Surly Lowside Frame Set, Blue Monday 2026

A single-speed bike, perfect for urban trails, pump tracks or simply having fun on two wheels.

Colour: Blue Monday

Sizes: S, M, L, XL

L in stock

The Surly Lowside 2026 frame set – Blue Monday is now available for pre-order.

To ensure on-time delivery, we recommend reserving early – as always, quantities are limited.

Specifications:

Single-speed mountain bike with trail character

• Ideal for singletrack, urban adventures and leisurely rides

• Inspired by BMX bikes – “the grown-up version of your childhood bike”

🧱Frame & fork

• Material: 4130 chromoly steel, Surly Natch Tubing

• Construction: Double-butted main triangle, TIG-welded, ED-coated

• Fork: Chromoly rigid fork with tapered steerer tubes

• Finish: ‘New Pig Smell’ – distinctive, matt look

⚙️Geometry & Compatibility

• Wheel size: 27.5" (650B)

• Max. tyre width: up to 27.5 x 2.8"

• Fork dimensions: 420 mm axle-to-crown, 47 mm offset

• Head tube: ZS44/EC44 (44 mm)

• Bottom bracket: BSA 73 mm, threaded

• Seatpost: Ø30.9 mm, dropper-compatible

• Seat clamp: Ø33.1 mm

🔩Axle & brake standard

• Rear triangle: Gnot-Boost 145 mm – compatible with 12x142 mm, 12x148 mm or 10x135 mm (with adapter)

• Front: 15x110 mm thru-axle

• Brakes: Disc brakes, IS 51 mm, max. 203 mm rotor

🧴Specifications & Features

• Bottle cage: 1 standard mount

• No mudguard or luggage rack mounting

• Optimised for single-speed, but with options for conversion

Verdict: The Surly Lowside is a minimalist, low-maintenance frameset for purists looking for a playful, sturdy bike – perfect for urban trails, pump tracks or simply having fun on two wheels.