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Polygon Bend R5 gravel bike review

The Polygon Bend R5 gravel bike comes with small wheels and a small price tag but it adds up to big fun

Polygon Bend R5
(Image: © Colin Levitch)

Our Verdict

Bang for your buck gravel bike best suited for big adventures over rough terrain

For

  • Comfort
  • Capability
  • Value

Against

  • Weight
  • Only comes in three sizes

Polygon is the consumer-facing brand of bicycle manufacturer Inserna Sena. In a similar fashion to Giant and Merida, the Indonesian brand manufactures bikes for various other brands and decided it wanted a piece of the pie itself. 

With that, its catalogue covers everything from enduro and DH bikes to carbon fibre race bikes, gravel bikes, and commuters too. 

The Polygon Bend R5 falls in as the brand's most rambunctious drop-bar bike designed to tackle everything from long gravel rides to steep and spicy single track. 

Design and aesthetics

The frame is made from the brand's ALX Alloy and is paired to a full carbon frame. There is nary a round tube in the mainframe with each hydroformed to tune stiffness into one plane and compliance into another. 

The full carbon fork has a tapered steerer tube and is wide set to allow for plenty of tyre clearance. The bike comes out of the box with 650b x 41mm WTB Venture tyres, and there is still plenty of room for bigger rubber. Polygon doesn't specify a max tyre clearance, but with 80mm between the fork legs, you should be able to slot in something in excess of two inches with room for mud. 

Polygon has quite a pedigree within the mountain biking side with its enduro and DH bikes ridden some of the sports best, and once you dig into the geometry chart, it's clear the Bend borrows some of that ethos. With a 71.5-degree head angle and 74-degree seat angle, the Bend sees a 51.9mm top tube and a 380mm reach, and a 590mm stack for an upright and relaxed position. The 420mm chainstays are relatively short for a gravel bike, measuring less than both the Specialized Diverge (432mm), Trek Checkpoint (425mm), and the Santa Cruz Stigmata (425mm). The BB drop is lower, too, clocking in at 80mm — the same as the Evil Chamois Hagar. 

Polygon Bend R5

The head tube is pretty tall, allowing for an upright position (Image credit: Colin Levitch)

While the top tube swoops low to provide for oodles of standover height, it only comes in three sizes, so if you're on either end of the bell curve in terms of height, you might be out of luck.  

All of the cables are routed through the downtube but reemerge just before the BB before branching off towards their final destination.

The overall aesthetic is quite subdued; the frame is painted silver, with the brown camouflage painted onto the fork, downtube, and chainstays — it looks ace covered in dust. 

Specification

Polygon Bend R5

The clutched GRX rear mech is flawless (Image credit: Colin Levitch)

With rack and fender mounts, as well as sturdy front and rear racks that come with the bike, the Bend R5 will happily serve as a commuter, or a bike to take on big adventures. 

The Bend R comes in two builds, one with a 2x Shimano drivetrain and the 1x version with a dropper post that I've been testing. At the back is a Shimano GRX 812 Shadow+ clutched rear derailleur, with allows for the 42-11t 11-speed Shimano SLX cassette. The GRX 810 levers are at the front, which have a lovely rubberized coating on the lever blades. This, combined with the redesigned ergonomics and raised pivot point, make one finger braking possible in the hoods or the drops. Unfortunately, this redesigns also means gloves are a must, as the ribs on the rubber hood covers eat my hands alive after a few hours. 

Spinning in a BSA threaded bottom brack is a Prowheel crankset with a 38t narrow-wide chainring with 170mm arms.

Polygon Bend R5

A 110mm dropper is usually what you would find on a XC bike, not a drop bar gravel bike (Image credit: Colin Levitch)

With only the right shifter required to change the gears, the left side lever has been cabled up to actuate the dropper post. The vast majority of drop-bar dropper post levers are absolute rubbish; they don't have enough leverage and usually feel extremely mushy regardless of how much you crank up the cable tension. Using the left shifter totally solves the issue. 

Speaking of the dropper, it's a Tranz-X 27.2mm diameter zero-offset seatpost with 110mm of the drop and stealth routing. I have been extremely impressed with this post, it has zero play or knocking as some vastly more expensive droppers do, and I didn't experience any binding or return issues. That said, 110mm is a lot of drop for a gravel bike and I think a shorter travel 80-90mm post would suit the bike a bit better. Even with the 650b wheels and tyres, it's not a mountain bike, and there is a benefit to being able to stabilize the bike against your thigh. With the full 110mm drop, the saddle may as well not be there at full travel, and if you're hitting terrain where you need the saddle that far out of the way, expect the rear tyre to buzz your butt.

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The cockpit, saddle, and wheelset all come from Polygon's in-house components brand Entity; all three are alloy and perform as expected. The wheels are tubeless-ready, as are the WTB tyres, but you'll need a roll of Stan's tape and a set of valves to take advantage.

