Gipiemme Carbon H5.5 Speed

Gipiemme's Carbon H5.5 Speed clinchers aren't particularly lightweight but they're stiff and aero and they've stood up well to abuse.

The rims are made from 6082 T6 alloy with a 55mm deep carbon-fibre section bonded to the inside. The carbon fibre is structural rather than just a faring, and it provides the housing for the spoke nipples.

The forged aluminium hubs are Gipiemme's own, spinning smoothly straight from the box on sealed bearings that are easy to access with a couple of Allen keys. Our rear wheel is Shimano/SRAM compatible although a Campagnolo version is available too.

Sapim provide the spokes in the shape of bladed Cx Ray Aeros. Strong, light and aerodynamic, these are excellent quality. Each wheel is built with 20, radially laced at the front and on the non-driveside at the rear, two-cross on the driveside.

Gipiemme give the weights as 757g (f) and 928g (r): a total of 1,685g (+/-7%). That's rather optimistic. According to the road.cc scales, the actual figures are 892g (f) and 1054g (r): a total of 1,946g without quick release skewers or rim tape. With those essentials added in, the all-up wheel weight is 2,094g, which isn't particularly light. A pair of 52mm-deep Mavic Cosmic Carbone SLs (£850), for example, is about 200g lighter.

While I'm pointing out the negatives, the valve extenders that come as part of the package wouldn't screw onto any inner tubes we have in the road.cc office. And we have a lot of inner tubes in the road.cc office. Not the biggest problem in the world, admittedly: we just fitted some others.

Out on the road, the H5.5s don't spin up to speed exceptionally quickly although they are impressively flex-free. Jack up the torsion and that rear wheel stays straight. There's certainly no problem with brake rub whether you're out of the saddle and hammering on the pedals or leaning your bike over into a fast, downhill bend. The aluminium brake track also offers more control than you get with carbon so you can attack the descents and ping yourself through the corners without too much fear or preemptive braking.

Once up to speed, the Gipiemmes spin along well, slipping through the air more efficiently than a set of standard, shallow-rimmed clinchers. Keeping them spinning on flat, open roads really isn't a problem - they fly along, eating up the ground. And the 55mm depth isn't difficult to control in most conditions. It has to be really blowy before handling becomes an issue in crosswinds.

You do lose that aero advantage when you hit a steep climb though. These wheels don't feel particularly lively when the roads get lumpy. More and more people are using deep section rims for road racing and all-round performance riding, but I'd want something a little lighter than this for hilly terrain. These wheels are more suited to flattish rides when you can make the most of their aerodynamics.

In terms of durability, the Gipiemmes have performed well. They arrived round and true with consistent spoke tension and they've stayed that way, pretty much, through testing. I've tightened precisely one spoke. Bear in mind that if you want to do your own maintenance, you'll need a bladed spoke holder to keep the aero spoke oriented correctly. It'll cost you under a tenner. Or you can innovate. The Ergal freehub body is very slightly marked from a couple of the sprockets but nothing to worry about there, and although there's nothing particularly flash about the sealing on the hubs, they've kept out water and grime.

Verdict

Stiff and aerodynamic although they're not lightweight, which limits the appeal