Bike test: Cannondale Synapse Sora and Spa Cycles Steel Audax 105

Built for comfort: these road bikes from Spa Cycles and Cannondale are designed for long days in the saddle
Comfort, not speed: road bikes don’t have to be designed for racing. Cycling journalist Simon Withers tests long-distance all-rounders from Spa Cycles and Cannondale

There’s more than one way to design a comfortable road bike for year-round riding, club runs, sportive or audax events, and commuting. The two test bikes both have 28mm tyres, a carbon fork, rack and mudguard mounts, and geometry that’s designed for long days out rather than racing. But the similarities pretty much end there.

Spa Cycles’ Steel Audax 105 is a traditional take on the endurance road bike, with skinny steel tubes, rim brakes, and a name that underscores what it’s for. Cannondale’s Synapse Sora typifies modern trends, featuring much larger diameter aluminium tubes and disc brakes.

While there is a difference in price, both bikes look to be good value. Spa’s bikes always are, and Cannondale’s Synapse is only £150 more than in 2018 – a nice surprise in these inflation-ravaged days.

Frame & fork

Spa’s Steel Audax has a TIG-welded Reynolds 725 chromoly frame, though all sizes except the 50cm model have a carbon-bladed fork with a straight 1 1/8in aluminium steerer. The test bike’s fork steerer had been left long, which results in a lower-back-friendly ride that’s good for urban riding and touring.

It’s excellent for seeing and being seen but you could cut down the steerer – or run more of the spacers above the stem – for a lower and more athletic riding position. The frame’s rear triangle has separate mounts for the rack and mudguards, and the chainstay bridge is mudguard ready.

While the TIG welding isn’t quite the neatest I’ve seen, I don’t doubt its functionality. The frame should last a lifetime as the steel is ‘ED coated’; this ‘electrophoretic deposition’ ensures a uniform thickness of paint. The finish is excellent: beautifully deep and lustrous.

There’s clearance for 28mm tyres with mudguards. Even without ’guards you’d struggle to fit tyres wider than 32mm, so it’s best suited to tarmac, smooth tracks and lighter loads. In many ways, including the colour, it reminds me of my first ‘serious’ road bike: a 1984 Raleigh Clubman. The Spa’s components and ride are superior, however. Not everything was better back in the day!

Cannondale was a pioneer in aluminium frame building so it’s no surprise to see a neatly welded, oversize aluminium frame at the heart of the Synapse. It features a chainstay bridge drilled for a mudguard and single eyelets at the rear dropouts for a mudguard and rack to share. The rear dropouts are quick release rather than a thru-axle, presumably as a cost saving. There’s clearance front and rear for 35mm rubber.

The frame is accompanied by a full carbon fork that uses Cannondale’s ‘SAVE technology’ – which is to say, the design and carbon layup are intended to improve comfort. The fork has a 12mm thru-axle, to make the most of the disc brake, and mudguard mounts on the inner faces of the fork blades. The steerer is tapered to maximise front-end stiffness.


The price difference between the two bikes is evident to some degree in the components, though if I’d tested the next model up in the Synapse range – the £1,200 Tiagra – the disparity wouldn’t have been as striking.

Spa’s Steel Audax 105 is equipped, as you’d expect, with Shimano’s 11-speed 105 groupset. A 50-34 double chainset is paired with an 11-32 cassette, though Spa can fit a bigger cassette to give a lower bottom gear if you prefer. (It’s also available with a triple chainset.)

Shifting is light, smooth and accurate, and the brakes are easy to set up and easily good enough for the steep descents around Bath, where I live. With 11 sprockets, the gaps between gears are less obvious than on the nine-speed Cannondale.

Spa doesn’t use Shimano 105 for the brake callipers. Instead they’re Tektro R737; the deeper-drop design allows the use of 28mm tyres and mudguards. Those full-length SKS mudguards are very effective at reducing the spread of road muck, though the gap between tyre and guard, especially at the front, is pretty tight.

Cannondale’s Synapse Sora also says in the name what groupset you’re getting. Nine-speed Sora is two steps down from 105 in Shimano’s gearing hierarchy. The shifting isn’t quite as slick and the front lever requires more effort to shift to the larger chainring.

Cannondale has, however, paired an FSA compact chainset with a larger (11-34) cassette. The resulting lower bottom gear compensates for the Synapse’s extra weight. Cables are routed internally, which makes for a very tidy-looking front end.

The Cannondale’s disc brakes are cable-actuated Promax Decode Rs. While they lack the power of hydraulic systems, they are consistent in all weathers and are pleasingly quiet, with only the briefest of squeaks from the front in the wet. The other advantage – particularly for those using the Synapse throughout winter or for year-round commuting – is longer rim life.

The standard Spa Cycles Steel Audax 105 comes with Shimano RS100 wheels but the test bike features an optional, £140 upgrade: handbuilt wheels with Bitex hubs and Kinlin rims. (Wheel-builder Bobby Stevens has done a sterling job.) I think it’s a price worth paying, as they ride beautifully.

The Synapse has more scope to tackle rougher surfaces than the Spa, having clearance for 35mm tyres. The Vittoria Zaffiro training tyres are basic compared to the Spa’s more supple Schwalbe Ones, but they’re tough and I’d be in no hurry to replace them.

