Unboxing the 2021 Polygon Siskiu D6

Last year I tested the 2020 Polygon Siskiu D7, and I was impressed not just by the value of the bike but also the ride quality on offer. Polygon overhaulled the Siskiu frame design for 2020, with a geometry update that saw the bike adapt modern geometry, with a slacker head angle, lower bottom bracket and extended reach. They also made room for a water bottle – mandatory gear for most riders.

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Times change, and the pricing of the D7 crept up and the 2021 Polygon Siskiu D6 comes in under the magic $2000 mark, hitting your screens on the Bicycles Online website at $1999. Bicycles Online have just sent me one to test, so here's a closer look.

The Polygon Siskiu D6 frame

There are no real changes here compared to the 2020 Polygon Siskiu D7 – but I waaay prefer this colour! Most brands keep a frame the same for a model for 3-5 years, and Polygon did the good work for last year on the Siskiu.

The frame has a tick list of features, like a tapered head tube, dropped top tube for standover, Boost (148x12mm) through axle, ribbed chain slap protector, internal cabling, and room for a bottle cage. The bottom bracket is threaded for easy servicing.

The linkage delivers 120mm of travel from the frame – and this one in large is built around 29" wheels. Small and medium come in 27.5" wheeled sizes, although medium can also be bought in 29". There is also an XL size.

Reach is 465mm on the large, with a 67 degree head angle. The steep 76 degree seat angle keeps you centred when climbing, and short 436mm chain stays help make sure the extra length doesn't make the whole bike a barge. 

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Gearing on the Polygon Siskiu D6

Polygon equip the Siskiu D6 with a Shimano Deore 1×10 group set. That includes a 32t chain ring on the Shimano Deore cranks, with an 11-46 cassette, plus a clutched derailleur. It's a very reliable setup, and after Shimano updated the whole Deore drivetrain range last year, you're getting some of the latest equipment.

We'd love to see the 11-speed range with 11-51t, but there's no two ways about it – that just costs more. And if you want that, the Siskiu D7 at $2399 has the Shimano 11-speed Deore on it, plus other upgrades.

The Shimano brakes are the basic BR-M201 two-piston brakes. They work fine, and the 180mm front rotor adds a little more oomph. I'd suggest keeping the levers inboard so their length doesn't tempt you to fit all four fingers on there!

Suspension duties

The Polygon Siskiu D6 comes with a Suntour XCR fork, with 120mm of travel, 32mm legs, lock out, an alloy steerer, a nifty 15mm through axle, and rebound adjustment. It is 'just' a 32mm legged fork, so don't expect it to help you navigate your local enduro trails with surgical precision. But the Suntour XCR fork does offer a lot of features and adjustment – let's see how it goes on the trail.

The rear shock is the same X-Fusion model as on the D7 I tested last year (the D7 now gets a RockShox unit). The rear shock didn't leave me wanting last year, so I'll see how the bike rides this time around.

Wheels and cockpit

Bikes at entry level pricing like this one usually leave something to be desired in the wheels and finishin parts. While $2000 is still a lot of money, it's not a whole lot to spend on a full-suspension trail bike with good parts. With Shimano hubs, double wall rims and sturdy 2.25" tyres, the Polygon Siskiu D6 is doing well! Sure, I'd love to see some slightly wider rubber as stock, and I'm sure if I weighed the wheels they'd be heavy – but they will be reliable. And that's probably the first thing anyone wants.

Entity make the bars, stem, saddle and grips, and along with a Tranz X dropper post, it's a nicely finished bike. Coming in at a little over 15kg it's no fly weight, but this bike is clearly aimed at on trail functionality, and as I said first up – it ticks all those boxes.

I'll have a full review on this one in a coming issue. At a glance I think it will feel a lot like the D7 in 2021 – but the longer dropper is a nice touch.

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