[freeriding]

I have a yt tues 2012, the LR chart is this:

Very progressive, with a low starting LR and a very very low ending LR.
At sag (30%) the LR is ~2.65.

Cane creek proposes for this frame 2.5 turns for HSC, which i find really high.

For reference, santa cruz v10 has this LR chart

at sag (30%) the LR is ~3.45 and cane creek proposes just 1 (one!!!) turn of HSC!!!

I can't find any logic in this.

Now i have 1.5 turn of HSC in my tues, and i find that in heavy sudden hits (big rocks and roots), that the rear suspension is kicking, so that my feet lose momentary the contact with the pedals.

My spring rate is ok, and the rebound settings are ok too. The LSC is also quite low at 10 clicks from supple.

Should i lower the HSC to 0.5-0.75 turn, or do you think it will be too low?

 

[jackalope]

I can't recall how CC provides their base tunes, but it sounds like they might be saying the HSC should be adjusted from fully closed. That would make sense in the case of the V10 anyway.

As for the base tunes themselves , I often deviated a fair bit from them as i tuned the shock to my preference. It's feeling harsh on big hits, I'd definitely back off more HSC.

 

[Happymtb.fr]

I don't know the answer but I would recommend you to find a track or even just a portion of a track where you experience the kicking and then ride it several time with different HSC values and so find out the most fitting.
Kicking can also be caused by a too stiff spring, too much LSC, too much rebound, worn out linkage bearing, too high tire pressure, too much preload or a sticky shock. Make sure you have these under control.

 

[freeriding]

No, 1 turn that cc proposes is from plush... No logic in this, really can't comprehend it!
I believe that with such a progressive LR in the tues and low LR rate in the last 100mm of travel, even if i lower a lot the HSC (~0.25 turns), i won't have a bottom out issue, or a mid support issue.

What do you think?

Kicking can also be caused by a too stiff spring, too much LSC, too much rebound, worn out linkage bearing, too high tire pressure, too much preload or a sticky shock. Make sure you have these under control.

These parameters are well sorted, little to be done with them in order to improve the problem.
I think HSC is the culprit combined with the highly progressive LR of the frame.

 

[jackalope]

No, 1 turn that cc proposes is from plush... No logic in this, really can't comprehend it!
.

That does seem bizarre. Maybe thats also why my settings were pretty different than than the base tune...

 

[SuboptimusPrime]

I think the base tunes are generated by end users in some cases, not necessarily by Cane Creek themselves--I've ended up pretty far away from the base tune in the past. In the past there was a rider forum that was part of the Cane Creek Lounge which had a bunch of user tunes for various bikes on there--I had a few iterations of what worked for me for my old Banshee. Now I can't find the lounge anymore so I wonder if they've taken it down?

How much do you weigh? In the past, I've found that the tune is based on some "normal" weight around 170 pounds. If you are heavier you end up with a stiffer spring and need more damping and if you're on the lighter side you may need less damping compared to the standard tune. I've talked about this with Matt at Guerrilla Gravity who agreed that this was the case (and is much smarter than I).

Regardless, the CCDB has a very wide tuning range (which is a two edged sword) so you should do what works for you and not worry about being on one end of the adjustment. Totally agree with Happymtb.fr that finding one section of trail that you can session and tinker is the best way to find out what will work for you.

 

[Udi]

I'm with the above - there's no guarantee that whoever published that tune is more competent than you at tuning your own bike.

Just keep in mind that HSC is not a position sensitive adjustment so it doesn't specifically pertain to bottoming out, nor support in any particular part of the stroke. It does however affect bump absoption and travel usage in *any* part of the stroke, and as a result, also things like pop off jumps / kicking off lips. There is also always heavy interaction between LSC and HSC adjusters (particularly on these shocks) so keep that in mind when you picture one single thing as being the culprit for your problem - like Happymtb says - even if you think everything else is "well sorted", a) that may not actually be the case, and b) even if it was, after you change one thing - it may no longer be true.

In any case, I'd definitely try less HSC and see, if that's what you suspect the problem is.

 

[Kanye West]

You assume that "bicycle engineers" know what they're doing. You so silly.

To keep the same zeta value for the system, the damping needs to go up or down directly with natural frequency. In other words, you need more rebound, and more compression for a stiffer wheel rate, assuming you're shifting from a balanced rate/damping setup already.


And good luck trying to make sense out of the CC HSC adjuster. You'll find a 1/8th turn range where it will have either no useful damping, or get back to the normal high-hysteresis lag that the poppet has on opening to pass a fuckload of oil - so momentary infinite stiffness. A few good bucks from the rear end and you'll be content with a Fox Vanilla or something.

 

[freeriding]

Another weird thing is that, if you see the LR above and the force chart below, you really wonder how is it possible commencal, norco and specialized to have higher forces in the 80-180mm region... Tues has the most progressive design with lower lr ratio in each wheel travel increment.
Bear in mind that the sag point is almost the same in these bikes (in the graph) - at ~60mm, so there is no need to make a parallel displacement of the force chart.

Any explanation?

 

[Flo33]

Current force characteristic is "calculated" for the rear wheel. It is dependen on the leverage ratio, it's variation over travel and the spring used. I don't know if @Vrock used the same spring in every bike compared in that chart. The Tues at least is pictured with an air spring.
Anyway, the low leverage of the Tues does exactly do this - result in a lower force at the rear wheel necessary to move it a specified amount of travel. But then the high progression of the air spring kicks in, resulting in a steeper curve.

 

[freeriding]

The low leverage ratio demands higher force at the rear wheel necessary to move it a specified amount of travel.

 

[Flo33]

The low leverage ratio demands higher force at the rear wheel necessary to move it a specified amount of travel.

True, I messed that up.

Then I guess it's the air spring.