Holy frijoles! 16 tooth!

Discussion in 'Dakar champion (950/990)' started by SF_Rider, Sep 29, 2012.

  1. SF_Rider

    SF_Rider Been here awhile

    Joined:
    Feb 2, 2011
    Oddometer:
    450
    Just had new chain and sprockets installed. Went with the 16 up front. Man. If you thought the 990 was fast to begin with, hang on tight.

    If your thinking of doing this just jump in. If you weren't thinking of doing this, start thinking of doing it!
    #1
  2. triplenickel

    triplenickel Long timer

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    Wait until you start playing with the back end.
    #2
  3. mousitsas

    mousitsas Long timer

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    I thought so myself until I started de-restricting the intake....
    #3
  4. Sporting Wood

    Sporting Wood I

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    2004 called, said something about getting caught up.
    #4
  5. HooliKen

    HooliKen Awesome is a flavor

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    :lol3
    #5
  6. BartG

    BartG Been here awhile

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    I went from 17 - 42 to 16 - 45... let me tell you, BIG difference!

    No point in having a ADV that can do over 200KPH
    #6
  7. mousitsas

    mousitsas Long timer

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    Gearing on its own does not mean much. Goes hand to hand with how good fueling is. Based on my experience with the different setups I have tried on my SE, I would say that 1st with 16/45 is a necessity on a stock carb-ed 950 but pretty useless on the street with a better carb/exhaust setup. Right now I have 17/42 and my bike can climb my garage ramp (not too steep but steep enough) on 1st at idle.
    #7
  8. DrKayak

    DrKayak Retro Rider

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    I run crazy low gearing on my 450. 50MPH is maxed out in 6th. I considered going lower than 17/42 on my 950 but just can't see wanting it geared any lower on the street.

    Once I was on some wicked technical stuff and the 950 got hot from slipping the clutch to go slow. On the other hand, I use 6th on the pavement every ride to milk more range out of the fuel hungry beast.
    #8
  9. rokklym

    rokklym one man wolfpack

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    I'm putting that on my bike soon, I've had the chain and sprockets a while, just haven't had a chance to do it yet. Can't wait!
    #9
  10. TheMuffinMan

    TheMuffinMan Forest Ranger Magnet Supporter

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    I run 16/42 and that feels a good mixed size. For all the mountains around me a 16/45 would be nicer for the technical climbs but I wouldn't want the deceased range brought on by the lower fuel economy at highway speeds (120-130 kph)

    Then again after going to a .5 clutch oil jet slipping the clutch for an extended duration isn't an issue with 16/42.
    #10
  11. rokklym

    rokklym one man wolfpack

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    With the stock gearing I rarely use 6th, so I think I should be OK with the lower gearing for now. Next springs long trip might be much, but maybe I'll just throw on a 17 for that.
    #11
  12. triplenickel

    triplenickel Long timer

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    The gearing changes really don't have much effect on range I find, I'm at 16/47 and still get the damn near same as I did with stock and there's no comparing the 2 fun wise.
    #12
  13. Just Paul

    Just Paul Pro Cat Herder

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    :d:d
    #13
  14. Sporting Wood

    Sporting Wood I

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    +1
    Its incorrect to associate lower rpm's at speed with better mileage. Its just an assumption, completely unsubstantiated, and a reflection of the posters misunderstanding of how motors work. If this were true, every vehicle would be geared to idle for cruise... Motor efficiency is a function of several factors, rpm being only a small part, torque curve being the biggest.

    Since you have your bike geared to where your riding right in the meat of the LC8's torque, your mpg is no worse.

    I personally found that running 16/45 slightly boosted my typical range over what I got when I first got my bike. Now typically getting the light around 180-190 miles, and running big fat 175 main jets to boot.:evil
    #14
  15. Navin

    Navin Long timer

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    16-50 is the cat's pajamas. +1 on the MPG, has little to no effect. The wrist controls the fuel.
    #15
  16. triplenickel

    triplenickel Long timer

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    I bet that would be a blast in the dirt.
    #16
  17. MortimerSickle

    MortimerSickle Semi-Adventurer

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    So, my math wasn't bad after all, when I thought my mileage improved with the 16/42? :D
    #17
  18. Navin

    Navin Long timer

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    :freaky
    #18
  19. tahoeacr

    tahoeacr Long timer

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    Not true. All things being equal, you will use more fuel with the 16. I have tested this extensively. Even to the point of riding slower so the rpm was the same. But, don't believe me let's look at the math.

    4,000rpm equals 5.37 lbs/min of airflow. Divided by 14.7 Air/Fuel ratio equals 0.3653 lbs per minute. Multiply by 60 equals 21.92 lbs of fuel an hour.

    Same speed using 16 tooth would be 4,250 rpm.
    4,250rpm equals 5.7lbs/min of airflow. Divide by 14.7 A/F ratio equals 0.3878 lbs per minute. By 60 minutes equals 23.27lbs of fuel an hour.

    All things are never equal so it will depend on how much fun your having with the new found wheelie king bike and of course your fuel map.







    :hide Just went thru a high performance EFI tuning class so I had to see how much I retained.
    #19
  20. DrKayak

    DrKayak Retro Rider

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    Yea, and I know people who have extensively tested on my FZ1 and my Diesel truck with the same results.

    But more than likely it's all just "a reflection of the posters misunderstanding of how motors work." :lol3
    #20