SRAM Reverb Stealth B1 Teardown AndrewM
Teardown

SRAM Reverb Stealth B1

Words Andrew Major
Photos Andrew Major
Date Jan 3, 2018

Reverb

The Reverb post is simply a given. It's one of those products I ride many times a year but don't ever think about reviewing because it's been around forever. While the Reverb has one of the best rebuild manuals on the market, there are a couple other important techniques and suggestions Jeff will demonstrate here.

This is a brand new Reverb B1 Stealth with the new shifter-style remote and the Connectamajig. It's a one to two beer, or case of beer and trip to the bike shop the next morning rebuild, depending on mechanical aptitude and experience. 

SRAM Reverb Stealth B1 Teardown AndrewM

A pro setup saves time and ensures perfect rebuilds for shops making money on Reverb service. It's a nice luxury to have at home but not necessary for rebuilds on a budget.  

SRAM Reverb Stealth B1 Teardown AndrewM

The Reverb has a reputation for complexity but I think that's largely assumed and comes down to the hydraulic remote actuator. The post itself doesn't have many parts. 

Mentionables

The two key features of the Reverb B1 series compared to past Reverbs are the newer generation seal on the internal floating piston (IFP) replacing the previous o-ring, (which does an excellent job of preventing any air/oil bypass under pressure) and the Connectamajig.

Connectamajig allows the Stealth post to be removed without having to re-bleed the actuator line. In this case, because the post was brand new, it meant we could rebuild and re-bleed the Reverb without having to do anything more with the remote and line than detach and reattach it.  

SRAM Reverb Stealth B1 Teardown AndrewM

The Connectamajig hose coupler is a zero loss system that makes removing the Reverb from Stealth-routed bikes a simple job. 

The Connectamjig hose coupler is not a new idea. Similar systems are used for many industrial and heavy equipment applications but it's a great example of looking beyond bikes for ideas that make service faster and easier. Another example of SRAM making service easier on hydraulic products is their quick connect bleed fitting

The newer Reverbs also have an inverted seal position which prevents oil from escaping when assembling the post. It's much less frustrating than the old posts. If you've tackled a rebuild in years past and it didn't go well, definitely consider giving it another shot. 

Oh, and please at the bare minimum get some aluminum soft jaws for your vice. Aluminum shaft clamps are the best option if you're going to be working on your own suspension a lot. Scratching anodized sealing surfaces gets f***ing expensive and it's not covered by warranty when you beaver the sh*t out of aluminum internals.  

Open Sesame 

SRAM does a great job of making specific tooling available to service their products. With all the Reverbs out there a shop doing service can easily recoup the cost of doing this right. Shops and tool nerds doing a lot of RockShox service will also likely be drawn to the SRAM & Abbey Tool collaboration tools

SRAM Reverb Stealth B1 Teardown AndrewM

The SRAM IFP tool is handy to have. Or you could grab a depth measurement at your friendly local bike shop and substitute the proper tool for a smooth cylindrical object with the same outside diameter. 

Bleed fittings aside, anyone who isn't rebuilding posts in a time-equals-money situation can do this rebuild with some Knipex pliers and carefully chosen, smooth, cylindrical objects. I've always believe best practices vary depending on whether I'm working on my own stuff or a customer's.  

SRAM Reverb Stealth B1 Teardown AndrewM

The Abbey Tools Reverb Wrench is handy and Jeff highly recommends it for tool nerds and anyone professionally servicing a lot of Reverb posts. 

SRAM Reverb Stealth B1 Teardown AndrewM

Thanks to Kali Protectives for the use of their space in North Vancouver. It was a nice change of venue from our usual digs at Bikeroom

Free The IFP

As part of our Race Face Aeffect dropper post teardown Jeff demonstrated the zip-tie trick for removing an IFP. His preference for the Reverb is actually to create some back pressure with his thumb and pump it out. 

SRAM Reverb Stealth B1 Teardown AndrewM

Smile and pump, pump, pump, POP! Out comes the IFP. 

SRAM Reverb Stealth B1 Teardown AndrewM

The high pressure seal on the newer Reverb IFP resolves the past issues with reliability. 

The new B1 Reverbs have an excellent reputation for reliability but still carry the weight of the product's early reputation. It's easy to forget that the Reverb was the first widely accepted dropper post on the market and has survived in the same basic form through complete redesigns by all of its early competitors. 

The Stealth routing is an obvious change but otherwise the biggest difference is the new IFP which replaced a simple o-ring with a large high pressure seal which flares under pressure. This seal prevents the air/oil bypass that created spongy posts, caused failures in the cold and a cost of ownership that was too high with the past models. A new IFP will require a break-in period, even with a good lubing. 

