Merida Silex 400

The Merida Silex 400 is one of the aluminium alloy models in Merida’s gravel and adventure lineup, and while it uses geometry that comes more from the mountain biking side of things, this 2x Shimano GRX-equipped version with multiple mounting points makes a lot of sense for the roadie too. It’s a do-it-all allroad machine, commuter, light tourer, winter trainer and anything else you want to ask it to do.

Merida Silex 400: Ride

As this is primarily a road bike website, the first thing I’d say is don’t be put off by the Silex’s very relaxed (compared with general road/gravel) front-end geometry. The numbers may look well off what you are used to, but as a package the Silex rides very well indeed; it’s very easy to ride on all terrains.

The handling is smooth and well balanced, and while the steering isn’t as quick as more aggressively designed gravel bikes, it’s still quick enough to have some fun on the descents while on the road, and gives a real sense of composure and control on looser surfaces.

With a longer fork than a road bike would have, paired to a tall head tube, the front end is quite high, and the long top tube adds to the reach figure (although that is offset by the short stem). But I found the riding position overall very comfortable – perfect for long hours in the saddle – and never feeling too upright.

With a pair of 38mm slick Panaracer GravelKings fitted, the Merida felt efficient on the road and would definitely work as a tourer where you want the ability to mix up terrains. It has quite a steep seat angle, which let me get into a forward position and push the power out through my legs. That worked well on long, steep drags as I could remain seated while still getting plenty of power out.

At 10.69kg it’s not exactly a lightweight bike, but it still feels nippy and rewarding if you want to get a lick on. The aluminium frame is stiff, which helps, and it copes well with being loaded up as well. I tried the Silex out with a large saddle pack, bar bag and some packs fitted to the fork legs, and the frame and fork coped with no issues whatsoever.

In fact, as an allroad kind of bike it works really well. It’s comfortable on poor road surfaces, and rides well on the smooth stuff too.

Obviously, it’s away from the road that the Silex really comes into its own thanks to the geometry, bolstered by the 45mm tyre clearance.

My main testing route is a mixture of hardpacked gravel tracks, chalk and grass-covered routes plus a bit of singletrack thrown in for good measure. The Silex worked brilliantly across all of these, and with the trails running very fast due to the dry weather, I felt comfortable in really letting the bike go and just enjoying how easy it was to ride.

The stability and easy nature of the frame means that even those new to gravel, or who aren’t comfortable on technical descents, would get on well with this bike. It responds well to small inputs from the rider and the geometry means it never feels twitchy or out of control, even when technically it is as it slides on some loose gravel.

On rocky, technical section I think the geometry helps it feel more poised than a road-based gravel bike, especially at very slow speeds when trying to pick your line. It feels kind of like a drop-bar cross-country bike.

The gearing is lower than a road bike, but the 2x option gives some close ratios which makes for plenty of efficiency and offsets some of the weight for use on the road compared with a 1x.

With the standard tyres fitted there is plenty of mud clearance, so this is an all-round machine too, perfect for the winter months when the conditions are wet and slippery.

On the whole, in terms of the ride, the Silex is a capable machine, primarily as a gravel bike but also as an allroad bike with extra tyre clearance.

Merida Silex 400: Frame & Fork

The Silex range was first released about seven years ago and had an update last year to some of the geometry and tube lengths, and an increase in tyre clearance from 42mm up to 45mm on a 700C wheel – helped at the rear by the use of a dropped chainstay. This allows it to run either a 1x or 2x chainset, and it’ll still take 42mm tyres with full mudguards fitted; the fork will actually take a 47mm tyre.

There is no option for a rear rack, but considering the amount of saddle-mounted bags on the market, they aren’t really necessary. There are plenty of other ‘extra’ mounts too: two sets on the top tube, one under the down tube, and three bolts on each fork leg.

There are also bottle cage bolts in the usual place, but you get three on the down tube to give you some flexibility when running a frame bag inside the main triangle.

The full-carbon fork also has routing for a dynamo hub, and Merida has now run all of the gear cables and brake hoses internally from the top of the head tube.

The Lite II frame is manufactured from Merida’s ProLite 66, which is a 6066 grade of aluminium alloy whose tubes have been hydroformed as well as triple butted, manipulating them for strength or comfort. Larger cross-sectional areas are used at the head tube junctions, while things are much more slender at the rear for some compliance.

If I’m being really picky, the welding isn’t the smoothest looking, but I do think the paintjob here offsets it well.

The Silex uses a standard round seatpost and seat clamp, which makes any upgrades easy, plus this latest design now uses a BSA threaded bottom bracket as opposed to press-fit.

As I mentioned earlier, the Silex uses geometry that is based on mountain bikes, which makes it quite long and tall. The model I’ve been reviewing has the newer frame, which was updated in 2024, but overall the riding position is very similar. Compared with earlier examples, the head tube is shorter by 30mm, but Merida has lengthened the fork from 397mm to 415mm, which offsets some of that. This not only allows the larger tyre clearance, but also the fact that the Silex can run a gravel suspension fork without it affecting the handling.

