Wilier Adlar GRX 1x12 review

The Wilier Adlar takes its inspiration from mountain bikes, though not to the extremes of some of its gravel rivals, such as the Rondo MYLC.

Overall, the Adlar takes the forward-thinking geometry of technically capable gravel bikes and melds it to a frame design (and suite of accessories) aimed at those looking to traverse the roads less travelled.

It’s a great idea that has been very well executed. With only a couple of specification tweaks, it’d be right at the top of the pile.

Wilier Adlar GRX 1x12 frame details

The Adlar's angles are relaxed to improve its rough-stuff stability. The frame has been reinforced where necessary to allow for a massive maximum load of 35kg.

This is impressive stuff from a frame and fork that weigh only 1,190g and 470g respectively.

The frame and fork can also take tyres up to 2in wide on a 29in wheel, with clearance for huge 52mm-wide gravel tyres on a 700c wheel.

Wilier also has a set of bespoke carriers for the bike that utilise the front and rear thru-axles to distribute the load. If you get the accessory-loaded version of this bike, bespoke bags come from Miss Grape.

There are triple bottle bosses, top tube bag mounts and proper mudguard mounts.

Even without mudguards fitted, the seat tube has been shaped and broadened with a forward curve to mirror the rear tyre shape, effectively creating an integrated mudguard.

The sloping top tube leaves plenty of exposed seatpost to add a bit of rear-end comfort, while the dropped stays are said to add compliance.

Wilier Adlar GRX 1x12 geometry

The front end is suspension-corrected should you want to add in a suspension fork.

Up-front, a slack 70-degree head angle and short head tube combine with a short 70mm-long stem (this uses the Stemma internal routing system, like Wilier’s road bikes).

My size-XL test bike comes with a 634mm stack and a long 431mm reach, with a trail figure just shy of 80mm. The resulting handling is stability personified.

Wilier has, much like the latest Rondo MYLC and GT Grade, got the long front-centre design dialled here.

The seat angle of 73.5 degrees is steep enough to centre you over the cranks, in theory for more efficient power delivery.

Wilier Adlar GRX 1x12 specifications

The Adlar comes with a Miche Graff XL gravel wheelset. This has a 22mm-deep rim, with a 24mm internal width (and broad 28mm external width). It has sealed-cartridge bearing equipped hubs.

At 1,735g a pair (claimed) they aren’t the lightest gravel wheels you’ll find, but exhibit very good build quality, while the freehub engages quickly.

These are shod with Pirelli’s largest Cinturato Gravel H tyres (50mm wide). The ‘H’ stands for ‘hard’ conditions, but more on that later.

Up-front, Wilier’s Stemma S stem tidily hides cables and hoses, clamped to the wildly shaped Ritchey Comp Corralitos bar.

This is 48cm wide (centre-to-centre) on my XL test bike, but adds in a huge 24-degree flare and super-shallow 67.5mm drop, and short 52mm reach.

Also throw in a 15mm rise and 5-degree backsweep, and the ride position on the hoods is more akin to a mountain bike than a road or gravel bike.

In the drops, the width gives very stable, balanced steering when the going gets rough.

At the back, a classic 2-bolt Ritchey post holds a nicely shaped Wilier saddle with titanium rails.

Driving the Adlar is Shimano’s latest GRX 12-speed groupset. The new GRX RX822 rear derailleur and M7100 10-51 tooth cassette are matched to an RX610 crankset, RX610 shifters and RX600 brakes.

Wilier Adlar GRX 1x12 ride impressions

The Adlar is a brilliantly capable bike off-road – the steering geometry delivers impeccable stability when the going gets rough.

It sails over hard-packed broken surfaces, the huge volume of the tyres squashing vibrations and chatter with ease.

The front end doesn’t feel overly tall, though the 15mm rise of the bar raises it up higher than its rival bikes.

However, for this build, the conditions need to be right, which is all down to the tyres.

The Pirelli Cinturato Gravel H is a great tyre, fast on tarmac even in this very generous size, and on hard-packed gravel roads it’s outstanding.

But hit any tracks or trails that are wetter than a coffee-stained napkin and they are outmatched. The tightly packed shallow tread fills with mud almost instantly, turning the tyres into 50mm-wide brown slicks with zero grip.

The Adlar, in this spec, is a great advert for bike brands to spec tyres with seasonality or local market in mind.

In this case, a mud tyre in the winter and a hard tyre in the summer, or a more all-round tyre for the often-muddy conditions of the UK, but sticking to the Cinturato H for regions where gravel might be less technical.

It’s a shame, because the Adlar has a great, progressive geometry, while the clever integrated mudguard and huge tyre clearances point to an excellent all-conditions gravel bike.

On my extended rides out (12 miles) to the start of my longest gravel excursions, I ran the tyres with more pressure than usual, which gave the Adlar plenty of zip.

That said, it made the rear end feel notably firmer than the front.

I’d look to take advantage of the exposed seatpost by upgrading from the standard alloy post to a more compliant carbon offering, or even a dropper post, to take advantage of the Adlar’s great handling on the steep stuff.

Shimano’s new 12-speed GRX groupset has a lot going for it. The wide range means you’ve always got a gear for any climb and the big 40/10t combination is plenty fast enough for off-road.

The brake feel is superb, delivering masses of power, especially when braking from the hoods.

The drivetrain is smooth and shifts accurately. Shifting up the block is rapid and I could feel the tension in the system as I asked for shifts at speed.

Downshifting has a slightly slower feeling, where the system seems to release tension and flop the chain down to the next sprocket.

The shifts are accurate, but I prefer the more forceful downshifting I’ve experienced with SRAM and Campagnolo Ekar.

GRX never put a foot wrong, however, so it’s more down to personal preference than any lack of performance.

Wilier Adlar GRX 1x12 bottom line

The Adlar takes the new-school long front-centre geometry that typifies the more rugged end of gravel and adds proper expedition features to the mix.

If your idea of a bikepacking trip is lots of trails, tracks and singletrack, then I can’t think of many better options available right now.

The build is competent, and Shimano’s new GRX has brilliant braking and accurate shifting. While it could do with more considerately chosen tyres and a seatpost upgrade, that’s all I’d change.