KTM 625 SXC vs 640 Adventure

Discussion in 'Thumpers' started by BooneDog, Dec 8, 2007.

  1. BooneDog

    BooneDog Been here awhile

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    I have an 2004 street legal SXC, and love it, but am about to start asking it to possibly start doing more street duty, to the point I'm wondering if I should spring for an Adventure (used)

    I know a lot of the differences, and figure I can make them non issues, but don't know if there are any more.

    Vibes are not an issue, at least with my bike.

    Differences I know are tank size, gearing, cush hubb, wind protection. Which I can easily duplicate those things on the SXC. Are there any other differences that would make the SXC not road worthy? Electrical output? Lighting? Carrying capacity? Brakes?

    I have 5 gallon tank on the SXC, so non issue, that's plenty.
    I have a Renazco seat on it, so the things about as comfortable as it can get.
    I can put a shorty fairing on it that would probably offer MORE protection than the Adventure if I want.
    I can change the gearing to be anything I want, and already have 40 and 45 rears, and 14,16,17 front sprockets. Though I've never tried the 40 rear.
    I can get a cush hubb wheelset and have two sets for dedicated dirt and true dual sport/street wheels.

    I would get some SW-Motech racks so I can mount aluminum panniers for when I need them camping, that's the same on both bikes.

    The only thing that concerns me, is the bike seems 'twitchy' on the road at 65 and above. I had a DR650, and riding them back to back was like night and day for cruising. The DR felt planted and stable at speed, the SXC feels like a racebike that is very tall and unstable. When I did that comparison, I was geared for dirt on the SXC, so very high revs. Other than that, I've not ridden road miles except connecting or getting to trails.
    It may also be tire differences.

    What else? Is there an reason I should try to replace the SXC with a true Adventure, or better to Adventurize my SXC? Dirt is still the priority.

    What I'll be doing with it is riding local dirt, real dirt riding, riding hard and falling sometimes. Then I'll be putting in on my bike-hauler and taking it up to Georgia/Carolina's, for some street/dirt combo tours, camping off of it. Sometimes with my 10 year old. Also Cont Divide or TAT type stuff, possibly in 2008, but more likely 2009.

    And I don't want to add any bikes, I'm simplifying things and if anything reducing the number of engines I have to maintain.

    Thanks for your help!
    #1
  2. Para504

    Para504 Spam, Spam, bacon & Spam!

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    Sounds like you have it covered actually. I can't think of anything "meaningful" that the adventure has beyond what you already scoped out.

    As for the the "instability" a couple of thoughts... Is your suspension setup correctly for your weight (front & back)? Have you experimented with the clickers? Did you lower the bike (raise the fork tubes through the triple clamps)? What tires & what are you running for pressure? I'm not positive, but I believe the adventure (older ones did anyway) had 18mm offset clamps, where the others ones had 20mm (quicker turning). However, I switched mine to 20mm, and I think its great on road & off.

    If those are spot-on for you offroad & that's your primary use, then so be it. You could probably tweak them for longer runs on road (especially with luggage); I suspect your current setup could be adjusted for more "stability" at speed. Also, consider a steering damper as a backup plan for a correctly tuned suspension.

    As for gearing, its subjective... I found the stock Adv gearing probably the best jack-of-all-trades if you set it & forget it. I would probably recommend going with a 40 or 42 in the rear and upfront a 15T for trail & 17T for highway - just flip the chain adjuster blocks on the axle with very little final adjustment (or none) between front gear swaps. If you do go with a 17t, you need to trim your metal chain guide around the front sprocket or buy the 17T one (off a Duke model, say '02 or so).

    Good luck!
    #2
  3. snaggleXR650

    snaggleXR650 Been here awhile

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    Other than what you have mentioned, the SXC and the Adventure is basically the same bike. Same frame, same motor, same electrical output. The SXC is just a trimmed down version. The SXC does have the Keihin FCR pumper standard, and a 94db competition pipe, and the High Flow Head which the '03 and newer Adv's should have. The SXC is the highest performance, and lightest 625 LC4 hands down. The best part is the core engine is the same so reliability has not been sacrificed.

