Mountain Bike Reviews Forum banner
1 - 20 of 20 Posts

·
Registered
Joined
·
250 Posts
Discussion Starter · #1 ·
The rear shock on my 2019 S-Works Epic has started making a "squishy squishy" noise when quickly compressing.

Is there anything I can/should do (as the owner) to quiet it down? Some kind of air sleeve service? Or is this something only the shop can do? I am comfortable doing this, as long as I have the right tools. I have done the air sleeve service on my 2011 Epic, but that has a Fox shock. My 2019 is RockShox, and I'm not even sure what model it is. It only says "RockShox Specialized" on the shock body.
 

·
Registered
Joined
·
5,819 Posts
When mind did that it was sign that the brain had failed to lock out. That was squishy noise when pedaling on flat ground. It will do this brain full firm or fully soft. While I have had poor brain-shock reliability, I have had great support from my shop. I have had 2 brain shocks fail in this way. Both were replaced under warranty.
 

·
Registered
Joined
·
250 Posts
Discussion Starter · #3 ·
As far as I can tell, it is only making the noise when the shock is compressing from a hit, i.e. the brain is holding it locked out on smooth trail. I'll double-check tonight though, but I don't think it is brain-related; rather it's shock-related. I am wondering if I just need to replace the oil and regrease the seals.
 

·
Registered
Joined
·
5,819 Posts
As far as I can tell, it is only making the noise when the shock is compressing from a hit, i.e. the brain is holding it locked out on smooth trail. I'll double-check tonight though, but I don't think it is brain-related; rather it's shock-related. I am wondering if I just need to replace the oil and regrease the seals.
Since yours is a 2019 I doubt you have enough miles/hours on it to need a service.

When my brain failed (Both times) it was not in the brain unit it back, but in the shock. What I determined was the "lock out" feature in the shock was not holding. I believe the brain mass was doing its thing properly, but in the shock there is fluid from the brain system that is supposed to lock out the the shock. That interface failed and as a result the shock never locked out. I could hear squishing every time I pedaled and could see the linkage moving. I believe that sound was evidence of some seal leakage. Now shops don't have any parts so can't do anything other than swap assemblies. My shop has had enough of these fail to be able to swap a brain-shock assembly in 15 minutes and happens to have a couple in stock just for issues like this. They asked Specialized for them due to constant demand and faster turns. Mine failed for 2nd time just 2 days before I was headed to Breckenridge for the Breck Epic and my shop had me turned around in 20 minutes. This is infact my 4th Brain-shock I have had on this bike. Mine is Feb 2018 build and with in 250 miles the shock failed to hold air. So pressure would bleed down during a ride. That one was replaced in May 2018 with an "Updated" version. That lasted for about 11 months before the brain failed in a race. Still finished the race as a brain failure is not ride ending, but it does reduce pedaling efficiency. It was replaced with a 2019 Brain-shock unit. That one lasted about 300 miles before it failed also. So now I have my 4th brain unit. It worked flawlessly at Breck Epic and for a couple rides before and after. I sure hope this one will last as when it works it is great. I don't get any noise from my shock, but there is very common slight "clunk" you feel when the brain mass tells the shock to open. Of course only notice on smooth trails with occasional bump. The harder I ride the less I even notice that light "clunk".
 

·
Registered
Joined
·
250 Posts
Discussion Starter · #5 ·
Boy, I sure hope it's not brain or shock failure -- I am racing the SM100 this weekend. But the "service interval" for Rockshox is 50 hours, and I've definitely got more than that on it. As of today it's got 760 miles on it.

I'll take a closer look at it. On my ride yesterday evening it seemed like the brain was holding as normal. But whenever it took a hit I got the "squish" noise as the shock compressed. I was able to recreate it rolling around in the parking lot and bouncing up and down after the ride. (I opened up the brain to test that out.) So I just figured the seals are drying out. I am going to try to open up the shock to see if they can be regreased -- hopefully that doesn't lead to another big can of worms.

Thanks for the insights.
 

·
Registered
Joined
·
5,819 Posts
Boy, I sure hope it's not brain or shock failure -- I am racing the SM100 this weekend. But the "service interval" for Rockshox is 50 hours, and I've definitely got more than that on it. As of today it's got 760 miles on it.

