Fork brace stopping forks from working ????

[Spamwood]

I haven't had my bike long, in fact I did 30 odd miles on it today taking the total to 50 miles since my recent purchase. 

 Needless to say I'm still learning all about it.

 Rather worryingly I realised during my ride today that my forks (fully adjustable zx6 items) were not diving under braking (not anti dive) and felt rather hard when compressed with the front brake on when stationary.

My thoughts turned to super thick oil, super hard springs, an inner valve problem etc etc.

Then I considered my Micron fork brace ????? 

Could a fork brace (poorly fitted ?)effectively reduce fork travel by 90% ish ?????

Any thoughts or experiences would be appreciated. 

 

[kja.busa]

Doubtful, unless they were slightly bent.

[jameskat]

Could do, if it splays or pulls the forks together then it will lock the forks up as they travel towards the yokes.

Edited April 11, 2017 by jameskat
still can't spell

[Cobby]

Is it definitely the correct brace for your bike? If the spacing isn't right it could be pulling the forks together causing them to bind

[bluedog59]

It certainly can. A badly fitted brace can easily pull the forks enough to cause problems. Try undo the clamps a little and give it another bounce.  

[Gammaboy]

Yeah, pop the brace off and go for a ride. They can certainly cause binding.

[Spamwood]

Brace is off, loosened bottom yoke and wheel spindle, gave it all a good bounce, still very little travel. Put a cable tie on fork leg, after a good hard bounce when stationary showing about an inch of used travel. Funny thing is though it seems to ride not bad. 

[Cobby]

Adjustable preload wound up to the max??

[bluedog59]

Waaay too much oil ?

[Swiss Toni]

I'd go with too much oil too!  Stick a box under the engine to get the front wheel off the deck. Top nuts off, springs out and check the oil level.  If that's ok, before putting it back together, lift the front wheel to compress the forks and check for 'sticktion'! If restricted travel I'd check the stanchions for truth. If forks free, at this stage I'd fit the brace and tighten to specs. Compress forks again to check movement. If restricted, and you live close to a particularly deep body of water, remove said brace, give generous coat of Red Lead, and try to hit opposite bank with it. Simples!

Edited April 11, 2017 by Swiss Toni

[nlovien]

if the forks are "feeling good" but not travelling as far as desired = hydraulic/ spring versus mechanical - if they are feeling harsh "sticky" = mechanical - fork brace being a potential culprit - and IMO once we moved beyond the days of skinny flexible forks these things are more bling than value - the comment to deep sea them is a good one 

don't pay much attention to static tie wrap testing, as you say - they feel good - go stand her on her nose with the front brake to see where the tie wrap goes, but do check your air gap / oil level 1st or you'll pop the seals

 

 

[maxwin]

When I bought my new front springs I filled the oil to what was recommended and it was way to much, from memory the sheet said 150mm from the top but I now run 300mm (just enough to cover the YSS cartridge) with 34psi of air pressure to get the best performance, I also tried racing without my fork brace this year... not even noticed its gone

[kiwi]

I'd say not fork brace as this is posted in Aircooled and mentioned Zx6 forks, so they've probably been upgraded possibly with new (2 strong) springs or too much oil to compensate for heavier bike, try a search on same bike forums for previously done mod and work out difference between yours and theirs, or take it to a suspension expert to resolve your riddle.

[johnr]

9 hours ago, maxwin said:

When I bought my new front springs I filled the oil to what was recommended and it was way to much, from memory the sheet said 150mm from the top but I now run 300mm (just enough to cover the YSS cartridge) with 34psi of air pressure to get the best performance, I also tried racing without my fork brace this year... not even noticed its gone
 

34psi? isnt that a bit excessive? every air fork ive ever had has only needed pretty low pressure, ive never put more than about 5-10 psi in a set, then again more modern stuff might be running high pressures, so what do i know.........

[maxwin]

@johnr

Provided you don't take the spring beyond it's plastic limit, peak fork pressure will be the same weather pressurised or not.  I use a high pre pressurisation because I run the oil so low, it's the only way I can get a good range of fork movement and no bottoming out with these skinny forks.

I use GSXR1100SD 37mm forks with the anti drive blanked off, and its for a racing application so probably not suitable for the road.

[markfoggy]

Simple static sag will give you a good clue if the spring weight is way too much for the application. Lift the front, wind all the Preload off and drop the bike gently onto the ground, measure the travel. Do the same with the preload wound right in. 

25-30 mm with no preload, 15-20 with all the preload should be about right.

But, everything said above about checking free movement and oil level needs to be right first.