On this medium model (the middle of five sizes – an XS was added this year) the head tube is 170mm long and sits at an angle of 69.5 degrees, slacker than the previous version’s 71 degrees, and the top tube is 580mm in length, 1mm longer than it was before.

Stack and reach figures are 607mm and 412mm respectively. All bike sizes use an 80mm stem.

The seat tube sits at a steep 74.5 degrees and the overall wheelbase length is 1,082mm. The bottom bracket drop is 75mm.

Merida Silex 400: Finishing kit

There are six models in the Silex lineup, three carbon fibre (we also have the £4,800 range-topping 8000 model in for review), and three aluminium, starting with the 200 at £1,200. This Silex 400 sits next in the hierarchy, costing £1,650, and comes fitted with Shimano’s GRX 400 2×10-speed groupset and alloy Merida wheels.

The Silex 400 actually uses a GRX 600 crankset, which has a 46/30-tooth combination paired to the 11-36T cassette. It’s a good spread of gears for all kinds of terrain, and the system works well in terms of gear shifting and braking.

Another thing it has inherited from mountain bikes is the size of the rotors, with the front sporting a 180mm rather than the usual 160mm. The rear is a 160mm.

You can read our full review of the 11-speed GRX 600 groupset if you’d like to know more.

The rest of the components are from the GRX 400 stable including the mechs, shifters and brake callipers.

Merida has a large parts catalogue so it’s no surprise that the Silex 400 is adorned with own-brand kit. The Expert GRII alloy handlebar comes in 40cm, 42cm and 44cm widths depending on frame size, and is comfortable in use. Like many gravel bars it has a gentle flare, with the bottom of the drops wider than the hoods. This allows a wider stance for more control on looser surfaces.

The Team CC III stem is also alloy and is designed to run the cables discreetly into the frame.

The seatpost is also aluminium, with a 5mm setback, and at 27.2mm diameter it’s a standard size, so easy to upgrade should you wish. The Merida Expert saddle has a decent shape, and I found it comfortable overall. A neat touch is that Merida includes a multi-tool underneath it.

This model also uses Merida rims and hubs for the wheel build. Again, they performed well, and I had no issues with them whatsoever. They seem reliable enough, and while they’re a bit weighty I wouldn’t be in too much of a hurry to swap them out.

They are wrapped in Maxxis Rambler tyres in a 45mm width, which are set up with inner tubes from the factory, but the rims are tubeless ready so you’d just need to add tubeless tape and valves to complete the setup.

The Ramblers are good for mixed conditions, with enough tread to cope with softish mud and loose gravel as long as things aren’t too extreme. They should suit the spring/summer/autumn months, with something with deeper tread required for the winter. Puncture protection looks to be good, and they roll on the road okay as well.

Merida Silex 400: Value

For a gravel bike with a good quality aluminium frame and this specification, the Silex 400 looks to be decent value, although there are some similarly specced options out there that slightly undercut it.

If you want a gravel bike that’s more on the mountain bike side of things then an alternative could be one of Boardman’s new TRVLs. All three bikes in the range are designed to work with a 40mm RockShox Rudy suspension fork and come with a 6061 grade aluminium frame. I reviewed the 8.9 DB model recently, which has clearance for 50mm tyres and a SRAM Apex 1x groupset, and is priced at £1,800.

The rigid fork option is the new ADV, which has more road-orientated geometry and 42mm tyre clearance. The ADV 8.9 uses the same groupset as the Silex 400 and also has an alloy frame, so it’s quite the bargain at just £1,200. (I reviewed the ADV 9.2 Carbon at the end of last year.) 

Marin’s Gestalt 2 is an alloy gravel bike with 45mm tyre clearance. It, too, uses the same groupset as the Silex and costs £1,449. (There’s a review of the Gestalt XR from 2023 on our sister site, off.road.cc.)

Ribble’s new Allgrit gravel bike range has clearance for 50mm tyres and multiple mounting points, like the Silex. We are yet to review one, but the aluminium option has a SRAM Apex XPLR groupset, DT Swiss G1800 wheels and Schwalbe G-One R tyres, and costs £1,699.

For more options, check out our guides to the best gravel bikes and the best gravel bikes under £2,000.

Merida Silex 400: Conclusion

Overall, the Silex 400 is a quality all-rounder. A bit of an allroad bike but with much greater capabilities. It’s best suited to gravel and off-road stuff, as you’d expect, but it’s very easy to live with on the road, and in this spec I’d say it makes the ideal all-season commuter or long distance machine too. It’s a great bike to ride, and at £1,650 it’s a decent price too.

Verdict

Very capable machine blending mountain bike geometry with drop bars and a rigid setup, an allroad bike on steroids!

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