Uh Oh!!!!! Stark guys keep an eye on your pivot mount.

[AL_V]

If I were to take a guess extreme pressure to start shipping and ramp production took its toll on QC.

Hope you don't get in trouble for that bit of speculation!

 

[SubSonic]

over the last few months watching Stark riding videos -
noticed a Clanking sound when - Some - Starks landed from larger jumps -
had been wondering what was making clank sound -

my guess is Shock spring is Bottoming out (coil lock ) before Rubber Bumper on shock is engaged -

if this is happening likely it would be on bikes with lighter spring rate -
Lighter springs can have More Coils and will Coil Lock in shorter travel distance

a Fix may be adding aluminum spacer Under rubber bumper so bumper engages Sooner in travel or
getting Longer rubber bumper

I heard clank sound was in 4 or 5 videos -
heard clank on Same bikes over and over -
jumps were big but not huge -

have seen Most Strarks land on similar or Bigger jumps and No Clank sound

 

[rayivers]

I hadn't thought about spring coil-binding, which I agree is the most likely problem - on nearly all the springs I've spec'd (all softer than stock) I had to be real careful to avoid it It seems to me that when the Stark shock hard-bottoms, the swingarm tries to keep moving up and the linkage 'knuckle' rotates with the shock stationary, pulling super-hard on the dogbones & frame mounts.

 

[UKLee]

over the last few months watching Stark riding videos -
noticed a Clanking sound when - Some - Starks landed from larger jumps -
had been wondering what was making clank sound -

my guess is Shock spring is Bottoming out (coil lock ) before Rubber Bumper on shock is engaged -

if this is happening likely it would be on bikes with lighter spring rate -
Lighter springs can have More Coils and will Coil Lock in shorter travel distance

a Fix may be adding aluminum spacer Under rubber bumper so bumper engages Sooner in travel or
getting Longer rubber bumper

I heard clank sound was in 4 or 5 videos -
heard clank on Same bikes over and over -
jumps were big but not huge -

have seen Most Strarks land on similar or Bigger jumps and No Clank sound

You would think KYB supply the springs as well and they would be wise to this.

 

[Redbull]

This is becoming an interesting subject. I went through a phase of not being confident that mountain bike shock coils were rated correctly, so I bought a cheap DECO coil tester. At first I didn't think about coil lock because the coils went far down the body much longer than the shaft. I didn't get it for testing coil lock testing but since I had it around I started testing for lock as a curiosity and it was an eye opener to see that the coils can lock not far from the stroke travel rating. This becomes much more relevant if using too light of a spring while trying to increase set proper sag by winding up the preload and effectively reducing the coil "travel" vs. the stroke travel.

I have always been a fan of as little preload on a coil as possible however it becomes much more of an issue when you are asking your bike/moto to work at two ends of the riding weight spectrum. An MX bike on a track wearing minimum gear vs. enduro/adventure where you are carrying tools, water, tube, food, med kits etc. simply can't be done on the same suspension set up. Riders wanting to do enduro on a Varg are certainly going to select a lighter spring rate to get a much more compliant set up but hopefully on track days aren't going to try and preload the hell out of it to get it to not wallow.

 

[TCMB371]

over the last few months watching Stark riding videos -
noticed a Clanking sound when - Some - Starks landed from larger jumps -
had been wondering what was making clank sound -

my guess is Shock spring is Bottoming out (coil lock ) before Rubber Bumper on shock is engaged -

if this is happening likely it would be on bikes with lighter spring rate -
Lighter springs can have More Coils and will Coil Lock in shorter travel distance

a Fix may be adding aluminum spacer Under rubber bumper so bumper engages Sooner in travel or
getting Longer rubber bumper

I heard clank sound was in 4 or 5 videos -
heard clank on Same bikes over and over -
jumps were big but not huge -

have seen Most Strarks land on similar or Bigger jumps and No Clank sound

I will say that my bike makes that sound, but i describe it more like a creek than a clank. Still not sure what is causing it, but it only happens when landing.

 

[Swank171]

Anyway we can compress the bike and see if it’s hitting the rubber bushing??

I’d like to think these sounds are unfamiliar because we are used to hearing the motor but it doesn’t seem like what you guys are describing is normal..?

Either way maybe Brian can put some rigging like straps or something to bottom the bike out and see what the bottom of the stroke looks like.

I’ve still not gotten a chance to ride one, definitely hope to soon.

 

[standbyu]

Either way maybe Brian can put some rigging like straps or something to bottom the bike out and see what the bottom of the stroke looks like.

remove the spring, measure the wire diameter, multiply by number of coils to get spring length at bind, push the shock shaft to full bottom with spring removed and measure between top and bottom spring seats, compare

 

[Swank171]

I’d prob just bottom it out and record shaft length and stroke. Prob be easier depending on your setup.

 

[rayivers]

remove the spring, measure the wire diameter, multiply by number of coils to get spring length at bind, push the shock shaft to full bottom with spring removed and measure between top and bottom spring seats, compare

Based on my experiences with this exact procedure, a few suggestions in bold that worked better for me in determining custom-spring specs that absolutely will not bind:

remove the spring,
measure the wire diameter,
multiply by number of coils in tenths (i.e., 8.7 turns; I found this difficult to determine exactly on some springs)
to get spring length at bind, push the shock shaft to full bottom with spring removed
measure between top and bottom spring seats,
subtract 1/2 bottoming-bumper length (I beleive this is usually included in 'actual-travel' specs)
compare

 

[SubSonic]

a YZ i just purchased the owner was Way overweight at 5'7 and 325 pounds -
he had spring preload cranked down at least half way down threads on shock -
had to oil threads and turn spring by hand for 10 minutes - it was crazy tight

looking at shock shaft dirt marks the last 45mm were pretty dirty and have not been used un a while
by the looks of it -