Front end washing out

Questions and comments about converting to beefier forks..
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KDXer
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Front end washing out

Post by KDXer »

What do you think would cause the front end to wash out ?? It did it a fair few times under different conditions. I have 12psi in a fairly new tyre (Kenda Millville). It happend a few times in soft sand while cornering and it also happend on asphalt whilst cornering causing a painful spill. I saved a few spills by getting my foot down just in time. My fork settings are 12r and 12c with .38's. Any idea's guy's ?? :mrgreen: :mrgreen:
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Post by IdahoCharley »

Really need some additional information. Your weight for one: In the sand washout were you on the power or off the power - uphill or downhill or flat cornering. Asphalt same questions. Even then it will be a big SWAG.

I'm not familar with the Kenda tire line. Could be part of the problem???

Do you have much experience in the sand? e.g. Generally when ever your turning in sand you should have power on - otherwise the front will knife in. This is different from 'washing out' in my opinion but sometimes terminlogy is not similar. Body position is sand plays a hugh role in bike's line through a corner. weight forward or back depends upon uphill or downhill cornering and speed. Sand density also plays a hugh role - slightly wet sand verses dry silt like sand are ridden slightly differently. Conculsion - can't likely help you with the sandwashouts too many variables.

If your bike washes out on asphalt there are a number of questions also. Where in the corner does it push or washout? Too little fork rebound will have it washing out before the apex of the corner: too little fork spring will have it washing out on the far side of the apex of the corner generally. If your shock rider sag is set too deep your forks will tend to washout in corners assuming the bike is balanced spring wise for your weight. If the rider sag is set to low then the bike tends to stinkbug into corners and pushs the front end.

Bottom Line - Really hard to give you good feedback. I suggest checking the rider sag on the rear shock and then ensuring the back end is balanced suspension wise to the front for your weight. Use the various suspension tuning guides from Race-Tech or MX-Tech for dialing in your clickers front and rear. Then report back how the bike is handling.
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Post by KDXer »

WOW. That's alot I failed to mention. I will check all the settings and see how I go from there. I may have broken my right wrist again so I will have a few weeks or months to repair the damages to bike and me, check the suspension settings and hopefully install RB carb and head. :partyman: Thanks for the pointers IC, you have given me alot to go off. :prayer:
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Post by m0rie »

Good info IC! :supz:
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Post by canyncarvr »

re: Too little fork rebound will have it washing out before the apex of the corner:

Rebound action is indeed what keeps the front planted. You can have 'too little' rebound because you have too much compression.

'Too much' compression can be a number of things...not enough air shock (too high an oil setting), pressure buildup, basic valving, clicker settings for a few.

Sand and asphalt washouts are likely different issues...IC's definition of sand turns is very good. Heck...most everything in sand is cured with 'power ON!!' :wink:

re: may have broken..

May have? Yes??...or no? Get it checked out!

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Post by KDXer »

I am going up tomorrow to have it X-rayed. I am fairly sure I have done something because I physically can not turn a door handle or bend my wrist sideways or back. The pain isn't too bad unless I do any of the above mentioned activities. It just feels like somethings about to dislocate or feels like something isn't quite in place, and I don't mean my brain either. :razz:

Now, I love sand and handle sand very well. I often play in a large sandpit section around 1m deep in sand. It was more in the hard pack stuff with a sandy surface that the front kept trying to lay down. On the asphalt it happend as I came around a right hand off camber sweeping bend. The road was crappy, like, uneven and just like tarred gravel. I was going roughly mid-2nd gear. I dont know if I lost the front end on slippery gravel or whether the arse end came out and threw me off or WHAT. If you can picture going around a right hand sweeper, the front wheel basically understeered (slid) causing the bike to highside me. I must of held on to the bars because the bike went down on the left hand side and slid down the road with me tumbling behind it. It felt like the wheel slid left, causing the bars to fall towards the right but somehow I and bike highsided off to the left... Weird... Thank god for barkbusters. My grip, lever and probably bars would be toast otherwise.

There are so many thing's to check. I will start with the simple things first and take it from there. I really appreciate the response. :supz:
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Post by canyncarvr »

Certainly there are instances when no amount of suspension work, tuning, setting or adjustment is going to keep the couple square inches of tire patch where you want it to be. A hard pack with sand on top is going to be one of those.

How long were you out of commission last time you broke it? This is a repeat for 'ya...right?

Sorry to hear that. Better take care of yourself. There will be no excuses come next May!!!

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Post by KDXer »

I rode the same area a few weeks back with the helcam and it didn't seem to try and wash out as much as Saturday. I DID increase my front tyre pressure from 9psi to 12psi but didn't think that would make this much difference though.

I broke both wrists last good crash I had (Dec03). By August 04 I was basically as good as I was going to get. My scaphoid is now fused so I only have about 75% range of motion when I bend my wrist back. In a way I hope it is broken so they can open it up and fix the scaphoid at the same time. September 04 was eye surgery time so a further 12 month hiatus awaited. :roll:

I'll be ridin' next May alright, you can bet your sweet bippy on that !!! I'll be there in a full body cast, pre moulded to a KDX if I have to. :shock: I will sure be careful the months leading up to May just the same.
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Post by skipro3 »

Why? What's happening in May? Someone let me in on this!!
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Post by KDXer »

Mem-or-re-al Day ?!?!?!? :razz: :lol: What, you haven't been invited yet ?? :blink:
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Post by skipro3 »

Man!! No one ever tells me anything.
BTW, My wife and I just bought new bedroom furniture for our 2 spare bedrooms. You guys are going to be living in the lap of luxury; we spent almost $7K :blink:
I feel violated after that shopping spree.

