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Off-road rear suspension: Linked vs Unlinked

Discussion in 'Moto Club' started by RickD, May 23, 2006.

  1. RickD

    RickD Pro-Open Curry Millennium Member

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    The Japanese bikes have linked suspension which appears to soak up bumps rather well. KTM used to have linked suspension, as I recall but now has gone linkless.

    What are the advantages and disadvantages of both?

    Please describe the handling characteristics of the 450 four-strokes from Honda, Yamaha and KTM.

    Thanks,

    Rick
     
  2. DaisyCutter

    DaisyCutter

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    I'll offer what I believe to be true, though I'm no expert.

    The KTM's are a linkless rear suspension design. Historically, the linkage used by the Jap bikes has offered better progressive rate compression. As of 2005 and especially 2006, the KTM's are described as being "as good as" the Jap bikes. Just like the rear shock, the same applies to the forks... the Japs have the better reputation.

    FWIW, a better rider will out ride a worse rider on any comparable bike. My two toughest competitor buddies both ride 2001 KTM 300 MXCs... and those shouldn't be able to hold a candle to my 2005 KX250. The fact is that the whole linkage/no-linkage controversy is way overrated.

    Arguing which bike has better stock suspension is like arguing which stock Nascar is the fastest. Everyone who can ride worth a damn WILL HAVE THEIR SUSPENSION REVALVED AND RESPRUNG SPECIFICALLY FOR THEIR NEEDS. Even most novice "C" class riders have a custom suspension setup.

    For instance, my suspension is ACME brand. It's been revalved for a very plush initial stroke and susbequently becomes very progressive and stiff toward the end of the stroke. It's also been respring with a higher spring rate, to hold a 190lb rider (I weigh 185 + gear). Unlike a stock KX250 my bike won't deflect on the high speed chop and square edge rocks that I see on the trails... Motocross bikes don't deal with this... they have stiffer initial travel to help with the "big air" landings.

    All my buddies have custom tailored suspension.

    After the necessary upgrades, arguing stock suspension is a moot point... 'cause it ain't near stock anymore. ;)

    Other points about linkless suspension:

    1. KTM riders run bucu more chain slack than Jap riders. Since the lack of linkage changes the distance from countershaft to rear sprocket more as the rear shock compresses. If they don't run enough slack, the rear hub or engine case may break.

    2. Lack of linkage on KTMs means less bearings and linkage to wear out. Removal and installation of the rear shock is easier without the linkage.

    Suspension work is by far the number one modification most people should make to a stock bike... and it's not cheap.




    As far as the 450's are concerned, I dunno. The Honda's and Yams use an aluminum frame... which is pretty cool. The KTM doesn't.

    The KTM's have vastly different ergonomics than the Jap bikes. You feel as if you're sitting higher and are less stable on a KTM. Once you acquire a taste for a particular style (KTM or Jap) the other will feel way different.

    The KTM4-stroke trail bikes have valve adjuster screws, so the frequent valve adjustments are easy. The Jap bikes all have shim under bucket valves, with are more of a PITA to adjust. IIRC the KTM motocross bikes have shim under bucket valves too.

    The KTM engines are powerful. My buddies 300's would run stride for stride with my old 2001 CR500 (yes a CR500) at the dunes and in the straights.

    the odds and ends: The KTM's come with nice nickel plated pipes, hydraulic clutches, and several other nice things you don't get on a Jap bike.

    The Jap bikes are generally cheaper.

    If I were looking for a trail bike, I'd likely choose a KTM. They are highly dominant off road. I was on the path a few months ago, but got an opportunity to buy a factory race bike and chose a latter.

    If I were looking for a motocross bike, I'd steer very clear of the KTMs. The Jap bikes dominate motocross.


    If I just wanted a badass all 'round bike... and nothing else...

    I'd pick the KTM 300 XC: http://www.ama-cycle.org/news/2005/KTMxc/XC.asp

    The 2-stroke that grunts like a 450 down low and pulls like an open class 2-stroke on top... KTM 300!
     

  3. DaisyCutter

    DaisyCutter

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    BTW, Tom at Bernies Cycle in Mesa sells KTM's for MSRP out the door. So unlike every other dealer in town, you don't pay $7000+ for a $6499 bike.

    If you haggle a little, you can get one for a couple hundred below MSRP.

    Tom is usually the only guy working sales there, and he races AMRA B class with myself and many of my buddies. Bernies sponsors part of the AMRA series, and gives freebies to all his KTM racers. Tom always shows up with the orange KTM van at the races.

