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RockShox Air Shaft Model Question

MikeD

Leader and Demogogue of the Ridemonkey Satinists
Oct 26, 2001
11,524
1,569
chez moi
K, so I ordered what was supposed to be a 120mm air spring for a 2019 Pike (allegedly; purchased used).

PN 00.4020.552.004 ordered and that's what it says on the package.


16537876559967446129890886530493.jpg


But after installing, I really only get 110mm out of it. Spent a week messing with things; the internet told me I likely clogged the transfer port with grease but no remedies worked, and nothing else was limiting travel.

I checked the air shaft, however, and it is marked "110" on the shaft right above the red foot nut. Unfamiliar with these things...is this actually a 110mm model in the wrong bag? I didn't even know they made 110...or does the red nut extend the effective length of the main shaft?

received_445953407339907.jpeg
 
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Jm_

sled dog's bollocks
Jan 14, 2002
16,638
7,594
AK
Have you attempted to verify that PN on other sites that offer the part? That's what I tend to do with some of the tricky stuff. Occasionally, something isn't adding up, or it's really really confusing, but when you start cross referencing the number more it tends to sort itself out. RS also has some pretty in-depth parts-guides these days. I would assume you could check the PN there too.
 

HardtailHack

used an iron once
Jan 20, 2009
4,985
3,060
Seems there is a 110mm shaft for the 26" DJ Pike.
If you can't work it out the Manitou Mezzer's travel can be adjusted with travel spacers and you can't block the transfer port with grease, hahaha!
 

MikeD

Leader and Demogogue of the Ridemonkey Satinists
Oct 26, 2001
11,524
1,569
chez moi
Have you attempted to verify that PN on other sites that offer the part? That's what I tend to do with some of the tricky stuff. Occasionally, something isn't adding up, or it's really really confusing, but when you start cross referencing the number more it tends to sort itself out. RS also has some pretty in-depth parts-guides these days. I would assume you could check the PN there too.
Yeah, the PN is for a 120mm air spring per the SRAM service guide and multiple sales sites.

Thus, I was confused by the 110 travel and the 110 printed on the shaft...but I figured maybe someone here knew some detail like "yeah models with the red foot nut give 10mm more travel than marked on the shaft" or "that's a model number not a travel number, etc."

Or "yeah, the wrong part was in that bag..."

If this is the right part, what could prevent it from getting full travel?? I have cleaned off grease and tried blowing through everything I can with compressed air, checked the fit of the stanchion and lowers to see if anything was hanging up...

Nothing on the damper side could be causing it, right?
 

Attachments

Jm_

sled dog's bollocks
Jan 14, 2002
16,638
7,594
AK
Seems there is a 110mm shaft for the 26" DJ Pike.
If you can't work it out the Manitou Mezzer's travel can be adjusted with travel spacers and you can't block the transfer port with grease, hahaha!
If it works like my Mastodon, there can still be issues. Hooking up a pump is what equalizes the chambers, except that's when mine sags down and I have to physically pull on the fork while the pump is attached or else it sucks down an inch or more and stays there after disconnecting. Also leaks a bit into the negative when it's real cold and does something similar. Got a seal rebuild kit in the mail just a couple days ago.
 

MikeD

Leader and Demogogue of the Ridemonkey Satinists
Oct 26, 2001
11,524
1,569
chez moi
Hrm. I tried cycling the fork while pumping it up but that didn't help...

I will try pulling up on it specifically.

Thx for the input; much appreciated.
 

Jm_

sled dog's bollocks
Jan 14, 2002
16,638
7,594
AK
I still get suck down on the RS stuff occasionally, it's not a huge deal, but it's about 10mm usually and can be hard to pull apart, you'll hear a little hiss when it does. Instructions for my Secus mention this and specifically state step on the wheel and pull up on the handlebars or fork crown. I've known about this for years though so it's just become second nature.
 

6thElement

Schrodinger's Immigrant
Jul 29, 2008
12,796
9,697
All of my older 27.5 pike air springs always had the stated wheelsize/travel amount on them.

Seems weird for it to have 110 printed on it. With zero air in there I would think you should have ~120mm of stantion showing (as above you might need to pull up to get the last few mm showing).
 

MikeD

Leader and Demogogue of the Ridemonkey Satinists
Oct 26, 2001
11,524
1,569
chez moi
Pulling up doesn't yield any change (again). Transfer port was clean as a whistle.

I installed the air spring but not the lowers, and pumped up to 50 psi, cycling a few times by hand. Amount of air shaft showing was more than 120mm, prob around 130-135. No negative travel except what the rubber bumper provides, which I think is the few mm I'm seeing when the fork is assembled.

But with the lowers added following confirmation of no-fork-down-suckage, this still only shows 110mm of exposed stanchion above the lowers. (Measured from base of seal, even, not even the highest point of the seal.)

I emailed Rockshox about it.

The fork seems really sticky and stiff, too. I kinda just wanna trash it at this point...
 

