Loosing front end in corners

[packetninja]

I am a C rider and ride enduros. I have a 2011 KTM 350 sprung and valved for my weight and riding ability/type. After getting the suspension back I worked with an A level rider friend who helped set it up for the rough stuff. I was having trouble in whooped out sections with the bike going all over the place. The bike now tracks striaght through the whoops and rough stuff but my trouble now is turning.

I have read and searched a lot in the forums and I keep reading terms like pushing/washing/knifing/tucking and I am not sure what it is that my bike is doing or what the difference in those are. What I do know is that when I come into a higher speed corner, not tight woods type corners, i sometimes end up on my face faster then I know what happend. If it is a right hand turn its like the bike slips out from under me towards the left and I end up on the ground.

I am loosing minutes in the enduros because of this happening several times during a race. I have read about tripple clamp offsets, Sag, and some mix of front end compression/rebound settings fixing the issue for others.

Anyone have any advice for what I should try? I also find that when coming out of a corner when getting back on the gas my rear end will continue to slide out and sometimes slide right out from under me causing me to crash.

Any help would be great.

[kan3]

Are these flat hard packed corners?

[packetninja]

Flat corners with no berm, sometimes its hard pack sometimes loose powder like dirt. I think I am sitting pretty far forward in the corner but when I do go down it happens so fast its hard to think back to try and figure out exactly what I did wrong or if something with the bike setup would help. I have my front end really soft right now, not sure if having it too soft could cause this problem.

[Stu2]

For the whoops the guy who helped you probly decreased rebound on the forks to allow them to extend fully before the next hit,

you may need to increase (turn in) rebound to help with your problem,

there is always a sacrifice with suspension, i run my rebound slow so i can make turns better/faster, and I ride with my weight over the back on whoops to keep the front light so it does not pack,

[mog]

yours is washing out, normally caused by not enough weight on the front, this can be due to too stiff fork springs, too much rear sag, too fast fork rebound( as stu said) you can pull the forks up more so more is showing above the clamps, soften compression on forks, but first is check the rear sag

Also don't overlook the obvious front Tyre and pressure

[dirtbikeroyal]

First you need to look at your form coming into the corner. Body position is really important. Loading front end and breaking prior to the corner is important . Also sit forward, elbos high, and load the outside peg....the farther forward you sit allows your back tire to reposition itself, and sitting on the gas tank allows your front tire to grab.... Also make sure you have proper air pressure and good tires, remember flat corners are hard.

if that didn't help you can look at fork height in your tripple clamps, but I would start at the basics.....

[packetninja]

Thanks for your responses. I have been running my forks at the second notch (ring) from the top which was stock. I run the tubeliss system and have been using 10 to 12 psi in the front and rear. I have a new mx51 for the front I am going to mount before the next enduro in two weeks.

At times I know I find myself not sitting as far forward as possible and I have a tendancy to brake, then let off then brake again, sometimes too late in the turn which I am sure would cause front end problems as well.

The only thing seperating me from the top 3 in my class right now is the time im loosing in these corner wipeouts. I of course loose time getting back on the bike then I have lost my rhythm and it takes a little while to get myself back in the groove.

Should I be looking at getting closer to 100mm on the sag? I am not sure exactly where its at right now. After I got my suspension back I had a friend quickly test it and it was "close enough" since I did not have a spanner to change the preload at the time.

Edited April 12, 2012 by packetninja

[Spokes391]

I would properly check your sag first, I would bet your sagging to much which is causingyou putting more weight on the rear which is why your front end feels light and washes out, I would play around with sag range from 100-104mm and see which one your most comfortable with. I'm super picky with sag myself and can usually tell when mine is a mm or two off.

[mikerides33]

I am a C rider and ride enduros. I have a 2011 KTM 350 sprung and valved for my weight and riding ability/type. After getting the suspension back I worked with an A level rider friend who helped set it up for the rough stuff. I was having trouble in whooped out sections with the bike going all over the place. The bike now tracks striaght through the whoops and rough stuff but my trouble now is turning.

I have read and searched a lot in the forums and I keep reading terms like pushing/washing/knifing/tucking and I am not sure what it is that my bike is doing or what the difference in those are. What I do know is that when I come into a higher speed corner, not tight woods type corners, i sometimes end up on my face faster then I know what happend. If it is a right hand turn its like the bike slips out from under me towards the left and I end up on the ground.

I am loosing minutes in the enduros because of this happening several times during a race. I have read about tripple clamp offsets, Sag, and some mix of front end compression/rebound settings fixing the issue for others.

Anyone have any advice for what I should try? I also find that when coming out of a corner when getting back on the gas my rear end will continue to slide out and sometimes slide right out from under me causing me to crash.

Any help would be great.

I, like you, struggled for a full season with it. 20.5mm clamps on the front were a revelation. I held out for a year and I would have saved hundreds of dollars in grips if I did it sooner. But in the meantime try a bit more HS compression as the bike is super sensitive to HS when it comes to front end bite. Sounds like you need to go in 1/4 and see how it feels. Also- a Pirelli MXMS 80/100 front tire is the best on this bike for confidence on the front end. I was right where you are now man. ?

[delleetodd]

Not enough sag, forks are too high (should be flush with tripleclamps, only caps above to start) and the MX51 front is horrible. Try Pirelli XCMS for enduro, you will love them. Still not enough? Triple clamps with less offset. Every KTM has the same problems with setup assuming the springs are correct for your weight. You are experiencing the famous KTM tuck and slam lol and you are probably having stability problems as well. You can thank me later.

