Weird steering problem??

[wence]

Happy new year to you all.
I have had the front forks worked on and the bloke went over the bike checking it.
Among other things he tightened the headstem bearings.
Now I like the steering to be light and be able to move freely.By this I mean , if it is on a stand and I move the bars to the centre I like the bars to drop back to the side.
The forks are better in that I can hit things a little harder and now have a little movement left on compression and rebound.
The problem with it now is that it is really unpredictable in rocks,seems to want to follow and railroad any sort of rut etc and generally feels really unpredictable.
My mate nailed it when he said it feels twitchy but steers slow.
I have mousse tubes front and back and had them before the work was done.I did pull out the front mousse and stuff a bit more in the tube to give the front a little more pressure and this seems to have helped a little but the problem is still there.
I have gone through and reset the axle by doing up axle bolt then tightening
one side and then bouncing front and then tightening up the other side.
I will change the front tyre next as it is fairly old and has seen a season last year.Come to think of it I may have turned the tyre around as it was worn to give me the edges again which may be causing the problem?
I am at my wits end as it feels good but bottoms out a little easy and just won't give me the usual gasser planted feel???
Please help......
Cheers Mark

 

[Jakobi]

That is a bit weird Mark.

Like 2 different symptoms at once. Have you spoke to the tuner regarding this?

A few quick things pop to mind.

You can add more oil to counter the bottoming (particularly if its only in the last half of the stroke). If its blowing throw too quickly you might want to address the valving again or look at spring preload or repsringing.

Slow steering. Was the shock done at the same time? It amazed me the effect the shock can have over the front of the bike, and the ride height at the rears effect on the steering. Also might be hard to recall, but has the tuner put the forks back in the same place in the triples. Have you tried moving these to see how they effect things?

I'm also thinking that it could be the rebound circuit isn't dialled in right. This is where the tuner would have spent most of their time as this is where you were at the end of the range. If its rebounding too fast it'll unsettle in corners. The front won't settle down which means it sits high and won't steer as sharp, and it'll also deflect or push back against ruts and rocks instead. Commonly known to climb out of ruts. If its really too fast you may notice the front end pogo when you land hard or punch into things. Compression doesn't sound too high as you keep saying it bottoms easily.

 

[pscook]

Over-tightened and worn steering bearings can cause issues with tracking. Actually, one or the other can do the same. It's worth it to loosen the stem nut and give that a go, nothing to lose. I know that on my road race bikes when I have the stem bearings too tight I get a "figure-eight" action, where I have to over-correct (and over-correct, and over-correct, and...) and that causes massive issues at low speeds.

Try having the bike on the stand and test the steering. Adjust the nut to get your favored results.

Also, check fork height. Jakobi touched on it, make sure your geometry is where you had it last.

 

[wence]

Thanks Jake,
I have spoken with the tuner who did it and also Terry.
They both said that it sounded like the compression and rebound needed to be wound up, which I have now done.
I know the tuner actually rang Terry regarding these forks, hence why I also spoke to Terry( who has been fantastic by the way).
I have been wondering whether he knew how to refill the oil correctly but I am sure he would know.He did service the shock at the same time and gave the bike back with more preload on the shock( not sure how much but guessing 15-20mm),and he had lowered the triples ie, raised the forks through about 5mm( which I have returned to normal.)

The rebound on the forks was played with and the freebleed (11mm?) shim at the base was removed .I now have a little play on the rebound cct instead of it being wound all the way in.
I did adjust the rebound at the last ride as it was bulldusty and sandy and the front was pushing through everywhere.Went in two clicks and increased compression two clicks also which did help a little.Even after all this the front was still real twitchy and slow to steer ( think slow like the steering damper being turned up).
I am seriously thinking I will send them to Terry and let him do his magic but I want to make sure all other options are taken care of first, hence putting a new tyre on the bike today or tomorrow.

The rear is very plush in rebound and compression almost to the point of being to slow although I set it up going through a whooped out hardpack set of whoops in 3rd and 4th gear on the power and got it so it was tracking nice and felt quite smooth.

My problem is that now sand and rocks give the forks a mind of their own and the slow steering feeling is stressing me out to the point I hate riding the thing.
Cheers Mark

That is a bit weird Mark.

Like 2 different symptoms at once. Have you spoke to the tuner regarding this?

A few quick things pop to mind.

You can add more oil to counter the bottoming (particularly if its only in the last half of the stroke). If its blowing throw too quickly you might want to address the valving again or look at spring preload or repsringing.

Slow steering. Was the shock done at the same time? It amazed me the effect the shock can have over the front of the bike, and the ride height at the rears effect on the steering. Also might be hard to recall, but has the tuner put the forks back in the same place in the triples. Have you tried moving these to see how they effect things?

I'm also thinking that it could be the rebound circuit isn't dialled in right. This is where the tuner would have spent most of their time as this is where you were at the end of the range. If its rebounding too fast it'll unsettle in corners. The front won't settle down which means it sits high and won't steer as sharp, and it'll also deflect or push back against ruts and rocks instead. Commonly known to climb out of ruts. If its really too fast you may notice the front end pogo when you land hard or punch into things. Compression doesn't sound too high as you keep saying it bottoms easily.

