Shimano SLX groupset review

Shimano's best mountain bike group - ever

Our rating 
4.5 out of 5 star rating 4.5
GBP £449.95 RRP | USD $771.80

Our review

It may not have the light weight sexiness of XTR or the bruising durability of Saint, but for sheer bang for buck, SLX is the best off-road groupset Shimano has ever made.
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Shimano’s new SLX group is a ‘best of’ compilation of the company’s technologies. It’s light, it’s designed to suit  any style of mountain bike and a full range of rider preferences and yet it’s still priced to be totally affordable.


A quick scan of the scores below will show you that we think SLX is pretty damn impressive. It might not be the highest-performance kit Shimano has ever produced, but in terms of value for money it’s outstanding.

If we had to gripe, we’d say the brakes are the weakest link, but they’re way better than previous mid-price Shimano offerings. The chainset and front mech are way ahead of the opposition, and as a whole SLX comes close to shaming Shimano’s own mighty XT in several aspects.

For most riders with an eye on budget but still wanting excellent performance and trail toughness whatever/wherever they ride, SLX is the best mountain bike groupset we’ve ever seen.

Double chainset: £99.99 – Rating:

The chainset is both the visual focus and lynchpin of a transmission, and this one is a beauty in both respects.

For a start, the raw metal and grey anodised ? nish looks great and stays that way, however many dirty ankles rub past it. It feels rock-solid underfoot, too, with permanently ?xed steel pedal thread inserts adding to its drop-proof durability.

Steel teeth on the outer ring doubles its lifespan compared with alloy rings, while the composite carrier keeps weight down. The 36/22 ratios give a great gear spread from behind the tough polycarbonate bash guard, too.

The simple twin clamp bolt offside arm attachment is well proven; the external BB bearings (same as XT) last okay now. It’s an absolute steal for more aggressive riders.

Outstanding cosmetic and mechanical lifespan with great gear ratio spread, on a toughened yet still reasonably light pedal platform

Front derailleurs: £22.99-£25.99 – Rating:

Wide range of front mechs suits different frames: wide range of front mechs suits different frames
Joby Sessions

SLX introduces the most universally capable family of front mechs ever – and they all work great.

Universal clamp top swing or down swing types, plus E Type or Direct Mount versions, all run with either top or bottom pull cables, so there’s almost nothing SLX won’t ?t.

The new compact option also uses a tighter curved, shorter and broader cage to follow double chainsets more closely and keep the tail away from fat tyres caked in crap. The more open pro? le means less grind on slacker seat angles, and the shifts on our Orange Patriot host bike have been spot on from the start.

Certainly way better than anything from the opposition.

Universal ?tting with speci?c double/triple crankset versions ensure superb-value shifting whatever rig you ride

Triple Chainset: £99.99 – Rating:

Smooth shifts and great value from quality triple chainset: smooth shifts and great value from quality triple chainset
Joby Sessions

If you’re after a full range of gears to go anywhere, the triple chainset looks like a very good option.

It uses the same hollow forged, bare metal outer crankarms as the double chainset, so the looks are long-lasting. Despite not having the steel pedal insert, it still feels solid underfoot, however hard you’re stomping.

By using steel teeth on a composite body middle ring, lifespan of the most regularly used gears is doubled, while the drilled inner looks Top Gear trick. Extensive ramp and pin pro?ling means shifts are every bit as smooth as we expect from Shimano.

Easy ?tment and reasonable BB life ?nish off an excellent-value all-round package that saves £40 compared with the similar performing XT, but offers signi?cant advantages over the £59.99 Deore.

Not as uniquely appealing as the double, but you’re still getting top-quality performance for mid-price money

Shadow rear derailleur: £39.99 – Rating:

Tight-shifting and rock-dodging fd-m665 rear mech: tight-shifting and rock-dodging fd-m665 rear mech
Joby Sessions

There’s no other option than the low-pro? le Shadow rear mech for SLX, but that’s okay by us.

The beefed-up cage adds a bit of weight compared with XT, but it matches the chunky looks elsewhere and gives it a bit more sideswipe survivability. The Shadow mount also stops mech-on-frame rattle, making for a much quieter ride apart from the occasional ‘clack’ from the mech stops.

We’ve had none of the mount loosening issues with our SLX that we’ve had with some XT set-ups, either, although it still makes sense to check the top anchor bolt regularly.

Most riders we know happily trade the loss of a cable adjuster for the lack of a big outer cable loop, too, making this a great-value way to get rock-dodging shifting.

A bit heavy, but a tough, tight-shifting and rock-dodging rear mech as long as you check the mount regularly

Hydraulic disc brakes: £69.99 – Rating:

BR-M655 stoppers provide simple but powerful and controlled braking : br-m655 stoppers provide simple but powerful and controlled braking
Joby Sessions

Shimano brakes were always smooth and reliable but never powerful – until Servo Wave came along.

By using a cam in the lever, Shimano alters the closing rate of the pads for greater clearance at ‘rest’ but more bite when it matters. The results are impressively powerful and controlled.

The latest resin pads aren’t as brutally powerful as XT sintereds, but they’re lasting well and help keep the brake happy on long-dragging descents. It’s signi? cantly cheaper than XT, too, and while it lacks bite-point adjustment, general consistency of braking has been greatly improved so far and the levers are a better shape.

Front and rear sets can be bought ready bled for easy ?tting, while rotors are sold separately for a full choice of 160mm, 180mm or 203mm (£16.99, £19.99 and £22.99 respectively) diameters in Center Lock or conventional six-bolt mount styles. 

Simple but powerful and controlled braking at a good price.

Gear shifters: £49.99 – Rating:

SL-M660 is a great value slick shifter : sl-m660 is a great value slick shifter
Joby Sessions

According to Shimano, the internals of the SLX Rapid?re Plus shifters are exactly the same as XT, which makes them an absolute bargain.

Apart from the plastic rather than metal push lever, the 2 Way action certainly feels exactly the same. Indexing is light, but not so quiet and soft that you’re lost on rougher ground like you can be with LX and Deore. Cables need regular cleaning to keep it sweet, but for the price these are great little units.


Still more dependent on clean cables than SRAM, but a great price for Shimano slickness

Product Specifications


Name SLX Groupset
Brand Shimano

Description Groupset includes- SLX Hollowtech 11 triple chainset & BB. SLX Front mech. SLX Rear mech. SLX Gear levers. SLX Cassette and chain. Front and rear SLX disc brakes with 160mm 6-bolt rotors