    Several of my a-hole buddies made $200-300 plus a few tires and other stuff last year, just for riding stupid orange pumpkin bikes. ;)

    IF you want a Jap bike, try Northland motorsports. It's owned by Steve Hengeveld's family (Steve is the long time standing Baja 1000 champion). They are our main series sponsor and are sympathetic to off road enthusiasts. Word on the street is that people are getting really good deals there too. It is in Flagstaff, but there's very few honest dealers in the valley (aside from Bernies).
     
  4. RickD

    RickD Pro-Open Curry Millennium Member

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    Wow. A wealth of knowledge !

    I'm a worser rider who will be doing XC single-track rides. No moto. So it will be a plusher KTM EXC model for me. It has been twenty years since my RM 250 days (I've been XC hang gliding since). The technology of bikes today is phenominal, both engine, suspension and frame. So, I'm starting from scratch.

    I'm a strong 5'9" and 185 (although I can get down to 170 at my leanest). My heart says go 2-stroke (KTM 200, 250 or 300). But my head realizes the realities and I'm very strongly considering 4t as well. While it may be a bit under-powered for my weight and my faded skills, I'd really like an EXC ("enduro") version of the hot 250 SX-F motor (it has to be streetable to connect trails). As well, if the technology in the SX-F motor reaches the 400 EXC and higher, that would be a strong pull for me. And then there is the the approach of electronic fuel injection (EFI) now that Polaris has purchased a share of KTM.

    So, it looks as if KTM doesn't yet make the dream bike I want, but rumor has it that 2007 will be an interesting year for them. I could find myself in good position when I buy.

    My buddy swears by his Yama WR 450F (he bleeds blue), and having ridden it, I can understand why he likes it. A neighbor has a fleet of 5 KTMs in his garage (SX85 ... up through 200 XC and the 250 SX-F). He has invited me to go riding with him, so I'll get a taste of Orange, as well.

    Having spent a good amount of time at KTMTalk.com, I can see that even the die-hard KTMers can't make up their mind which model they like. 2-t, 4-t, 200, 300, 400 EXC, 450, should KTM go linkless, or not, etc. The standard answer is "buy two." I can't do that.

    KTMers there spend an awful lot of time talking about their suspension mods. This means (they say to each other) that "either the KTM requires it or the 50,000 members have a lot of knowledge about it." ;) The readily admit the differences of the jap bike suspensions, but differ as to whether it is good or bad. Most say the KTM is tuneable to wherever one like it, and even the jap bikes get tuned by moderate to serious riders.

    It's a good thing I've given myself plenty of time to decide. $7,000 is a lot of money to spend on the wrong bike.

    Thanks for your insight.

    Rick
     
  5. fnfalman

    fnfalman Chicks Dig It

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  6. DaisyCutter

    DaisyCutter

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    Well Rick, if you're going to be doing recreational singletrack, the KTM 4-strokes are good bikes, and KTM's will have better stock off-road suspension than the Jap motocross bikes on the trail.

    Several people have told me that the 400 EXC is a beautiful combination of power and rideability. People also tell me that they like the 450 and low end grunt of the 525 too.

    I think the only way you'll truly know what you want, is if you get some seat time and try out the bikes you are interested in.

    I'd recommend buying a well used $2000-$3000 bike that is "set-up" for singletrack, Like THIS, or THIS.

    Then hook up with the "guys" for some weekend rides. during the course of a weekend trail ride, you can play the bike swap game and FEEL first hand what you like.

    When the proper choice becomes apparent to you. Sell the used bike (you can't lose much), and get the dream bike.

    You'll also benefit of scratching up a used bike first, instead of a nice new beauty.

    Cool local forums: http://www.southwestdirtrider.com/cgi/yabb/YaBB.cgi

    http://www.arizonatrailtalk.com/cgi/yabb/YaBB.pl
     
  7. Motor-T

    Motor-T Windbag

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    My last dirtbike was an 02' KTM 400SX. The motor in that thing was great! There was plenty of torque there when needed but not so much that it would hurt you. The EXC 400s are generally considered to be the best off road (read not moto-x) thumper on the market.
    I haven't really looked closely at the CRF450Xs or the WR450Fs If you have a chance to ride somebody else's bike try them all. You'll know which one is right for you (KTM) ;) .
     
  8. RickD

    RickD Pro-Open Curry Millennium Member

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    Great advice.

    I've heard good things about the Kaw KDX220.

