BMW G650X Challenge Thread Index

Discussion in 'Thumpers' started by GB, Apr 24, 2008.

  1. pampaX

    pampaX Been here awhile

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    Didn't mean my 14 was the original, I have the original 15 that came with the bike on a box no in use (anecdotal data).

    What I have is a 14, which was changed together with chain (112) and rear sprocket (47). Now when at 6000K I replaced it had surprisingly bad wear.

    So my point Q is having all new, bearings also new (on the hub and carrier) how was possible that much damage on relatively little K?

    My worry is that the transmission shaft could be bent, causing the sprocket to move unevenly. Now this may only mean change sprocket more oven, maybe 4000K.

    Thanks for the replies
  2. dakardad

    dakardad Not waiting for anyone

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  3. BaldEagle

    BaldEagle Adventure Bound

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    What year 450 and what is the mileage?
  4. an13

    an13 Been here awhile

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    Might not be the cause, but check the diagnosis plug cable for wear anyway, it's on the right side of airbox. Mine had rubbed to someplace on the frame and bare wires were showing.
  5. pampaX

    pampaX Been here awhile

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    besides suspension thread I found useful info on



  6. Don't shoot me!!!

    Don't shoot me!!! Snowflakes are cold...

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    So, your recomendation is uneven length of the chain if your front sprocket is 14?
    What about the rear sprocket that has an uneven number?
    The rear cost three/four times more than the front sprocket.....
    I'm about to replace my chain and sprockets today, I have 14X51.
    So, do i go on even or uneven chainlength :huh
  7. The Jester

    The Jester Long timer

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    You can't have an uneven chain length as the links come in pairs, inner and outer. The theory is that your chain length should not be a multiple of your sprocket sizes. eg 14x8=112 so a 14 sprocket is not good.

    Of course chain length is also affected by your sprocket sizes and the limits of adjustment at the rear of the swingarm.
  8. snooker

    snooker AttitudeIsEverything

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    +1

    I recently was educated on this as I have a 15/49/112 combination (I can verify that the chain is long enough for this to fit - barely) and I learned that the 49 is not the greatest. I have also abandoned the 14 except on special weekends - very steep or very slow places (like Moab), then I put the 15 back on for most of my miles. Of course a 14 stresses the chain more than a 15 simply because it's diameter is smaller so I try to avoid it for that reason as well. YMMV.

    The gnarly and confusing details someone posted over on the f650 site:
    http://faq.f650.com/FAQs/SprocketsOtherSizesFAQ.htm#Chain Wear - The Theory

    The chart there shows you the number of CHAIN revolutions necessary for the same sprocket tooth to hit the same link of the chain. You ideally want this to be a big number and certainly not 1, which is what BMW ships with the 112 chain and a 16 front tooth sprocket: (112/16 is an integer 7, so 1 chain revolution has the front sprocket revolve 7 times and the same tooth hits the same link). How do they justify this?

    Looking on the chart, a 51 is good, so is 47, but the 49 I run is not great.

    If you really want to run a 51 then in theory 15/51/112 would be good, however I SERIOUSLY doubt if that would fit on the bike (chain too short!).

    If it were me I'd stick with 15/47/112 unless you really want to lower the ratio. This is just data and nothing is perfect but I would personally avoid a 14 with a 112 chain for sure. You're gonna have to pick... Also be sure the sprockets are steel and not aluminum alloy.

    Anybody else have advice on a good low geared compromise? This detailed info is all new to me as well...
  9. Rev Kiecker

    Rev Kiecker Been here awhile

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    This assumes you are going to still use the same chain you currently have. However if you are replacing, most likely you are replacing it as an entire set and many chains when sold are 120 links. Just cut it down to whatever you want and such that it fits. Now regarding fitment I think you'll have no problems with a 51 tooth chainring, however if you are running a chain guide such as http://www.touratech-usa.com/Store/2075/PN-049-0380/G650X-Off-road-Chain-guide you'll need to do some modifications to make it work with a 51.
  10. tbarstow

    tbarstow Two-wheelin' Fool Super Supporter

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    True. Even a 49 cuts into the TT chain guide.
  11. gsstampeder

    gsstampeder Long timer

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    Anyone using kn air filter. Pros and cons????

    I've read where these are not great for dual sporting.....and I've read where they are great
  12. racki

    racki Been here awhile

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    I don't know much about airfilters, but I've got K&Nand I'm happy with it. Currently I'm doin long ride so I took two little bottles of cleaning agent and oil and it's easier to carry than paper filter that gets squashed after one week. So far I cleaned it twice, due to some very dusty conditions on one occasion and mud bath on the other one.

    It might be easier to run foam filters - you don't need special cleaning agents (kerosene will do) and you don't need much filter oil to carry with you for one or two cleanings.

    No idea about power gain/loss though - I put it as soon as I got the bike and never test ridden it wthout K&N.

    Bart
  13. bigdon

    bigdon Long timer

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    I would not use a K&N on anything that will be used in a dirty environment!

    I had one on a Ford Diesel P/U that let enough dirt get through that it ruined the Turbo Charger. My Dealer would not warranty the Turbo because of the K&N filter. You could feel the dirt inside the intake.
    No more K&N for me!
  14. markwoodlief

    markwoodlief Long timer

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    im waiting for another foam filter from touratech... i have the K&N in there now, and am waiting to throw it as far as i can away from my bike.. K&N works well in my porsche.. not so well with a bike that gets ridden a lot offroad..
  15. Muddler

    Muddler Long timer

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    Get a Unifilter, the're good in dirty conditions. They do a pre filter too
  16. Niedz

    Niedz Been here awhile

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    why so much hatin' on the K&N? the inside of my airbox is pretty clean.
  17. bigdon

    bigdon Long timer

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    For me a $1000 Turbo caused my hate of the K&N !:evil
  18. Niedz

    Niedz Been here awhile

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    how often did you clean it?

    on my motorcycle i basically make sure to clean it after dirty and dusty rides. since im on the east coast i dont have crazy desert dust on every ride, so maybe thats why it doesnt work for some.
  19. slide

    slide A nation with a future

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    The point is that experience has shown that the K&N lets dust through. It isn't a matter of cleaning. If it needed cleaning, it'd not pass debris but just clog. K&N doesn't clog that easily because it lets a lot of stuff - some of which is pretty big - through.
  20. quota

    quota Been here awhile

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    K&N let a lot of dirt through on my Transalp. A lot of premature wear on that engine :waysad