2012 Rockshox SID 29er suspension fork review and weights

SRAM launched the SID 29er fork at Sea Otter earlier this year, but it’s only recently been available for aftermarket. We got a quick ride in on some mid-summer on demo bikes from GT and Niner, but you can never really tell how it performs until it’s on your own bike.

With that in mind, I’ve put about 15 hours on a SID 29er now, weighed and photo’d it and, basically, been smitten. The test model is the XX with 100mm travel, X-Loc hydraulic remote, tapered alloy crown and 15mm thru axle. It replaced a Reba XX with straight steerer and 9mm QR.

Skip past the break for weights, photos, comparisons and the initial ride review…


2012 Rockshox SID 29er suspension fork review and weights

Actual weight without Maxle Lite and uncut steerer: 3lbs 9oz (1,630g).

2012 Rockshox SID 29er suspension fork review and weights

Actual weight with Maxle Lite and uncut steerer: 3lbs 12oz (1,700g).

2012 Rockshox SID 29er suspension fork review and weights

Weight of the cut portion of steerer tube: 35g.

Net weight of the fork without Maxle Lite: 3lbs 8oz (1,595g).

2012 Rockshox SID 29er suspension fork review and weights

For comparison, here’s the weight of the 2011 Reba XX (9mm QR version w/straight steerer) with same X-Loc hydraulic remote lockout lever: 4lbs even (1,800g).

Weight savings with the swap from Reba to SID: half a pound, give or take.

Does half a pound really matter? Absolutely. Lifting the front end of the bike over logs and rocks feels effortless. In fact, on the first few rides, I felt like I was yanking the bike twice as high as necessary! And on those days when your tired and half-assed attempts at clearing a log sometimes end in head-over-heels acrobatics? Well, consider this insurance against such things as it take considerably less effort to lift the bike.

I just reread that paragraph, and it seems silly to think that half a pound can make that much difference, but it does.


2012 Rockshox SID 29er suspension fork review and weights

At albs for a 100mm 29er fork, the Reba XX was no porker. But progress is as progress does, so to trim the fat, Rockshox made a number of changes to the lower casting. NOTE: the SID only appears to be sitting higher because it’s resting a bit further back on the sidewalk…they’re exactly the same height in reality.

2012 Rockshox SID 29er suspension fork review and weights

The bulge at the base of the brake arch (top of each leg) is considerably shorter on the SID, and most of the edges have been softened. The newer forks also get the screw-in guide for the front brake hose, which is much cleaner than zip-tying it to the arch. Just be careful not to over tighten it, the screw is tiny and weak.

2012 Rockshox SID 29er suspension fork review and weights

The Positive Air cap has been chiseled down significantly (left). The Arch is a bit thinner front to back on the SID…

2012 Rockshox SID 29er suspension fork review and weights

… and from the rear the triangular bracing seems slightly shallower. The Power Bulge on the legs has been streamlined, too, going from a thicker 360º bulge to a tapered bulge only on the outside. Generally, this is where the lower bushing sits inside the leg between the casting and the stanchion. The newer Rebas get this redesign, too, and actually share the same lower casting as the SID 29er for 2012. The comparisons here are for those considering upgrading or just interested in progress.

2012 Rockshox SID 29er suspension fork review and weights

The SID gets their Dual Flow Rebound and the new Motion Control DNA.


Truth be told, when I first rode it on the GT Zaskar 29er hardtail, I wasn’t all that impressed. It felt really harsh, as if it was only getting 80mm travel. It wasn’t until I returned the bike (which is pretty fast and stiff, BTW) that they confirmed it has 100mm of travel.

Then, on the Niner RDO, it still felt a bit firm, but better. In both cases, I didn’t spend too much time fine tuning the air settings or rebound, so that probably had something to do with my initial opinions of the fork.

Once I had it installed on my own Niner Jet 9, things got dialed. I find that Rockshox’s pre-printed air settings guide on their forks’ lowers are typically spot on for the Positive Air pressure. For Negative, I typically add a bit more than what I put in the Positive. For the SID 29er, this means about 120psi (+) and 135psi (-) for my 180lb-ish body. Combined with about 32psi in the tires, this provides a very supple front end without my having ever bottoming out the fork. Rebound has been set right about in the middle.

Switching from the Reba wasn’t exactly apples to apples. The SID upgraded to a tapered steerer and 15mm thru-axle. The combined result of the lighter, chiseled casting but added strength of the upgrades was a much lighter fork that felt as stiff as the Reba it replaced. That’s a compliment, but I’d perhaps suggest that anyone upgrading go with the tapered, thru-axle model if your bike can handle it. As is, I’m getting the impression that no sacrifices in performance are being made to attain some seriously feathery weights.

While there are differences in the air chamber volumes, damping and internals between the Reba and SID, I’ve been able to make them feel similar. In fact, I’m liking the way the SID feels better than I did the Reba, which served me quite well for more than a year with zero issues.

The other difference is the Motion Control. The new DNA version uses a helical coil that is a bit lighter than the prior XX Motion Control. In addition to that, the new damping and design feels a bit more compliant than the older versions. As in, it doesn’t take as much force to compress it, and when it compresses beyond a certain point, it opens Rockshox’s Floodgate blowoff valve, moving the shock into full, open action. I don’t generally use a lockout, but the new MC DNA does a really good job of mimicking a platform. How? Floodgate can be set very light. With the X-Loc hydraulic remote, the FG controls are inline near the lever. Dial it all the way open, lock out the fork and you have a mild platform that’ll quickly blow off and move the fork into normal travel. It’s still not quite as plush as when the lock out is turned off, but if you’re not paying attention you can easily forget that the fork is locked. I’ve done it on more than one occasion until things got really rough.

So far, so good, but thus far, all testing has been on our local trails. I’ll be putting many, many more miles on it over the next few months on some more technical terrain.

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10 years ago

I’ve had my 29er SID XX WC for a bit more than a month. I love it!

9 years ago

What was the length of steerer that was removed? I’m trying to calculate the weight savings for cutting down 20mm of 1-1/8″ steel steerer tube.

Great write-up!