Spin K2 Carbone XLR38 25mm Fat Boy Clincher wheels

Spin's K2 Carbone XLR38 25mm carbon fibre clincher wheels offer bags of speed with a fat rim profile reminiscent of a Zipp or Enve but at a fraction of the price, making them an ideal upgrade for anyone looking to invest in their first deep section carbon heels.

The all-carbon rims are 25mm wide at their widest point, with a toroidal rim profile. It's the way most rim manufacturers are going, as it's commonly accepted to be faster in a greater range of yaw angles as well as being more stable in crosswinds than the previous generation of narrow V-shape rims. They certainly feel fast in testing and hold their own against more expensive wheels.

One easily detectable benefit of the wider rim is that the 23mm Schwalbe One tyres I fitted actually measured 25mm across, providing the benefits of a wider tyre with no weight increase. This also produces a nice seamless rim and tyre profile – no light bulb effect here – which produced a very stable tyre and was a noticeable benefit through hard cornering, such as in a criterium race.

Spin offer a choice of rim depths. At 38mm, these are the shallowest option. It's a good all-round option, more stable in windy conditions than a deeper rim, and obviously lighter as well, so ideal for hilly terrain. A deeper rim might be more aero, and better suited to heavier riders and flatter terrain, but I think the 38mm is the perfect choice for a wider range of applications.

The rims are laced to Spin's own SPN Precision hubs. These hubs are diminutive in size and the HyperDrive freehub produces instant engagement and a pleasing sound when freewheeling, without the excessive noise of some hubs. It's an 11-speed freehub with a spacer provided if you're running a 10-speed setup. Any problems Spin might have had in the past with hub reliability are firmly in the past; these hubs were utterly reliable.

These wheels feature Sapim CX Ray aero bladed spokes, 20 in the front wheel and 24 in the rear. Spin build all their wheels at their own facility in the UK and it's testament to the build quality that I have ridden these wheels through some very unfavourable conditions and rough roads, and the spokes are still showing good tension, and the wheels still very straight.

The wheels weigh 1,465g for the pair. That's 655g for the front and 810g for the rear. It's a very competitive weight, certainly for the price. You won't get much lighter unless you're prepared to spend quite a lot more money.

Braking performance has been an issue for carbon rims in the past, but with the supplied QuickStop Black Shadow brake blocks, there were no issues with braking. In fact, braking was excellent and up there with the best braking carbon rims. No noise, no drama, no fuss, just solid and dependable braking all of the time. That's good to know if you want to ride the wheels all of the time, every day. With this level of braking, there's really no reason why you can't.

They're fast and fun wheels to ride. They accelerate very quickly, with nice response when sprinting out of the saddle, and no detectable flex at extreme lean angles. Get them up to a fast cruising speed and they feel wonderfully stable even in blustery cross winds. Over rolling terrain they exhibit a nice nippiness when cresting rises and swoop through steep descents. What I wasn't expecting was for them to be as sublimely smooth as they proved to be.

There has been a rapid rise in the choice of carbon fibre clincher wheels at the £1,000 mark and it can be difficult to differentiate between them. Spin have a good few years behind them, and it's nice to know they build all their wheels by hand in the UK. These have a thoroughly modern rim design echoing that of more expensive wheels on the market, but at a fraction of the price and with fantastic speed, reliability and dependable braking performance. That they look good too makes them easy to recommend.

Verdict

Deliciously fast and smooth carbon clincher wheels at a great price and weight