more gear please

Discussion in 'Thumpers' started by Loadedagain, Apr 22, 2005.

  1. meat popsicle

    meat popsicle Ignostic

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    1700 miles in a weekend? :huh what's your ass made of?!? :D

    anyways, creeper had a good sounding trick for fork seals: something about packing the shroud? with grease so you have a first line of defense. he will probably wade in here with the details.
    #41
  2. creeper

    creeper Still alive...

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    Asside from getting the Motion Pro bleeder valves, nothin' fancy.

    Pull down the dust seals (after you get the lip down a bit, push into the side firmly with a screwdriver and twist to pull the dust seals... the lip is not reinforced and will just tear)... clean the fork seals by wipping with a business card or piece of 35mm film (I like a nice white business card, so you can see when it comes back clean), clean and pack the dust seals with a medium body waterproof grease (BelRay is good) and reassemble.
    Work the forks a few times and wipe off the excess grease... Mine haven't leaked in going on a year now I think.

    G'night folks :wave
    #42
  3. txrider

    txrider Been here awhile

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    Well it was 3 days and I used an airhawk pad which is all that made it possible, otherwise I would be in a wheelchair.

    I'll have to try that seal trick, I keep seeing somethign called a seal saver that looks like foam pipe insulation or something, are those any good? Seems they might trap dirt and scratch up the fork legs to me.
    #43
  4. meat popsicle

    meat popsicle Ignostic

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    the neoprene fork covers are pretty popular in europe I hear. not sure about here or what are the ups and downs.
    #44
  5. Loadedagain

    Loadedagain making chips

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    so.... does that mean you combine the gear ratios with the primary ratio? for example..

    1) 5th 22-18=1.22:1
    2) primary = 30-81=0.37
    3) an input to 5th of 6000rpm (* 22/18) gives you 7320rpm out...
    4) then input to the primary is 7320rpm (* 30/81) and output to the counter shaft sprocket is 2708 rpm?
    5) take the 2708 rpm and multiply with desired ratio to get wheel rpm.
    6) divide by inches/rev for one wheel rotation... and we've got speed :clap

    the only thing here i don't understand is the primary ratio. is that on the output shaft of the transmission? it applies to all gears then.?
    #45
  6. txrider

    txrider Been here awhile

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    Well lets get this figured out as I'm going to be open for this pretty soon now. I've got the 625 SXC now and just ordered up all the DS parts for it so it'll be my main DS ride in about 3 weeks. :)

    I'm about to pull the front end off the '96 RXC and change forks, add a fork brace, custom offset triple clamp and a scott's damper. Then I'll be ready to pull the engine and try this gear thing and replace the roller bearing while I'm at it.

    I'll post up my gear ratios etc. and see what you guys think would be the best way to go both for narrowing my 1st to 2nd gap and making 5th a bit taller.

    What LC4 has the tallest 5th gear btw? I would assume a Duke model but could easily be wrong.
    #46
  7. BlitzBike

    BlitzBike LC4 Pilot

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    Yes, the Duke supposedly does have the tallest 5th according to another thread I read somewhere.
    #47
  8. Loadedagain

    Loadedagain making chips

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    all information and manuals i can find indicate the duke has the same 22-18 5th gear as all other lc4 engines.

    the change is in their final drive ratio (sprockets) which are 17-38 (2003) compared to 16-40 on the sxc (2003) and 16-42 on the 640 (2003).
    #48
  9. Loadedagain

    Loadedagain making chips

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    i'm doing up an excel spreadsheet for the hell of it... kinda like maxpowers, but lc4 specific... anything else you guys would like to see on it?

    does anyone even want this?

    yeah yeah... i know it's metric... i'll do an imperial one too :rolleyes

    this is for the stock saharas for those of you who don't have excel:

    [​IMG]
    #49
  10. Loadedagain

    Loadedagain making chips

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    #50
  11. meat popsicle

    meat popsicle Ignostic

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    good job Loaded!

    now, um, what do we do with it? change the sproket sizes and see what happens to the speeds? change the tranny cogs and... ah. Gotcha! :D
    #51
  12. potatoho

    potatoho Cheese and Rice!

