9th September 2018 / Comments (11)

Review: Marin Four Corners

Marin Four Corners

Sunshine day dreaming

In the early 90s Marin were one of the most exciting mainstream manufacturers. A product of the nascent mountain bike scene in Marin County, the imagery they used in their promotional material was stunning. By the standards of the time, their bikes were pretty cool too. And when they formalised their association with F1 engineer Jon Whyte, they came up with one of the first really credible full suspension bikes. The world seemed to be within their grasp but they lost contact with the pack, fell off the back and joined the ‘autobus’.

Fast forward to today, and under new management, Marin is producing probably the most exciting and relevant bike range in it’s long history.

Marin Four Corners

Value for money?

As well as mountain bikes, Marin have a comprehensive range of drop-bar bikes suitable for gravel or adventure riding. From the full-blown ‘cross-racing’ Cortina, through to the alloy Gestalt and steel Nicasio all-road bikes, they appear to have all bases covered.

The bike that most caught our eye was the Four Corners. At £850 this sits firmly in budget territory. Having said that, not everyone wants to, or can afford to, splash out thousands on a new bike. We wanted to see whether, despite the lowly price tag, the Four Corners was up to the job.

The frameset is made from 4130 Butted CrMo tubing. Sensibly, wheel size is determined by the frame. The XS and S come with 650b while the M,L and XL with 700c wheels. (The 700c option has clearance for 700×42 tyres).

There are braze ons aplenty! Enough for six bottle or gear cages, front and rear racks and mudguards. At first glance it looks very much like a direct competitor to a Salsa Vaya or Fargo. At £850 though, it is considerably cheaper than any Salsa – at least in the UK.

There is a Four Corners Elite that retails for £2000 but that is way outside the test parameters we had set.

Marin Four Corners

The heart of the matter

Marin dub the geometry Utilitour. This seems to be shorthand for multi surface, long distance,adventure geometry!

The super-long headtube (229mm on our Large test bike) makes for an upright and stable riding position.

The tubing is classic skinny steel without a hint of oversizing or fancy manipulation. Combined with the retro Marin graphics and satin black paint, it is smart looking bike. It almost goes without saying that Marin have sensibly specified a standard threaded BB shell.  Alongside the many other practical features this was almost an obvious choice. The neat welds, downtube gusset and bolt on cable guides are all smart touches, let down slightly by the rather basic stamped dropouts. The Four Corners weighs in at 13.2 kg (29.1 lbs), it’s no lightweight, but neither is it a deadweight!

The use of QR’s front and rear is a little old fashioned but no doubt help keep costs under control.

Clearances around the supplied 42c tyres are good. Fitting mudguards, or slightly bigger tyres shouldn’t give you any problems. Just don’t try and fit any full blown MTB treads.

Marin Four Corners

Unbroken Chain

Apart from a KMC chain, the drivetrain is the much improved, though utilitarian, 9 speed Shimano Sora. It isn’t fancy, it isn’t slick but it does the job reliably. Let’s face it, that is ideal on this type of bike.

Pairing a triple chainset (50-39-30) with an 11-34 cassette gives you a spread of gears from around 25″ to 127″. By way of comparison the 1×11 Bombtrack Hook EXT we recently tested with a 40 x 11-42 gives 26″ to 98″. Ironically, you might find the extra range of the triple drivetrain to be of limited benefit.

Braking is provided by the increasingly popular TRP Spyre-C brakes paired with 160mm rotors. The Spyre’s are easy to adjust and generate decent stopping power – for cable actuated discs. It is easy to see why Avid’s BB5 and BB7 have fallen by the wayside.

Marin Four Corners

Let the good times roll

The finishing kit on the Four Corners is unexciting but perfectly functional. Marin specify 70mm stems for all sizes. Along with the 12º flared bars, this combination puts you in an upright riding position. You definitely don’t feel tipped over the bars!

The handlebar tape is quite rubbery and gives you a decent amount of cushioning.

The WTB Volt Sport 142 saddle was very comfortable.

The wheelset combines black hubs, stainless spokes and unbadged double wall alloy rims. It’s a basic set-up and there’s no mention of tubeless compatibility on either tyres or rims.