[_nothing_]

yours is washing out, normally caused by not enough weight on the front, this can be due to too stiff fork springs, too much rear sag, too fast fork rebound( as stu said) you can pull the forks up more so more is showing above the clamps, soften compression on forks, but first is check the rear sag

Also don't overlook the obvious front Tyre and pressure

If the forks are too soft, wont that decrease traction on the front tire?

[grayracer513]

Part of what you're fighting is the fact that you really have too shallow a steering head angle to corner well, a fault shared by every MX or off road bike I can think of. Because of the necessity of being able to properly control the bike at speed over extremely uneven ground, they are all built with steering axis angles around 27 degrees. If you look at flat trackers you find the ones that are built for the purpose are closer to 21-24 degrees, a huge difference. Part of what makes an off road bike corner at all is for the fork to "dive" on entry to the corner, as that effectively reduces the head angle in a dynamic sense. The dive is usually aided by braking and a forward rider position.

The rebound thing is complimentary to the dive. If the forks dives a lot because you brake hard, but then fails to rebound rapidly enough, you may end up with a bike that "tucks in" or turns under itself because the effective head angle is too steep. If the rebound is too quick, the front end will simply push outward in the corner without biting (understeer) because the head angle is too shallow. This can also be because you sat back, or didn't brake hard enough. So, quite a bit depends on how you ride.

Another part of the equation is the very high center of gravity involved with most dirt bikes. This causes the bike to lean less at any given speed in a given corner, which means it has to steer more by turning the steering than by the natural tendency of a leaning wheel to roll around a corner. I find my '06 YZ450 pushes a lot less if I lean it farther than I myself lean, if you understand what I mean.

[packetninja]

Not enough sag, forks are too high (should be flush with tripleclamps, only caps above to start) and the MX51 front is horrible. Try Pirelli XCMS for enduro, you will love them. Still not enough? Triple clamps with less offset. Every KTM has the same problems with setup assuming the springs are correct for your weight. You are experiencing the famous KTM tuck and slam lol and you are probably having stability problems as well. You can thank me later.

Thanks for your responses. By not enough sag you mean I need to increase the preload on the shock? It was my understanding that lowering the forks in the tripple clamp would cause it to track better in high speed but turning would suffer, I guess I have that backwards?

[grayracer513]

By not enough sag you mean I need to increase the preload on the shock? It was my understanding that lowering the forks in the tripple clamp would cause it to track better in high speed but turning would suffer, I guess I have that backwards?

No, you had it right. The advice would be true if your complaint were the that the front end wants to turn itself inward, or climb over the inside edge of ruts. If it's pushing to the outside, you were seeing it correctly.

[packetninja]

The rebound thing is complimentary to the dive. If the forks dives a lot because you brake hard, but then fails to rebound rapidly enough, you may end up with a bike that "tucks in" or turns under itself because the effective head angle is too steep. If the rebound is too quick, the front end will simply push outward in the corner without biting (understeer) because the head angle is too shallow. This can also be because you sat back, or didn't brake hard enough. So, quite a bit depends on how you ride.

Thank you for your responses. I have not been riding very long so excuse my ignorance. Can you explain a little on the difference between tucking in and pushing? Since I would adjust the rebound differently for both situations. I will try to pay more attention to how the bike is reacting in the corners to get a better idea.

[packetninja]

On the subject of tires should I use the XCMH or MXMH front? They only have the MXMH in 19 for my rear wheel, the MCMH rear only comes in 18.

[grayracer513]

Can you explain a little on the difference between tucking in and pushing?

With a bike that pushes, it often simply does exactly that when you try to corner it. If you had it on a concrete pad turning circles faster and faster until one end or the other let go, the front end would go first. This can happen either when entering a turn or as you roll the throttle on to exit, or anywhere in between.

"Tucking under" sometimes causes the front to push, but it depends on the surface, and usually only does that if it tries to climb up the inside of a rut. You probably experienced an example of it while riding a bicycle as a kid, where you took a turn with the bike and the front edge of the tire grabbed at the ground and pulled the steering inward toward the apex of the turn

[delleetodd]

On the subject of tires should I use the XCMH or MXMH front? They only have the MXMH in 19 for my rear wheel, the MCMH rear only comes in 18.

XCMS I was recomending for Enduro.

[delleetodd]

Thanks for your responses. By not enough sag you mean I need to increase the preload on the shock? It was my understanding that lowering the forks in the tripple clamp would cause it to track better in high speed but turning would suffer, I guess I have that backwards?

You need at least 110mm of rider sag and lower your forks flush. Try it out. Grayracer513 is very correct if you are talking about Japanese bikes but the KTMs are different and you need to go the opposite direction to create stability and good turning. Try it out! Less offset on your tripleclamps is icing on the cake but try the free adjustments first. Better yet, try it both ways and you will see.

Edited April 16, 2012 by delleetodd

[packetninja]

You need at least 110mm of rider sag and lower your forks flush. Try it out. Grayracer513 is very correct if you are talking about Japanese bikes but the KTMs are different and you need to go the opposite direction to create stability and good turning. Try it out! Less offset on your tripleclamps is icing on the cake but try the free adjustments first. Better yet, try it both ways and you will see.

Thanks for your response. I am pretty new to all this. Wouldnt lowering the forks in the tripple clamp have the opposite effect of less offset? If I reduced the offset from the stock 22 to 20.5 that would bring the front wheel in closer to the engine. Wouldnt lower the forks extend it out and move the wheel farther away from the engine?