Stripped

If you're going to strip down a Reverb, clean it and then rebuild it, please change the seals at the same time. Relative to the rest of the effort, it's a small cost. 

On any product where seals are being removed and replaced Jeff recommends stabbing the seals themselves with the removal pick. This destroys the seals but should prevent any scratches to air cans or other anodized surfaces. 

SRAM Reverb Stealth B1 Teardown AndrewM

All the small parts, including key ways, are easily replaced on the Reverb. Seals and oil are the only things that need to be replaced with a regular service. 

SRAM Reverb Stealth B1 Teardown AndrewM

Pierce the seal itself with a pick to remove it. This destroys the seal, which we're throwing away anyway, but it should prevent accidental scratching of important sealing surfaces. 

IFP Install

Reinstalling the IFP is a straightforward task. Grease the IFP, press it in to the required height and then fill the upper tube with oil. As with any hydraulic system, patience is the name of the game. As Jeff says, "bubbles are dicks", and if there's remaining air there's a good chance the post will be spongy no matter how the rest of the rebuild goes. 

SRAM Reverb Stealth B1 Teardown AndrewM

Best practice is to sing to the IFP while setting it to depth. 

SRAM Reverb Stealth B1 Teardown AndrewM

For faster performance, particularly in the cold, a lower viscosity full synthetic oil like Motul Factory Line 5w is a great choice. If in doubt, the stock Reverb fluid works well enough in most conditions. 

Poppet Performance

There seems to be a lot of confusion about how the hydraulic remote on a Reverb works. Like many cable actuated dropper posts, the fluid in the remote is simply depressing a poppet valve which in turn opens the (blue) piston assembly in the inner shaft and allows fluid to travel. Along with the rider's weight depressing the saddle, this causes the post to compress until the rider releases the remote which closes the system and locks the post in place. Push the remote without the rider's weight on the saddle and air pressure acting on the IFP causes the post to extend. 

SRAM Reverb Stealth B1 Teardown AndrewM

The remote is bled as a system with the poppet valve cover. Actuating it depresses the poppet valve.

The hydraulic system that is the remote, hose and poppet assembly is bled separately from the post itself. Bleeding the remote won't solve issues with the post being spongy and likewise rebuilding the post won't solve issues with air in the remote system. 

SRAM Reverb Stealth B1 Teardown AndrewM

When the poppet valve is depressed it opens the inner shaft piston, allowing fluid to flow. 

SRAM Reverb Stealth B1 Teardown AndrewM

Jeff demonstrates how the inner shaft integrates with the IFP tube. 

Before the poppet valve assembly is installed it's important to set the oil height inside the inner tube. SRAM makes a handy tool for removing fluid from the inner shaft but I've seen quite a few do-it-yourself versions that seem to work fine for anyone who wants to bypass the 45 USD cost of the tool. 

SRAM Reverb Stealth B1 Teardown AndrewM

Jeff sets the RockShox Oil Level Adjuster for our 150mm travel Reverb Stealth B1...

SRAM Reverb Stealth B1 Teardown AndrewM

and sucks out the excess fluid. It's simply that easy to do. 

Assembly

As with a lot of the teardowns with Jeff or with James at SuspensionWerx, the name of the game here is Slickoleum, or in this case SRAM Butter which is the exact same stuff. Brass key ways, seals, o-rings, the outer post tube, the bottom out bumper and definitely every facet of the IFP. Go to town. 

There are two assembly steps that folks seem to regularly screw up. The first is forgetting to install the seal head onto the upper tube before sliding on the outer tube and tightening everything together. Nothing like having to tear the post back down because the seal head assembly is still sitting on the bench. The second issue is to not allow the inner shaft to compress when installing the poppet valve. This changes the IFP depth and requires the post to be fully disassembled again.  

SRAM Reverb Stealth B1 Teardown AndrewM

Slickoleum on the key ways. Replace the key ways before the post gets a lot of twisting play and the channels they glide in will last much longer. 

SRAM Reverb Stealth B1 Teardown AndrewM

Set your confidence level to one step below smug. Dropper posts can sense fear and 93% of post-service issues stem from their attempts to assert alpha dominance over your mechanical capabilities. 

Bleed

Because Jeff knows the fluid in this brand new post is good and since it functioned perfectly before undoing the Connectamajig, he just bled the poppet valve cover itself to be sure that when the line is reattached there is no air in the system. Around Bikeroom this is called 'The Egor Method' since it was one of Jeff's assistants that suggested it. It's a great application of one of my favourite Tao 'don't fix what ain't broke.' Unless of course it is due for a service. 

SRAM Reverb Stealth B1 Teardown AndrewM

The bleed fittings are the one piece of specific tooling that is necessary for a Reverb rebuild. 