The tyres are 42c WTB Resolutes. Our recent test of the TCS Light Resolutes mirrors in our experiences here. Even in the modest OEM puncture protection variety they roll well on smooth surfaces and are grippy and stable in the rough.

Marin Four Corners


So how does the Four Corners work as a complete package?

The utilitour geometry with its high front end instantly puts you into a comfortable riding position. Having said that, it manages not to feel too ‘sit up and beg’. Putting extra power down instantly reminds you that the Four Corners is a steel tourer. If you are content with swift as opposed to fast you will not be disappointed.

The short stem keeps handling pretty lively and the high front end keeps the drops usable for most riding situations. Hit the rough stuff and the Four Corners ‘comes alive’. The traction from the Resolutes and the low gearing means that the bike will get you up most climbs.

On open trails, the relatively large volume of the tyres, the skinny steel frame and forks combine to take the edge off the harshest bumps. On descents you start to appreciate the well balanced riding position. The only thing holding you back on rapid descents is the prospect of a snake-bite puncture or dropped chain through rubble sections.

The high front end has another helpful side-effect, it opens up space for a second bottle cage on the downtube, or the option to forego the cages and use the space for a vast frame bag!

Marin Four Corners

And we bid you goodnight

We’ve really enjoyed our time with the Four Corners, it’s a lot of fun, if not super-quick. It is ideal for touring or commuting duties.

The 9 speed road gearing has the range for adventure riding but precludes upgrading to  a clutch mech.

Tubeless-specific rims should really be standard nowadays. This offsets the plus points such as the WTB tyres and saddle, gel padded bar tape and Spyre brakes.

Lets not forget the asking price. Marin are offering you a complete bike for the price that some brands would charge for a 4130 steel frameset alone!

If you’re on a budget and want a bike to get you out there and back again, you should have a long hard look at the Four Corners.

Marin Four Corners


Bombproof long distance fun



  • Value for money
  • Long distance comfort
  • Fun in the rough stuff


  • Weight compromised by cost
  • Groupset makes upgrades difficult
  • Non-tubeless wheel system

Last modified: 10th September 2018

11 Responses to :
Review: Marin Four Corners

  1. Avatar Charles H says:

    Can you elaborate on how the Sora groupset makes it difficult to upgrade?


  2. Avatar Nigel Leech says:

    Hi Charles,

    The upgrade issue, as I see it, is that the FC uses “new” road-spec 9 speed. Upgrading to Tiagra, etc. couldn’t be done in stages as it’s 10 speed so isn’t compatible. It also means it isn’t compatible with MTB 9 speed either.

    If you wanted to upgrade gearing it’ll have to be done in one go.

    1. Avatar marcus says:

      I have changed my Four Corners gearing. Swapped in a 9 speed 11-36 cassette and changed the chainset for an Alivio 26-36-48. No real problems, had to use some BB spacers I got from a BB52 to space the chainset appropriately to the sora front mech as the Alivio has a longer axle by about 5mm, but with some delicate adjustments…it works – near the limit for sure. The Sora rear derailleur coped OK with the 36T fine, and so far I havnt had to drop the height of the front mech to allow for the 2T difference on the large chainring. The 26T chainring is easily accomodated in the depth of the front cage. I may drop the FD a mm or two to see if it improves shifting, which is already 99%.
      Next plan is to swap in a 9 speed XT MTB RD and maybe the FD as well, as after researching cable pulls and ratios, I believe the new 3×9 Sora is still compatible with 3×9 speed MTB.

      1. Avatar Nigel says:

        Top experimentation there! Please keep us updated to how you get on!

