Shak'n, front end

MudnRocks

Member
Apr 15, 2003
42
0
I ride a KTM 400 EXC and have always noticed the front end seems to be shaky. It's not only that I can feel everything (terrain)it is almost as if the front tire feels kinda flat, it's a wobbly feeling usually at slower speeds. Not a good thing when you get tired. Finally someone else noticed it also, it's not just me (being a newer rider and first KTM total relief). I run M12's usually about 16#'s front. I've taken my front tire off and remounted it. It's not 100% tru but only has a very slight curve when free spinning. My husband says it's very minimal and shouldn't affect the bike's handeling. My forks will need to get their annual service in another couple of months. They aren't twisted, they sit straight. I've checked all my torque specks from handlebars to wheel. Recent additions are steering stabelizer and 18mm offset's (bikes done it with and without). The only thing that I can think of that might be affecting me is that I keep the forks pretty short, raked in, unless I'm in the desert, and I can't remember if I experienced this in the desert.

I appreciate your thoughts and advice.

Kimberly
 
B

biglou

The "raked in" thing would quicken the steering, possibly exascerbating (sp?) the feeling at the grips. The only other thing that comes to mind is worn/loose steering stem? Just throwing some ideas out there.
 

Fark

~SPONSOR~
Aug 12, 2002
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Have a look at the stem bearings and if they are OK, repack and try a tad more torque on the adjusting nut. You want the bars to swing freely but with a little push. After a few tries with that; if the handling still feels shaky, raise the fork tubes in 2mm increments evenly in the clamps.
 

a454elk

Mexicutioner
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Jun 5, 2001
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You mean drop the forks in the clamps, raising them will drop the front end down and cause more shake. And be careful about tightening the steering head too much, it'll wear on the bearings.
Elk
 

jmics19067

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Jan 22, 2002
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I thought if it shakes while braking you want more sag and rebound damping in the back more fork and more compression dampening in the front.To try and keep the front of the bike "chopper " like. If it wanders under throttle you want less sag and more compression dampening in the back, less fork more rebound dampening in the front.To try and keep the front wheel biting. I couldn't tell these things unless they are violent but I have as much finesse as a bull in a china shop when it comes to "feeling" suspension.

As you describe the problem it is only when you putting around? Is it possible that you have put a new chain/different sized sprockets on it so that you had to change the wheel base? runningthe rear wheel adjustment form one extreme to another? Beside that effectively changing your wheel base you should also recheck the sag since you will have more or less leverage on the rear shock. Another thing I would think about is that at 16# of air maybe your front tire is getting worn out enough not to bite the way it used to. the cost is traction to avoid flats.

This is to assume that the chassis of the bike is in decent operational order. double check everything in the back of the also . It may be something pushing not straight ahead but just off center enough that you front end doesn't want to truly go the direction it is pointed.
 

Fark

~SPONSOR~
Aug 12, 2002
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Elk thanks for clarifying, I usually for some reason mix p the idea.
 

MudnRocks

Member
Apr 15, 2003
42
0
OK, my sag is set at a little more than recom. and I think I'll double check my compres. and rebound dampen.. My forks are "up" approx. 2 to 3mm even with 18mm offset triples so maybe I'll double check that also.

I have brand new tires, don't think thats it. I do have new (7months) sprockets and chain. I did go up from a 50 (stock) to a 52 tooth rear sprocket, but the bike has handled like this from day one. I have however changed my compres. front and rear after getting the new chain and sprockets, (maybe?? the way I'm changing it I'm keeping the problem?). My husband did check, repack stem bearings late March 03.

As for being able to really "feel" the suspension, I wish I could say that I'm that good. It just has never felt right and finally after a half a dozen other people have ridden my bike someone said...... exactley what I've felt, been saying all along (sometimes you think it's just you).

I appreciate your suggestions, I'll let you know what's happening (It might be a couple of days or sooo).

Thanks
Kimberly
 

Danman

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Nov 7, 2000
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Have you checked the true on the rim? Loose spokes can make it feel wobbly as well as worn spacers on the axle.
 

a454elk

Mexicutioner
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Jun 5, 2001
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You might want to start from stock settings on your suspension and go from there. Don't try and change too many things at once, you may not figure it out. Go over the same section of track, outdoors, whatever and change the settings slowly. If you chop when you brake, front end, try slowing down the rebound in the front. Set the sag to around 3 inches when sitting on the bike in full gear. If it has handling problems when you jump, that's a different story. Starting from stock may get you started at a good base. You can bring the forks flush to the top of the clamp and tryit that way as well. Good luck
 

Jaybird

Apprentice Goon
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Mar 16, 2001
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Charlestown, IN
I'm like elk and don't like to tighten the steering stem up too tight. But on my KTM 125 I need to have it snugged or headshake-o-rama. Also, my 43mm's hate to be higher than 3mm max over the top of the clamp. 5mm's makes it turn snappy, but shakes like crazy in 4th pinned (very scarey).

After re-reading your post, it sure seems to me like you may be using your fork adjustment as a tool to get the bike to fit you. Don't make that mistake. Forks need to be set properly to function well. Look for other methods to get the bike sized correctly. Seat foam, shock spacer, etc....
 
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MudnRocks

Member
Apr 15, 2003
42
0
I said it might be awhile and I apalogize, it has been. I'm hoping to get into my bike this weekend.

Jaybird, I think you could be right. I might be trying to fit the bike to me. I'm not a short woman, a bit over 5'8". I just really want a snappy or sharp turning bike.

I'll keep y'all posted. Thanks for your patience.

Kimberly
 
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