    Another difference is the lower oil capacity on the '03-'04 US SXC models. The oil is held only in the crankcase, and not in the frame and crankcase as in SMC, ADV and old LC4E bikes.

    The lower oil capacity is only an issue IF you are one of those people that thinks they should be able to go 3-4-5000 miles before changing the oil. Single cylinder motors live a HARD life compared to twins and inline 4's no matter how much oil your single holds.

    To be honest, the BIGGEST difference between the Adventure and the SXC is in the name, and the artificial price hike that goes along with it. The prices on new and used Adventure models are INSANELY high. People are simply paying for the name. You can buy a newer SXC, often with less miles, and fix it up with big tanks etc... and have a lighter, higher performance bike, with the same capabilities and reliability (and less stuff to break when you drop it) as the Adv and pay ~3/4 the price of what older, higher mileage Adventures go for.
    #3
  4. snaggleXR650

    snaggleXR650 Been here awhile

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    On the stability. I don't see it on my '04 SXC. I've got springs setup for my weight, ~220lbs front and back. Even with the way undersprung stock springs, I could do 80-90mph with no instability problems. More than likely what you are feeling is the unbalanced rims (rim locks) that the DR650 doesn't have. Throw some lead wheel weights on and balance your rims and then see what you have.
    #4
  5. BooneDog

    BooneDog Been here awhile

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    Cool. What you've all said is what I was thinking, I just wanted to be sure their weren't some key differences that I was misssing.

    And no, I've not done anything at this point to work on any instablilty issue, it works great in the dirt, and I've never really tried to use the SXC in any seriuos street manner.

    I really didn't notice it exept the one time I rode the DR and SXC back to back anyway, and if I get a set of different wheels with Cush Hub for more serious street duty(possibly 17's, though I doubt it), then I can really experiment with tires, etc.

    As long as I know I have a bike that can work, then I'm good.

    Thanks!
    #5
  6. 4seven4

    4seven4 >>>>:

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    if you decide to do the 17" route....might have a full motard set up from my fathers sxc.
    #6
  7. BooneDog

    BooneDog Been here awhile

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    Let me know, I'm not 100% sure on the 17's. I'm leaning more toward pure dirt set with aggressive knobs, and still dirtable dual sport set. Not sure I could get 17 tires that would work for mostly street dual sport? Of course, then I'd have wheels for an awesome track day.

    I also don't want any hassles with changing brakes though.
    #7
  8. Para504

    Para504 Spam, Spam, bacon & Spam!

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    ww.supermotojunkie.com is a good place for getting details on this. A lot of guys seem to use the caliper spacer to get around the brake issue. Should probably be fine for "normal" riding. If you're more aggressive (track days, etc.) you may just want to switch to a 4 pot setup & run the same disks on both sets of wheels (then the brakes will act like they do on the new EXC's! one finger, light touch...).

    Anyway, the Pirelli MT60's seem to get good reviews for on-off road motard tires, though they will wear out a lot faster than less grippy tires. http://arizonamoto.com/Merchant2/merchant.mvc?Screen=CTGY&Store_Code=SWMT&Category_Code=MT60-R
    #8
  9. Ned1

    Ned1 Lend Me Yu Choppa

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    The beauty of the SXC is that you already own it, there's less crap hanging off it to break and just as you've done, it can be scaled up into a longer haul bike. A set of 17's is nice to have to keep things interesting, the only bitch I have is the rear wheel re/re but it's not bad once you get the hang of it. And nope, seeing as I'm not a track rat I didn't bother with the brake kit... don't need more part time duty parts sitting in my garage when I've got kids to feed :)

    16k miles on mine............ 16k more to go before I even consider replacing it. :deal
    #9
  10. Para504

    Para504 Spam, Spam, bacon & Spam!