I'll take a closer look at it. On my ride yesterday evening it seemed like the brain was holding as normal. But whenever it took a hit I got the "squish" noise as the shock compressed. I was able to recreate it rolling around in the parking lot and bouncing up and down after the ride. (I opened up the brain to test that out.) So I just figured the seals are drying out. I am going to try to open up the shock to see if they can be regreased -- hopefully that doesn't lead to another big can of worms.

Thanks for the insights.
Don't open the shock. Only bad things will result. If you try to open it you will not be under warranty anymore and doubt you can make anything better by doing so. If it just noise and you have SM100 this weekend just ride it as it. If it is not working after then take it into your shop. I did 45 miles of Whiskey 50 with a failed brain. Not ideal, but worked just the same.

BTW... published interval for maintenance is 200 hrs for rear shock brain not 50.
 

·
Registered
Joined
·
250 Posts
Discussion Starter · #7 ·
Don't open the shock. Only bad things will result. If you try to open it you will not be under warranty anymore and doubt you can make anything better by doing so. If it just noise and you have SM100 this weekend just ride it as it. If it is not working after then take it into your shop. I did 45 miles of Whiskey 50 with a failed brain. Not ideal, but worked just the same.
Probably wise advice! I was watching the Rockshox official service video on YouTube last night and they make it look relatively straightforward -- but that was without the brain obviously.

BTW... published interval for maintenance is 200 hrs for rear shock brain not 50.
Here's the service interval chart for Rockshox. I just assumed the Epic's shock is one of those listed in the 50-hour column. But again -- there's no model name on the Epic rear shock so I really have no idea. But it seems like most require air can service at 50 hours.
 

·
Registered
Joined
·
250 Posts
Discussion Starter · #8 ·
So I checked it out last night and it seems like my brain is still holding. When I open up the brain and bounce around, I get the squishing noise coming from the shock. I can feel the shock getting warm to the touch also. So I'm thinking it's probably just dry seals?

I was watching this video from another post where the head engineer for Specialized suspension was discussing how they intentionally made the shock easy to do the air sleeve service, so that dealers or even owners can do this. He mentions this at 43:13 in the video.
 

·
Registered
Joined
·
250 Posts
Discussion Starter · #9 ·
So against my better judgement I went ahead and removed the shock to try to perform an air sleeve service. I was able to remove the shock from the bike without much trouble.
Stationery Writing implement Office supplies Pen Paper


I unscrewed the air sleeve from the top piece, but for the life of me, I can't figure out how to get the top off of the shaft in order to remove the sleeve.
Finger Carmine Stationery Nail Tool


Carmine Bottle Bird Nail Beak

(I have no idea why those two images are rotated, or how to rotate them 90 degrees so they show the same as they do on my phone.)

From this picture that I found on bikerumor.com, it looks like it's threaded on.
Product Cylinder Transmission part Suspension part Silver


But the center shaft spins when I try to twist off the cap, unless I have some way to hold that shaft stationary. I thought of using vise grips, but I don't want to muck up the shaft.

In the end, I put a squirt of shock oil in the body and put it back together. It didn't silence the squish noise. So after the SM100 this weekend I guess I'll take it to the shop.
 

·
Registered
Joined
·
246 Posts
A special tool is required to service the air can on MY18 and newer Epic shocks. Specialized is not making that tool available to dealers. Specialized services the air can as part of the major service that is recommended every 200 hours.
 

·
Registered
Joined
·
9,754 Posts
If the shock makes excessive squishy noises, that usually means there is air in the damper fluid where it doesn't belong, in which case it's time for an major service. These new brain shocks use a pressurized bladder to instead of an IFP. It may be the bladder lost pressure allowing air into the damper fluid or cavitation to occur.

When the shock compresses it forces fluid through the brain passage and compresses the bladder. If the brain passage is blocked by the brass mass, it prevents the fluid flow and prevents the shock from compressing. Hitting a bump moves the brass mass opening the passage allowing the shock to compress. (actually, the brass mass stays put and brain housing move relative to it opening the passage).
 