DaveW

Space Monkey
Jul 2, 2001
10,331
1,911
The bunker at parliament
I half wonder if your fork is actually a 2017 A1/A2 solo air?
wouldn't rule out a bike purchased in 2019 having a 2017 fork (some bikes pre covid could sit around in shops for a year or so)
 

HardtailHack

used an iron once
Jan 20, 2009
4,985
3,060
I half wonder if your fork is actually a 2017 A1/A2 solo air?
wouldn't rule out a bike purchased in 2019 having a 2017 fork (some bikes pre covid could sit around in shops for a year or so)
It was good when they used to cast the date in to the lowers, my first Marzocchi had a leg from 97 and 98 and it was a 99 model.
 

MikeD

Leader and Demogogue of the Ridemonkey Satinists
Oct 26, 2001
11,524
1,569
chez moi
I half wonder if your fork is actually a 2017 A1/A2 solo air?
wouldn't rule out a bike purchased in 2019 having a 2017 fork (some bikes pre covid could sit around in shops for a year or so)
Would that change its ability to accept the air sping I bought?

this was a Pinkbike budget purchase, not on a bike-
 

6thElement

Schrodinger's Immigrant
Jul 29, 2008
12,796
9,697
Serial # on the back of the crown will tell you what exact model of fork it is if in doubt.


When inflating the newer forks you definitely have to do it in stages:
  • inflate some
  • remove pump
  • cycle fork a bunch of times to equalize +/-
  • repeat
  • ???
  • profit

But none of that explains not getting 120mm when the fork has zero air and is fully extended.
 

MikeD

Leader and Demogogue of the Ridemonkey Satinists
Oct 26, 2001
11,524
1,569
chez moi
Damn, dougal spelling it out here-

 

Westy

the teste
Nov 22, 2002
50,084
15,516
Sleazattle
[coolstorybro] when I changed the travel on my Pike it kept sagging an extra 20mm or so into the travel. turns out it was a dog hair on the quad ring was letting air bleed into the negative chamber. [/coolstorybro]
 

MikeD

Leader and Demogogue of the Ridemonkey Satinists
Oct 26, 2001
11,524
1,569
chez moi
I think the "110" may be a model number and not a travel number, as I see reference to 3-digit code numbers for other air shafts that don't correspond to length, such as "090"...and I think this may be an issue of a fork not made for this air spring. Investigation continues.
 

6thElement

Schrodinger's Immigrant
Jul 29, 2008
12,796
9,697
I think the "110" may be a model number and not a travel number, as I see reference to 3-digit code numbers for other air shafts that don't correspond to length, such as "090"...and I think this may be an issue of a fork not made for this air spring. Investigation continues.
Didja check your serial# on the link I gave above?
 

MikeD

Leader and Demogogue of the Ridemonkey Satinists
Oct 26, 2001
11,524
1,569
chez moi
Nope, at work...will check it when I get home. Thx for the link!
 

MikeD

Leader and Demogogue of the Ridemonkey Satinists
Oct 26, 2001
11,524
1,569
chez moi
Hm, under upgrades:


00.4019.931.009
Air Spring Upgrade Kit - DebonAir (Includes DebonAir Assembly, seal head) - PIKE (A1-A2/2014-2017) 120mm-29", 140mm-27.5" 150mm-26"


I guess I got the wrong kit!

Corollary: it is not a 2019 fork? When I look at the info from the site, it gives no model year, but the associated documents are 2014-2017 and 2018 model-specific.

FS-PIKE-RCT3-A2 - 07T64910847 Does the A2 air spring indicate a specific year/range?
 
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6thElement

Schrodinger's Immigrant
Jul 29, 2008
12,796
9,697
Hm, under upgrades:


00.4019.931.009
Air Spring Upgrade Kit - DebonAir (Includes DebonAir Assembly, seal head) - PIKE (A1-A2/2014-2017) 120mm-29", 140mm-27.5" 150mm-26"


I guess I got the wrong kit!

Corollary: it is not a 2019 fork? When I look at the info from the site, it gives no model year, but the associated documents are 2014-2017 and 2018 model-specific.

FS-PIKE-RCT3-A2 - 07T64910847 Does the A2 air spring indicate a specific year/range?
The serial # tells you when it was made on anything SRAM.

WWTY###### - first couple of digits are the week of manufacture, then a T, then the next digit is the year, e.g. a 9 would indicate 2019 (unless it's something really old and 2009), then the rest are the unique identifier.

The A2 refers to the revision # which generally spans across a few years. e.g. A1 was the original release, then A2, then on the Pike I think they changed enough stuff that wasn't backwards compatible and it was B1.
 
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MikeD

Leader and Demogogue of the Ridemonkey Satinists
Oct 26, 2001
11,524
1,569
chez moi
Soooo it's a 2016, then...

Learn something new every day. Thx!!
 

6thElement

Schrodinger's Immigrant
Jul 29, 2008
12,796
9,697
Soooo it's a 2016, then...

Learn something new every day. Thx!!
So unless the seller had updated it, probably an original charger damper, not the newer 2 or 2.1 iteration that a 2019 would have come with (not sure when 2.1 came out).

Sounds like an asshole PB seller.
 

