e*thirteen XCX-ST Guide - Tested

Jan 25, 2011 at 16:29

e*thirteen's XCX-ST lightweight guide is designed for those XC and trail riders who have converted to a 1by setup on their bikes and want a simple chain retention solution.

e*thirteen XCX-ST



What is it: e*thirteen's solution for those who run a single ring, but don't need the protection and weight of a full sized chain guide. The XCX-ST is a compact, seat tube mounted guide, ideal for bikes that use press-fit bottom bracket bearings, that makes use of an upper slider for chain retention - there is no lower roller or guard. This is not the guide for those who send jumps or session stunts, don't go putting this on your 7" travel play bike just because it's light as hell. But if you run a 1by setup on your XC or trail bike, and are looking for a lightweight option, this could be it. With the availability and cost of wide range, 10 speed cassettes improving all the time, a single ring user no longer has to have the legs of a National XC champion, although local terrain will always play a part in gearing choice. A reasonably fit XC rider can now seriously consider an 11-36t cassette spread combined with a single 32 tooth ring up front, and that is exactly who the XCX-ST guide is aimed at.



The details: The XCX-ST is designed to be very minimalistic, but still rugged enough to stand up to proper XC riding, and even some aggressive trail or enduro use. The mounting bracket is hinged, as opposed to being a two piece design, and machined from 7075 aluminum. It's been made in such a way to minimize flex - the guide needs to be as rigid as possible - but at the same time, it's light, at only 75 grams. The polycarbonate slider is the very same as found on e*thirteen's popular LG1+ guide, and is keyed with the aluminum mounting bracket to prevent it from rotating. There has been quite a bit of detail work put into this small guide that is only apparent upon closer inspection. Not only has the mounting bracket been relieved of any unneeded material, but the XCX-ST also uses very chi-chi anodized aluminum captive hardware to keep the small bits from rolling under your work bench, never to be seen again. The slider uses a honeycomb construction for its inner half, keeping the grams to a minimum, but the strength high. Chainline is anything but standard from bike to bike, but e*thirteen has designed the XCX-ST to work well with standard 50-53mm setups by way of adjustable eccentric shims that are used between the clamp and your bike's seat tube. This system also allows you to fine tune the guide's position with no set stops in-between, a nice point considering the amount of funky bottom bracket, crankset, and ring combinations out there. As long as your chainline is nothing too out of the ordinary, the XCX-ST should mount up easily. Those with older bikes and drivetrains may want to check out the BB mounted XCX guide that fits 49mm chainlines, but you may be in for some tinkering if your bike utilizes the older 47.5mm number. The shape of the slider is designed to work with any ring size between 32 and 44 teeth - I bolted up e*thirteen's sharp looking red anodized 33t Guidering to complete the package.



Installation is very about as straightforward as you'd expect. The XCX-ST is available in two very different configurations: a low mount and a high mount version. This refers to the height of the slider in relation to the guide's seat tube clamp, and is important to note because many bikes are only compatible with one type. As a general rule, whatever mounting type of front derailleur your bike would use is the same mounting that the XCX-ST will use. The guide was put through its paces on my rolling testbed, a Trek Remedy, so the model tested was the high mount version. Because the slider can be split by removing the single mounting bolt, there is no need to break your chain (although you will need to shorten it if you are going from a double or triple setup to a single ring) to install the XCX-ST. Once attached, adjusting the guide's chainline is pretty self explanatory: rotate the eccentric plastic shims until the desired position is achieved. They can be a bit hard to turn with just your fingers, although there are pin spanner holes to make it easier. There is a very fine line in regards to the perfect position; I set the angle of the slider up so that it just clears that chain when in the largest cog, but the chain still made light contact with the guide when in the 11 tooth cog. I was never able to fully dial out the slight contact when in this gear, but I'm not in the 11 tooth cog often, and when I am, I'm not concerned with the the very small amount of drag. There will certainly be those out there who will be, but do keep in mind that it is much less friction than even the best set up chain guide could ever hope for.



Performance: In the case of the XCX-ST, less is more. The 75 gram, pocket sized guide worked well, despite it seeing more abuse on my 6" travel bike than e*thirteen probably intended. It doesn't keep chain noise to a minimum like a full sized guide would, but there is also basically zero drivetrain friction when using the XCX, something that a proper DH style guide could only dream of. Trail conditions are atrocious right now, which is the norm for our local mountains during this time of the year, but it performed well despite the slop. Not even a thick and heavy mix of mud and snow could jam things up, certainly proving that simple and well designed parts have their advantages. The slider itself never shifted once, nor did the clamp ever rotate on the seat tube, the XCX-ST was as set-and-forget as you could hope for. One caveat: back pedaling over rough terrain, something that is needed from time to time in order to get the desired pedal position, can derail the chain from the bottom 2/3rds of the ring. I never managed to have it come off the ring completely, The XCX's slider always prevented that from happening, and I always had it back on within seconds by putting in a pedal stroke, but therein lies the XCX's fly in the ointment; because it is a minimalist guide sans a lower roller, it will always be susceptible to this snag. For this reason, I wouldn't recommend the XCX-ST to those who frequent rough terrain - check out e*thirteen's LG1+ if that sounds like you. Chain guides as a group are a very specialized piece of equipment, but the XCX guide is even more so.

The XCX-ST works as advertised and is well suited for XC and trail riders who have made the jump to a 1by setup. It's not only much lighter than a full guide, but also doesn't have the drivetrain friction associated with a heavier DH orientated system. It will pay dividends to be honest with your riding if you are considering picking up an XCX-ST guide; this isn't the unit for riders looking to lose grams from their long travel bikes or for those who's terrain is gnarly and rough. But it could be just the ticket for many XC racers or fit casual riders that are looking for a lightweight guide alternative for their trailbike.

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