MRP SXg Chainguide

When getting into mountain biking, there are components that are mandatory for riding like wheels, frames, and forks and then there are other components that improve the quality of riding, improve your performance, and keep your bike running the way it should. I would classify chain retention systems as part of the later. Although through the improvement of other components we don’t see them as common, there is certainly a time and place for chain guides. MRP, one of the chain guide kings, came out with the SXg model not too long ago and it’s said to be one of the best, most widely versatile ones to date. Having been running chain guides since 2001 and knowing just how far some of them have come, here are my impressions on the MRP SXg carbon chain guide:

Key Specs:

Whippersnapper™ lower guide.

Full-size, nylon HD upper guide with co-molding.

Aluminum and Carbon backplate options provide a stiff foundation at two price points.

Integrated SX skid provides safeguard to the chainring and glides over rocks and obstacles.

Nylon and TPU co-molding in the Whippersnapper™ provides durable protection from external blows and mutes internal contact with the chain.

Swingset™ hardware.

All installation and adjustment operations are possible with just a single 4mm HEX wrench.

Available in 30-34t and 34-38t sizing.

Oval compatible

Alloy guides compatible with chainlines 49mm and wider, carbon 50mm and wider. Boost 148 compatible.

ISCG-05 only. Three mounting bolts required (included).

106g (30-34t Carbon ISCG-05) - 149g (34-38t Alloy ISCG-05)

US MSRP $149.95(alloy) 199.95 (Carbon)

Out of the Box:

Coming in at a staggering $200 MSRP (for the carbon boomerang), you’ll be glad to see that MRP steps their packaging up a bit above normal. When opening the box, I was pleased to see that, along with a gorgeous carbon based component came a clean MRP cloth bag. Although it doesn’t improve the performance of the chainguide, it sure makes you feel better about dropping some serious cash.

Aside from that, the quality of the carbon boomerang as well as the upper and lower mounts is top notch. The SXg chainguide is the perfect mix between the Trail and AM rated AMg and the full on DH rated G4.

A big plus for the SXg over the AMg is that it houses the same upper chain guide that fully encloses the chain as it feeds onto the front chain ring. This makes installation slightly more difficult because you need to remove the mounting bolt and open the guide itself to install/remove it from the bike but overall, is a much more secure system than what is found on the AMg.

As stated in the key specs, the SXg also comes with the Whippersnapper™ lower guide. This is a new feature that acts as a bashguard but also as a retention system so the chain doesn’t unwind from the chainring in the middle of the chunderiest of trails.

As for weight, my carbon SXg (34-38T) came in at 122 grams without any hardware. That falls within the same weight specs of the other versions and sizes so I can only assume they are accurate.

Comparing the weight of the different versions there’s about a 50 gram difference between the smaller 30-32T carbon and larger 34-38T alloy options. Is that worth an extra $50 ($1 per gram), that’s up to each rider to decide.

Installation:

Getting the SXg chainguide on your bike has never been so easy. This is thanks to the non-enclosed ISCG area of the SXg (which is only found on the carbon version; sorry fully enclosed on the alloy). What this means is you don’t actually have to remove the crankarm to install it. This may not sound like a big deal but if you label yourself as an OCD home mechanic like myself, the time you save sure adds up. As for durability, I wouldn’t imagine the non-enclosed boomerang to be any less durable than the enclosed one found on the alloy version but with a 1 year warranty, I would imagine MRP would take care of their customers (especially since the SXg high end price tag.)

Besides not having to remove your crank arm to install it, the chainguide comes with multiple washers with different thicknesses as well as long and short bolts so you are able to get the perfect spacing between both sides of the guides and the chain.

The most difficult thing about installing the SXg chainguide that I encountered was having to remove and open the upper chain guide so I could place the chain through it and removing a bolt on the lower Whippersnapper™ guide to get the chainring tucked in. All of which wasn’t too difficult as well compared to previous versions they have made.

Installation took less than 15 minutes to get dialed which is by far the quickest and most straight forward install I’ve ever had with MRP. (back in the day I have to grind chunks of the inner bash guard and boomerang to have it clear off linkages; none of which is an issue now days thank goodness.)

On the Trail:

 Unlike other chain guides which have a bottom pulley or slider, the SXg’s bottom guard doesn’t make contact with the chain during regular pedaling cycles. This is a major difference from the traditional G4 version. What this does is allows for a quieter system all together and also removes the hassle of serving or replacing wear proned parts. In essence, I don’t even notice I have a chain guide while pedaling which is the perfect scenario in my book.

The AMg and SXg are very similar in how quiet the guides are but the SXg has a slight advantage over the smaller brother because it contains the Whippersnapper™ lower guide. To be honest, the chance of chains falling off with modern derailleurs (with clutches) is pretty unlikely. But, if you have a history of “Murphey’s Law” or want to eliminate any possible issues during a race run, the SXg will put to rest any chance for the chain to fall. Since I installed the chainguide, my drivetrain has performed perfectly with no hickups with the chain falling off whatsoever.

Bottom Line:

MRP incorporated a lot of awesome technology into the SXg chainguide. It’s easy to install, works flawlessly, and is silent. Although I’m not exactly looking to smash it up anytime soon, I feel it will handle most anything thrown at it. At $150-$200, it’s certainly not the most budget friendly option out there. But if you can justify such a purchase, I feel it’s a purchase well made.