Shimano 2012 SLX Trail Brakes - Long-Term Test:

Nov 29, 2011 at 22:12

Shimano launched their sexy, new XTR Trail Brakes to a great reception from riders in early 2011. For its 2012 range, Shimano adapted many XTR features down to the rest of its disc brake lineup - including its value-priced SLX group. We got our hands on a set of the mid-range SLX Brakes back in August 2011 and have been running them since on big, alpine terrain. If we had to take an educated guess at how much use they've had, we'd say we've put well over a hundred hours of trail time on them.


Shimano SLX disc brakes at a glance:
• Claimed 25-percent increase in braking power
• Two-finger ServoWave brake lever, featuring on-the-fly reach adjustment dial
• Oversized 22mm twin ceramic pistons optimised for heat insulation
• Lightweight forged two piece calliper design is both rigid and durable
• No-shim post-mount caliper allows for quick installation and setup
• One-Way brake bleeding system
• I-Spec compatible shift-lever mounting
• 310 grams: lever, hose and caliper (F)
• $124.99 USD per side (£89.99) - rotor and adapters sold separately (about $50 USD)


SLX Disc Brake Overview

Shimano basically took the 2011 XTR brake lever and caliper and adapted it for mass production. Its shorty aluminum lever has the same profile without the tactile drilling on the face. The lever's in-line reservoir is essentially the XTR item in function, but with an 'industrial' finish, and the I-spec-compatible clamps allow for Shimano's integrated shifter option. Down low, the post-mount caliper shares the heat-blocking 22mm oversize ceramic pistons which are largely responsible for the brake's 25-percent increase in stopping power. Aftermarket SLX brakes are equipped with hard-stopping, sintered metallic pads with the funky looking aluminum cooling fins which reportedly reduce braking temperatures by 50-degrees C. The top-loading pads are fixed with a tragically simple cotter pin - certainly not an XTR hand-me-down. Like all Shimano disc brakes, the SLX system runs on mineral oil and its hose has a banjo on the caliper end to ensure perfect hose routing. In case you wanted to know, XTR brakes average 250 grams for a front lever, hose and caliper. SLX weighs 310 grams in similar trim. Shimano offers rotors and adapters separately. We used monster-sized 200mm IceTech aluminum-core rotors for this long-term evaluation - overkill by most AM/trail rider standards, but quite effective.


SLX Ride Test

Setup and alignment the SLX system was quick and painless. Shimano kept things simple with the mounting process. There is nothing more complicated than a couple of bolts and washers, but it works. The calipers stayed put too, we didn't have to worry about drag or rub through our test period with the SLX brake pads. We teamed the calipers up with big, 200-millimeter rotors, which is cheating slightly. Outside downhill racing, few riders are likely to team brakes up with dinner plates like those. What this means is that we got to find out just how much power we could generate with 2012 SLX brakes.

Steep learning curve: Well, it turns out that we had a handful of crashes due to the amount of power the SLX calipers and metallic pads produce - and the way they deliver it. A small distance of lever travel would grab the wheel and lock it dead. If you’re used to dragging your brakes then you'll need to get yourself out of that habit, fast (it's something I tend to do after using a different brake that required this to keep some heat in the system). There was very much a learning curve to using such strong stopping calipers with big rotors, and for the first few rides we had doubts about whether we were going to be able to live with them.

We shouldn’t have worried. We adapted to them in no time, once we stopped trying to drag the brakes, and began to get a feel for how they worked. The best test of how a brake modulates its power is when grabbing a load of front brake to lift the back of the bike through switchbacks. It's all about fine front brake control - and finding and shifting your balance point. The sign of a good brake is the speed you can take into tight switchbacks without having to make your peace with god first. There was no sudden epiphany when we became one with the SLX brakes. Instead, it was a realisation some time later that the brakes gave us the confidence to come into tight corners faster and faster. We felt completely in control and instinctively knew how hard we could haul on the levers. We struggle to think of another brake that handles this much stopping power quite this well (except for Shimano's XT and XTR trail brakes).


Down to business: That power really came into its own on the long descents as well. Because you don’t need to apply much force at the lever, it noticeably reduced forearm fatigue. What’s more, the SLX brakes kept their performance all the way down the mountain, and we put the brakes through hour-long descents to test their heat resistance and consistency. Maybe in lab tests you’ll find more powerful brakes, but out on the trail it was the tyres and ground conditions that limited how fast we could stop. The new mid-priced Shimano brakes deliver more usable power than other supposedly more powerful systems.

Close to XTR, but: When we looked at the XTR trail brakes last year we were very impressed by the lever feel and we're happy to report that these SLX brakes feel just as good out on the trail. For us, the most important thing with the XTRs was how comfortable that the lever feels in your hand and none of that has been lost. When first setting them up, it might take a bit longer, as the blades are noticably shorter than other system's levers, but it's worth the faff. When you find the sweet spot, these are some of the most comfortable to live with of any brake out there. Unlike the XTRs, the blades don't have machining on the grip area, but in all honesty, we never lost a lever with them, even in torrential rain, so we can't say for sure whether it matters or not. The more expensive XTs and XTRs also have free stroke adjustment, but we’d stick our necks out and say you won’t miss it.

Brake pad notes: The lifespan of the stock sintered pads that SLX brakes come with is pretty good - about what you’d expect these days. One problem we did find is that it’s hard to get spares for them right now, so when the stock pads wore out, we had to fit aftermarket pads without the cooling fins. We can’t say we noticed a huge difference without the fins. Out of preference, we’d run the finned pads, but if you can’t find them, it’s not a huge deal.

Room for improvement

One thing Shimano still has not changed, which we would niggle about, is the ability to run the levers on either side of the handlebar without changing hoses. It’s a shame and for some people, this is a problem. Shimano has changed something more important though. You can pop the levers off without the hassle of having to slide them down the bar like you had to with its previous levers. It’s quite a cool system they have come up with. Rather than the usual split-clamp affair, Shimano uses a single clamping bolt with a hinged clamp. The top section swings up, but the hinge is controlled by a little release button that you need to get at with a small Allen key (remember to carry one out on the trail with you). Although it can be a fiddle to pop them off, it does mean that when you put the levers onto the bar, they won’t fall back off again as the hinges stay in a nearly-closed position. There’s none of that trailside juggling with two bolts and half the clamp business here.

In terms of finish, of course they don’t compete with the XTR. Gone is that oh-so-pimp chrome, detailed machining and texturing on the blades. But SLX was never intended to compete with XTR on those grounds - and that’s not to say STX is ugly. 'Functional' is probably the best word. The mix of dark grey and silver is classy enough to look at home on nearly any bike. If all you want from your brakes is to win the car park bling contest, you’re going to need to invest some more cash, but SLX definitely doesn't look like a budget brake.


Pinkbike's take:

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