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    Acutally, nevermind about the caliper spacer - I was thinking about coming from an RFS bike, vs LC4. I believe you are already running a 320mm disk & caliper setup. Looks like swap the wheels & go!
    #10
  11. BooneDog

    BooneDog Been here awhile

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    I think its got 260mm disk on there now, at least on front. I'm not 100% sure though, I do know I have to work on them, the lever pulls back to the grip right now.

    I know whatever multi wheel setup I went to, I want the same disks on both wheels (even if I have to go to a larger disk for the dirt wheel), so I don't have to relocate calipers or anything on wheel change.
    #11
  12. BooneDog

    BooneDog Been here awhile

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    SOOOOO..... Next question concerning wheels, any idea what will fit my SXC?

    Will 525 wheels fit? Any particular year, they seem pretty easy to find.
    Any LC4 based will work?
    I'll probably be searching ebay, and classified's, and pick up what I find first that fits, whether it's 17/17 or 18/21. I really think I'd be happier with 18/21's. (as much fun as I know sport rubber on this bike must be)

    Would wheels like this work?
    http://cgi.ebay.com/ebaymotors/KTM-RACING-WHEELS-EXCEL-PRO-SERIES-BLACK-ORANGE-HUBS_W0QQitemZ170175658749QQihZ007QQcategoryZ34284QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

    http://cgi.ebay.com/ebaymotors/KTM-Black-Wheel-set-18-21_W0QQitemZ250194612583QQihZ015QQcategoryZ35624QQssPageNameZWDVWQQrdZ1QQcmdZViewItem
    #12
  13. zugy

    zugy My brother wheeling SXC

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    A lot of good stuff written here. I had both bikes at the same time the 640 ADV is the better bike for stability and crussieness on the street. But if you planning on dropping the bike or are in tight areas I think the SXC is better. I have after market Triples and stabilzer on mine. So road riding is not so bad, just a bit windy without the faring.

    I had custom wheels made for my 04' SXC, All in Gold, HAAN hubs, stainless steel spokes,nips and excel rims in stock size. Really a lot smoother acceleration on the road plus I don't blow off the bolts on the sprocket. I might sell the set with the bigger rotor on the front and stock on back. These wheels just go right on with no spacers. Very Expensive! Good luck having a set made. It took me two months and overseas German help.
    #13
  14. meat popsicle

    meat popsicle Ignostic

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    As I understand it, a larger oil capacity helps keep oil temperatures lower, so the concern is the SXC will run higher oil temperatures than the ADV. While I have not seen any evidence of this presented here it seems to be a reasonable concern.

    I have two suggestions for you, he who wants to use his SXC like an ADV and is worried about it:

    1) Get one of the oil temperature dipsticks from Sommer KTM:
    ÖLTHERMOMETER LC4
    [​IMG]
    that way you can keep track of your actual oil temperatures instead of trying to infer them from coolant temperatures through your temp gauge. I want one for my ADV, but I have failed to get one, for too long... :bluduh

    2) If you find that your SXC's oil temperatures are excessive when ridden like an ADV then you can try to increase your bike's oil capacity and/or oil cooling. I suggest you find a suitable aftermarket oil cooler, which will do both of these things. Here are two threads from the index for you to review:

    http://www.advrider.com/forums/showthread.php?t=169989
    http://www.advrider.com/forums/showthread.php?t=74910

    One thing to note: you must find out your oil's recommended operating temperature range AND consider that with KTM's recommended max operating temperature. You need to know when the oil will begin to breakdown from excessive temperatures and I think you must also be concerned with when the engine will exceed its engineered temp range and begin having problems with thermal expansion of parts (the hotter the engine gets the more metals expand right?).

    For my 03 ADV the following applies (not sure if its the same as your SXC):

    It seems that regardless of what temperatures the LC4 is capable of enduring your radiator cap is designed to vent just shy of 250° F; you could use whatever temp your manual says in this case as a max operating temperature because if your radiator cap blows you won't be going far...

    Someone might post concerns that the oil will still break down faster than usual. Fine, if you are worried too you can check by sending oil samples to a tester such as Blackstone Labs that specializes in testing motorcycle (shared sump) oils. Just send them at intervals like 1500, 3000, 4500, and 6000 miles until you get negative results. Try to ride as you usually do so the results are valid for you. Then you will know for sure what the SXC does to oil when you use it like an ADV.

