<p>Your post got cut off.</p>

 

 

We dyno mountain bike forks upwards of 200ips. Lol



Edit- but yeah low speed compression = cornering forces, braking/accelerating, pedaling/pumping (on a bike)... basically vehicle/rider inputs on smooth ground. You want lots of damper force here to control motion. We consider similar speeds 'low'- up to about 3 ips.

High speed compressions are from hitting stuff or jumping off tall things on your bike. Either way you really don't want the shocks to be generating significantly more forces up here because it will feel harsh and cause loss of tire contact or rider control.

We (Rock Shox) use digressive curves in both compression and rebound.

 

<p>Emilio, are Xidas digressive?</p>

 

Gen1 XIDAs are digressive on compression. I added my own custom digressive rebound pistons.

Gen2 XIDAs are digressive on both compression and rebound.

"progressive" = disproportionately more valving force as damper speed increases (progressive shocks are shitty)
"linear" = valving force rises proportionately with damper speed (linear isn't great, but most low-buck shocks are linear)
"digressive" = disproportionately less valving force as damper speed increases

If you want more force at low speed (good driver input control), and not a lot more force than that at high speed (good road input control without being harsh), you want digressive.

 

<p>That makes sense.</p><p>Are Rovers shocks better than Gen2 Xidas?</p>

 

Rovers shocks are Gen 1 Xidas. Not possible to get the linearity and range with that 40mm piston that we get with the gen 2 46mm piston and greater oil volume. So Andrews shocks are very good, but no, they're not as "good". When he revalved his, gen 2's were still a year and a half away from being released.

 

"better" is way too general of a term to use. I'd say probably, having never driven Gen2s, and only looking at the charts. The adjustment range is a bit better, especially on the soft rebond adjustment side.

Those shocks are either the first or second production set of gen1 XIDAs (I owned both at one point). Purchased and installed in 2011. I had HVT upgrade Rover's shocks 2.5 years ago when the Gen2 XIDA was a fetus in Emilio's mind. Today, you'd be silly to spend the $3k+ duplicating my shocks when you can have a very similar (probably better) part for $1k+ less from Emilio, though.

When HVT rebuilt my shocks, they were probably the best single-adjustable shocks in existence for a Miata. Today, they no longer are. Thus is the life of a race car

 

<p>Cool. Thanks for the info guys. Where do you do most of your suspension research/reading? Books? Other forums?</p>

 

 

Appreciated Sav's post on page 4 re low and high speed. That was helpful.

 

I have Xida Gen 2s on the red car. I think I was the first or second customer to get them.

Car is responsive to inputs. Car soaks up the bumps. Car is fast.

That's dual-digressive in layman's terms.

 

Let's see some undoctored Gen 2 shock dynos
I'll be Dynoing a set next week regardless

 

Those are straight from the Roehrig software. Screen cap cut off the force values so I added them back in manually.

Just for the record, we are not the type of company that publishes false or doctored data. You might be confusing us with some other vendor. Don't really appreciate the insinuation either.

 

I appreciate the fact that there are multiple options for the Miata that allow us to even have these discussions. That being said, RACELANDS RULE.

 

Question for you guys:

The force vs. absolute velocity graphs that greddygalant posted don't have origins at 0 pounds -- they're slightly offset which I "think" is showing some hysteresis from friction. The force vs. absolute velocity graphs that Savington and Emilio posted for the Xidas have their origins at 0 pounds.

I'm a newb looking at these and wonder what the difference is? Is that just a presentation option in the Roehrig software where it is removing hysteresis? Or is there less hysteresis in the Xidas? Or??

 

A lot of times the graph isn't centered at zero because the dyno load cell isn't zeroed before runs.

 

I'm downright puzzled by the MCS plots. The most aggressive setting on those matches about what I set my 441s to when I hitch up the tire trailer and cruise home after an event.

Comparing dyno plots, on the rebound side those almost make the new Fox stuff look like a decent track option...

-Ryan

 

The bottom (i.e. stiffest setting) rebound curve there is all between 70-77% critically damped for a 2350lb car w/ 750lb/in front spring between 0-5IPS. If you're aiming for a baseline/starting point of 65% critical damping at low speeds then they're probably good for most.

I do wonder if they digress at all beyond that or if they're using linear pistons...

 

Might be a silly question. But why is digressive faster than linear?
<br />Or is it just for ride comfort?