RockShox launches two new SID forks and a new shock for 2021

The US brand claims its latest SID SL fork will be the lightest on the market, and unveils a totally new, beefed-up version of the SID for more demanding terrain

RockShox’ SID fork has been around for years now and is used by some of the biggest names in cross-country racing and to great success.


But with XC tracks becoming more technically demanding of both rider’s skills and the bikes they’re piloting, it’s no surprise we’re starting to see big brands such as RockShox plough more development dollars into associated products.

For 2021, RockShox is launching three new products: the SID SL and SID forks, and the SIDLuxe rear shock.

Its popular, lightweight fork receives a complete overhaul in a bid to ensure it can handle the demands of modern, highly technical XC race circuits and it’s introduced a beefier version of the fork for those planning to tackle more demanding terrain that are still keen to keep weight low and put the miles in.

There’s also the SIDLuxe shock, which is designed to be paired with either the SID SL or SID fork.

Before we get into forks’ specific details, let’s cover off some of their similarities…

New Charger Race Day Damper

RockShox wanted to save weight with the new SID, but without scrimping on performance. As a result, it’s developed the new Charger Race Day damper, which weighs roughly half as much as the previous Charger 2 RLC damper.

The Race Day’s predecessor weighed a claimed 186g, but the new damper weighs a scant 86g and is built to fit inside the new 32mm SID SL.

This damper is also used in the SID Ultimate but uses a different top cap to accommodate the wider diameter upper tubes – more on that later – so is a touch heavier.

This weight loss is down to a number of factors, including a reduction in fluid volume.

Essentially, RockShox had to manage a fine balance, ensuring there was just enough fluid to keep damping consistent on extended descents and not overheating, but without adding too much extra weight.

Charger Race Day damper for mountain bike forks
The new Charger Race Day damper offers significant weight savings over the Charger 2 RLC damper that it replaces, but is said to perform even better.
Max Wilman

It’s also shrunk down the seals, but claims this hasn’t had any kind of negative effect on performance, and the new forks still run to the same 200-hour service interval.

The Charger Race Day offers two-position compression adjustment (open or fully locked-out) via a neatly machined lever or using the TwistLoc bar mounted remote, which does add some extra cost (£70).

Those of you with a keen eye will have also spotted the bleed port, which is located right next to the compression lever. This allows you to burp bleed the damper while the fork remains on the bike, should it not be feeling 100 per cent.

Low-speed rebound damping is adjusted via a small 2.5mm Allen key that’s nestled up inside the base of the lower legs. The idea here being that the Allen key helps save weight over a traditional dial-style adjuster, and it can also be used to tweak the rebound damping on the new SIDLuxe rear shock (which doesn’t have a rebound dial to help save weight).

All you need to do is pop it out from the base of the fork. Getting it to pop back into place is a little fiddlier but easy enough once you’ve done it a couple of times.

If you’re not planning on buying a new SID fork any time soon but wouldn’t mind a bump in performance, the Race Day Damper (in its 32mm guise) is backwards compatible, so it can be bolted into older SID forks all the way back to 2014 models.

New DebonAir spring

RockShox SID Ultimate fork has a revised DebonAir spring
Inside the new SID fork sits a revised DebonAir spring. This has been designed to allow the fork to ride higher in its travel and ensure every millimetre of travel is available to use when called upon.
Steve Behr

In a bid to make the most of the 100/120mm travel, RockShox went back to the drawing board and altered how the DebonAir spring works.

It’s not only wanted to ensure every millimetre of travel is accessible, but also wanted the fork to ride a little higher in its travel, yet still feel supple initially.

By shifting the air bypass port/dimple lower in the upper tube, the positive and negative air chambers are equalised when the fork is fully extended/topped-out, rather than equalising after sinking into the initial part of the fork’s travel.

RockShox claims that by doing this, along with changing the shape of the bypass port, using the same top-out bumper as used in Pike and Lyrik forks, and making the seal head smaller and lighter, it’s managed to create the perfect air spring feel for XC riding.

Unlike the new Charger Race Day damper, the new DebonAir spring isn’t backwards compatible and can’t be retrofitted to older SID forks.

Why no carbon crown/steerer assembly?