    Hope that helps. I don' think you should have to sell your SXC for an ADV. Just get a cush drive hub for the rear (I would put one on an SXC anyways) and check into this oil concern and you should be ready to do some long-range adventure touring.

    PS - if you find you need a bit more tank range than the 5gal offers, I'd suggest getting something together like braaap!: http://www.advrider.com/forums/showthread.php?t=151999&highlight=tank
    I would rather have fuel weight spread out more like the rally, which uses rear tanks.
    #14
  15. meat popsicle

    meat popsicle Ignostic

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    Avon Distanzas are one mostly street D/S tyre, but the Metzeler Sahara III (stock on the ADV) are too. Look around, and you will even find full DOT knob sets for 17" tires... :wink:
    #15
  16. zugy

    zugy My brother wheeling SXC

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    I sould have never sold my 640 Adv. :cry That Braaap set up is tight! I love the tanks and bags too.
    #16
  17. Ned1

    Ned1 Lend Me Yu Choppa

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    Good technical slice 'n dice from Meaty on the oil degradation due to temps arising from lesser capacity. I do my fair share of 3-500 mile day rides and rule of thumb is to drop the oil after such a ride. Especially if it involves any crawling along at low speed where motor temp goes sky high when maybe you'd be benfiting from a trials bike :idea:.,,, heh heh, I bought Mr Cob's old trialsin rig for that type of riding and glad I did!

    Careful on the 17" tire selection, especially if you've got the 5" rear rim. I'm on a 5" with MT60's and that's about the limit of fit. You need a 'true to size' 160 to squeeze into the swingarm and have the chain clear the tire. Best bet is to get a 4.5 or 4.25 rear rim to get a rounder profile- I find my 5" flattens out the profile just a shade. Pirelli's run true to size and I think the Conti's run close.

    On wheel fit you can push in any RFS rear wheel. But, with the 43mm fork you have 20mm axles which obviously won't work with the 48mm fork's 26mm axle.


    Anyhoooooooooooooo....
    #17
  18. BooneDog

    BooneDog Been here awhile

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    I like the oil temp gauge idea! I've never seen that. Especially considering the SXC doesn't have a temp guage or fan. ( and I really want to avoid putting on a fan if I can)


    I can sort out the wheels sizes, etc. I know there are adapters for the axle size, and much info on KTMTalk. I suspect I'll end up with some used 18/21's, with street oriented dual sports, but if 17's come my way I'll grab them. A little worried that the 17's would change the geometry in a negative way, but then again, they might be better being a little lower to the ground.


    #18
  19. meat popsicle

    meat popsicle Ignostic

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    No fan eh... Well, that might hurt.

    Why the aversion to fans - fit? If you can't fit the ADV fan and cap maybe the RFS fan and cap will fit. The cap is a tad smaller.

    Do you at least have a temp idiot light on the dash? If not then I am not sure how you will wire in an automatic fan (unless the SXC comes with the same theromstat as the ADV and then you are golden pony-boy). Of course you could always set it up manual.

    I would look into a fan. How does the SXC get on without a fan? :scratch
    #19
  20. BooneDog

    BooneDog Been here awhile

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    You don't sit and idle. :nod No idiot light, no nothing to tell me I'm overheating until it's too late. Remember this was sold as a pure dirtbike, not street legal here.

    Some people add them. I will if I have to, and could wire it to a manual switch, I think the actual Adventure fan does fit, maybe with some tweaking.
    BUT I just don't want to
    a) buy it
    b) have to install it
    c) just prefer not to have anything I don't really need on the bike to clutter things up. I probably won't add one unless it becomes a problem.

    So far I've had no problems, but I do stop the engine if I'm just sitting for more than a minute or two. Oil gauge would give me something to watch just to see how hot things are getting. I've never ridden where I have very high loads and very low speed rock crawling. I never ride where I'm in huge traffic stops for long periods, like a large city.
    #20