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Merida Silex 400 review

Mountain-bike influenced design

Our rating 
4.0 out of 5 star rating 4.0
GBP £1,400.00 RRP | EUR €1,499.00 | AUD $2,199.00
Pack shot of the Merida Silex 400 gravel bike

Our review

Huge fun factor from this very accomplished machine
Pros: Very clever chassis design; handling; value
Cons: Sticky freehub and slender rims
Skip to view product specifications

Merida’s Silex takes more influence from mountain biking than road. The difference lies in the increased stack to a tall 663mm, and a long reach of 430mm.


Longer reach usually means a lower position because you are more stretched out, whereas a taller stack means a more upright position. Here, Merida combines this mix of dimensions with a short 80mm stem. This means a position similar to a standard endurance bike, but with handling optimised for off-road because a slack 71-degree head angle increases the trail; this stabilises the front wheel while a short stem speeds up the handling responses from a long fork (397mm).

The Merida Silex 400 gravel bike comes with a tall front end with a short steering cockpit
A tall front end with a short steering cockpit works well.
Russell Burton / Immediate Media

Stem length has a big influence on how a bike feels to steer: a long stem gives you a longer steering arm – so it’s less responsive but more stable, think of a steering wheel on a truck, whereas a shorter stem makes it more responsive to steering inputs but feels less stable.

Cleverly, on the Silex, Merida has sped up the steering response while slackening the head angle and lengthening the fork, so you have a bike that feels absolutely at home in the rough. It tracks superbly well and cuts through bumps with assured control without feeling sluggish.

I was hugely impressed with the carbon Silex when I rode it back in 2018, praising the comfort of the chassis over rough, rutted tracks. This more affordable aluminium interpretation deserves high praise too, with the same full carbon CF2 fork, which is brilliant at cushioning the worst of rough surfaces with its swept-forward legs that taper down towards an almost vertical 12mm thru-axle.

The CF-2 carbon fork on the Merida Silex 400 gravel bike can be fitted with full length mudguards
The Merida’s full carbon fork is drilled to fit full-length mudguards.
Russell Burton / Immediate Media

At the back, the alloy 30.9mm post can’t quite keep the same plush feeling as the front, though it’s topped with a comfortable perch in Merida’s Expert saddle.

The frame features ‘guard mounts, rack mounts, two cages (with two positions on the down tube) and double bosses on the fork legs for either a further two bottles or low rider/Anything mounts. That means it could easily be put into service touring, bikepacking or adventure cycling (it’ll also take 650b wheels). Or just simply commuting during the week and exploring at the weekends.

Equipment levels are a good-value mix of Shimano’s gravel-specific GRX from both 400 and 600 levels. The sub-compact 46/30 chainset and an 11-34 cassette give an excellent spread of gearing for off-road and on.

Shimano GRX400 gears on the Merida Silex 400 gravel bike
Shimano’s GRX features a switchable ‘clutch’ on the rear mech.
Russell Burton / Immediate Media

The same is true of the Maxxis Rambler tyres, the 38c volume is covered with a tightly packed small-block tread that rolls well on tarmac and hard-packed dirt. The large shoulder blocks on the tyres provide bite in corners off-road but are so tall (and soft) they squirm somewhat when cornering.

Merida provides the lion’s share of finishing kit with own-brand parts. The cockpit is a fine combination of a smoothly shaped, minimal, alloy Expert CW stem and Expert GR bar. The bar shape is excellent offering a small amount of flare. Along with its oversized tops, padded textured tape makes for great hold on the tops, drops or hoods.

The hydroformed and shaped alloy give the Merida Silex 400 gravel bike a touch of class
Hydroformed and shaped alloy give the Silex a touch of class.
Russell Burton / Immediate Media

The Merida Comp SL wheelset runs cartridge bearing hubs, although I did find that the freehub was somewhat draggy initially. On inspection the freehub had been packed with too much grease. A quick wipe and it was friction free.


The shallow aluminium rims roll well but the dimensions are narrow (for gravel) internally at between 17 and 18mm. The 38c tyres are about as large as I’d go. Going to the maximum allowed by the frame and fork of 42c (in either 650b or 700c) would need a wider rim to get the best performance.

The Silex offers something quite different in what is a rather packed playing field of gravel bikes. It blends superb ride position and brilliant off-road handling with fantastic ride quality making it a bike that combines value with performance.

Merida Silex 400 geometry

Seat angle (degrees)74747474
Head angle (degrees)71717171
Chainstay (cm)43434343
Seat tube (cm)47505356
Top tube (cm)55.457.96062
Head tube (cm)18202224
Bottom bracket drop (cm)
Wheelbase (mm)1,0341,0601,0821,103
Standover (cm)74.477.279.982.6
Stack (cm)60.662.564.466.3
Reach (cm)384041.543

How we tested

Gravel bikes can open up a whole new world of routes and tracks to explore without slowing you down on the tarmac. But these popular bikes needn’t cost the earth and we put four of the best go-anywhere machines under £2,000 to the test.

Also on test:

Product Specifications


Price AUD $2199.00EUR €1499.00GBP £1400.00
Weight 11.7kg (XL)
Brand Merida


Available sizes XS, S, M, L, XL
Bottom bracket Shimano Press-fit BB71
Brakes Shimano GRX400 with Shimano RT10 rotors
Cassette Shimano CS-HG50 (11-34)
Chain KMC X10
Cranks Shimano GRX600 (46/30)
Fork CF-2 carbon
Frame Prolite 66 triple butted aluminium
Handlebar Merida Expert GR
Headset Merida M2331
Saddle Merida Comp CC
Seatpost Merida Comp CC
Shifter Shimano GRX400
Stem Merida Expert CW
Tyres Maxxis Rambler 700 x 38c tyres
Wheels Merida Comp AL rims on VP CLK hubs