 

[wence]

Over-tightened and worn steering bearings can cause issues with tracking. Actually, one or the other can do the same. It's worth it to loosen the stem nut and give that a go, nothing to lose. I know that on my road race bikes when I have the stem bearings too tight I get a "figure-eight" action, where I have to over-correct (and over-correct, and over-correct, and...) and that causes massive issues at low speeds.

Try having the bike on the stand and test the steering. Adjust the nut to get your favored results.

Also, check fork height. Jakobi touched on it, make sure your geometry is where you had it last.

Thank mate,
Have already loosened the nut underneath and then locked the top one back up after tighteneing the top triple again.Have the looseness that I like but it still has a slow( damper like feel) when riding.
Cheers Mark

 

[Jakobi]

Do the bars still roll freely side to side on the stand and the slowness is just when riding? I still think its geometry and balance front to back. If the back end is too soft and squatting/compressing easily and the fork is reboudning too fast what will happen is you'll get a bike that is plush in the back and hooks up really well but doesn't want to steer.

I had a similar thing happen with the TTX setup where when I would get the back end right (like a carpet) the front would push a bit too much. If I reduced the compression on the front to balance it out it would then blow through the stroke, bottom too easily and feel sloppy and nervous on big hits. If I stiffened the front end up to deal with the hits I'd then find the front end pushing and steering slow. When I went to the 888 again it was too stiff, would kick and lift, and would put too much weight onto the forks making them harsh, but the bike steered like a beast again.

I'm looking at adding more oil to the fork to resist bottoming which should allow me to run the clickers out a bit softer to deal with rocks and roots.

Its an art form mate. Something I haven't mastered yet. Did they respring the forks at all?

 

[wence]

No , no respring but I have pulled the headstem bearings out, cleaned them( they were full of crap ), although the bloke reckons he did regrease them, and refiitted.
I have noticed now that with the triple off or just sitting on lose I have the perfect bar tension but when I do up the top lock nut ( the one on top of the triple), the bar gets tight before it is tight enough.
I have just had to come in for tea and I am about to go back out and have a better look now.
Also , I checked the sag settings and the bloke has the rear set at 41mm static and 100rider( minus riding gear).
Seems a bit odd as he was going on about it so much when I went to pick it up I hadn't checked it till now.
Cheers Mark

 

[wence]

Just an update, I went through and found a problem.
The sub mount tower setup has moved slightly upwards( not sure whether he removed this or not), but it was high enough to interfere with the cap that covers the headstem bearings etc.
Anyhow I moved this down 1mm and then tightened the headstem locknut and all good.
This has got to help me with the slow steering thing.
Just got to ride it now and check.
Hopefully one drama out of the way.
Cheers Mark

 

[Jakobi]

Good work Mark! Hope thats a fair chunk of your problems solved. I'm surprised you dropped the whole bike in and not just the forks and shock.

We're riding this Friday if you can make it!

 

[bukwheat]

I had a buddy that bought a used 2007 250 ec. He also had weird tracking when he first got it. When he tracked it down, he found the lower bearing seat in the steering stem was totally wallowed out. He ended up parting out the bike and still made money on the bike.

 

[GMP]

By "slow" steering do you mean in response to rider input, or just physical resistance to turning through the bars?

From all that was said, I have to think that something is screwed up in the valving/assembly. Also, the guy would your shock spring preload to 15 - 20mm? Thats just wrong.

 

[wence]

By "slow" steering do you mean in response to rider input, or just physical resistance to turning through the bars?

From all that was said, I have to think that something is screwed up in the valving/assembly. Also, the guy would your shock spring preload to 15 - 20mm? Thats just wrong.

By slow I mean physical resistance to turning, although I reckon I have that fixed (re above).

What do you think of the sag settings?
I am not sure of the preload but assumed he had it wound up.After checking the sag yesterday and having a static of 41mm , I may be wrong.
I will see how it is now with what I've done and if it is still bad I will loosen the preload and see what it was.

I did notice when I had the headstem apart that the bottom bearing had a little rust therefore preventing it from being removed
Bearing was in good nick though and I cleaned it up and repacked it situ.

Jake, The bloke lives fairly close and was recommended through friends .He said he would rather have the whole bike so that he could see the entire package and try and get it sorted better.

Cheers Mark

 

[Jakobi]

No worries Mark. Also you can disregard most of that stuff was I was talking about as I was working more towards slow steering as a result of geometry and not physical resistance. The same basic logic applies if you find it pushing etc but you already know of all this.

Also, if you loosen the preload you'll end up with even bigger static sag figures. I find it hard to believe with 15-20mm of preload that you'd be able to get a spring to sag that much. I get around 35mm of free sag running 12mm of preload on a 5.4 rate spring.

 

[wence]

Yeh I know mate , I better check it I reckon. Can't be that much,
Cheers Mark