·
Registered
Joined
·
250 Posts
Discussion Starter · #12 ·
A special tool is required to service the air can on MY18 and newer Epic shocks. Specialized is not making that tool available to dealers. Specialized services the air can as part of the major service that is recommended every 200 hours.
If that's true, it contradicts what the guy in the video (Mike McAndrews, head of suspension at Specialized) I posted above explains. He specifically mentions how easy it is to service the air sleeve, and they designed it that way so it can be done at the dealer level, or "even some of the savvy consumers can do it as well."

Also, that picture of the exploded view of the shock is from a Bikerumor.com article that states: "Another nice update is the improved serviceability. Because the oil and IFP are contained inside the BRAIN unit, the air canister can be easily removed with common shop tools and cleaned, lubed and inspected, then right back on the bike in about 10 minutes." Somehow they got it apart to take that picture.

Nonetheless, I couldn't figure it out so it's going to the shop.
 

·
Registered
Joined
·
250 Posts
Discussion Starter · #13 ·
If the shock makes excessive squishy noises, that usually means there is air in the damper fluid where it doesn't belong, in which case it's time for an major service. These new brain shocks use a pressurized bladder to instead of an IFP. It may be the bladder lost pressure allowing air into the damper fluid or cavitation to occur.

When the shock compresses it forces fluid through the brain passage and compresses the bladder. If the brain passage is blocked by the brass mass, it prevents the fluid flow and prevents the shock from compressing. Hitting a bump moves the brass mass opening the passage allowing the shock to compress. (actually, the brass mass stays put and brain housing move relative to it opening the passage).
Yep, agreed, probably time to hand it over to the professionals.
 

·
Registered
Joined
·
246 Posts
If that's true, it contradicts what the guy in the video (Mike McAndrews, head of suspension at Specialized) I posted above explains. He specifically mentions how easy it is to service the air sleeve, and they designed it that way so it can be done at the dealer level, or "even some of the savvy consumers can do it as well."

Also, that picture of the exploded view of the shock is from a Bikerumor.com article that states: "Another nice update is the improved serviceability. Because the oil and IFP are contained inside the BRAIN unit, the air canister can be easily removed with common shop tools and cleaned, lubed and inspected, then right back on the bike in about 10 minutes." Somehow they got it apart to take that picture.

Nonetheless, I couldn't figure it out so it's going to the shop.
That video and the article appeared just as the new MY18 bike was being released. Specialized obviously changed their mind. Check with your dealer-the air can is not dealer or user serviceable. My shop mechanic tried (as did you) and he quickly realized that a special tool would be required for the job.
 

·
And I'm out.
Joined
·
506 Posts
So to sum up: The service interval is 200 hours on your RockShox Epic BRAIN, it _cannot_ be serviced outside of the Authorized Service Center due to the in-house-only tooling required. A pair of 12mm tube clamps, a 27 mm super-thinwall socket (2.5mm thick!) and a seal bullet to fit over the damper body are needed just to do an air can service.... and don't as k me how I know that a _super_ thin wall socket in 27 mm is needed.
 

·
Registered
Joined
·
250 Posts
Discussion Starter · #16 ·
So to sum up: The service interval is 200 hours on your RockShox Epic BRAIN, it _cannot_ be serviced outside of the Authorized Service Center due to the in-house-only tooling required. A pair of 12mm tube clamps, a 27 mm super-thinwall socket (2.5mm thick!) and a seal bullet to fit over the damper body are needed just to do an air can service.... and don't as k me how I know that a _super_ thin wall socket in 27 mm is needed.
What's a seal bullet?

TPIWWP
 

·
Registered
Joined
·
12 Posts
I have a brand new rear shock/brain 2.0 that I got directly from Specialized that I don't need. Selling it for $200 plus shipping if you wanted a spare or know anyone looking for one. Thanks
 

·
Registered
Joined
·
250 Posts
Discussion Starter · #18 ·
Brief follow-up: My shop sent the shock off to Specialized, who serviced it and sent it back. The squish noise is gone--totally silent. The service was indeed covered under warranty (as mentioned in the other recent thread about Epic shock troubles). I had just over 1000 miles on the bike this season, so still a little early for the regular shock service interval. But glad it's fixed.
 

·
Registered
Joined
·
5,819 Posts
Glad to hear it is working fine now. Do you notice anything different other than the lack of noise?
 
1 - 20 of 20 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top