Aluminium crown on the carbon RockShox SID Ultimate mountain bike fork
Unlike its predecessor, the top-tier SID Ultimate Carbon, the new SID fork doesn’t use a carbon crown/steerer assembly. Instead, RockShox has used aluminium and heavily machined the crown before anodising rather than painting it.
Steve Behr

Unlike its top-tier predecessor, neither the SID Ultimate or SID SL Ultimate use a carbon steerer or crown.

While RockShox says it’s not ruling out creating a carbon CSU for the SID, it’s admitted it takes a lot of development time and money to create one that’ll trump what it’s achieved here in aluminium.

The new crown is forged then CNC machined before being anodised to help save weight and remain pleasing to the eye.

Wheel size and offset

RockShox is only making the SID SL and SID compatible with 29in wheels, stating that it’s seen a notable drop off in smaller 650b-wheeled bikes in this particular category.

It also only comes with a 44mm offset, which is something the brand claims is industry driven and should deliver improved stability at higher speeds.

Keeping weight to a minimum

Look closely and you’ll not see anything extra that really doesn’t need to be there.

There’s no large circumference air top-cap to cover the air spring valve, instead there’s a simple Schrader cap and nothing more.

Rebound adjuster on the RockShox SID Ultimate mountain bike fork
To save weight, there’s no traditional red rebound adjuster knob on the new SID. Instead, rebound damping is adjusted using the small 2.5mm Allen key which plugs into the base of the damper. This can be popped out of the fork and used to adjust the rebound damping on the SIDLuxe shock.
Steve Behr

The same goes on the damper side of things. A small, machined lever is used instead of a larger dial/lever combo to keep the weight down further. And the small Allen key inserted in the base of the damper leg replaces a big red adjuster knob to allow you to tweak the low-speed rebound damping.

Then, of course, there’s extensive sculpting throughout the lower legs, particularly around the arch, as well as the stepped cutaways (which look very similar to that of the Fox Step Cast forks) as you near the axle interface.

This all adds up to extra weight saved as well as a very svelte, chiselled look.

Sensitive soul

Minimising friction is always a battle when producing suspension forks/shocks.

To help in the never-ending battle with this, RockShox uses low-friction SKF wiper seals in all its SID and SID SL forks.

They’ll also use Maxima Plush damping fluid, which RockShox claims helps to extend seal life as well as reduce the dreaded friction.

SID SL Ultimate fork

While we’ve covered a lot of what the new SID SL Ultimate and SID Ultimate have in common, they still differ quite a bit in terms of construction and intention.

The SID SL Ultimate is aimed at those looking for a lightweight race fork. In fact, at 1,330g the SID SL is 57g lighter than Fox’s 32 Factory Step Cast 29 fork (if we go by Fox’s claimed fork weight), which is seriously impressive.

The SID SL Ultimate delivers 100mm of travel and uses its new super-light Charger Race Day damper to keep things under control.

RockShox SID Ultimate mountain bike fork
RockShox claims the new SID SL Ultimate is the lightest cross-country race fork on the market at 1,330g. The SID SL uses 32mm upper tubes and offers up 100mm of travel.
Max Wilman

Along with the machined crown and intricately formed lower legs, the SID SL uses 32mm diameter, straight-wall aluminium upper tubes to help keep weight down. It’s also narrower in profile than the current 2020 SID Ultimate Carbon as well as being just over 160g lighter too.

There’s a TwistLoc remote option for those that like to keep their hands firmly on the bars when they’re riding, accounting for the two prices.

The SID SL Ultimate is available in the SID blue or gloss black.

  • SID SL Ultimate: £779 / $799 / €869
  • SID SL Ultimate with TwistLoc remote: £849 / $869 / €949

SID Ultimate fork

If you’re still into hammering out the miles but feel like you need a burlier fork that can handle a real pasting, then the new SID Ultimate might be just the ticket.

It’s designed to work on the burlier breed of XC bikes we’re now seeing in abundance. While they might only sport 100 to 120mm of rear wheel travel and barely tickle the scales, they’re also adorned with short stems, wide bars and tougher, more aggressively treaded tyres to ensure they’re that bit more capable than a run-of-the-mill XC race machine.

While the SID Ultimate is a touch heavier than its SL counterpart at 1,610g (including the bolt-on fender), it’s still far from a heavyweight.

