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Front end losing it in corners...

3113 Views 9 Replies 6 Participants Last post by  SMR
Hey all... looking for a little advice...

Riding a 2002 ktm 640 smc
Got Metz M1's on it, 28psi front, 28 psi back
I'm 6', 150lbs.

The suspension is great most the time, but in faster sweepers (fast enough that I wanna put a knee out instead of a foot or just sitting normal) that have some bumps in them the front suspension doesn't seem to absorb the bumps. It feels almost solid and you skip a bit off the bumps and drift across the road some. Little unnerving to say the least... this normal? I'd think not. Is there a point when leaning that the suspenion kinda stops working? THe forces are always going up the forks are they not?

I don't know much about tuning, but any guesses where to start adjusting?
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Andrew-4ce said:
Tires are good. Never managed to get them looking shaggy yet.

Not leaning far enough to touch anything but getting over pretty good.

I could be back on the seat a little bit.

Thanks for the tips... I'll try playing with the compression a bit.

Anyone else, feel free to through your money in the pot.

Hi Andrew,

It is always difficult to know what is best as we do not know what changes you have made to the settings if you have used the bike on the road; you will have made some changes yes?

The general rule about suspension settings is to make a note of your start point. Change one thing at a time and keep notes as you go. Concentrate on one aspect of the track to solve problems.

From what you originally said, I would say BACK OFF the compression unless you have not changed compression settings since riding on the road. If I assume you have brought the bike racing from riding on the road it is normal practice to leave the compression alone and raise the rebound. Picture your bike wheels moving over the surface of the track or road. On the track you are moving faster than on the road so you would hit the same type of bump (not the size but the shape) and move over it much quicker. Imagine your front wheel moving up and down while going over the same shaped bump twice, once slow then once fast. If you increase the compression it will be harder for the wheel to move (compress) as quick as it needs to go over the bump faster when before it was fine. Similarly, it will have to rebound much faster to stay in contact with the track when it comes down the back of the bump while moving faster.

In this situation;

It feels almost solid and you skip a bit off the bumps and drift across the road some.
The wheel has not followed the back of the bump and has lost contact with the surface, so you understeer. Remember also, on a fast sweeper you are leant over so the force of the bump will come from an angle on the fork legs so there will be flex and this causes stiction. This may be the source of your feeling that the compression phase feels solid (unless you had already increased compression), stiction is BAD! Use good oil and grease your seals, check they are ok and that there are no burrs on the fork inners.

The best you know is the best you remember

Good luck :thumbup:
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