Polygon’s new €1,299 Siskiu could be a budget trail shredder

With a host of top-performing parts, the Siskiu’s size-specific wheel sizes could offer great performance without breaking the bank

cream and black full suspension mountain bike

We last reviewed the Siskiu D7 back in 2017 and found that despite the bike having a great overall feel, it did suffer from some slightly questionable forks that flexed at the first opportunity and tyres that struggled to grip when it got wet and sloppy.


It looks like Polygon went back to the drawing board, building on their capable chassis with a host of new and better-performing parts. The new Siskiu D7 could be contending for your cash, riding hot on the heels of Marin’s highly-acclaimed Rift Zone 1.

internal cables on full suspension mountain bike
The bike’s cables are internally-routed.
Alex Evans

Polygon Siskiu D7 frame details

With 120mm of travel, the Siskiu uses a four-bar style rear suspension system where the rear wheel is bolted to the chainstay rather than the seat stay. The bike has internally-routed cables and while it doesn’t feature a dropper post, it’s dropper-ready.

rocker link on full suspension mountain bike
There’s a rocker link that drives the shock.
Alex Evans

The bike uses size-specific wheels: the smaller 15.5” frame has 650b hoops while the 17in frame can be used with either 650b or 29in wheels. The larger bikes — 19in and 20.5in frames — get 29-inch wheels and all frame sizes have a tapered head tube.

Polygon Siskiu D7 geometry

The Siskiu has promising geometry for a budget 120mm travel trail bike. The 19in, 29er size large bike has a 76-degree effective seat tube angle, a 67.5-degree head angle, 465mm of reach and a 1189mm wheelbase with a 436mm chainstay length.

The 650b bikes get 432mm chainstays, a 70-degree seat tube angle and a 67-degree head angle.

Polygon Siskiu D7 spec

cream and black full suspension mountain bike
Despite sponsoring plenty of top-level riders, Polygon’s name is still relatively unknown in the West.
Alex Evans

This is where the Siskiu D7 really shines and Polygon must’ve been listening to our every word when we reviewed the previous model.

Now fitted with a RockShox Recon RL fork that has a 15×100mm axle and 120mm of travel (for both the 650b and 29er bikes), we’re optimistic that the front end won’t be nearly as flexy as on the old model.

rockshox suspension fork on full suspension mountain bike
The RockShox Recon is a welcome addition and has performed well in previous tests.
Alex Evans

The forks are matched with an X-Fusion O2 Pro RL rear shock that has both externally adjustable rebound and a lockout function.

You’re treated to an 11-speed Shimano XT mech, SLX shifter and a Sunrace 11-speed 11-46t cassette. You also get Shimano’s M201 disc brakes with a 180mm front rotor and 160mm rear.

shimano drivetrain on full suspension mountain bike
The Shimano 11-speed drivetrain is a great performing bit of kit usually specced on bikes more expensive than the D7.
Alex Evans

The bike’s finishing kit is taken care of by a host of Polygon in-house parts, branded as Entity. There’s a 780mm wide bar, a 45mm stem and XL2 wheelset.

The wheels are wrapped in WTB Trail Boss tyres that, whether in 650b or 29in versions are 2.25in wide.

Polygon Siskiu D7 pricing and availability

x-fusion shock on full suspension mountain bike
The X-Fusion rear shock has external rebound adjustment and a lockout lever.
Alex Evans

The Siskiu D7 costs €1,299 but there’s an even lower-priced D5 that has a lower spec — a 9-speed Shimano Alivio drivetrain and Suntour fork and shock — that costs €899.

The bikes are available to buy direct from Polygon’s website, now.