My front fork travel is not smooth

[Joshman]

Here's what I have noticed:

Yesterday I was sitting on my bike in the garage slowly loading the suspension and unloading it by sitting on the seat, and then slowly standing. I noticed that the front forks unload to a certain point then stick. Then after I unload it even more the forks suddenly give and come up to position.

My bike has about 11k on it, and it's a 2007. I had my suspension re-adjusted not too long ago at my last track day.

For about a month now I've noticed that every so often accelerating out of a corner my front tire will quickly give out (slide maybe about 6in to 1ft). I assumed this was due to rider error but lately I've been very careful about my steering inputs and I don't think it's me.

1: What could be causing the forks to stick and is it a problem?

2: Could the sticking be causing the front end sliding I've noticed?

I'm planning on taking it into Dave Moss or Evolution to get it checked out, but any thoughts would be appreciated.

Thanks,
-Josh

 

[Joshman]

I should mention that it's my zx6r street bike that I bought off the factory floor.

 

[Aluisious]

Well if your forks don't extend as the front comes up, and then suddenly squirt out and knock the bike upwards, you can bet that's not going to help your traction.

Major problem, IMO.

 

[Hooli]

If you bought the bike two years ago, I think it's about time to have your forks serviced. Factory fluid isn't the best quality, IMHO.

 

[teclador]

Another vote for getting it looked at as soon as possible. If your front tire should lose enough traction in a lean you're going down.

Have you checked the front fork tube at all? Try to unload the suspension as much as possible (i.e. by holding up the front) and check whether there is any damage (e.g. deep scratches or something) on the tube that might cause it to stick.

 

[Joshman]

I checked the tubes and they look fine. Still nice and shiny with absolutely no scratches.

If it was purely a fluid problem I would think that it wouldn't stick but act bouncy (oil degradation). I was planning on changing the fluid at 14k along with everything else, but it looks like it might happen sooner.

I was thinking, could it possibly be a strange combination or the settings for the forks that are causing it? If the preload was too loose as well as the rebound damping being too high, could I see this problem?

Any quick checks I can do to help pinpoint the problem?

 

[Joshman]

Another vote for getting it looked at as soon as possible. If your front tire should lose enough traction in a lean you're going down.

That's exactly when it looses traction; in a lean when I'm getting on the gas after the apex. It's pretty damn scary.

It doesn't do it all the time mind you. Typically once or twice on the more goaty roads (lower speed).

 

[latrlg's]

I checked the tubes and they look fine. Still nice and shiny with absolutely no scratches.

If it was purely a fluid problem I would think that it wouldn't stick but act bouncy (oil degradation). I was planning on changing the fluid at 14k along with everything else, but it looks like it might happen sooner.

I was thinking, could it possibly be a strange combination or the settings for the forks that are causing it? If the preload was too loose as well as the rebound damping being too high, could I see this problem?

Any quick checks I can do to help pinpoint the problem?

Has your bike fallen over? It could be that the forks are twisted in the triples (not bent just misaligned) which would cause what you have explained...... sticky forks.

 

[Marlowe]

+1 to the comments on fluid. It's possibly your springs as well, but I find the fluid more likely.

That fluid has to flow through various apertures in there...if it's old and sticky, and possibly contaminated (how are your seals?), it won't flow well, which is why they stick for a while and then finally move.

Since you're doing track days, I'd suggest more frequent service intervals for all fluids -- including your forks.

 

[latrlg's]

+1 to the comments on fluid. It's possibly your springs as well, but I find the fluid more likely.

That fluid has to flow through various apertures in there...if it's old and sticky, and possibly contaminated (how are your seals?), it won't flow well, which is why they stick for a while and then finally move.

Since you're doing track days, I'd suggest more frequent service intervals for all fluids -- including your forks.

:rofl

I doubt this is the case trashed fluid shouldn't make the forks sticky.
+1 on the more frequent service

 

[afm199]

If you have the rebound damping screw in all the way it will vastly retard return once compressed. If the oil is cold it will be worse.

 

[Blade56]

Another problem can be the slider bushings inside. Forks (depending on amount and type or riding) should be serviced at a minimum of once a year.

 

[Joshman]

If you have the rebound damping screw in all the way it will vastly retard return once compressed. If the oil is cold it will be worse.

I don't think it's all the way in, but I'll check it. Thanks :thumbup

 

[Joshman]

Another problem can be the slider bushings inside. Forks (depending on amount and type or riding) should be serviced at a minimum of once a year.

Hmm, I'll have to look into that. Pretty much all the miles on the bike were mountain/track miles...mostly mountain though.