Without pedals, this build in size M tipped the scales at 10.86kg / 23.94lbs

Polygon Bend R5

The left shifter isn't a dummy, it's wired up to serve as the dropper lever (Image credit: Colin Levitch)

Ride experience

The Bend R5 is a bike that can wear a lot of hats. With the upright geometry and heavy-duty racks, if you were to chuck a set of flats on it would be a fantastic commuter. However, the clutched rear mech, burly rubber, and dropper post make it ready for just about any gravel adventure you can throw at it. 

Whether it be fire road bashing or a bit of single track, the Bend R5 is supremely capable. With the long front centre and the ability to get the saddle of the way, I was surprised at the degree of terrain I was able to tackle with this bike before I got in over my head.

Even with the upright position, the short stem and wide bar combo make for precise handling that keeps its composure through rough ground and steep gradients. With the 450mm width and the drops, you can really put the bike on edge and push in on the shoulder tread to find grip when pinning a loose gravely corner — especially with the seat dropped. With the shorter rear end, it doesn't feel as though you're tiring to guide a boat around a sharp corner, especially if you need to make a quick adjustment to your line and the bike maintains a sprightly character. 

Polygon Bend R5

A 90mm stem at the front is paried to the flared drop bars (Image credit: Colin Levitch)

It's well established that bigger wheels and tyres roll faster than their smaller, fatter counterparts. However, with the Bend R5, I was surprised at how efficient it was along flat ground and mountain goating up climbs. Some credit is due to the WTB Venture tyres, there are supremely supple, and the tightly packed tread in the centre strip doesn't make them overly draggy.

However, this efficiency is also a nod to the frame itself, as nothing from your pedal stroke is lost to flex or wiggle, and each turn of the crank is rewarded with a surge forward. 

As much as I love the simplicity of 1x gearing, there will always be some degree of sacrifice, which manifested in the 38T 11-42t combo the Bend R5. The range at the low end of the spectrum was fantastic, and that 42T ring allowed me to spin up steep grades that I have walked up many times in the past. However, I did find myself running out of gears, or close to it on flat tarmac liaisons — especially if I had a wheel to follow. Putting a 40T ring on the would solve the top end speed issue, but at the same time, I don't know that I want to sacrifice the winch-ability of that granny gear.  

Polygon Bend R5

(Image credit: Colin Levitch)

With improvements in the manufacturing of aluminium over the years, it can be tuned to the degree that it almost competes with carbon fibre. It's clear that Polygon has made good use of this calibration with the Bend R5. With some other alloy gravel bikes that feature carbon forks sometimes, the ride quality can feel a bit unbalanced with the front end feeling transmitting noticeably less harsh vibration than the rear; however, the R5 doesn't leave you feeling beaten and battered at either end after a long ride over rough terrain. 

Having said that, there is no getting around the weight of the Bend R5, and you can feel it, especially a few hours in when you hit those 20-plus per cent switchbacks. But, the weight is two-fold, as when you come over the top of that brutal climb, the additional weight prevents the bike from getting bounced around as much on the decent and helps to keep the ride composed. 

Polygon Bend R5

The carbon fork is beefy and there is heaps of tyre clearance (Image credit: Colin Levitch)

Verdict

Over the past month or so, I've ridden the Polygon Blend R5 almost exclusively when I head out in lycra. That means road rides, gravel rides, fire road bashing, and even a bit of singletrack. It's not a racer by any means and lacks the tautness required to respond to changes in pace. 

It's a bike more for the moustached flannel-shirt-wearing gravel crowd and less for the skinsuit and power meter breed. With provisions to add racks and a third bottle cage, the Polygon Bend R5 excels through big all-day adventures, especially on those where you're not totally sure whether the terrain warrants a hardtail MTB or if you can survive on drop bars. 

What is most shocking about this bike is the price, pledged for $1,599.00 / £TBC / $2,699.00; this bike is dirt cheap for the performance on offer. There are few bikes on the market that offer this level of smiles and performance to dollar ratio for those looking to dip their toe into gravel riding.

Logbook: Polygon Bend R5

  • Time: 1 month
  • Rides: 16
  • Mileage: 676.2km
  • Punctures: 0
  • Ride types: Road, gravel

 Specifications: Polygon Bend R5

  • Price: $1,599.00 / £TBC / $2,6999.00
  • Frame: Polygon Bend R5 
  • Size: Medium
  • Groupset: Shimano GRX
  • Crankset: ProWheel Alloy 2-Piece Crankset, 38T Narrow-Wide Chainring, 170mm 
  • Wheels: Entity Alloy Double Wall Wheelset 32h, Tubeless Ready,
  • Brakes: Shimano GRX (160mm rotors)
  • Bar/stem: Entity Xpert Alloy, 450mm, Flare 16°, Entity Xpert, Alloy, 90mm 
  • Seatpost: Tranz-X JD-YSP38J, 27.2x405mm, Zero Offset, 110mm Travel
  • Saddle: Entity

Polygon Bend R5

(Image credit: Colin Levitch)