Rockshox SID 120 RLT QR15 fork review

For aggressive cross-country riding

Our rating 
4.0 out of 5 star rating 4.0
GBP £745.00 RRP
Rockshox SID 120 RLT QR15 forks

Our review

Aggressive riding cross-country riders form an orderly queue here
Skip to view product specifications

RockShox have sold the SID fork with the label ‘the best cross-country fork on the market’ since 1999, only now in 2011 it might finally be true. They’ve melded their updated 2007 SID chassis with their 32mm stanchions and stiffer PowerBulge lowers to incorporate a through-axle 15mm lower leg.


At the same time, the new trend towards tapered steerer tubes has added further strength and stiffness to the fork. During the ’90s SID was a spindly, poorly tracking item for cross-country whippets only. The 2011 SID is now capable of holding its own in a square fight with burlier trail-orientated forks like the company’s Revelation or Fox’s F32 QR15 models.

Available in 100- or 120mm-travel versions and in standard and taper steerer options (‘open’ 9mm dropouts still available), the SID is being reborn for a third time, bigger and better, but intrinsically still the same lightweight race fork that it’s always been. Even the middle-of-the-road, straight steerer QR15 120mm RLT version that we have still only weighs in at 1,512g; RockShox claim 1,484g (with full length steerer and Maxle Light axle).

Considering the extra travel and stiffness of this fork, that’s a weight that the likes of Marzocchi can only dream about (their 130mm 44 Micro Ti QR15 tips the scales at 1,944g, albeit with an extra 10mm of travel). So it’s light, stiff and has 120mm of travel and the established vice-free Maxle Light axle, but what does that mean you can do with this SID that you couldn’t do before?

You’ll have to fit it to the new breed of 120mm-specific hardcore cross-country/trail hardtail and full-suspension bikes to find out. Where the standard SID is too short and, depending on your perspective, flexible in its steering, this burlier version gives riders the confidence to pitch it further into the unknown, even if the terrain is trying to steer you elsewhere. It places more emphasis on the front tyre because you are asking more of the fork in every trail situation.


We ran wider, more predictable, less cross-country-race tyres so that we could enjoy all of the fork’s new-found abilities. As a fork to slap on virtually any mountain bike, from a trail hardtail to a race hardtail, a race full-susser or a 5in trail weapon, this fork has only really got the Fox 32 120 QR15 for company. In a straight fight between the two we’d be hard pressed to call a winner.

Product Specifications


Name SID 120 RLT QR15 fork (11)
Brand RockShox

Features • 2 chassis options: 120mm and 80/100mm travel. • 15mm Maxle Lite option. • Tapered steerer offered in all models. • New Keronite® Grey finish option on World Cup Models saves up to 20 grams. • New graphics. • Dual Flow rebound now featured on all models. • Tapered carbon-fiber crown steerer saves 100 grams. • New disc brake hose guide. • New lightweight bushing system.
Weight (g) 1512
Stanchion Diameter 32
Spring Type Dual Air
Lowers Post Disc Mount