Reviewed by Evan Turpen // Photos by Brandon Turman
The technology and design of chainguides has come a long way over the last decade. With so many similar looking designs out there, how did MRP manage to come out with a new and unique guide with features unlike the rest? Read on to find out…
G3 Chainguide Highlights
- Available in "Mini" 32-36 tooth and "Mega" 36-40 tooth sizing
- Alloy or carbon backplate options
- One-piece integrated bash guard and lower guide
- Glass-filled nylon used for upper and lower guides, which is more resistant to deterioration from chain lubes
- Swingset, G-Slide, and Quietring features
- ISCG, ISCG-05, and BB mounting options (BB mount not available for carbon models)
- Compatible with 8-11 speed drivetrains
- Available in black or white
- Weight: 167grams (Mini ISCG-05 model with alloy backplate)
- MSRP $150
The G3 guide is the next evolution of the popular G2 chainguide from MRP. With unique features such as "Swingset," "G-Slide," and "Quietring," it might sound like a bunch of marketing mumbo-jumbo, but each feature has a real benefit.
"Swingset" refers to the ability to easily swing the entire lower bash guard and roller out of the way as well as the upper guide with the removal of a single 4mm bolt each. This makes installation and maintenance on your cranks, chainguide, and bottom bracket very simple.
"G-Slide" refers to MRP’s included optional slider block that allows the user the option of a sealed bearing lower pulley or sliding lower guide. This is something that is becoming increasingly more popular in guides due to its distinct advantages and it’s nice to see MRP include it as an option.
Lastly, they’ve included a "Quietring" bumper on the upper guide's tail to help keep chain noise to a minimum when the going gets rough. A very simple yet nice touch.
Installing our G3 "Mini" guide was simple and pain free. We bolted up the ISCG-05 guide before installing the cranks or chain with the top guide removed. Next we utilized the lower Swingset feature to install the cranks and properly spaced our guide with the provided spacers. At this point the upper guide simply slid on and was installed from the top. We then utilized a quick-link and routed our chain through the guide. If you don't have a quick-link or want to break your chain, that's fine - the upper and lower swingset features make installation a breeze. Once everything was installed we adjusted the angle of the guide via the 4mm ISCG mounting bolts, snugged everything up and we were ready to go!
On The Trail
We choose to start the test with the more traditional sealed bearing lower pulley installed. This allows for a very quiet and smooth movement of the chain in all gears forwards and backwards.
Once on the trail you simply can’t help but NOT notice the guide. Throughout our test there was never a dropped chain or anything to draw attention to our guide. It is very quiet. The redesigned lower bash did its job of protecting our chainring and we have the dings and scratches on the bash to prove it. Combined with our clutch derailleur and upper guide's bumper, the drivetrain worked smoothly and quietly no matter how rough the trail got.
When conditions turned south and the trails got muddy, we installed the slider block in place of our lower pulley and were pleasantly surprised to find quiet and smooth operation in all gears. There was however a very slight amount more chain noise while pedaling compared to the pulley (although lubing our chain helped to minimize this). With the G-Slide installed, the guide never clogged with mud or ceased to operate smoothly. It's a nice option for when the going gets messy.
Things That Could Be Improved
When installing the slider block we found out that the piece that the lower bolt threads into was not captive like on the upper guide. Making this piece captive would ensure that it couldn’t be lost and would simplify installing the pulley or slider.
Long Term Durability
After about 3.5 months of use, dozens of days on the downhill bike, and a few solid rock strikes, the guide is only showing one area of concern - a crack on the inside of the guide near the lower pulley.
Given the location of the crack on the upper side of the lower guide, how it occurred is a bit of a mystery to us and one we've been scratching our collective heads about. It's not in an area where rock strikes are common, but there's a small chance that a stray rock flung by the tire inflicted some unexpected damaged. The crack formed after exchanging the lower pulley for the G-Slide a few times, so there's a chance that the nylon was weakened as a result of the swaps. Whatever the cause, it certainly seems like one of those one-in-a-million things. We've continued to use the guide since the crack first formed with no noticeable performance loss.
Additionally, as a word of caution, take care when torquing the bolts. MRP's bolt heads are notorious for stripping if you get overzealous. Our's didn't strip, but we've seen others that have.
What's The Bottom Line?
The MRP G3 is an excellent, functional, user-friendly chainguide that is easy to install and does its job extremely well at a very competitive weight. It is a set and forget item that you truly might forget about, and that's a good thing. It's also a guide that can be at home on any style of bike whether it be downhill, trail, slalom, or freeride. The G3 offers a level of refinement that really benefits the end user and we like that.
Functionally, the G3 has been dependable from day one and deserves an "Excellent" 4-star rating, but the random crack forced us to dock it slightly to a "Very Good" 3.5 star rating.
For more info or to check out MRP's other chain management solutions, visit www.mrpbike.com.
About The Reviewer
Evan Turpen has been racing mountain bikes for over 12 years. He raced downhill as a pro for the last 8 years with his career highlight being selected to represent the U.S. in the 2006 World Championships. More recently he can be found competing in enduro races and having a blast with it. His first ever enduro event being the 2012 Trans-Provence 7-day adventure race through France. He is an aggressive yet smooth rider who loves to flick the bike around to put it on the fastest line or to smooth out the rough sections. Fast flowy trails and long technical descents (Garbanzo style) are his favorite. Whistler and Santa Cruz are his two most favorite places to ride, but he can have fun wherever he goes. With an extensive knowledge of the mountain bike industry and its technologies, Evan is able to take all things in to perspective during a review. He has helped design, develop, and test products for multiple major mountain bike companies and has an attention to detail well above most. When he's not out ripping around on a bike he helps run the recently introduced California Enduro Series and is also in charge of the bike park at China Peak Mountain Resort.