Repowering a KTM 640 Adventure

Discussion in 'Some Assembly Required' started by Z50R, Oct 19, 2017.

  1. Z50R

    Z50R Not lost yet

    Joined:
    May 11, 2009
    Oddometer:
    1,544
    Location:
    Boston Mass.
    The above part is quite generic, to fit it on my bike I fabricated a copper bracket and sweated it onto the manifold side.

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    I turned the old mount off the valve and cut the bracket to fit then installed it on the bike.


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    Roofchop likes this.
  2. Z50R

    Z50R Not lost yet

    Joined:
    May 11, 2009
    Oddometer:
    1,544
    Location:
    Boston Mass.
    I got a private message asking for details on the high fender conversion done prior to the fork swap. Lets discuss it here.

    The 2006 KTM 640 adventure comes from the factory with a dual disk front end and an unsprung fender that hugs the front wheel. This setup works well on the street and in the desert but in muddy terrain the fender will get clogged with mud, prevent the tire from shedding mud, and in extreme cases can lock the front wheel. The obvious solution is to mount a high fender on the bottom of the lower triple-tree clamp. KTM knows this needs to happen and they provide tapped holes for the fender to mount to. Once you decide to go this route, a problem crops up; the brake lines need to be rerouted. KTM sent the brake line down the left leg of the fork to the left caliper where a double banjo bolt allows a second brake line to run between both calipers. The easy answer is to ditch the second caliper and run a single disk. I was not satisfied with this solution and the very first mod I did to my 640 Adventure was converting the single disk high fender back to a dual disk while retaining the high fender.

    Parts needed to pull this off:
    A high fender... any with the same pattern will fit. Mine is KTM part 76508010000
    KTM part 0024060256 25mm M6 Screws to hold the fender on
    Buy 4 of that part!
    KTM part 62508009000 top hat bushings to protect fender from screws
    Buy 4 of that part!
    KTM part 60013012000 A second long length brake hose
    KTM part 60013025100 A second Brake Hose Guide. You need to modify this part by bending the wire into the mirror form it comes in. Use your existing part as a guide.
    KTM part 60013025050 A rubber for the above
    KTM part 59008019000 A lower brake line guide without the second speedometer hole.
    Buy two of that part! You need to cut two mounting holes off one of these and two mounting holes off the one on your bike now so that the left side of the bike still has two line guides and the right now has one. The second part needs all 4 holes cut off and a new one drilled in whats left of the arm. It mounts to a hole next to the key switch under the top triple tree.
    KTM part 0024060106 10mm M6 screw to mount the brake hose guide to the top triple tree clamp.

    Fork guards...
    Hers’s where things get funky. You need new lower fork guards because that was part of the low fender that is being replaced. I am not aware of a set that fits this application out of the box... or, said another way, I couldn’t find a set 6 years ago and haven’t looked too hard since. You need the left guard to accept two lines and the right to accept 1. I couldn’t find such a thing so I made my own. I started with KTM part 7800109420028. Quite a few recommend the guards from a KTM 85 sx but I do not. The 85 sx guards bolt onto these forks without modification but they do not cover the entire chromed area as well. Since these are getting modified elsewhere, it isn’t too much to modify a better part to fit the application. I heated the screw mounts with a Mapp gas torch gently until they were slightly pliable without being gooey. You want to let the heat soak into the center before the outside gets melty so hold the torch way away and heat slowly. When things are just starting to get plastic, screw the guards into the fork and let them cool in place.

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    This is a “6 years later” shot. Basically the center pinched in a bit and the outside tucked in.

    Next, you need a donor fork guard with a two hose mount on it. I used a part that has been superseded by KTM part 7800109420030 but the new one will work just as well. Cut the single line mount off the left guard and weld it on the right one. Cut the double line mount off the donor left guard and weld it on the left guard on the bike. There is a decent amount of info earlier in this thread on how to weld polypropylene but basically, get it molten and mix it together with enough filler that it sticks permanently.

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    Again, these are 6 years old but you get the idea.

    Bolt the fender on using spacers where designed and run long cables down both sides. Last useful tid-bit of information: route the brake lines like this:

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    Note that the one closest to the master cylinder doesn’t change. The one going down the right fork leg is installed backwards so that it’s coil stays out of the way. The speedometer cable should be taped as shown, the wires inside are too delicate for a zip tie.
  3. Scaz0r

    Scaz0r Adventurer

    Joined:
    Jan 22, 2019
    Oddometer:
    40
    Location:
    Germany, Munich
    Awesome! Thank you very much!!
    Z50R likes this.
  4. Roofchop

    Roofchop Hands up mother stickers, this is a f**k up!

    Joined:
    Jan 9, 2016
    Oddometer:
    479
    Location:
    Carool, NSW
    All very awesome, but it's still not finished yet....



    Side stand is too short:D
  5. jfman

    jfman Long timer

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    Mar 10, 2012
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    2,933
    Location:
    Montreal (traveling Americas June '17 to May '18)
    Weird concept but I like the fab work.
  6. Scutty

    Scutty Talent-limited bike builder and rider Supporter

    Joined:
    Jul 19, 2011
    Oddometer:
    707
    Location:
    Sunny Surrey, UK
    Z50R likes this.
  7. Z50R

    Z50R Not lost yet

    Joined:
    May 11, 2009
    Oddometer:
    1,544
    Location:
    Boston Mass.
    It is the ram from an Autococker abused into looking like a three-way
  8. Z50R

    Z50R Not lost yet

    Joined:
    May 11, 2009
    Oddometer:
    1,544
    Location:
    Boston Mass.
    Today I made a tool box mount for the rack.

    I cut the handles off a small (3.5” by 10” by 7”) ammo can and welded two brackets on. One has a pair of hooks to engage the tubes on the rack. The other has a vertical bushing to accept a bicycle quick-release.

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    On the rack I welded a bracket that I drilled a hole in then cut a slot to the hole a bit narrower than the hole’s diameter. There is a second slot serving no purpose other than to reduce weight and play with the mill.

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    The tool box is installed such that the latch to open the can faces the seat. This makes it more difficult for things to accidentally open. The box is installed by inserting the hooks under the front tube on the rack then dropping the quick-release to the left of the bracket, sliding it sideways, and clamping it with the quick release. A top-hat washer prevents the box from sliding out unless the quick-release is really loose, again to prevent “accidental deployments”.

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    And view from a step away.

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