SRAM Reverb Stealth B1 Teardown AndrewM

Jeff doing his able best to keep the fluids straight. One synthetic for the Reverb and organic for the mechanic. 

Air in the remote system will result in a spongy feeling at the remote since the air can compress when trying to depress the poppet valve. In most cases, the post will still hold solidly at the chosen travel point even if the remote is spongy.

On the other hand, if the remote feels solid but the post doesn't hold solidly in position (sags or telescopes) that is a sign that the post itself has an air bypass issue and bleeding the remote won't help. 

Ride & Repeat

It's highly recommend by most mechanics I know that riders remove the seal head and re-lube the upper tube every 50 hrs of riding or so. This can be accomplished without removing the post from a bike and is a three-minute job at most. SRAM also recommends removing the lower post body and cleaning, inspecting and re-lubing the key ways at the same time so I'll call that best practices while recognizing it's a lot more work. The full rebuild service is recommended every 200 hrs of riding which is about two years' worth for most riders. For anyone getting after it with one bike I'll call that a yearly service. Best practice is to replace the brass key ways at that point. 

More shops are recognizing that service is an increasingly important aspect of a healthy bottom line. In the past many places shipped out Reverbs for a rebuild but most now handle it in-house, slashing down time for customers and adding service revenue. 

The little post that could. It's impressive how little the Reverb has changed in almost a decade since it was released and also how much more reliable and easily serviced they are today. 

Kudos to SRAM for supplying detailed rebuild manuals for their products that are easy to locate for shops and home wrenches. Manuals like the one for Reverbs give the do-it-yourself-er an honest shot at pulling off a good service without damaging their product or voiding their warranty. Consider giving it a go.

Comments

krisrayner
0
Kris Rayner  - Jan. 2, 2018, 11:17 p.m.

I just installed this post a week ago.  Unfortunately I needed to shorten the hose without a bleed kit handy.  Did my best, and everything works, but the post has a small of amount of vertical play accompanied by a tap noise that it didn’t have before I shortened the hose. I figured that I just need a remote bleed, but from your write up it sounds like it might be internal.  The only thing that changed was the hose shortening.  Any ideas?

Reply

drpete61w
+1 Cam McRae
DrPete61W  - Jan. 3, 2018, midnight

It probably is the hydraulic remote. Replacing the remote with a Wolf Tooth ReMote Sustain is a great move. Gets rid of the hydraulic hose and the lever feel is much nicer. I cut the cost of the upgrade by selling my 1x remote.

Reply

AndrewMajor
0
Andrew Major  - Jan. 3, 2018, 12:18 a.m.

I always go with the obvious first. If all you did was shorten the hose I'd assume the issue has to do with enough air being introduced when you shortened the line that the poppet valve is not properly supported? Bleeding the line is super quick (especially compared to servicing the post) so I'd certainly try to bleed the remote first.

If you haven't checked the air pressure in the post I'd do that as well. Just to be sure before you go and open it up.

Reply

AndrewMajor
0
Andrew Major  - Jan. 3, 2018, 12:18 a.m.

I'm a big fan of the ReMote Sustain as well. I like the ergonomics of the new SRAM remote, I like the hydraulic action and on a stealth routed bike I certainly don't mind never having to remove the housing completely to change it. BUT, the new remote is 'UGE. The Wolf Tooth remotes are really nicely made with great ergonomics and they're petite.

Reply

wfo922
+1 Andrew Major
Wfo922  - Jan. 3, 2018, 6:31 a.m.

The last post I rebuilt had a scratch in the internal shaft that allowed the air and oil to mix. The Teflon on one of the bushing looked to be rolled over on original assembly. Park Tools and I think Birzman offer some sweet tube holder vice clamps for around $30. Nice tech write up thanks NSMB

Reply

AndrewMajor
0
Andrew Major  - Jan. 3, 2018, 7:53 a.m.

Shaft clamps are so handy but I regularly don’t have the one I need (Jeff has the full BBI set so he’s gold).

Soft jaws for the vice are a good fall back for anything that isn’t super thin wall.

In the case of many dropper posts clamping them in a frame can be helpful as well. As a last resort I try a strap wrench before pedaling to the local shop to see if they have the right one.

I’ll check out the Birzman vice insert to see if it has sizes I don’t. Haven’t seen it before.

Thanks!

Reply

Lornholio
0
Lornholio  - Jan. 3, 2018, 3:35 p.m.

"It's highly recommend by most mechanics I know that riders remove the seal head and re-lube the upper tube every 50hrs of riding or so. This can be accomplished without removing the post from a bike and is a three minute job at most."

How about a how-to for this procedure sometime?

Reply

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