In eight months of testing RockShox’s £599.99 SID RLT 120mm fork has been utterly reliable with flawless performance.

The RockShox SID line of forks were previously intended solely for cross-country racing. The latest version offers up to 120mm of travel, opening up the SID to people aren’t going to zip tie a number to their handlebars and generate crippling lactic acid, but just want to enjoy one of the lightest and best-performing forks for trail riding.

The lowers are made from magnesium with the Power Bulge adding extra material where needed and less where it’s not. There are 32mm stanchions and you have the option of dropouts for a 9mm quick release (as tested) or 15mm bolt-through axle. While the 15mm bolt-through will undoubtedly be a bit torsionally stiffer, I never felt the 9mm lower was lacking in most riding. Weight is 1385g.

Inside the fork is RockShox’s highly acclaimed Motion Control damper with two air springs, positive and negative. Setup is straightforward. RockShox even prints the  recommended air pressure settings on the rear of the leg and  sag markers on the stanchion. No need to scrabble around for a tape measure or the manual.

The RLT model tested here boasts an adjustable lockout threshold so you can set just how much force is required to overcome the lockout. A dual flow position rebound dial lets you fine-tune the way that the suspension and handles bumps on your trails. The fork came supplied with a neatly machined remote handlebar mounted lever which makes it very quick to engage the lockout mechanism.

Stiffness is impressive for what is essentially a skinny cross country fork. I haven’t been using them much for racing, instead they’ve found their home on a lightish trail bike with a few concessions to comfort and fun. They’ve excelled in this application, never feeling out of their depth or struggling with the irregularities of trail features on proper back country rides.

We would recommend getting the version with the 15mm bolt-through axle lower legs if you’re going to use them for trail riding, but that does mean buying a new front wheel unless you’re already on a 15mm front end.

As for the suspension performance, it’s silky smooth. And controlled, very controlled. The damping is of the best on the market and ensures the 120mm of travel is well damped on big hits and smaller ripples are smothered. Regular servicing has ensured they’ve continued to work as they did out of the box.

The SID has made the transition from the race circuit to the trail centre with commendable ease.

Verdict

No longer just for cross-country racers, the latest SID is a worthy fork for any lightweight short travel trail bike.

Price: £599.99
UK Supplier: Fisher Outdoor
Manufacturer’s info: RockShox SID RLT

The official line

Here’s what RockShox has to say about the SID RLT:

“Even 100 grams lighter in 2012! And the ultimate race fork is upgraded with the new Motion Control DNA damping system. SID’s Superlight Integrated Design structure plus 15mm Maxle Lite and the BlackBox carbon crown steerer create a chassis with all the stiffness you need at the weight you want.”

And the SID line in general:

“SID’s supremely svelte design puts hill-charging, race-winning lightweight suspension in a stiff 32mm chassis that doesn’t flinch when the trail gets tough. Combining the uber-light Dual Air spring with BlackBox Motion Control and the PowerBulge design of the lower legs, SID delivers unparalleled plushness and control in the world of lightweight suspension. Now offered in a brand-spanking new 120mm travel option, with 15mm Maxle Lite option and a lighter 80-100mm chassis. At a slim 1345g for the SID World Cup, you might hear people call you a weight weenie—that is, if they weren’t so far behind you.”