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Increased Ride Height?

Riding (and installing) the new RockShox DebonAir Spring

Words Cam McRae
Photos Cam McRae
Date Apr 9, 2020
Reading time

All sorts of things are tricky in the time of COVID-19. Like shipping. UPS had a package from RockShox for us for a week, but it got stuck near Vancouver Airport. Eventually I got somebody on the phone and redirected it to a local UPS location and it arrived three days later, just in time for the place to close for the weekend. By the time we had access to a couple of forks to try, it seemed unlikely we'd be able to break them in adequately before the embargo lift. Luckily there was a work around.

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As I said in a recent article, dropping your lowers is no big deal.

This air spring upgrade is backward compatible with a bunch of Lyrik, Pike, Yari and Revelation models, and you can buy the parts in two formats; either the two new bits( for 2020 forks only), or the entire air spring assembly. As luck would have it, Rockshox sent one of each kit, so we decided to retrofit a couple of already-broken-in forks we had on test bikes for a direct comparison. We went out for a socially distanced ride, and then dropped the lowers on a couple of a different Lyrik Ultimates, (a 150mm and a 160mm) and then saddled up again for the identical ride the next day.

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Air spring disassembly was entirely straightforward.

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New sealed at far left, (but wrong way up) next to original sealhead. Further right is the new footnut, also in red, next to the original, in silver.

The swap involved dropping the lower legs and servicing or replacing the air spring, depending on which kit you buy. Since I took the kit that had the new foot nut and seal head I had to disassemble the air spring and put it back together, which looked easy at first. The original seal head has a flat bottom with the o-ring closest to where it sits in the uppe tube. In the absence of instructions I first assembled the mechanism in that manner. Fortunately the diameter is such that it can't be installed incorrectly so it was easy to figure out something was wrong. It took some pondering but eventually I realized my error and swapped it around.

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This seemed to make sense, since the original sealhead mounted with the flat side toward the footnut.

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Actually it goes like this, with the flush side up, leaving a hollow at the bottom of the lower leg and a little more volume in the positive chamber.

Before we went for our ride I wanted a little set up advice. Since the volume was a little lower, should I remove one of the two tokens in the fork? Should I lower the pressure a little? I got RockShox product manager Jon Cancellier on the phone and he told me to stay the course; don't change the pressure or the tokens. Once everything was back together I aired the fork up to the 73.5 PSI I'd measured the day before..

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Old air spring in the foreground.

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New spring in the upper left.

Our route was sort of a combo. Ideally we would have ridden something long and steep, since taller ride height is a big advantage in those situations, but managing risk is a priority right now so we opted for an older janky trail that had some steep and rough sections and lots of steps and roots. I was on a Santa Cruz Hightower, which I'm a big fan of, and the ride went great. Neither of us had complaints about the Lyriks on either bike.

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Chunky lines like this felt significantly better on the upgraded airspring, without any loss of small bump performance. Photo - Pete Roggeman

I'll admit that I was a little skeptical that I would notice much difference after the swap, but I tried to keep an open mind. On the first short downhill sections of trail, before our climb beyond the 5th switchback on Mt. Fromme, everything felt fine but I couldn't have told you if anything was different. Once we got onto Crippler I started to notice I was riding with more confidence and control than I had the previous day. I began to storm into sections with a wee bit more abandon, without putting myself at undue risk of course. A bonus of a higher ride height is that your head angle stays in a slacker zone for longer, and it also gives you more suspension to work with at any given moment, as long as you aren't bottom out, and both were easily felt.

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Your riding buddies won't be able to see your upgrade, but you'll be able to feel it. Pete Roggeman getting old school on Crippler.

Jon Cancellier of RockShox explains the new DebonAir Spring

There was a line I wasn't up for on the previous ride but with the new airspring it actually looked different to me, and I rolled it with confidence. The last trail we rode before emerging from the forest is a bermy flowfest and both of us ended up carrying more speed than the day before. I more easily cleared a double that is sometimes a reach for me and landing the one slightly larger drop felt more controlled on landing than it ever has.

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Actually maybe they will be able to tell... Pete Roggeman standing high in his travel.

By my reckoning, while this isn't a huge change in terms of parts or cost, the performance gains on steep terrain or when traction is at a premium are substantial. If you have a RockShox fork and you ride challenging terrain, you are going to want to perform this upgrade. Both Pete and I were very impressed and the difference in ride quality surpassed our expectations. Despite a slight decrease in positive spring volume, I used more of my travel on the second ride, probably because I was riding a little harder and with more confidence.

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It's hard to imagine when increased ride height wouldn't be an advantage. The new pair spring is also easier to set up and equalize because of the piston's new alignment with the dimple.