        1. Avatar Marcus Rivers says:

          In the name of science…..The XT rear mech worked fine…I have about 10000km on this so its far from new, but shifting was good. The issue is that this mech has no barrel adjuster, so setting it up was a major hassle using the inline adjusters fitted to the Sora brifter, but it was possible. I have no doubt that the ratios of this new triple sora set is the same as 9 speed MTB, at least as far as the rear mech goes. Have not a suitable MTB front mech to test at the moment…..Now i have a 11-36 mated to 26-36-48 via MTB components all working fine with the road bottom bracket that was fitted, but as I said above had to be spaced out a bit with spacers to align the longer axle of the Alivio crankset within the range of the Sora triple front mech So far have not adjusted the chain length nor did I drop the front mech to the slightly smaller 48T…A success you may think….but there is more….I had a 24T XT granny ring hanging around….would it work???? Yes it does!!!! 24-36-48 mated to 11-36. World record??? HOWEVER…..in the 24-11 ratio the chain was slack….now I know you should not use this gear but it does happen by accident, so I looked at the 48-36 combi…again a gear that should not be used, but the poor XT rear mech looked like it wouldnt survive taking a link out of the chain. But there is a solution…On the RDM771 rear mech there is a pin that hits the body when in the 24-11 ratio. There is capacity in the angle of the mech to wind up a bit more, so I filed down the lip on the body until the cage wrapped around such that the chain in the upper jockey wheel just began to rub on the chain coming around from the crank. However in this position, nearly all the slack was taken out of the chain…so I consider it working. Under testing there was an occasional slip of the chain, but as we shouldnt be using this gear anyway, I dont consider it a problem, and it works well enough that I wont be regretting when I make a shifting mistake. I could file off a bit more, but I suspect that this may be risky – if I remove the derailleur – as it prevents the spring in the cage “wrapping up” when the derailleur is not under tension of the chain…so a bit risky to remove it all for marginal gains…

          I will be testing this over the next few weeks, so I will report back if anything significant happens…if not consider this a success. BTW, the new Alivio RD M4000 has the same specs as the old M771 rear mech I used, but also includes a barrel adjuster, so I may try this combo in the future.

          1. Avatar macias says:

            The FD swap from MTB world does not work out of the box (of course for the basics I assume you have correct crankset, correct FD). You need also to have cable converted — I use JTek, it looks maybe funny but does the job. So now I have both RD and FD from MTB and I am pretty happy (i.e. I am unhappy that Shimano refuses to set one standard, but it is another story).

            Use google translator to read my story: https://przypadkopis.wordpress.com/2019/04/21/nabiraj-oboroty/

  3. Avatar Darren Page says:

    I recently got a Muirwoods for towpath commutes – it too has plain black rims with no mention of tubeless compatibility. I asked Marin tech support if the rims could be used tubeless and the answer came back as yes (with tape/valves) and that’s actually how they set up their test fleet for demo events

    1. Avatar Nigel Leech says:

      Hi Darren,

      Thanks, that’s handy to know! Hope you’re enjoying your Marin. 🙂

  4. Avatar macias says:

    “The 9 speed road gearing has the range for adventure riding but precludes upgrading to a clutch mech.”

    Do MTB RDs have clutch by your definition (like Shimano Deore XT RD-M772)? I assume yes and since I upgraded with no sweat it is very possible to “upgrade”.

    1. Avatar Nigel Leech says:

      Hi Macias,

      Not all Shimano mechs have a clutch. Have a look at something like a Deore M6000 and compare it to the M772. There is a clutch-tensioner that can be switched on/off. Sadly the M772 and other 9 speed mechs don’t have them. Microsoft do a 9 speed with clutch but have gone for a different cable pull ratio.

      1. Avatar marcus says:

        Hi Macias,

        did you try the fitted sora derailleur with the Alivio chainset? I got mine to work, but I am thinking of fitting a 22-32-42 for a tour and I am not sure the FD cage profile of the Sora will suit. I have a lot of trouble getting theAlivio FD-T4000-DS3 in Norway, so I may have to order from overseas, but not keen if I need JTek adapters. I was under the impression that the sora 3 speed front was still the same as MTB and it was only the 2 speed that changed, but this info is very hard to come by with any certainty. I really despise Shimano though they make good gear. There was no need to complicate things, the last few years things have really become a mess for no good reason at all, and while I have nothing against 1by and 2by, the simple fact is that 3×9 still has/had the widest range and most reliable components- at least for touring bikes, and Shimano is killing it off. GRX is a fad for beardy hipsters!!!

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