    Looks expensive :) (and heavy). Too bad I couldn't find the english subtitles for the specs. :)

    I spend some time on the ridingarizona.com forum, but it is not as active as I would like it to be. I'll have to check out your forums as well.

    Thanks, all.

    Rick
     
  9. fnfalman

    fnfalman Chicks Dig It

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    Hmmm...no weight listed for the Aprilia RVX dirt bike. But it's a dirt bike so how heavy can it be?

    But supposedly the rumor is that the 550 model is putting out 70-hp.

    And these things are retailed for around mid to high $8,000. Is that pretty expensive?
     
  10. RickD

    RickD Pro-Open Curry Millennium Member

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    The 450 single 4-stroke "enduros" (for lack of a better term) with e-starters, batteries, lights, etc from KTM, Honda, Yama, and Kawa are all at 250 pounds. That's light compared to a street bike which could be 400 pounds for a small one, but off-road bikers take weight seriously. Many handgunners complain about a few ounces from one gun to the next, or the balance of a gun. Same with dirt bikers.

    Then you have the DR bikes from Suzuki which are around 265 pounds. People tend to shy away from them.

    The 4-strokers are not only heavier than 2-strokes, but their weight is up higher (overhead cam assembly) when compared to the 2-stroke variety (which are more powerful cc-to-cc and pound for pound) and have no valve train high up in the CG. It makes them more "flickable." The same 4-stroke without battery, starter, lights, etc would be twenty or thirty pounds lighter, (10% can't be sniffed at). Check out DaisyCutter's hill climbing videos he linked to. Some of those bikes are in the low 200 pounds. How much weight would you want to pick up on a narrow uphill switchback when you dump your bike and then have to kick start it cause your MX 4-stroker doesn't have e-start?

    If the Italiano bike is both heavier (it likely is since it has the weight of not just one but two cylinders, pistons, and valve train), but since it could also be more powerful, it could lead to a heavy, difficult to control powerful bike. Or they may have struck a deal with the Devil and have found the magic combination. The 450 cc 4-strokes put out around 52(Yam)-59(KTM) HP, so 70 HP would be phenomenal, but that doesn't mean that this bike was designed to be a tight single-track machine. It might be best set up for flat-out hauling down an open desert straight. Of course, the behemoth KTM 540 puts out about 65 HP (still single cylinder), so the difference would be in responsiveness and power band.

    As for the MSRP, $8,000 would be another $1,000 above the Austrian-made KTM, which is already a few hundred above the Japanese bikes. That 90-degree V-twin would be really smooth, however... not just powerful.
     
  11. DaisyCutter

    DaisyCutter

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    At the moto-X track, the 4-stroke 450's are very popular. However, in the enduro/harescrambles arena the 2-stroke is still holding strong. As Rick mentioned, riding 50+ miles in a couple hours, over rough terrain... and 30 lbs makes a big difference.

    Amatuers especially like 2-strokes since the engine rebuilds are so cheap. Modern two-strokes are also very reliable and very easy to start.

    For those of us who have our AMA membership, and receive the free "American Motorcyclist" magazine... The March 2006 issue had a good article titles "Last Stand of the two-stroke". I'll post a scanned copy tommorrow when I get to work.


    BTW, Rick, that KDX220 that I linked to is pretty well set-up for off-road. The steering stabilizer is $400 alone (most people keep the stabilizer when they sell, since it's a big investment). It also has all the handguards, pipe, frame, and other guards. Plus it's street legal.

    I don't know the guy personally. But if I were looking for a good bike to get my skills back on, and establish a good performance baseline... I'd be tempted to check that one out.
     
  12. RickD

    RickD Pro-Open Curry Millennium Member

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    I just logged on and posted to him.

    This is really too fast for my liking (school). But we'll see.

    Rick
     
  13. DaisyCutter

    DaisyCutter

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    Here's the story I promised.

    [​IMG]

    BTW, Rick, I'm not trying to steer you into something that you don't want. My only reasoning for a used bike is that once you start riding a bit, your idea of what you want may change.

    When I got into riding, I only wanted a CR500... so I got a 2001 (the last year they came from the factory). After a couple years, I really started noticing how much of a PITA that dream bike was to ride.

    Your tastes may evolve rapidly in the first few months back in the saddle. ;)
     
  14. RickD

    RickD Pro-Open Curry Millennium Member

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    I don't doubt your wisdom. Others have advised the same.

    He e-mailed me back. I might take a look at it on Monday morning at 99th Ave and CareFree. It's a good deal... the sticking point is how much riding time I can afford myself in the coming months (near zero).

    Rick