YZ 450 2014 LOOSE FRONT END

[grayracer513]

I tune my own suspension as well as a handful of local riders.

Your understanding of the stock rebound stack is backwards. Rebound increases progressively as return speeds increase.

Imo most likely your oil height is too high and low speed damping too light causing your harshness. Valve it stiffer and run the oil height around 325-330cc.

 

Something to bear in mind when thinking about rebound is that whereas compression force is essentially an unlimited function of the speed of impact, rebound speeds will reach a limit when they balance with rebound damping resistance and spring force.  There will never be any greater force on the rebound stack than the springs can deliver, while the compression force can be increased more or less at will by hitting the obstacle harder. 

[JS264]

You got .51 fork springs Ghill?

[GHILL28]

.50kg, stock 2014 springs, flipped bleed stack, float .2, 335cc

[JS264]

Tighten that float up to .1mm.

I just poked in some DRD engine relocation collars tonight, I'll try to get to the arena in the next few days and see if i notice anything...

[yzUSMCf]

Tighten that float up to .1mm.

I just poked in some DRD engine relocation collars tonight, I'll try to get to the arena in the next few days and see if i notice anything...

I'd like to see what you think. I just got some 2015 motor mounts . Aparently they help a good bit.

[JS264]

I'd like to see what you think. I just got some 2015 motor mounts . Aparently they help a good bit.

I installed the 15 mounts a while back. Small but good improvement.

[yzUSMCf]

I installed the 15 mounts a while back. Small but good improvement.

I'm exited

[rk8950]

Tighten that float up to .1mm.

I just poked in some DRD engine relocation collars tonight, I'll try to get to the arena in the next few days and see if i notice anything...

I put them and the new engine mounts in mine a while back, I could tell a difference.

[Envisage]

I installed the 15 mounts a while back. Small but good improvement.

What difference did you notice ?

 

This on yr 14 model ?

[GHILL28]

I did the same 15 mounts. Seemed to hook better on choppy flat corners.

[GHILL28]

Yeah I'm either going to put the bleed stack back with some reduced bleed, tighten the float, or add another 32 in the base stack I think.

[Envisage]

Right, I have tried that a bit, and have always ended up back at R 8 (gone out to R 12).  The lighter front end on this thing likes a little bit tighter rebound to "stick" in ruts it seems.  The faster rebound made it more nervous over braking and accel chop as well.  Normally on KYB stuff I'm running R 12, but this chassis is different in a lot of ways.

Have to agree there, tried mine at 12, but its too fast. Had it at 8, (rough sand track) felt dull & a bit too slow, think 9 is about right.

 

Like to hear any suggestions on what i need to do the take that harshness out of the stroke ?

[MESSMAKER]

Have to agree there, tried mine at 12, but its too fast. Had it at 8, (rough sand track) felt dull & a bit too slow, think 9 is about right.

 

Like to hear any suggestions on what i need to do the take that harshness out of the stroke ?

 

Whenever my forks started to feel harsh the needed to be bled. I put the motion pro micro bleeders on and it makes it much easier.

 

RM   https://www.rockymountainatvmc.com/p/1049/33926/Motion-Pro-Micro-Fork-Bleeder

[Tiago]

So far i like my setup and feel the front planted on the ground while cornering into ruts and still pretty easy on straights to pull the front to clear bumps at high speed.

Front rebound and compression 8 clicks, 110mm sag and standard rear specs. At hard terrain, the front suspension it bottoms when i overjump the landing on bigger jumps but other than that it feels pretty spot on. My weight with gear is 210lbs.

Clamps 15mm away from top forks. Handlebars mounts on front on clamps and rotated backwards. Almost perfect aligned with the center of the forks. And since i have 6ft of height it has fastway pegs on lowboy position and 0.8inch handlbars mounts height over stock.

I believe that the loose front it has more to do with the rider body position than suspension setup. Since i feel pretty confort and i'm almost straight while riding standup, it is easy to me to sit over the fuel tank while entering into corners, giving load to front end and grip.

Edited February 17, 2015 by Tiago

[GHILL28]

Sounds pretty much my exact setup.  110 sag, forks pulled up to first line, Fastway pegs, forward bars, 6' rider, 185# + whatever gear I'm carrying.

 

The front has a bit of a wobble to it in fast sandwashes.  I'm thinking the bleed stack needs to go back in, with maybe 1 or 2 face shims put in the back in the passive part of the bleed stack.  The weird thing is that when I stand and get over the front with my elbows out, the wobbling is greatly reduced.  This chassis is so strange.  Good, but strange.

 

I don't know that I liked having the forks pulled up in the clamps.  I made that change the last time and it didn't seem to offer the usual better turn-in that I expect when doing that.  It did seem to twist/push more coming into loose corners however.

 

 

JS264, are you still running the bleed stack in your forks?  Have you tried flipping it?

[JS264]

Got a lot of info to add to this thread, keep leaving my computer at work though. Hopefully I'll have a post with something to chew on for tomorrow evening.

[GHILL28]

Got a lot of info to add to this thread, keep leaving my computer at work though. Hopefully I'll have a post with something to chew on for tomorrow evening.

 

JS, still curious to hear your input!

[JS264]

JS, still curious to hear your input!

I know I've been slacking on that. Soon

[GHILL28]

I know I've been slacking on that. Soon

 

Still waiting to hear the input on the valving.  

 

I'm at the point where I'm about to change mine up a bit.  I've got the shock pretty well sorted, now the forks need some attention.  Either tighter float/lighter mid, add the bleed stack back in, or go stiffer on the BV.  The "sting" is what I'm trying to tune out, and my feeling is that something in the valving is hitting a harsh transition somewhere.  On certain high speed impacts it's very nice and smooth and still supportive.  On low speed rollers, it's great.  The occasional square edge at high speeds, hardpack chop and braking bumps, especially on downhills, seems to transmit a LOT to the hands and result in unwanted chassis motion.  I suspect it's just getting down into the harsh part of the stroke.

 

I'm thinking a .15 foat, tapered MV stack with 3x20, clamping on a 10mm, and the bleed stack back in with 1 or 2 face shims removed.  Stock BV otherwise.

 

Very few people go stiffer on these, so I'm curious to see what the results have been.  This is a mix of recreational MX, and fast aggressive offroad.  Rocky, whoopy, fast, dry terrain.

[GHILL28]

Went to .1mm float, tapered mid as described above, no bleed stack, stock BV, 335cc oil.  Really good composure through soft stuff and downhills and braking and holding up against fast steep takeoffs.  Definitely beats me up on the big hardpack square edge chop though.  Our stuff here is a mix of sandy and concrete-style hardpack.

 

Not sure if I want to go to a crossover in the BV?  Smaller clamp shim?  Less face shims?

 

Still can't quite pinpoint where the abrupt mid-stroke and square edge harshness in this fork comes from.  I guess it's gotta be the mega heavy BV stack, but that's also what seems to give it a lot of support.