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Ax-Lightness Ultra 25T wheelset

The German carbon specialist brings 15 years of knowhow to bear in this 790g wheelset

Sam Challis
30 Nov 2016

In a way, Ax-Lightness’s Ultra 25T wheelset is a buy one get one free. Its weight of 790g wouldn’t be unreasonable for a single wheel, so for a set of two it borders on the unbelievable. Surely such lightness cannot be achieved without some sort of compromise in their construction?

‘There is no concession – you could ride these wheels at Paris-Roubaix,’ counters Ax-Lightness’s Nils Wiedemann. ‘Not that they’d be the best for that, but I just want to stress that they are in no way weaker or less durable than other wheels.’

He’s remarkably casual about the creation of the Ultra 25T’s – a wheelset that’s around 200g lighter than the nearest competitor. ‘They were a bit of a coincidence. We never set out to build the lightest. We just set out to build a low-profile, regular wheelset with the knowledge and resources we have available and we succeeded - they have a rider weight limit of 100kg, brake brilliantly even on Alpine descents and the strength of our rims is twice that of our nearest competitor.’

Playing the angles

At the top end of the market, a wheel’s rim is the area in which most of the weight can be lost or gained. The Ultra 25T’s rims are constructed from a pre-preg (ready-made carbon and resin sheets) unique to Ax-Lightness, and the company claims its special manufacturing methods allow it to produce a rim weight of just 200g.

‘We aren’t a large-scale manufacturer and we make things in-house, so we have no limitations,’ says Wiedemann.

‘We can realise any fibre orientation and angle that we need with specific CNC cutting. For instance, if we need to lay up at a 27° angle for a certain characteristic, we can, whereas mass production facilities in Asia typically only have the capacity to lay up at 0°, 45° or 90°.’

This means that while other manufacturers have to use a convoluted combination of layers to achieve what they want, Ax-Lightness doesn’t. ‘We use less material, but can use it more efficiently,’ says Wiedemann.

The rims are laced to DT Swiss Aerolite spokes, with Extralite Cyberhubs completing the wheel.

‘We chose Extralite’s hubs because we think they’re the best-engineered lightweight hubs. US firm Dash makes lighter hubs, and likewise we could use lighter spokes. This would create a wheelset approaching 700g, but we’d need to introduce restrictions such as lowering the rider weight limit,’ says Wiedemann.

‘As it stands, we don’t consider the wheels to have any restrictions. Most of our staff use them day-in, day-out.’

While a price of £2,100 might be a bit steep for an everyday wheel, there’s no doubt they would do wonders for your acceleration away from traffic lights on the morning commute.

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