 mile track; I'm still getting setup advice myself to run at Montpelier, but don't ditch the tensioner! Foz makes a pretty good setup and it's not an arm and a leg.

1 tooth on the front is 3 in the rear so going 14\54 is actually going to up the rpms try maybe 14\51. What I doto fine tune is devide 51/14 then multiply that times the 2nd gear trans ration and and then times the primary trans ratio to get final ratio we run somewhere near 12.5

I recommend you ask a few racers at the track you plan to attend for the gear ratio they use to get a ballpark idea (wing/non-wing, length of straights/tightness of curves, slick or tacky all make a difference). For example, we may run a 12/52 in 3rd in our R1 on a 1/4 mil track for a 11.54 ratio. You will need to look at a gear chart for the GSXR, as the primary ratio and the individual gears will be different by motor. Check out http://speedpartz.com/techarticles.htm for the chart applicable to your '08 motor. Looks like a 12/52 is pretty close for your motor too (11.53) or a 13/47 (also 11.53) but if you prefer 2nd gear you could go with a 12/43 (11.42). Use the tach to adjust from there to get into your target RPM range. For a 3/8 mile track you may need to be under 11.00, for example a 12/49 in third (10.87) or 13/45 in second (11.04)

The other consideration is chain length - depending on the other tracks you plan to race, it may be better to go with 3rd than make up a short chain for the smaller gear (assuming you run out of adjustability in your radius rods). I agree with jjones - use a tensioner; we've used Speedparts for several years, replacing the blocks periodically, and have had no issues.

Big thank you to all, I found a set of blocks that are not in bad shape. I ran my PMP micro with an 08 GSXR 600 with 13-48 in 3rd(10 inch wheels with 70 in RR) at all the 3/8ths tracks but pushing 15,400 on the tach (it didnt live long). I think I'm close with 13-50 in third gear and an 82 inch right rear.

whip city was a 3/16 mile track im from that area and raced there, prob know the guy you bought the car from....we run a 14 /51 on 1/4 mile tracks around here... ones a high bank paper clip type track we run a 14/51, the other 1/4 mile track we run a 14/50 its more of a semi banked bull ring..... we only run a 3/8 mile twice a year i usually go 3 less teeth on the rear sprocket to start see what kind of rpms it turns maybe a tooth down or up from there depending on track.... id start with a 14/47 ish