RockShox SID Ultimate mountain bike fork
The new RockShox SID Ultimate is one of the new breed of cross-country forks, boasting stiffer (than the standard SID) 35mm upper tubes and 120mm of travel.
Steve Behr

The weight difference is primarily down to the bigger 35mm internally tapered upper tubes (the same diameter that’s used on the heavier hitting Pike and Lyrik). Why go for 35mm uppers? It’s all in a bid to bolster stiffness and improve steering accuracy.

In terms of travel, the SID Ultimate sports 120mm, and, like the SID SL Ultimate, is all taken care of using the Charger Race Day damper.

Should you want to make your ride as efficient as possible, the SID Ultimate is compatible with the TwistLoc remote.

As mentioned earlier, there’s also a bolt-on fender for the winter months. This is attached via two 2.5mm Allen bolts. It’s a little fiddly to get attached but seems to work well enough.

Like the SID SL Ultimate, the SID Ultimate is available in SID blue or gloss black.

  • SID Ultimate: £869 / $899 / €979
  • SID Ultimate with TwistLoc remote: £949 /$969 / €1,059

SIDLuxe Ultimate rear shock

RockShox SID Luxe rear shock
To match the new forks, RockShox is also launching the new SIDLuxe rear shock. This features a tunable air spring and two-position compression lever.
Max Wilman

Something we’ve not really mentioned yet is the SIDLuxe rear shock. It’ll largely be available on OEM bikes and features a lock-out lever to help firm it up for more efficient climbing.

You can also tune the air spring using tokens to alter its progressivity. Rebound damping is adjustable too, but it requires a small 2.5mm Allen key to tune it (there’s no rebound dial, to help save weight).

As you can see, this shock is pretty small and, as a result, has a relatively small overall air volume.

RockShox claims the small volume gives a supple initial touch and progressive end stroke, which should suit the demands of XC racing very well indeed.

My trunnion mounted shock (185 x 47.5mm) weighed a scant 253g.

SID SL Select and SID Select forks

If you don’t have the cash to drop on either of the Ultimate models or the new 2021 SID fork, RockShox is offering aftermarket Select fork options.

Both the SID SL Select and SID Select use the same DebonAir spring and chassis as their pricier counterparts, but the damper is different.

In this case, it’s the Charger RL damper. That said, the Select models do get the same SKF seals and Maxima Plush damper fluid.

  • SID SL Select: £579 / $59 / €649
  • SID SL Select with remote: £649 / $669 / €729
  • SID Select: £679 / $699 / €759
  • SID Select with remote: £749 / $769 / €839

SID Ultimate initial ride impressions

I was impressed by how solid the new, burlier SID felt from the get go. It’s supple too, and seemed to track the trail’s undulations and chatter really well.

I’d settled on 70psi in the air spring with no Bottomless Tokens fitted because things felt progressive enough for my liking. RockShox recommend between 59 and 73psi for my 68kg weight, so I was just within this.

This pressure managed to give the fork enough initial sensitivity to keep it tracking the trail well and reduced small bump and chatter but, even after some really hard riding, I never managed to use the last few millimetres of travel.

The stiffness on offer certainly adds an accuracy to steering precision and helps to keep things feeling direct when you’re stood up out of the saddle climbing and really hauling on the bars.

Getting the rebound dialled in took a little bit of experimentation, and twiddling the small Allen key at the base of the damper worked just fine but isn’t as comfy to use as a regular adjuster dial.

Cyclist riding full suspension mountain bike
Rob’s spent a decent amount of time aboard the new SID Ultimate and will be following up with a full review very soon.
Steve Behr

Set to my preferred rebound setting, when I did give the bars a sturdy yank when lifting the front wheel there was a noticeable, albeit soft, top-out when the fork fully extended. It’s not harsh in any way though, and when the fork rebounds from deep in its travel you don’t feel this.

Although the initial touch is pretty sensitive, the SID Ultimate remains supportive and doesn’t sink too deep into its travel.

This is part of the reason why it feels so capable, as if it’s punching above its 120mm of travel. Even when stoving it into really chunky rock slabs, it was the fork that felt more capable than the bike it was bolted to.


Overall, the new SID Ultimate feels composed and more steadfast than the amount of travel or its light weight might suggest it can handle. Watch this space for a full review coming in the next few weeks.