So what's going on here? It used to be that the piston sat a little lower at sag, and below the dimple in the fork uppers that equalizes air volume. This meant the negative spring retained lower pressure at sag or top out, allowing the fork to move easily into its travel. The downside was less than optimal support and ride height. The new sealhead and footnut move the piston up by 10mm so it's more often in range of the dimple, allow pressure to equalize after each extension.

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Into the abyss... Photo - Pete Roggeman

The Lyrik's air pressure chart remains unchanged, while your pressure might go down slightly in a Pike. All model year 2021 forks will include the new air spring. The upgrade kits are available as an entire air spring for 42 USD or just the footnut and sealhead for 25 USD. More info in the product press release here...

cam@nsmb.com
Cam McRae

Age - 54

Height - 6'/183cm (mostly legs)

Weight - 165lbs/75kg

Ape Index - 0.986

Inseam - 33"/84cm

Trail I've been stoked on lately - Fifth Horseman

Bar Width - 770mm

Preferred Reach - 475-490mm

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Comments

pete@nsmb.com
+3 goose8 Jugger Dan
Pete Roggeman  - April 9, 2020, 7:21 a.m.

So, just to be clear here: RockShox is offering an upgrade that:

1) is noticeable to your fork's performance

2) retro-fits to the fork you may already have, 

3) is easy to install yourself (or by a shop or tech - and they can do a 50-hour service at the same time)

4) and it costs just $25 or $42 US

Reply

tehllama42
+2 Pete Roggeman Cam McRae
Tehllama42  - April 9, 2020, 7:35 a.m.

I think the subtle adjustment that alters the equalization point is cool, otherwise I'd just be asking what this achieves that a Vorsprung Luftkappe doesn't already do... for for my part, that's been my favorite answer because I can keep rocking a 2015 OEM takeoff Pike, and keep rocking that.

Reply

D_C_
+1 Agleck7
DMVancouver  - April 9, 2020, 7:59 a.m.

What’s the install like for retrofitting the new nut and seal head? For home mechanics without a vice, what is a safe bodge for clamping the air shaft to unscrew the nut?

Reply

pete@nsmb.com
0
Pete Roggeman  - April 9, 2020, 8:06 a.m.

A friend with pliers? Of course, not a good bet these days! Maybe someone else can comment but I think without a vice this would be difficult - but easily handled by your shop.

Cam and I were installing our kits at the same time, in very different areas. It led to all sorts of running around to find tools, "did you do this yet", and "what about this part of the procedure?".

Reply

D_C_
+1 Andrew Major
DMVancouver  - April 9, 2020, 9:19 a.m.

This comment has been removed.

jcancellier
+6 DMVancouver Pete Roggeman AndrewR Karl Fitzpatrick Agleck7 Dan
jcancellier  - April 9, 2020, 8:15 a.m.

The top of the air piston has an 8mm Allen hole molded in. Use an 8mm and an adjustable wrench and you can take the old air spring apart and then install the new sealhead and footnut.

No vice required!

Reply

D_C_
0
DMVancouver  - April 9, 2020, 9:57 a.m.

That's awesome! Thanks for the info.

Reply

pete@nsmb.com
+1 Dan
Pete Roggeman  - April 9, 2020, 9:58 a.m.

Thanks for weighing in JC!

Reply

cam@nsmb.com
+2 Pete Roggeman DMVancouver
Cam McRae  - April 9, 2020, 9:58 a.m.

The air shaft isn’t clamped. An 8mm hex wrench is in the vise so you could easily do it with no vise.

Reply

sandy-james-oates
0
Sandy James Oates  - April 9, 2020, 8:33 a.m.

Will it fit lyrics with travel adjust?

Reply

jcancellier
+3 AndrewR Pete Roggeman Cam McRae
jcancellier  - April 9, 2020, 10:04 a.m.

Unfortunately, no. This only fits the DebonAir forks, not the Dual Position Air models.

Reply

rolly
0
rolly  - April 11, 2020, 8:54 a.m.

So, there are no upgrades available at all for a 2015 Dual Position Pike?

Reply

Brumos73
0
Brumos73  - April 9, 2020, 9:20 a.m.

Does this decrease the volume in the negative air chamber?

Reply

AJ_Barlas
0
AJ Barlas  - April 9, 2020, 9:29 a.m.

My understanding is that it makes it smaller, Brumos. They found issues with how large the neg chamber was.

Reply

D_C_
+1 Cam McRae
DMVancouver  - April 9, 2020, 9:56 a.m.

I think it's more that positive and negative chambers equalize sooner in the travel, which results in a lower negative spring pressure.

