Gearing - Summit, change from 21 to 20 or 19
Gearing - Summit gearing from 10th 2.52 to 8th 2.86
Gearing - Trail, change from 27 to 26 or 25
Gearing - Rpms during long touring
Gearing - XP 800 - My gear is 27 top, how low can I go without a new chain?
Gearing - XP 800 - My gear is 25 top, how low can I go without a new chain?
Gearing - XP SPROCKET and CHAIN chart.
Gearing - Lowering ratio and effect on flyweight.
Gearing - Summit, change from 21 to 20 or 19
Question) Joe, I have an 07R summit 159 at 5000 to 8000 feet. What do you think about going from a 21 to a 20 or 19?
Facts; Any lower gear will help enhance acceleration.
Observation - You can hit the bottom of a hill with a few more speed units and help maintain that holding power needed without track speed diminishing too quickly.
Facts; Track speed will diminish at a slower rate with any lower gear.
Observation - "Elevation" Feedback I get from tuners is many who run higher than 7500’, they seem to like the lower gearing as they see power loss as elevation increases. The engine power decreases however the driver can still maintain a good track speed.
Observation - "Snow load" Where tuners get into deeper snow, or wet/heavy snow and observe an example of 29mph~35mph track speeds, then the lower gearing will be beneficial to hold track speed for a longer time especially when it’s hard running. Improves "holding power" regarding track speed.
There are guys I talk to who run from 3500 to 7500 feet that particularly boondock, not running on big climbs at all. Guys report back to me they like the lower 20 and 19 gears for technical riding in the trees when they need that extra quick burst of acceleration to climb little hills and get into side hilling, winding up through the salad.
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Gearing - Summit gearing from 10th 2.52 to 8th 2.86
Question)Hey Joe, I have an 05 summit X 800. I'm going to run the 06 440 Racer 2.86 8 tooth drivers with the new 155 camo extreme. I ride at 5-8,000' and weight about 230lbs w/o gear. I was running 19/46 with the stock 10 tooth & have your SX8 clutch kit, I was wondering what you'd recommend for gearing.
Stock gearing is 19/45. Thanks Brent
Answer)That 440 2.86 driver set is nearly the same diameter as a 9th 2.52 driver, however the 2.86 is slight more efficient. So then you can think of the 8th is like a 9th then can calculate the ratio difference. 10th / 9th = 1.11 or 11%
19:46 is 2.42:1 ratio. You changing nothing in the system except the drive sprocket, you are lowering your gearing by another 11% which would be (2.42 x 11%) = 2.69
To find out the new "overall gear ratio" you take 46gear and divide by 2.69ratio = 17gear.
Going from a 19:46-10th{2.52} driver to a 8th-{2.86} driver would be the equivalent of gearing to a 17:46
You did not mention the reason why you wanted lower gearing so I cannot recommend a gear ratio. If you wanted to go to the 440-8th{2.86} and maintain the same "overall" gear ratio as your 19:46-10th{2.52}, then you would have to go to a 21:46 and that would be "mathematically" the same gear ratio as you presently have however 1 size smaller drive sprocket. 19gear x 1.11% = 21 gear
Result; 19:46-10th{2.52} = 21:46-8th{2.86}
Don't forget to try the Gearing Calculator.
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Gearing - Trail, change from 27 to 26 or 25
Question) Joe, I have an 08 XP trail sled and wonder if there is a benefit to gear down? Will I get more performance from lower gearing than factory?
Answer) A gearing decision is influenced by “Application” so then what kind of gearing applies to you?
Facts; Any lower gear will help enhance acceleration.
Observation - Using traction products and having good capacity for your suspension to hook up, you can gain acceleration over a similar sled. The gear reduction increases the available torque to the track to move the sled quicker in a shorter amount of time.
Facts; Track speed will diminish at a slower rate with any lower gear.
Observation - Snow depth, where rider gets into deeper snow, or wet/heavy snow and observe an example of 59mph~65mph track speeds, then the lower gearing will be beneficial to hold track speed for a longer time especially when it’s hard running. Improves "holding power" regarding track speed.
Facts; Any lower gearing will raise rpms when using sustained throttle positions cruising at sustained sled speeds.
Observation - A clutched 800R with 27:45 can cruise at a sustained speed of 65mph(105 km/h) with 6200 rpms. Using a 26:45 on the same pass, will be about 6350 rpms. Using a 25:45 on the same pass, will be about 6500 rpms.
Taller gearing delivers very smooth power delivery when cycling the throttle. Gearing lower will make the sled react with a more sudden power feel.
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Gearing - Rpms during long touring
Question) Joe, what rpms does your kit see when I am doing long mileage touring?
Answer)My clutch kit offers 350~400 rpms Lower than stock calibration. Clutch kit is about 6200 rpms, stock calibration is 6500~6600 rpms under sustained throttle position - The reason why is the clutch kit uses 23g of flyweight compared to the 18g of stock pinweight.
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Gearing - XP 800 - My gear is 27 top, how low can I go without a new chain?
Question) I have a 27 top gear on my sled, what is the lowest gear I can go without changing the chain?
Answer) The 27:45 and 26:45 use the 106P chain. To go to a 25 gear you must reduce the chain size to 104P.
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Gearing - XP 800 - My gear is 25 top, how low can I go without a new chain? Question) I have a 25 top gear on my sled, what is the lowest gear I can go without changing the chain?
Gearing - Lowering ratio and effect on flyweight
Here is what happens when you change a gear ratio to a lower ratio
or
When you change the overall ratio (aka smaller drive sprocket diameter)
The term(s) tuners use "gearing too low" or "geared lower" is a "label", a descriptive marker that is attached to a result of reducing "overall drive ratio"
Gearing commentary
IF you can remember the theory "The law" of how the parts work, then you change your overall drive ratio and see "X" result...
THEN you can apply other theory "the law" of how the parts work to compensate for the lower gearing.
An example.
You can run a gear set with 21:49 as stock with a 413 ramp and reveal "rated rpms" (8150) right to full shift.
If you were to run a 20 or 19:49 then make the same run down a road to full speed, there is a great chance that you'll observe rpms that will stay at 8150 until the load changes (bumps, cycling throttle for a corner, snow getting slight deeper) then the rpms will reduce. [remember the lever is doing more work being farther out on the ramp]
Alright...
You reveal lower rpms under re-applying full throttle.
Ramp example illustration ( i will get a picture of 413 vs 410 vs 417 and post)
You can take the 413 ramp out and install a 410 or a 417 as each of these ramps have an increased angle towards full shift compared to the 413.
Law - If ramp angle increase; Then rpms increase. Then rpms quicken from one rpm to a higher rpm / time.
You reveal lower rpms under re-applying full throttle.
Example question arises - what spring force is being used at an example 45mph track speed? (look at track speed at bottom of chart)
You can look at your primary spring final force. The rpms reduced with a xxx/260.
You can remove the xxx/260 and install a xxx/290 or a xxx/320.
Each time you raise the final force then you will be adding more spring force at-the-moment-during-upshift where the rpms start to diminish or become sluggish.
How much spring force you add at-that-point-on-the-up shift will determine 1)how much the rpms will drift low. 2)how quick the rpms will recover.
there is always an easy way to get around drifting rpms due to a gear change.