MikeD

Leader and Demogogue of the Ridemonkey Satinists
Oct 26, 2001
11,524
1,569
chez moi
Well it was cheap as shit. Came with the damper he advertised, the three-position HS compression cruddy one. I just don't follow products enough anymore (nor have I ever been a Rockshox guy till now) to notice this detail re: a specific model year range.

Course I think it should be upgraded...if the chassis feels good, and I have no reason to think it wouldn't be as stout as a Lyrik or Yari, right(?), a better damper would be key. The Charger in my Lyrik is great, but my Zeb with the HC97 and luftkappe is amazing.

I kinda like the cheap chassis, a la carte upgrade approach. I DO think the bushings on this seem tight, but I'll do a full service of all the stuff when I put the proper air spring in anyhow.
 
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MikeD

Leader and Demogogue of the Ridemonkey Satinists
Oct 26, 2001
11,524
1,569
chez moi
So unless the seller had updated it, probably an original charger damper, not the newer 2 or 2.1 iteration that a 2019 would have come with (not sure when 2.1 came out).

Sounds like an asshole PB seller.
Dammit, since it's not a Charger 2 I can't upgrade to HC97 like I planned without spending a bunch more.
 

Jm_

sled dog's bollocks
Jan 14, 2002
16,638
7,594
AK
Dammit, since it's not a Charger 2 I can't upgrade to HC97 like I planned without spending a bunch more.
Would you want the HC97 over just modding the charger to work?
 

MikeD

Leader and Demogogue of the Ridemonkey Satinists
Oct 26, 2001
11,524
1,569
chez moi
Don't know anything about them, really...just purchased a Zeb with the HC97 already installed and like it.

Is there a tutorial on Charger mods somewhere?
 

MikeD

Leader and Demogogue of the Ridemonkey Satinists
Oct 26, 2001
11,524
1,569
chez moi
The Zeb is on the full susser and slaying it...this Pike is for my new hardtail...
 

two-one

Chimp
Dec 15, 2013
59
59
Eindhoven, the Netherlands
Charger 1 has a pretty simple shim stack, so if you know what you want to change, it's kind of easy.
I once changed the lockout/pedal adjuster into a HSC adjuster, and that worked pretty neat as well, but for my hardtail/xc purposes, the default configuration with debonair spring upgrade was just fine.
But I'm curious about your modifications (if any)
 

Jm_

sled dog's bollocks
Jan 14, 2002
16,638
7,594
AK
Charger 1 has a pretty simple shim stack, so if you know what you want to change, it's kind of easy.
I once changed the lockout/pedal adjuster into a HSC adjuster, and that worked pretty neat as well, but for my hardtail/xc purposes, the default configuration with debonair spring upgrade was just fine.
But I'm curious about your modifications (if any)
I've looked at a couple outfits for the Charger 2.1, they seem to be unanimous in their approach to lower the mid-valve spring force. Otherwise it's just a couple shims in other places, but the midvalve seems to be a point of contention.
 

6thElement

Schrodinger's Immigrant
Jul 29, 2008
12,796
9,697
I updated my 2014ish Pike to the Debonair and used it with the Charger 1 for 5+ years without too many issues. I did update to a 2.1, but wasn't on that for too long before I upgraded bike.
 

two-one

Chimp
Dec 15, 2013
59
59
Eindhoven, the Netherlands
I've looked at a couple outfits for the Charger 2.1, they seem to be unanimous in their approach to lower the mid-valve spring force. Otherwise it's just a couple shims in other places, but the midvalve seems to be a point of contention.
So I'm extremely sceptical about this analysis. Dougal at emptybeer seems to promote the theory to sell his selfdeveloped 'unharsh' mod.
Push industries actually posted a response to this theory using their dyno to generate graphs showing the midvalve is hardly influencing the compression stroke at all.

Dougal is probably right in a different way. He says charger2 is mostly a design that is easier to produce than charger1. They also improved the basevalve by moving to a 3-port piston, so they can use a simpler lighter shimstack to provide the same damping curve.
For charger2.1 they made everything a bit less sticky with better gliding surfaces, and even lower compression tune.

My theory is that the lower compression tune of C2 and C2.1 is made possible by moving to the improved debonair spring, that generates more midstroke-support.

So if you want to tune your C1, i would make the following suggestion:
  • Change the basevalve shimstack by moving the ringshim&centershim up 2 positions.
  • Remove the preload from the rebound stack (rapid recovery, my a$$) and stiffen that stack a little.
  • Crank the LSC a bit more closed.
 

MikeD

Leader and Demogogue of the Ridemonkey Satinists
Oct 26, 2001
11,524
1,569
chez moi
Seller sent me $50 back for the air spring change and the trouble, so I think all in all I still made out pretty well on a cheap-ass fork chassis I planned to upgrade anyhow.

I've never mucked around with the internals of a damper before...refilled and bled lots of them and serviced lowers is about all. @two-one, how do you differentiate between the different shim stacks? Is there a good tutorial/video you'd recommend? And what's the procedure/source of supply on stiffening the rebound stack...I assume to stiffen I need different/additional shims?