gear setup for drag

[08BUSAMAN]

what is a good starting point for drag gear have stock now with the best of 1.44 60ft time don't want to go down on front sprocket was thinking of going up 2 in rear????????????????????????

 

[peanutrobber]

Went down one on the front of mine and it made a world of difference. It is also still great for highway.

 

[Draco1340]

Need more info like the weight of the bike and rider, and the MPH that you are running. Your at the top of 4th now. The next step up in gearing needs to take you to the top of 5th, or there really is no benefit. If you have to shift into 5th going through the traps, you may actually slow down because every shift is 120 milliseconds off the gas. 16/43 or 16/44 should get you close to the top of 5th if you are currently running 152 mph. 16/43 is about the same as a 17/45 or 17/46, and there is less wear and better mechanical efficiency with a 17 tooth counter sprocket. Again, let us know what the weight and MPH is.

 

[peanutrobber]

The 08 has a 18/43 from the factory. 16 front on an 08 is too much I think. As stated above you need to know your rpm going through the traps and then play with it from there.

 

[08BUSAMAN]

1/8 mile track i'm in 3rd gear about 10,000rpm i weight 205 i was thinking about going up to a 45 in the back 8th mile time was a 6.11et 1.44 60ft time @ 116.765mph

 

[boosta1395]

With stock gearing and a sterch much like yours (7inch) I was making 119 in the 1/8 and 145 inthe 1/4. I weigh 220. I am going to 2 up on the back. I also have a MPS auto shifter (air) And love it, no looking at the tach. I set the shift point at 10,200 as any higher it would mixup with the stock rev limiter and cause problems. Going through the lights and shifting into 5th a little out the back door. Hope this helps.

 

[Draco1340]

1/8 mile track i'm in 3rd gear about 10,000rpm i weight 205 i was thinking about going up to a 45 in the back 8th mile time was a 6.11et 1.44 60ft time @ 116.765mph

Math is always truth. If you are going 117 mph in third at 10k, then you will whant to run it out all the way in 4th. 1 or 2 teeth (45 tooth) in the back will probably make you go SLOWER because of the time lost during shifting. Based on the primary gear ratio difference of 3rd vs. 4th, you need to change your 18/43 to a 16/45 or a 17/47. You can run your genII all the way up to 11k with no problems, so that gives you about 130 mph in 4th with a 16/45 based on the numbers you gave me. That still allows you about 150 in the quarter, and 160 mph in top gear. Don't go with opinion, go with math. If your concearned about wheeling, thats a different problem. I run a 16/45 and never wheelie at 65" (and a leaded axle).

 

[08BUSAMAN]

so what do you run in the 8th mile and what gear are you in????????????

 

[Draco1340]

Generally run high 123 to 124 mph in the 1/8 in 4th gear. But I'm a little bit lighter at 180 lbs. Combined bike and rider weight is 706. These bikes are fast but they are heavy.

 

[Elganja]

17/46 will be just about the top of 5th gear depending on your mph:

MPH  150    150.5  151    151.5  152    152.5  153    153.5  154    154.5  155
RPM  10108  10141  10175  10209  10242  10276  10310  10343  10377  10411  10445

 

[08BUSAMAN]

Well i was going to try some gears changes this weekend but no gears to be found tried everyone there out for two weeks or more this sucks

 

[peanutrobber]

Did you try Driven?

 

[bigbadboy]

have u ever thought abt going down 2 in the back?? stock gearing my bike will go 122 in the 1/8. my friend running -2 in the back, stock front running 5.9-6.0 in the 1/8 at stock wheel base at over 126 not sure but he's ran 130 but not sure of the time