Reply

AJ_Barlas
0
AJ Barlas  - April 9, 2020, 12:54 p.m.

Yup, but the neg is smaller. Brumos was asking how it affected the neg.

Reply

D_C_
0
DMVancouver  - April 9, 2020, 1:02 p.m.

I would think the negative volume remains about the same. The piston head is advanced about 1 cm upward into the air chamber, but top-out bumper side of the seal head is also shifted 1 cm upward (by having the seal head being about 1 cm thicker, with the seal moved upward). 

Wouldn't the volume be the same but shifted upward?

(Not arguing - genuinely asking)

Edit: you're right - if you look at the two air springs side by side, the new one clearly does have less negative spring volume.

Reply

jason
+3 DMVancouver Pete Roggeman Cam McRae
jason  - April 9, 2020, 12:12 p.m.

I was wondering who was riding that janky trail.  Saw tracks the other day when I rode it and was surprised....:)

Reply

D_C_
+1 Pete Roggeman
DMVancouver  - April 9, 2020, 12:56 p.m.

I have been riding it too, figuring it was a good way to not see anyone else on my ride. Sounds like others have the same idea.

Reply

pete@nsmb.com
+3 DMVancouver Jugger Stephen Norman
Pete Roggeman  - April 9, 2020, 2:07 p.m.

Just rode Boundary for the first time today since Karen did all that work on it. Can confirm it is a LOT of fun. And yeah, it's a good time to be trying out some old classics, just having to look twice at a few lines and decide where they rate on the ol' 'risk-meter'. Decided against a few things over the last week, and had no qualms whatsoever about saving it (and myself) for a proverbial tomorrow.

Reply

Nikolas
0
Nikolas  - April 17, 2020, 3:57 a.m.

Hello,

I ride Pike Ultimate 130 mm. If I feel sitting too deep in the travel - I see two ways how to get higher: I can get this upgrade obviously - or - get a 140 mm airshaft and continue sitting deep in the travel - but overall 10 mm higher. What is a difference for me between this upgrade and changing travel to 140 mm without the upgrade (except the upgrade is a little cheaper)? I mean - without the uprgade, the equalizing dimple is a bit higher than the piston - let say 10 mm - so the equalizing point on 130 fork without upgrade is on 120 mm - the point, where I get the same negative and positive preasure. When I get the upgrade, I move the piston higher, so I meet the dimple - so I have equalized preasures in the beginning of the travel - in 130 mm. When I don't do that upgrade but change to 140 mm travel instead, I get the equalized preasure in the same hight - 130 mm (140 minus 10). The only difference I see here is, that on 140 mm fork without upgrade, when it's in 130 mm travel with equalized preasures, it has a bigger negative chamber, because there is not the bigger red sealhead - there is 10 mm of free space. Which means the fork goes more easily further into travel in the beginning. This is what the fork designers were going for for years - getting a bigger negative chamber and making air forks softer on beginning the travel - and now we are reducing the negative again? Was it too big?

Of course - there is one more thing. The same negative and positive preasure does not mean the same force. The negative piston area is a little bit smaller than the positive, so when the preasures are equalised, the positive force is bigger than the negative force - that is what moves the piston further over the dimple until it hits the top-out - or - until the forces equalise - which is why the fork sinks in its travel even under the weight of a sole bike (the weight of the bike adds to the negative piston force). With the upgrade - on the beginning of travel in 130 mm, the preasures are equalized, the positive force is higher than negative, so it pushes the fork against the top-out - so even when I add the weight of the bike to the negative piston force, it still remains its 130 mm. On the other hand - if I have 140 mm fork without the upgrade, it will not remain on the top of its travel (140 mm), but sinks a little bit under the weight of the bike (a few mm). When pushed to its 130 mm, it should meet the same conditions as the upgraded 130 mm fork (I mean the same forces).

So the thing is - why do we test a pre-upgrade fork and upgraded one of the same travel against each other? Why don't we test a pre-upgrade one against an upgraded with a 10 mm reduced travel? I thing these two should be more similar. Of course - if you ride pre-upgrade Pike on 150 mm, there is no room for getting more travel - I get this one...

Reply

Machuqueiro
0
Nuno Machuqueiro  - May 20, 2020, 2:18 a.m.

I finally received the new debonair for my old A1 version pike.

my older Pike is already upgraded with the older debonair and it is working great but wanted to try the new shaft as it says it works higher in travel.

Yesterday also stumbled on a video with a guy that made the test and says it's turned harsh and more difficult to tune!

so all this huge test just to ask if anyone here has tested this upgrade on 160 pikes and how it's working?

Reply

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