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MRP G3 Chainguide (discontinued)

Average User Rating: (Very Good) Vital Rating: (Very Good)
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Tested: MRP G3 Chainguide - Easy Chain Management

Rating: Vital Review

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

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.

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3 comments newest first

Maybe use chapstick. That would keep it from cracking. Seriously though, another great review Evan! Thanks!!

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The mystery crack could be from the chain lube you're using...? I know my chain guides crack in strange places if i use the wrong chain lube.

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3 member reviews

Best Chain Guide on the Market

The Good:

strong, light weight, affordable, does what it is supposed to do, adjust to chainline w/ shims

The Bad:

could have more color options but I am nit picking to find a flaw

Overall Review:

I have had a couple of these on diff bikes and to be honest, I don't notice it which I think is the point. The chain stays put, it is relatively quiet and maint. free.  has protected my chain and sprocket many times during both DH and AM riding. 

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0 comments newest first

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lasted six short runs

The Good:

looks awesome and did run smooth

The Bad:

made from plastic that breaks easy.

Overall Review:

Mine broke in the same place as mentioned in the review. It cant be blamed on using unapproved cleaners or lubricants because the whole transmission was new.Should last more than six runs at the ski hill for the price. I think they need to go back to the drawing board on this one and make the slider out of alloy or Al.

I hope the customer service is better than the product.

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1 comment newest first

Sorry you had an issue, give us a call and we'll help you out. As for "going back to the drawing board" the truth is, we never leave. We're always looking for ways to improve our products. Cheers

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MRP G3 from Tazer255's opinion

The Good:

The guide is a huge improvement from the G2. the hinged uper and lower guides are very nice and make for easy chain install

The Bad:

bolts are very weak. I went to torque to specific torque value provided by MRP however the head snapped off. MRP replaced in a very quick and professional manner

Overall Review:

The guide is a huge improvement over their previous one the G2 and has allot of cool features. the bolt kinda sketched me out when i was torquing to their own specs the head snaps of (Bad bolt of the line i suppose). would be nice to be able to use any chainlube you want rather that "MRP approved ones" kinda annoying.  I have been having a real problem with finding a chain lube that works here in socal that doesn't dry out that also works with this guide.  If you are looking for an improvement over your G2 but don't want to run anything other than MRP than this is a great upgrade and it is also very light.  The guide is also alot more dependable than the G2 and other comparable E-thirteen guides.  Also it is allot quieter  with improvements such as a little rubber on the bottom of the top guide which also protects the guide i feel.  It is also very quick easy to install.  I would have no problem giving it 5 stars even with the broken bolt like i said earlier it was probably just a bad bolt it happens whatever, but i really wish that i can use chainlubes other than white lightning.  The only reason i bought is because I liked my G2 so much and it broke due to using the wrong chainlube.  I woulda bought another brand due to the chainlube problem however i was misled "by another reviewer on another website" to think that I could use whatever lube i wanted on it.

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1 comment newest first

Sorry about the problem you had with your bolt. We did have a few that were machined a bit deep, we've since rectified the problem. As for lubes, I find it's as much application as it is contents. By that I mean you can use nearly any lube you want and get a long life out of your guide as long as you use it appropriately. From my experience it's those who apply lube or degreaser ON THE GUIDE that have problems, also those that wash their bike with degreasers with great frequency. Run your chain through a machine or take it off to clean it and then wipe it down and you shouldn't have any issues. Same goes for lubes, apply the lube, let it settle in the chain's bushings then wipe off the excess and you'll be golden. Steer clear of any spray lubes or degreasers for sure.

I'll say these issues aren't specific to our parts, these are good rules to follow if you have any polycarbonate parts on your bike.


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Product MRP G3 Chainguide
Riding Type Trail, Freeride / Bike Park, Downhill, Dirt Jump / Slopestyle
Material Nylon upper guide with Quietring wrap // Alloy or Carbon backplate options
Speeds 1x
Tooth Range Available in “Mini” 32-36t and “Mega” 36-40t sizing
Mounting Type BB, ISCG, ISCG-05, Other
Bash Protection Yes
Colors Black or white
Weight 0 lb 6.7 oz (189 g)
Miscellaneous Swingset pivoting skid mount for fast and easy crank and chainring installation // Optional G-slide slider block (included with every guide) can replace the lower guide pulley for muddy conditions

BB mount option not available for carbon models
Price $150
More Info

MRP website

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