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    [font=Verdana, Arial, Helvetica, sans-serif]I looked through the fiche and couldn't find a Duke that used that 583.33.008.006 [/font]"[font=Verdana, Arial, Helvetica, sans-serif]GEAR 5TH M/S 27T"[/font][font=Verdana, Arial, Helvetica, sans-serif], but who knows. Did you ever get more information from steelhead on that thread?
    [/font]
    http://ktmtalk.com/index.php?showtopic=107044&hl=5th
    #52
  13. Loadedagain

    Loadedagain making chips

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    nope... nothin, but i gave it a bump anyway.
    #53
  14. Loadedagain

    Loadedagain making chips

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    what can i say? i'm an engineer.. we're wierd ass spread sheet lovin homos :dunno
    #54
  15. txrider

    txrider Been here awhile

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    Ok here is what I've found/figured out so far.

    My owners manual shows this...

    Primary ratio 30:81

    1st 14:35
    2nd 16:24
    3rd 18:21
    4th 20:19
    5th 22:18

    I read that they changed the 2nd gear in 97 or 98 and the fiche shows a #56533010300 for a 15 tooth mainshaft. That would close the first to second gear ratio that me and others didn't like on the '96 RXC. Looks like most LC4's after 96 use this gear.

    1st 14:35
    2nd 15:24
    3rd 18:21
    4th 20:19
    5th 22:18

    The '95 shows a 15t first and a 16t second, would make a closer ratio overall without a gap from second to third I would have with a 14t first and a 15t second. They called the '96 a "wide" transmission. using a '95 first gear would give..

    1st 15:35
    2nd 16:24
    3rd 18:21
    4th 20:19
    5th 22:18

    I think that might be the best bet but I am not so up on the math to convert that to RPM and speed.

    So what do you engineer geeks think?

    Use a 15 first for close ratio and add the 27t fifth for overdrive?

    Or leave the 14t first, go to a 15t second and a 27t fifth for ultimate wide ratio tranny with overdrive??

    I have a 3 day ride in Wyoming June 10th, after that I'm free to go for it. I want to close up the first/second gear gap, have since the first single track I rode it on. If the fifth will fit I'll do it as well.
    #55
  16. txrider

    txrider Been here awhile

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    I have a 40 tooth rear on now, and I have a 14 tooth counter sprocket in the garage... Does this look insane??

    [​IMG]
    #56
  17. Loadedagain

    Loadedagain making chips

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    insane? define insane... i've got a 16, 17, 38, 40, and 45 on order... should be here tomorrow. i will get the perfect combo figured... i promise.

    chains? well.... that's another story... i figure i can get all ratios combined into two or three chains. two of those coming too :D
    #57
  18. txrider

    txrider Been here awhile

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    Well I've got a 48 and 52 tooth in the garage as well, I ran a 16/48 for a while but went back to a 16/40 for highways swapping out to a 15/40 for dirt.


    So does that chart look like a the perfect LC4 gearset?
    #58
  19. Loadedagain

    Loadedagain making chips

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    define perfect.

    i've got a dirtbike for dirt, so my 640's ideal gearing is ideally suited to 80 mph at a reasonable rpm... for road use. your gearing may be different.

    for my 640's dirt wheels i have a 48 tooth sprocket that i ordered for my old exc and seems to work all right. if i ever use it in the dirt for long periods of time i'll prolly play with those sprockets.

    for now i'm playing gear boy... arch set me on this course... it's all his fault. if i find the holy grail i will never tell.
    #59
  20. GODSPEED

    GODSPEED finger lickin' good

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    I am planning on running a 16/44 and swapping out for a 17/44 for highway use. These combos are just above and below stock gearing.

    I want me one of those fancy STEALTH sprockets and the smallest they make is 44T.
    #60