(Yup, it hurts to sit down now)

Front end washout: Sit further forward on the seat, grip the tank hard with your knees, put LOTS of weight on the outside peg, do most of the braking with the front brake. (Yes, You heard me right, the FRONT brake. It will force the tire harder into the soil.) It's been my experiance that a front end washout occurs when the front end is not in good contact with the earth. What front tire are you running and how worn is it? The only way I can usually tell is to have a brand new one of the same model sitting right next to it. Front tires wear strange; it's hard to see the wear like a rear tire. If you are unsure about the wear on the rear tire, post a photo close-up of the knobs.

****EDIT****
Come to think of it, when I'm riding lots of twistys fast in the woods, it feels like I'm peddling a bicycle, that's how much I am shifting my weight from outside peg to outside peg as I make left, right, left turns.
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Post by quailchaser »

>|<>QBB<
KAY DEE EXER wrote: I DID increase my front tyre pressure from 9psi to 12psi but didn't think that would make this much difference though.
This little tire pressure change can definatly make a difference. If you are use to riding with 9psi (don't your gauges read in metric? :hmm: ) it's definately going to be a tad different running 12psi. Especially on hard pack stuff. I ussually run around 10 psi up front (even in rocks). I definatley can tell the difference in hanlding between 10psi and 13psi.

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Post by canyncarvr »

Tire pressure change:

Don't discount the differences from small pressure changes. One pound makes a difference.

If you have bleeders in your OEM forks, experiment with them: Bleed regularly, set with/without pressure applied to the forks to change the air shock 'size'.

BTW...my USD forks do not build pressure anywhere close to what the OEM forks did. Actually, I've never gotten a h-i-s-s-s out of them. The OEM forks?...all the time!

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Post by m0rie »

>|<>QBB<
canyncarvr wrote: BTW...my USD forks do not build pressure anywhere close to what the OEM forks did. Actually, I've never gotten a h-i-s-s-s out of them. The OEM forks?...all the time!
I wonder why that is? More internal air volume?
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Post by canyncarvr »

Maybe 'cuz they are, after all, upside down. Maybe the bleeders need to be on the bottom....

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...just kidding. :rolleyes:

I have no idea...but it is a fact. Same fluid used in both fork setups. Maybe a matter of fluid whipping/frothing/cavitating in the 'lesser' fork?

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Post by KDXGarage »

I wonder if perhaps greater fork flex would allow more air to enter past the dust and oil seals? That, or canyncarvr bought a pair of eBay special $9.99 with free shipping brand oil seals. :grin: Yeah, porbably the flexing. :grin:
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Post by canyncarvr »

There's an intended gibe in there somewheres....... :hmm:

I ain't never got no special seals from ebay. Mine have come directly off the WalMart shelf!!

:wink:

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Post by jafo »

From my first person experience with washing front ends, I can usuall count on it being about 20% mechanical and 80% rider. I've had my front end wash, so I adjust tire pressure accordingly before I even take a warm up ride. second, I run my forks kinda soft, I like rocks and logs. :blink: My forks are about 8 clicks from bottoming out. Third, I'm by no means a riding expert, but I've found that body position along with how you guide the bike, how you use the throttle and brakes has alot to do with the front end either biting or washing. I use alot more front brake than rear brake on most turns. When it's a moderate turn, I use almost all front brake from 1/4 the way into a turn to just halfway through just to help shift some weight quick onto the front end. Tight turns I like to use a combo of front and rear. I use alittle front into the corner and alot of rear brake to help slide the back tire around and hit the gas. Sometimes if theres nothing close I have to worry about hitting I just use a lite front brake and roll it into the corner and gas it never hitting the back brake. Just depends on the situation. Fourth, some areas you just have to be careful because the terrain is just realy unstable. Different terrain sometimes calls for different technique. I have some areas with sand that is just so totaly different it freaks me out on the first pass, but I adjust the next time through and pick up speed everytime I go back through until I scare myself again. :lol:

Hope this helps. It's all a matter of experimenting and finding what works for you. Obviously, it's not working right now and i don't know your riding experience so don't take the above as being insulting. Sometimes it is mechanical but sometimes it's alittle mental also.

Jon.
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Post by jafo »

Oh, one other thing. They had a neat little article in Trail Rider Magazine, the latest edition I got. It had like some top woods riders and what they do to get through tight woods. One thing kinda stood out to me. They concentrate very hard on what they are doing and whats around them. That may be something you might try. I would help to know how your forks react when cornering and where your body is on the bike, ect. Then go from there. Oh by the way, I know the rear Kenda tires are pretty good for the money but I don't know about the front tires. I put a Shin crap front tire on my bike one time and experienced a similar problem. I went back to the stock Dunlop and got alot of riding experience after and have'nt washed it since.

Jon.
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Post by KDXer »

OK well I'll put it back to 9psi and try that again first. My front tyre is new and my second one so I sorta know it's grip levels. Like I said I didn't do it the week before but that was before the pressure increase. I will try one thing at a time and see where it gets us. It washed out as I was exitting the corner. In retrospect I really should have been able to take that corner faster than I did without washing out. My guess is rider error and possible tyre pressure issues, more the former. :oops:

Test 1. Reduce tyre pressure and re-test...

My wrist feels a bit stronger today so I will wait a few more days and get it X-rayed if the pain doesn't go away. It seems to be getting less sore and more flexible as the days go by. Plus it's been raining cats and dogs and I gotta walk to the doc's. I may just bite the bullet and go tomorrow to be safe. :? :roll:
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