On the Cheap– (Don’t?) Try This At Home: Rockshox Coil to Air Fork Conversion

On the Cheap– (Don’t?) Try This At Home: Rockshox Coil to Air Fork Conversion

Full and utterly not shocking disclaimer: The advice in the forthcoming article WILL (not maybe, probably or might) void any SRAM/RockShox factory warranty on your fork. If you’re not comfortable reading service manuals and/or if the thought of beating your forks with a mallet makes you ill, don’t try this at home. If you’re ok with those things, by all means, try this at home.  

I recently purchased some stickers from AHTBM which read, “My Life Is a Cautionary Tale.” Those words echoed in my head as I stood on the deck of my apartment beating the lower legs off my 2014 RockShox XC 32 29er forks. Up until this moment, the forks had another year left on their factory warranty.

Let me back track to explain how a man in his late 30’s gets to the point where he feels the need to take a plastic mallet to a perfectly good suspension fork:

I purchased a squishy bike on clearance from my LBS late last summer. Obviously, a budget bike isn’t going to be spec’d with a high end menu of parts. In the case of the Fuel EX 5, that means a  fantastic Monarch R  air shock in the rear and a coil XC32 fork up front with a 15mm thru axle. While there is absolutely nothing wrong with either of those products on their own, the mix of a tunable air shock on one end and a basically non-tunable coil on the other end makes the bike do sketchy things when the terrain gets sketchy at sketchy speeds.

I’ve been a fan of RockShox products for years, mainly due to their easy maintenance. In the case of the XC32 coil, there is basically no maintenance to be had and changing spring internals to help “tune”  the fork to the rider’s weight is a 10-15 minute process with spring kits running about $25 from my LBS. Changing the firmness of the springs on this fork really does make a significant difference. You can even adjust travel from 100–120mm by adding or removing the rubber spacers included in the spring kits, which is a nice feature on such a wallet friendly fork.

But I was also aware that RockShox makes a Solo Air version of this fork, which I could purchase for a couple hundy. However… I heard rumors on the ol’ interwebs that any rider worth his blood alcohol level could convert one of these babies for around $70. Since the Solo Air system is a self contained cartridge system, it appeared to be a simple plug and play process as the IT nerds say.  I found out that it really is pretty much plug and play, but with fork oil and hammers involved.

Things you’ll need:

1) A copy of the SRAM/RockShox service manual

2)  A SRAM/RockShox Solo Air cartridge for the XC32 fork (DUH!!). I managed to finagle one from Bikewagon for about $55.

3) A long handled 5mm hex wrench, or in my case, a ratchet with a long extension and 5mm hex attachment. More on tool length to cum.

4) A 2.5mm hex wrench

5) 24mm wrench or socket.  An adjustable Crescent style wrench will do the trick as well since this is just used to remove the top caps from the fork.

6) 15wt fork oil

7) Graduated fork oil syringe with about 5″ of rubber tubing. Brake bleed kits work great for refilling this fork. I tossed my brake bleed kit because I’m an idiot, so I used the body of an old ball point pen to get all up in there.

8) Not a requirement, but I also recommend a seal kit because you’re going to have the whole fork pulled apart anyway, so why not rebuild the whole damn thing, Capt. Halfassington?

9) A bike stand or at least a good bench vise. Remember, you will be beating things off with a mallet, and everyone knows that beating off requires good grip.

10) A rubber tipped or plastic mallet

11) Last, but not least: a drip pan. There won’t be a lot of oil that comes out with this procedure, but you probably don’t want fork oil all over the floor. But if you don’t mind a little floor lube, who am I to judge?

The Plan:

In hindsight, I recommend removing the fork completely from the bike. Just makes shit easier to work on. I kept the fork attached to the bike, so it’s definitely possible to do it, but I think it would have been easier to remove the fork before proceeding.

First thing’s first: Pop the preload cap off with a 2.5mm hex. Then, use your 24mm to undo the preload “assembly.” From here you have 1 of 2 options: you can unscrew the upper portion of the coil from the lower internal or leave it alone and remove it as a single piece later on. I chose to remove the upper portion of the coil for photo sake.

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Then, you’ll need to employ your long 5mm hex to undo the lower fork bolts. Pulling the rebound adjustment knob off the drive side will reveal the bolt/seal for that side. Just give it a good yank straight down, it will pop right off. Unlike most RockShox products where the lower bolts are easily accessible, the bolts on the XC32 are recessed a few inches up in the stanchions. Hence, the need for a long tool: you have to go deep. Don’t pull the lower bolts all the way out just yet. Stop a few turns shy of removing them completely.

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Lower fork bolts are recessed on the XC32

 

 

 

 

 

 

 

Now comes the fun part! Grab your mallet and give the end of your 5mm hex a few good smacks while it’s still connected to the lower fork bolt(s). This will release the pressed fitting inside the fork lowers. If you pulled the upper coil stack already, keep smacking the thing until the lower coil stack comes loose. You’ll see it shoot up into the fork upper like a midget being shot from a cannon. Give a tug on the fork lowers. If they don’t slide off easily, get back to smacking that azz. You may need to give the non-drive side stanchion a few taps to shake it loose.  By no means at any time, hit the brake arch. This can cause structural damage to the fork which can, in turn, result in a costly visit to the dentist to have your teeth replaced if the fork collapses underneath you.

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There will be a small amount of fork oil that spurts out as the lowers slide off.

Once you have the lowers removed, you’ll notice a little grey retainer on the non-drive side fork upper. Pull this off. Underneath, you’ll find a little plastic spacer. This is essentially a bump stop for the coil. You’ll need to get crafty in order to remove this puppy. It’s tapered to the exact same diameter as the inside of the fork. I used a really long screwdriver to carefully push this out through the top of the fork. The nice thing about this particular conversion is that, since the SoloAir is a sealed, self-contained unit, you don’t need to be especially careful not to scratch the inside of the forks.Which is great for ham fisted fucks like me.

Be careful, but you don’t have to have the precision of a surgeon to do this.

Retainer and plastic bump-stop

Retainer and plastic bump-stop removed

 

After everything is disassembled, be sure to clean the fork sliders inside and out as well as the inside of the fork lowers. This is similar to how fat Bart Simpson washes himself–with a rag on a stick. Once everything is clean, put a few dabs of light grease on the SoloAir cartridge and pop that fucker in. If you want to replace the fork slider seals/wipers while you’re at it, those are easily removed with a screwdriver. Just be sure to wrap the blade in tape so as not to scratch the seating area for the wiper seal. Be sure to soak the foam seals in a little fork oil before installing them. This will keep your newly upgrade fork well lubed and slippery.

Fill each side of the fork lower with 6ml of 15wt fork oil before bolting everything back together. This is where you’ll need the graduated syringe and tubing.  Again, this is due to the fact that the bolts are recessed on this fork model. Stick your tube in the bolt holes and shoot your 6ml load all up in the for lower. Use the SRAM/RockShox air pressure chart as a guide for airing up your new upgrade.

Ta da! Cheap air fork upgrade in a little over an hour.

Note: this upgrade is really only worth the $$ and effort if you already have a coil sprung fork. If you’re looking at buying a fork, just get the air fork from the get go. It will cost you more to buy a coil fork and upgrade it than it will to just spring (pun intended) for the air fork.

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Goodbye useless preload “adjustment.” Hello air upgrade!

 

 

 

 

 

 

 

 

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