There’s not too much to choose between the finishing kit of the bikes. Both have perfectly serviceable aluminium components – own brand for the Cannondale, Deda for the Spa. I had no issue with either saddle. Both bikes use high-quality bar tape with gel padding, which is good to see as it’s an area where some brands cut corners.

The ride

Both bikes offer ample long-distance comfort. You might look at the oversized tubes of the Cannondale and think the resulting ride would be as hard as Jason Statham. The chunkier main triangle, tapered steerer and front thru-axle do provide a more planted feel, especially when riding out of the saddle. But the slimline seatstays, which change profile along their length, help take the edge off rough road surfaces, and the narrower seatpost surely helps.

The Synapse handles confidently even on unsurfaced tracks like towpaths, and with wider tyres could tackle more adventurous routes. You barely feel the extra weight over the Spa even on steeper climbs, and its lower bottom gear helps out in any case.

You can choose whichever clichés you like about steel but there really is a zing to the Spa Audax, which has a lovely, lively ride. Even though the bottom gear is a tad higher than the Cannondale’s, the Spa’s lower weight helps on climbs. It’s fine when riding in or out of the saddle, and slightly to my surprise provided to be decently zippy when I put the hammer down (as much as I can these days).

With my thick winter overshoes on, there was a tiny amount of toe overlap with the Spa’s front mudguard – although not with the tyre or sans overshoes. It wasn’t enough to concern me but you might want to check Spa’s geometry tables. The Synapse’s front-centres measurement is 10mm longer so I had no toe overlap on that, and wouldn’t expect any even with a front mudguard fitted.


Both the Spa Audax and Cannondale Synapse deliver on their promise of long-distance comfort. They also have the fittings necessary for riding in manky weather on audax-type rides, commutes, training rides and club runs. The Spa even comes with mudguards.

If you’re not looking to stray away from tarmac or fit (much) larger tyres, Spa’s Audax is an all-day cruiser with classy looks and oodles of comfort. The Cannondale is a well-priced all-rounder that balances stiffness, comfort and versatility well.

Other options

Trek Domane AL3 Disc (2022-23) £1,100

Trek’s ‘smooth, stable and super fun road bike’ comes with an aluminium frame, Shimano Sora, Tektro cable disc brakes, 32mm tyres, and mounts for mudguards and a rear rack.

Vitus Substance V-2 Gravel Sora £899.99

Nominally a gravel bike, the well-priced aluminium Substance comes with 40mm tyres and mounts for everything. It looks like it would make a versatile all-rounder, commuter bike and more.

First published in Cycle magazine, February/March 2023 issue. All information correct at time of publishing.

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Tech specs

Cannondale Synapse Sora (2022)

Price: £1,000.

Sizes: 48, 51, 54, 56, 58, 61cm.

Weight: 10.36kg (54cm, no pedals).

Frame & fork: SmartForm C2 alloy frame with fittings for flat-mount disc brake, rack and mudguard, and two bottle cages. Full-carbon SAVE fork with tapered steerer, 12×100mm thru-axle, and fittings for flatmount disc brake and mudguard.

Wheels: 28-622 Vittoria Zaffiro tyres, RD 28h rims, stainless steel 14g spokes, Formula CRX-512 12×100 thru-axle front, alloy quick-release rear.

Transmission: no pedals, FSA Vero alloy 50-34 chainset, FSA cartridge BB30 bottom bracket, KMC Z9 9-speed chain, Shimano HG400 11-34 cassette. Shimano Sora shifters, Shimano Sora front and rear mech. 18 ratios, 27-121in.

Brakes: Promax Decoder R cable disc, 160mm rotors.

Steering & seating: Cannondale Grip bar tape w/gel 3.5mm, Cannondale 6061 compact alloy bar, Cannondale 4 6061 alloy stem (31.8mm, 7°), threadless headset. Cannondale Stage Ergo saddle, 25.4×350mm Cannondale seatpost.

Spa Cycles Steel Audax 105

Price: £1,265 as tested (from £1,125).

Sizes: 50, 52, 54, 56, 58, 60cm.

Weight: 9.54kg (54cm, no pedals).

Frame & fork: Reynolds 725 double-butted steel frame with fittings for rack and mudguard, two bottles. Carbon fork with 1 1/8in alloy steerer and mudguard fittings.

Wheels: 28-622 Schwalbe Pro One tyres. Front: Bitex RAF 28h hub, Sapim Race spokes, Kinlin XR22 rim. Rear: Bitex RAR 32h hub, Sapim Race spokes, Kinlin XR22RT offset rim.

Transmission: no pedals, Shimano 105 50-34 chainset, Shimano BB-R60 bottom bracket, KMC 11-speed X11-93 chain, Shimano CSR7000 11-32 cassette. Shimano 105 shifters, Shimano 105 front and rear mech. 11-ratios, 29-121in.

Brakes: Tektro R737.

Steering & seating: Spa EVA Cork Gel tape, FSA Wing compact handlebar, FSA Omega OS-168 stem, FSA Orbit Equipe sealed bearing headset. Spa Navigator saddle, Deda Zero 1 27.2mm seatpost.

Extras: SKS CAB 35mm mudguards.