NoPains Merida Silex Gravel Dropper Project

Aside from the adventure look, the Silex impressed with its geometry and riding characteristics: 'Inspired by MTB - with a high front, short stem, and steep seat angle.' It's incredible how differently the Silex rode compared to the Scott Addict Gravel. Although comparing the two gravel bikes is like comparing a rally car to an off-road vehicle, since both bikes were originally developed for completely different purposes, my home trails remained the same.

The Merida Silex possesses enormous tire clearance, a slack head angle of 69.5° for more stability and higher off-road capability, 180 mm disc brakes as standard, is compatible with dropper seat posts, and has numerous mounting options.

Primarily, however, it offers tremendous comfort and glides over rough rubble as smoothly as over firm gravel or asphalt. And it does so even with the aero-optimized DT Swiss GRC carbon wheels of the first generation, which, due to the high rims and short spokes, tend to be on the unforgiving and harder side.

The most significant performance and comfort gain for me was achieved by switching from Shimano's "old" GRX 2x11, specifically designed for gravel riding, to the latest GRX with 1x12 gears. Not only can every gravel racer appreciate the tight, precise gear ratio of the RX820 1x12 setup with a 10-45T cassette, but the new GRX, assuming the corresponding rear derailleur (RD-RX822-SGS) is used, is also compatible with Shimano's 10-51T MicroSpline cassette. Combined with a chainring of 40T or 42T, everyone should be able to find the optimal gear even on the steepest gravel paths or ascents in the mountains.

The first rides already hinted at what was later confirmed by sober calculation.

Comparison: GRX 1x12 42T (10-51 MSR) vs GRX 2x11 48/31T (11-36 HG)
GRX 1x12 (lowest gear): 42:51 = 0.8235 (smaller ratio = better)
GRX 2x11 (lowest gear): 31:36 = 0.8611

GRX 1x12 (highest gear): 42:10 = 4.200 (almost as fast as with 2x11)
GRX 2x11 (highest gear): 48:11 = 4.3636

Conclusion: The biggest advantage over the previous GRX 1x11/2x11 is the expanded cassette range of 10-51 across the 12 gears. Finally, there is no real disadvantage downhill compared to the 2x version, and uphill it even offers at least one additional lifeline, making climbing more relaxed and enjoyable.

Furthermore, chain sucks and chain drops are virtually impossible (I've had none so far) and the GRX 820 crankset is visually and technically identical to its predecessor (810), which is why I was able to continue using my old 810 Stages arm (both 172.5 mm).

However, there were two small downsides. First, a special MSR MicroSpline Road Freehub was required for the MicroSpline cassette, which initially was very difficult to find for my wheels, second, the new Shimano GRX 1x12 is only available in a mechanical version for now. However, the mechanical group offers the possibility to control a Dropper Post without an additional lever with the left mechanical GRX lever (ST-RX820-LA). How I managed to combine the Shimano lever with the FSA post, you can read in the related Thread.

With the new GRX group, Shimano is once again mixing road and MTB components and complements the ensemble additionally with their Microspline MTB cassettes. To mount a Microspline cassette on the wheel, one needs a Microspline freehub - so far so clear. However, current HG-Road freehubs compared to MS-MTB freehubs are about 1.1 mm longer, which means that after the freehub upgrade (switching from HG-Road to MS-MTB) a rear hub designed for 142 mm in total could only be 140.9 mm wide (!).

Although this is not so tragic when installing it in a gravel bike, the gears will most likely need to be readjusted because the derailleur hanger will no longer be perfectly aligned and the gears may not shift optimally or the chain could even fall off the 10-tooth sprocket. Additionally, swapping the rear wheel with multiple wheelsets proves to be a test of patience.

Our Tip: When ordering a retrofit of your gravel wheelset (based on a road setup), make sure to get a Microspline "Road" freehub and check afterwards if the hub has an installation width of 142 mm. If you ride a gravel wheelset based on an MTB setup, you might need a standard (MTB) Microspline freehub, otherwise you might end up with a width of 143.1 mm. Those who have purchased a complete bike with a 10-51 setup probably don't need to worry, as the manufacturer has hopefully taken this into account.

We asked ChatGPT what he thinks about Dropper Posts on a Gravel bike and the arguments against it. His answer was quite clear:

"A dropper seatpost allows you to quickly and easily lower the saddle to improve handling and control on challenging terrain.

Arguments against using a dropper seatpost on a Gravel bike could include:
1. Weight: A dropper seatpost adds extra weight, which could be a disadvantage for some riders, especially those who prioritize a lightweight setup.
2. Complexity: A dropper seatpost is technically more complex than a conventional seatpost and may require more maintenance and service, which could mean additional effort.
3. Reliability: Dropper seatposts may be more prone to issues and failures, especially under the harsh conditions of Gravel biking, which can lead to unexpected breakdowns.
4. Cost: Dropper seatposts are generally more expensive than conventional seatposts, which can be a decisive factor for some riders.
5. Redundancy: Some riders might argue that a dropper seatpost on a Gravel bike is superfluous, since Gravel bikes are primarily designed for mixed surfaces and not for technically demanding downhill trails.

Ultimately, the decision whether a dropper seatpost makes sense for your Gravel bike depends on your personal preferences and the intended use.", Chat GPT 3.5 on April 15, 2024

Well, that's true. Personally, I wasn't really sure what a Dropper Post could do or whether it was sensible before the review, and after many test rides, I must confess that I'm still undecided. Purely rationally, I could probably do without it without any problems.

However, lowering the seatpost does make a significant difference on extremely steep descents. On one hand, it allows for easier weight shifting to the rear, and on the other hand, the feeling of safety increases so much due to the proximity to the ground that one throws oneself into the descent with even more courage than usual.
Of course, everyone must ask themselves how often they want to tackle such technical descents at high speed, and whether the technical extra effort (installation and maintenance), the less pleasing aesthetics, and the extra weight are really worth it. Aside from that, I was able to identify another disadvantage in practice: any "shifting error" at the left GRX lever, when you want to shift from the large to the small chainring as usual with 2x setups, is immediately punished with the loss of 10 cm of seat height.

Note: When tightening the seat clamp, one should proceed with caution and by no means skimp on the use of carbon paste, in order to keep the required torque as low as possible. Presumably due to the low weight, the FSA seatpost begins to deform minimally with too much torque, which can lead to the dropper not extending as smoothly. Even at the maximum specified 5 Nm, blockages can already occur.

All in all, I would describe a Dropper Post on a gravel bike as a hobbyist feature, but also as a game changer in specific situations.

Because even on fast asphalt descents, the lower center of gravity can be exploited to the fullest. A lower seat at high speeds means a sometimes extreme aero advantage, in addition, the center of gravity is lower and allows for better bike control (see Mohorič's victory at the Milan-San Remo race 2022).

And even the safety advantage cannot be denied for city bikers or world travelers. With the FSA post that can be lowered by 10 cm, it doesn't matter whether you're being chased downhill by a rabid fighting dog in Favoriten, a pregnant hippopotamus in Africa, or a Mongolian snow leopard: With the ultra-low center of gravity, the 180 mm discs at the front and rear, and the endlessly grippy Schwalbe G-One R/RS tires, you can throw yourself into the next descent without reservation and escape from your pursuers with confidence.