Cydonia Martyr DH Chain Guide Reviewed

Cydonia was born when its founder, Frenchman William Ortin, was searching for a chain guide that didn't utilize any plastic components in its construction. When he couldn't find one, he designed and manufactured his own. Taking on that challenge in an arena that is, for the most part, owned by two brands - e*thirteen and MRP - isn't anything to sniffle at, but the Martyr DH is certainly different enough from the competition to stand out. The most obvious talking point is its one-piece aluminum backplate and taco guard, a departure from most other options that utilize a bolt-on, replaceable guard. Clearly, this means that replacing the taco necessitates replacing the entire backplate, but we can't deny that the 222 gram Martyr DH sports a clean and purposeful appearance. There are a few questions to answer, though, mainly if an all aluminum approach, one that stems from Ortin's environmentally friendly attitude, makes sense, and if the $220 USD guide performs as well as it looks.

Martyr DH chain guide details • Intended use: downhill/freeride • All aluminum construction • Sealed bearing lower pulley • Two sizes: 32 - 36, 36 - 40 (tested) • Mounting: ISCG 05 or ISCG • Anodized with laser etched graphics • Weight: 222 grams (36 - 40) • MSRP: $220 USD

Construction

The Martyr DH features a one-piece backplate and taco style guard that is in contrast to the bolt-on, modular designs used by the competition, with weight saving reliefs cut into both the face of the guard and the opposite side of the backplate. The guard itself is attached to the backplate via two machined extensions, and it also serves as the mounting point for the lower roller assembly that attaches onto a short arm via a single bolt. Slotted and countersunk holes fit the included flush mounting ISCG hardware, and Cydonia has laser etched both the recommended torque figure for the bolts and the mounting designation, either ISCG 05 or ISCG, so you don't have to guess or measure.

The Martyr DH features plenty of impressive machining throughout.
Whereas the upper guide unit found on most of the competition is usually manufactured out of some type of plastic, mostly used for its ability to dampen the sound of the chain slapping and rubbing against it, Cydonia has gone with an all aluminum assembly with large openings machined into both the inboard and outboard faces that should allow mud and debris to escape. While it may look like the top section is solid, it has actually been machined out hollow in the name of reducing weight, and a chamfer has been added to the trailing edges of both inner faces of the guide unit where the chain might come in contact. A single steel nut and bolt hold it onto the backplate, with it being prevented from rotating by a keyed backside that fits into a corresponding slot machined into its mounting point on the upper arm. A small nut fits into the same slot, an arrangement that both prevents it from rotating and from requiring a wrench to hold it, but it is not captive and can easily be dropped if it isn't being held in place with a finger during assembly. Somewhat surprising given the attention to detail found elsewhere on the guide, the main mounting bolt (which could stand to be 5mm shorter) requires a 3mm hex key, but the countersunk bolt at the rear of the upper unit calls for a 2.5mm hex tool - it would be nice to see only a single hex key sized being needed.

An aluminum pulley wheel is used to add tension, with it spinning on a sealed bearing.

The lower guide unit, which can be removed in its entirety by undoing a single bolt with a 3mm hex key, employs an aluminum pulley wheel that spins on a sealed bearing. Much like at the top of the guide, Cydonia has removed plenty of material from the inboard and outboard plates to allow mud to pass through, and it also bolts to the backplate using the same single bolt, non-captured nut and keyed design to prevent it from rotating. Again, the unit's mounting bolt is a good 5mm too long, with it protruding out the back of the Nylock nut far enough to make us want to take a saw to it, and both a 3mm and a 2.5mm hex key are required for complete disassembly. The design also leaves the bottom third of the aluminum pulley wheel exposed, although it is mostly up and out of harm's way regardless.



Installation

We installed the Martyr DH on our GT Fury for testing, replacing a chain guide that had been bolted in place since we built the bike up back in early June. Fitting a new chain guide can be a tricky job depending on the type of guide and the bike that it's being mounted to, and it quickly became obvious that the Cydonia guide has both pluses and minuses in regards



Performance

Mounting foibles behind us, we loaded up the Fury and headed to the Whistler Bike Park to put the Martyr DH to the test. Alas, it didn't take long to run into trouble, as the chain came off of the top of the 36 tooth ring part way through our first run of the day. The same thing happened again during our next run, and although the lower guide unit managed to keep the chain from completely derailing, it continually popped out from under the upper unit on rough terrain. While we initially suspected a setup issue, it soon became clear that the dimensions of the upper unit, as well as its height relative to the 36 tooth ring, were both conspiring to keep the chain from staying put. The latter surprised us because although Cydonia advertises the Martyr DH guide as being compatible with chain rings ranging from 36 to 40 teeth - it's even laser etched onto the guide's backplate - the top unit isn't able to be lowered enough to provide proper coverage (note the setup in the photo below). On top of the lack of security, it also meant that the chain would make excessive contact with the rear section of the unit when shifted to the smaller cogs, an issue that caused much clanging and rattling when on fast, rough sections of trail. This could be lessened somewhat by rotating the guide counterclockwise on the bike's ISCG tabs, although that then puts the guide's bottom roller in a lower and more exposed position than is ideal.

The Martyr DH mounted to our GT Fury test rig.

While the noise was admittedly annoying, having the chain derail during nearly every run is a far bigger issue, and one that could lead to a serious problem if it were to happen at the worst time. Comparing the Martyr DH to other guides revealed that its upper unit features a far wider gap, and hence there is more room for the chain to dislodge. While the guide might have performed better had we used a larger chain ring (despite the fact that Cydonia says it will work with a 36 tooth ring), we doubt that it could ever be entirely reliable with such a wide upper guide design as there is enough room between the side of the chain ring and the guide for the chain to easily slip past. It doesn't take an engineer to see that Cydonia need to redesign this component, as well as allow for a wider range of height adjustment that would allow it to be used with 36 tooth rings. Talking to Cydonia's William Ortin revealed that he is aware that the width up the upper guide is an issue, and that it was done on purpose to allow the Martyr DH to be used on enduro or all-mountain bikes without any chain rub. While we didn't install the guide on a mid-travel bike to see if it resulted in smoother operation, Ortin admitted that the next production run will see the Martyr DH utilize a revised upper guide that will be both longer and narrower, two revisions that should remedy our concerns.

The guide's trouble can be sourced to its upper unit that is both too high to work well with a 36 tooth ring, and too wide to keep the chain in check.


Pinkbike's take:

www.cydonia-bicycles.com

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