Specialized rear shock "Brain" rebuild with pictures & now forks too
- Thread starter link1896
- Start date
link1896
Mr Greenfield
Let's wait till I've safely anodised it before we call it a win. I guess it has to be purple so it's lighter?
link1896
Mr Greenfield
Orings required to rebuild the top adjust brain fork cartridge. N70 are fine
position...............................................................................I.D........C.S
not listed is the main damping rod seal, it is a custom sized shaft seal that looks more like a miniature power steering pump shaft seal then a rod seal.
I'm going to turn up a new two piece seal head for it. If your shaft seal is leaking, your only choice is to make a new seal head or send the cartridge back to Specialized.
position...............................................................................I.D........C.S
| top cap to csu | 26.5 | 1.8 | |
| brain adjuster | 19 | 1.5 | |
| top cap top damping rod | 6 | 1 | |
| rebound adjuster | 2.9 | 1.78 | |
| damping body top and bottom | 16.5 | 2 | |
| brain to inside of IFP body | 20 | 1 | |
| IFP to upper body of brain | 21 | 1.5 | |
| IFP | 17 | 3 | |
| IFP body to existing lower fitting | 21 | 1.5 | |
| IFP chamber bottom to hollow rod | 10 | 1.5 |
not listed is the main damping rod seal, it is a custom sized shaft seal that looks more like a miniature power steering pump shaft seal then a rod seal.
I'm going to turn up a new two piece seal head for it. If your shaft seal is leaking, your only choice is to make a new seal head or send the cartridge back to Specialized.
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I really need this..do you have pict to show?tks
Sent from my SM-G7102 using Tapatalk
link1896
Mr Greenfield
I've sent you a pm, hopefully you get it.
link1896
Mr Greenfield
Specialized rear shock "Brain" rebuild with pictures & now forks too
Tried to turn down a solo air piston rod to connect to the fork cartridge to allow IFP pressure tuning but found the solo air rods taper on the inside till their ID is 7.8mm and I was trying to bring its OD down to 7.7mm for Schrader and
FAIL
Tried to turn down a solo air piston rod to connect to the fork cartridge to allow IFP pressure tuning but found the solo air rods taper on the inside till their ID is 7.8mm and I was trying to bring its OD down to 7.7mm for Schrader and
FAIL
link1896
Mr Greenfield
Specialized rear shock "Brain" rebuild with pictures & now forks too
It's a huge mix of manufacturers. These shenanigans are isolated to Specialized brain technology ( for now )
Latest generation Epic's (2014 till now), use Rockshox forks with Specialized's own brain cartridge. Rear shock is fox. Same inertia valve in both assemblies ( with different shim stack configs) so I'm guessing Specialized is making the custom parts themselves.
Hoses for rear shocks have never changed from what I've seen ( apart from shape at shock end)
In parallel to this project, I have the somewhat dormant Frankenfork project. Just need to finish the brain fork cartridge rebuild first. Plan b might be modifying a cartridge leg rod and adding an external Schrader valve for now, but want to be able to move cartridges between RS Sid and Frankenfork.
It's a huge mix of manufacturers. These shenanigans are isolated to Specialized brain technology ( for now )
Latest generation Epic's (2014 till now), use Rockshox forks with Specialized's own brain cartridge. Rear shock is fox. Same inertia valve in both assemblies ( with different shim stack configs) so I'm guessing Specialized is making the custom parts themselves.
Hoses for rear shocks have never changed from what I've seen ( apart from shape at shock end)
In parallel to this project, I have the somewhat dormant Frankenfork project. Just need to finish the brain fork cartridge rebuild first. Plan b might be modifying a cartridge leg rod and adding an external Schrader valve for now, but want to be able to move cartridges between RS Sid and Frankenfork.
MarioM
Likes Dirt
From what I know in the last two years there was an admit by Specialized , not public , that there was a problem with the forks . All components went back and were all replaced with complete RS hardware .
link1896
Mr Greenfield
Interesting. I did ponder if the reason for such super secret squirrel business was a silent mass Warranty exchange program.
I've had a few PMs from people on the inside, no mention of this.
MarioM
Likes Dirt
Limited to pros .
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link1896
Mr Greenfield
It would be easier getting Moorey to eat red meat then getting commercially confidential info like this from people.
link1896
Mr Greenfield
Specialized rear shock "Brain" rebuild with pictures & now forks too
Fork cartridge needs to be vacuum bled, can't get all the air out doing a hand job.
Turn up a new IFP from delrin ( or anodise aluminium ) and go to a bigger bleed port fitting, I like m4
Or
turn up a male unc no 4 40tpi tiny fitting that will be super delicate for vacuum bleeding.
Fork cartridge needs to be vacuum bled, can't get all the air out doing a hand job.
Turn up a new IFP from delrin ( or anodise aluminium ) and go to a bigger bleed port fitting, I like m4
Or
turn up a male unc no 4 40tpi tiny fitting that will be super delicate for vacuum bleeding.
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link1896
Mr Greenfield
And it's works. Wow locked out forks again. Like the rear, IFP pressure tunes brain threshold.
Easy to get lost with setup.
Err, just a few variables.
Brain cartridge oil viscosity.
Brain IFP pressure
IFP depth
Rebound setting
Brain fade setting
Positive air pressure
Negative air pressure
Easy to get lost with setup.
Err, just a few variables.
Brain cartridge oil viscosity.
Brain IFP pressure
IFP depth
Rebound setting
Brain fade setting
Positive air pressure
Negative air pressure
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