DH Security, Trail Bike Weight — it’s the promise of the SXg chain guide, the new hotness from MRP. Offering both upper and lower chain retention, plus integrated protection, without the weight of a full blown DH chain guide, the SXg is an exercise in minimalism, made possible by the new Whippersnapper lower guide.
At 106 grams, the new SXg chain guide (in the carbon iteration) is only 32 grams heavier than the XC specific 1x guide. By integrating the lower guide into the skid plate, MRP has been able to minimize weight and moving parts. Billed as a gravity guide, this device is sure to be spotted this season on everything from downhill bikes to slopestyle sleds to short travel trail rigs.
- Full-size, nylon HD upper guide with co-molded TUP material on the interior that silences chain contact
- Whippersnapper lower guide keeps the chain in check and limits chain whiplash on impact
- Alloy and carbon backplate options with complete guides weighing in from 106g (30-34t carbon ISCG-05) to 149 (34-38t alloy ISCG-05)
- Swingset technology allows upper guide and skid to swing out of the way during installation and service
- ISCG only, boost 148 compatible
- Alloy guides compatible with 49mm chain line and wider. (carbon 50mm and wider)
The new Whippersnapper lower guide is what sets the SXg apart. Previously, traditional DH chain guides used a lower roller to tension the chain. With clutch derailleurs handling the duties of keeping the chain tensioned, MRP integrated the lower slider into the skid/ bash plate. Not only are there less moving parts that previously required maintenance, it keeps the chain in check and limits the amount of chain whiplash on impacts, using TPU material on the interior to mute chain noise and slow things down.
Unboxing the MRP SXg
The SXg packaging includes hardware for bolting it onto ICSG mounts as well as a variety of spacers, instruction manual, a decal and a bag that can hold it all.
Installing the SXg is as easy as it gets. Every bolt (you only need to tighten 5) can be tightened with a 4mm hex wrench.
Step 1: Remove old guide and crank.
Step 2. Clean bike
Step 3. Install SXg.
This is obviously where things get tricky, as spacing the guide is often a matter of trial and error. The top and bottom guide has a swing away feature that allows removal of the chain/crank without having to fully remove or dissassemble them. I was using a wide spacer on my previous guide, so picked the widest spacer to match.
Fortunately, you may be able to add or subtract spacers without removing the crank each time. With my setup, a Shimano XT crank and E.13 ring, I was able to fine tune the angle without having to remove the crank.
Like the top guide, the chain isn’t actually in contact with the guide most of the time. MRP calls it defensive retention, as the Whippersnapper is only there to help control the chain under impacts. The chain runs cleanly through it, so there isn’t any energy stealing drag when it’s correctly installed.
Back on MRP
The SXg is extremely well thought out, and I’m looking forward to spending some time on it and seeing how it performs in the long term. Things are looking good though; the cranks spin freely, and it’s exciting to have this level of chain retention without any noise or drag whatsoever.
MRP SXg carbon plate: $224.95
MRP SXg alloy: $169.95
Check it out at MRP.com