e*Thirteen single ring conversion

The not-so-minor details


XCX-ST D-Type chain guide and Guide Ring


Dirt Works



XCX-ST D-Type chain guide


Guide Ring



So simple, light, and perfect in its operation.


We can't think of any.

Single chain rings: everyone is doing it, and the trend of the one ring mountain bike is not going to go away either. Running only one chainring is a compromise of gear range in exchange for dependability and reduced weight, and in many cases it’s a compromise worth making. [private]

Quite and unassuming in its operation, this guide gets the job done without any fuss.

Converting an existing double or triple chain ring to a single chain ring setup is about easy as buying the right pair of shoes; sometimes you’ll find perfect compatibility, sometimes you’ll need to try a few to find what fits best. In this case, e*thirteen have done all the research for you, and offer a chain guide for practically any bike and purpose, so all you need to do is know what your bike can accept and say the word.

We wished to convert our bloody lovely Yeti SB66 Carbon to a single-ring all-mountain machine. The Yeti did come with an ISCG adaptor around the bottom bracket, but we went for the XCX-ST D-Type guide which mounts straight of the direct-mount derailleur tab (an increasingly common derailleur mounting system). The guide can handle any chain ring size from 34 tooth up to 42 tooth. Then we chose a chain ring, the e*Thirteen Guide Ring; a specific chain ring for single setups, with no shift ramps and a very stiff looking construction. It’s available in plenty of colours and sizes in one-tooth increments. After a bit of umming and ahhing about gear ratios, we chose a black ring in a 34 tooth size.

It is worth opting for a chainring designed for a chain guide. Stiffer, stronger and more durable than one that is designed to have a chain shifted onto it.

When it comes to fitting chain guides, the bad old days of grinding, adapting, dodgy parts, cursing and late nights are well behind us. The fitment process of this chain guide took about 20 minutes. Cranks off, chain ring on, guide on, chain back on and it was time to fine tune. The instructions were as clear as could be, and the trial and error was over and done in no time. There are thin spacers provided to get the guide centred over the chain ring, but our Yeti didn’t require them. So simple, and perfectly effective.

Via the use of shims, the alignment can be tuned so it’s just right, and drag free.

Our big questions were: would the gear ratios on offer be ok? Would the chain stay on without a lower roller on the chain guide? The answers to both questions are a definite ‘yes’.

On the trails, we instantly forgot the guide was there. It weighs a measly 60g and never once dropping the chain again was a big win. The lowest gear (34 up front, 36 out back) was fine to grind up the steep climbs, though tough at times, and we did run out of gears when flying down fire trails. But the silent running and perfect confidence in your pedal stroke was worth it. That uncertain feeling of when you put all your power into a pedal stroke out of a corner and wondering if the chain is 100% on the right chain ring, was all gone. Our Yeti runs an XTR Shadow Plus derailleur which does a good job of keeping the chain stable. We honestly think that with this new style of derailleur (or the SRAM Type 2 mech), the need for a lower roller on a chain guide on anything but a downhill race bike is no more.

Used in conjunction with a Shimano Shadow Plus rear derailleur (or a SRAM Type 2) we found no need for a lower roller or guide. Lower guides add drag and noise to the systems, running a bike without one is refreshingly quiet and smooth.

Losing the front shifter gave us more flexibility in our cockpit setup too; we were then able to run the fairly large FOX D.O.S.S. adjustable seatpost lever where the front derailleur shifter used to be – much neater! Front derailleurs are on thin ice; their future in high-end mountain bikes is not bright. With the onset of SRAM’s single-ring eleven-speed XX1 drivetrain (and whatever Shimano will fight back with), we will be seeing a lot more of single ring bikes. So give it a try, and join the single ring revolution. [/private]

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