Bike test: Spa Cycles Audax Mono fixed-wheel bike

The Spa Cycles Audax Mono, a bronze fixed-wheel bike, propped up on a tarmac tree-lined path
First look: Sensible geometry, practical frame fittings and room for 28mm tyres. The components are decent, too
Fixed-wheel bikes have fallen out of fashion but still make great commuters, winter trainers and more. Cycle magazine editor Dan Joyce tests an £800 model from Spa Cycles

While the fixie fad has long since faded, you still see a fair few metropolitan singlespeeds with bullhorn handlebars and cheap parts. What’s far less common is the classic, drop-bar fixed-wheel bike with mudguards – a bike beloved of roadies in search of souplesse, experienced commuters and audax riders with a mad gleam their eye.

The Spa Cycles Audax Mono is one such. I planned to test it alongside a Dolan FXE but couldn’t get hold of one in time. Aside from the Genesis Flyer, which has turned into the old Day One 10, pickings are thin. Which is why this is, literally, a Mono bike test.

Frame & fork

Like a lot of fixies, the Audax Mono has a steel frame. It’s TIG welded from Reynolds 725 chrome-moly. But it differs in two important respects: it has practical frame fittings, including separate eyelets for a rear rack; and the geometry is more audax bike than track bike.

The head tube is taller and the seat tube is only 72.5 degrees, so you can sit up and back more instead of being forced down into a hand-numbing racing crouch. A shallower head angle and longer chainstays yield a more stable ride, which is particularly welcome on high-cadence descents.

A close-up showing the front brake and brake blocks of the Spa Audax Mono
There’s just about room for 28mm tyres

The front-centres distance is longer too, reducing the likelihood of toe overlap. Note that the effective wheelbase and chainstay length will depend on rear wheel setback.

I often upsize when choosing road bikes, to win toe room and get a high-enough handlebar. I didn’t have to with the Audax Mono: the 54cm model was roomy and tall enough, once I’d added another 5mm spacer – something the longer fork steerer allowed.

The fork is carbon, with an aluminium steerer, on all Audax Monos except the smallest. The 50cm model uses a steel fork, presumably with more offset. All have mudguard mounts.

There’s just enough room here, front and rear, for 28mm tyres and mudguards. It’s fairly tight, however, as the frame and fork don’t utilise all of the space available from 57mm-drop sidepulls. Check out the brake block positions (pictured above).

As well as black, the Audax Mono is offered in this metallic bronze and in Mediterranean blue.


For a budget bike, the Audax Mono has nice wheels. Sturdy 17mm cyclocross rims are laced to Sturmey Archer hubs with good-quality, well-tensioned spokes. They’re absolutely true and look likely to stay that way.

They’re fitted with Schwalbe One tyres – the rebranded Schwalbe Durano and a decent all-rounder. I’d switch to Schwalbe One Plus (Durano Plus as was) if I were buying an Audax Mono primarily for commuting.

A close-up of the Spa Audax's stem with three spacers
Plenty of steerer height and a stem to suit your back

There’s some choice with the specification, which is why the test bike has an 80mm stem and a 38cm handlebar: I asked for them. Similarly, I picked the 42/18 gearing because 63in will get me up and down local hills. You get a freewheel as well as a fixed sprocket on the flip-flop hub, and could have a tooth or two’s difference between them.

The chainring is a narrow-wide one you normally see as part of 1× drivetrains. While you don’t really need this, a narrow-wide ring’s improved retention should reduce the risk of unshipping the chain, which is dangerous on fixed if it jams.

The test bike has upgraded TRP RRL-SR brake levers (+£25). These are among the more comfortable non-integrated levers I’ve used. If you’ll only ride fixed, you can legally dispense with the rear brake as you can slow the rear wheel through backpressure on the pedals. If you’ll ever ride with a freewheel, you must keep both.

The ride

It’s a few years since I was riding fixed on a daily basis. I’d forgotten what a leg-taxing, full-body workout it can be. Riding fixed won’t just make you pedal more fluidly; it’ll make you fitter, full stop. There are really only two ways to go faster on a bike: pedal faster or push a bigger gear. Fixed-wheel trains both. 

To spin smoothly you need a gear that suits you and your terrain. The Audax Mono can provide this because you choose it. (Not sure? Try 42/18, 42/17 or 42/16.)

Close up of the chain on the Spa Audax
The narrow-wide chainring should reduce the risk of unshipping the chain

You also need the contact points just so, to avoid bouncing around like a sack of potatoes. The Audax Mono helps with this, too, as you can choose the bar, stem and cranks.

I don’t know that I’d do a long audax on fixed but I’d happily do 100km on this one if I could ride at my own pace. Fixed doesn’t work so well if you have companions on gears as you get dropped on descents, and I found single free oddly unsatisfying.


With practical fittings, less racy geometry and clearance for 28mm tyres, the Audax Mono has the key things I want from a fixed-wheel frameset. The fact that the complete bike comes with well-built wheels and components you can tweak to your taste makes it an even better buy.

I’d like a smidgen more space under the brake callipers but if you’re looking for sensible fixed-wheel bike at a sensible price, this has to be on your shortlist.

Other options

Dolan FXE Aluminium Fixie £699.98+

Dolan FXE Aluminium Fixie, a black fixed-wheel drop-bar bike with mudguards

Aluminium fixie with steeper angles than the Spa but still with rack and mudguard mounts. Fitted with a flip-flop 120mm hub and 57mm-drop sidepull brakes.

Genesis Flyer £699

Genesis Flyer, a blue fixed-wheel, drop-bar bike, no mudguards

Commuter-focused singlespeed with cable disc brakes, 35mm tyres and a wider rear axle spacing and chainline. Lacks the pep of a lightweight fixie.

First published in Cycle magazine, February/March 2024 issue. All information correct at time of publishing.

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Tech spec

Spa Cycles Audax Mono

Spa Cycles Audax Mono dimensions in millimetres and degrees

Price: £820 as tested (from £795, frameset £375 at time of writing).
Sizes: 50, 52, 54 (tested), 56, 58, 60cm.
Weight: 9.69kg/21.32lb (inc guards, no pedals).
Frame & fork: TIG-welded, double-butted Reynolds 725 steel frame with 120mm rear-facing dropouts, 68mm threaded bottom bracket, and fittings for rear rack, mudguard and two bottles. Carbon fork with 1 1/8in aluminium steerer, 100mm QR dropouts and mudguard fittings.
Wheels: 28-622 Schwalbe One tyres, Kinlin XC-279 rims (622×17) rims, 32×3 Sapim Race spokes, Sturmey Archer HBT 30 hubs with solid axles & track nuts.
Transmission: no pedals, 165mm Spa TD-2 chainset with 42t narrow-wide chainring, First Components DX-30 square-taper bottom bracket, 1/8in KMC Rustbuster chain, 1/8in 18t Spa fixed sprocket, 1/8in 18t Sturmey Archer freewheel. One ratio, 63in.
Brakes: TRP RRL-SR levers, Tektro R737 callipers.
Steering & seating: Spa Cork EVA Gel tape, 380×31.8mm FSA Wing Compact handlebar, 80×6ºFSA Omega stem, 1 1/8in FSA Orbit Equipe threadless headset. Spa Navigator saddle, 27.2×350mm FSA layback seatpost, Spa seatpost clamp.
Equipment: 35mm SKS CAB mudguards, two Spa alloy bottle cages.