I have been riding a 2018 Marin Four Corners for a few years now, and wanted to share some long term thoughts about the bike. At the time I bought it, I was looking for something utilitarian that could fill multiple roles. I needed something to commute with, bikepack and tour with, and even shred some local trails with, and I wanted a steel frame and fork. I ended up going with the Four Corners because it hit many of the marks, and at around $1300 CAD (2022 MSRP is $1539), the bike-to-price ratio seemed solid.
The bike has a pretty unique geometry, due in part to the long head tube (198mm on the medium size frame), lending itself to a more upright riding position which immediately felt good, but did take some getting used to. I have ultimately come to appreciate the geometry of the frame. It’s comfortable for long days in the saddle, but can definitely feel a bit sluggish on climbs, and somewhat cumbersome to handle through more technical terrain. The bike is on 700C wheels, although it’s available in 650B on the smaller frame sizes. I appreciate the 700C wheels for long gravel rides, touring, and bikepacking, which is now mostly how I use this bike.
The stock compenents on the bike are decent and really have put up to lots of abuse. The groupset is Shimano Sora in a 3×9 speed configuration — certainly not winning any cool points — but functional and offering decent range. I have recently replaced the drive train, which I will get into shortly, but the Sora groupset worked flawlessly for years with minimal maintenance, as per typical Shimano quality. I am still running the original bottom bracket (Hollowtech II) with no issues. The TRP Spyre C mechanical disc brakes are a good stock compenent, and have been bullet proof thus far. They are simple to work with and function well.
Much of the cost-savings on this bike come from the wheels, as is typical for bikes of this price range. They are basic aluminum rims laced to forged aluminum cup and cone style hubs. Good enough to run without issue for many years if cared for, but probably won’t stand up to serious off road abuse forever, particularly if you are in a wet climate like I am. The stock tires are WTB resolutes, a solid tire that worked well for me on and off road for years, and when fresh, the tan side-walls look very nice.
Over the years I have upgraded and swapped out parts to improve the performance and feel of the bike. I replaced the stock bars with Salsa Cowchipper’s for a little more width and added flare (Cowchipper article + video here), and for me that was a good step in improving the feel and handling of the bike. Additionally, a Brooks B17 helped me dial in the saddle comfort, although the stock saddle isn’t bad, and I am currently running it on another bike.
I replaced the Sora drivetrain with a Microshift Advent X groupset paired with a Shimano GRX 1x crankset. The gearing now is 1×10, which I love. I am a firm believer in 1x drivetrains, I love the simplicity in performance and aesthetic. The Advent X compenents are working well so far. The clutched derailleur feels solid and shifts well paired with the aluminum cassette with an 11-48t range. These components are very affordable when compared to new Shimano or SRAM groupsets, and gives the bike MTB-style gearing with no compatibility issues or new standards. My intention was to save some money on the drivetrain and invest in wheels. So far I have replaced the back wheel with a DT350 hub laced up with a WTB ST rim. This is the nicest and most noticeable upgrade by far. A good wheel (or two) goes a long way in bike feel and performance. I am going to build up a front wheel next, more on that to come.
My overall experience with this bike has definitely been positive. It served my initial needs really well, and has been a good platform to upgrade and evolve with, keeping it fun and feeling solid. It’s definitely not for everyone; it’s not super fast or particularly nimble, and the geometry might be hit or miss for certain folks, but it’s solid and compliant, and feels great when loaded down touring and bikepacking. The Four Corners has a utilitarian feel, and features like 6 cage mounts for bottles and gear and the upright riding position make this an excellent rig for travelling by bike days at a time.
If you’re in the market for a capable steel frame bike but don’t want to break the bank, or if you’re looking to get into bikepacking or need a general use utilitarian rig, The Marin Four Corners is definitely worth a test ride.