The Assos Mille GT Ultraz Winter Bib Tights are among Assos’ warmest designs, pitched towards comfortable winter mile gathering.
The design is a great success and manages to combine good joint articulation with the thicker fabrics associated with greater weather protection.
However, the premium price is a downside.
Assos Mille GT Ultraz Winter Bib Tights details and specifications
Assos says the Mille GT Ultraz Winter Bib Tights take the design of its standard insulated bib tights, with an added protective softshell fabric on the front-facing panels.
This two-layer fabric – called ‘Neos Ultra’ – is said to be windproof and breathable, and features a polyurethane membrane to keep water at bay.
On the rear-facing panels, the construction is much lighter to promote breathability and flexibility, while the entire leg is lined with brushed fleece.
This also takes a two-level approach, with greater thickness (‘RX Heavy’) on the more exposed frontal areas, and less on the less exposed sections (‘RX Light’).
All in, Assos says the tights should function best in a -4 to 8ºC window.
The fit is claimed to be ‘regular’, as opposed to Assos' racier cuts, although it says the Ultraz tights are still designed to offer a good level of compression.
The brand says that makes the Mille GT Ultraz Winter Bib Tights ideal for longer winter rides and base training.
The panels are shaped to keep seams away from moving joints, while Assos hasn’t included an ankle zip to reduce the chances of rubbing.
Your undercarriage is taken care of by Assos’ 8mm-thick Mille Winter Insert, which features a ‘Golden Gate’ design – essentially, the stitching on the sides of the pad is removed to enable it to more easily settle in the best place for the rider.
The straps are well constructed with tidy seams, sitting flat on the shoulders. The Y-shape is claimed to reduce pressure while avoiding covering the shoulder blades.
The tights also feature reflective tabs over the calves.
Assos Mille GT Ultraz Winter Bib Tights performance
The Assos Mille GT Ultraz Winter Bib Tights blend weather protection and comfort to an impressive level.
Compromises are made in the design of even the best bib tights – either they’re light and flexible, but less protective, or they’re thicker and more protective, but at the cost of comfort.
There’s still a balance struck here, but the drawbacks are far less than one might assume of bib tights aimed at offering the best protection.
As someone who generally prefers lighter, more flexible bib tights, I’ve been impressed by the sensation of flexibility and balanced compression on my legs.
Yet, they stand up to showers with almost equal ability, and the technical fabric has come through multiple washes with ordinary detergent well.
Inside, the fleece fabrics are comfortable against the skin, while the seams are well-positioned and kept away from the areas you don’t want them.
Unlike the Castelli Sorpasso RoS Wind bib tights, for example, there are no seams above and below the knee, while the fabrics used are nicely stretchy over the knee.
In short, the restriction on knee movement is minimal – a very good thing.
The only flaw would appear to be on the reverse of the knee, where even Assos’ carefully produced product page film shows some bunching.
That said, while I noticed this when I started testing the tights, it didn’t cause discomfort and I’ve since learned to ignore it.
The centralised Y design of the bibs distributes any tension very well and they don't over-insulate the back, which helped me avoid overheating on (slightly) milder days.
Assos’ suggested temperature range seems accurate, having ridden in the tights with varying suitable upper layers.
I got away with one ride nudging into double figures, while the coldest ambient temperature was 0ºC with a far lower windchill factor.
Overall, the comfort is excellent – shored up by a well-padded chamois.
I’m not sure if the Golden Gate open-sided design makes a big difference compared to conventionally stitched bib tights. However, I found the pad ideal for three-hour long rides, and suspect I’d remain comfortable for substantially longer.
The cost is relatively steep, though – £250 ($325 / €290 / AU$530) is expensive in anyone’s book, even if Assos makes even more expensive models.
That said, if any bib tights I’ve tested in 2024 justify this kind of outlay, the Mille GT Ultraz Winter Bib Tights are the ones.
The similarly priced, 4-star rated Castelli Sorpasso RoS Wind Bib Tights and Rapha Pro Team Winter Tights with Pad II are both excellent performers, but neither quite get the comfort-protection balance as well-honed as here.
Those who can’t stretch their budget this far, though, would be well advised to opt for the dhb Aeron Lab Winter Bib Tights.
These, too, are very comfortable, and come in at £70 cheaper – earning a 4.5-star score.
Assos Mille GT Ultraz Winter Bib Tights bottom line
The Assos Mille GT Ultraz Winter Bib Tights are excellent. They’ve stood out as arguably the best all-round performers I’ve tested in 2024, getting the blend of comfort and protection about as good as it can be.
The only thing that may put some buyers off is, understandably, the price.
