Assos iJ.Bonka.6 Cento jacket review

Assos’s top-line winter jacket is designed for riding in the coldest conditions and is packed full of technical details

Cycling Weekly Verdict

If you want the best winter jacket there is, this is it.

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    Very well insulated

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    Excellent fit

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    Super breathability

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    More waterproof than most softshell jackets

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    Built to last

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    Some people may not like the integrated buff

The price tag adorning the Assos iJ.Bonka.6 jacket - £330 - is a lot of money by anyone’s standards to pay for a cycling jacket, but if you can afford it then this garment will repay you with really exceptional performance.

Assos iJ.Bonka.6 tech

There’s such a bewildering amount of tech in the iJ.Bonka.6 that Assos’s website and the label inside our test garment can’t even agree on how many different textiles, patterns and components are used.

Our label says nine textiles so we’ll go with that: the highlights are a composite of Assos’s own windproof and waterproof stratagonUltra fabric with insulating RXQ. It calls this double layer twinDeck.

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The lightweight, stretchy fabric on the back is water resistant too, and there are three good-sized rear pockets located there, plus two zipped valuables pockets and a reflective trim.

The 32 pattern pieces (or 29 depending on your Assos source) are sewn into a technical tapestry that fits the body perfectly when in a bike position thanks to Assos’s racingFit – which, as Assos warns, feels slightly restrictive when you’re standing around but backs up the Swiss company’s claim of becoming like a second skin once you’re riding.

The collar is higher than most, and for extra protection against draughts on the chilliest days the Assos ij.Bonka.6 has an integrated buff sewn into the back of the collar that you pull over your head. When not in use the buff is stored down the back of the jacket under a loop.

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We weren’t convinced by this at first: the buff was folded perfectly flat under its loop when the jacket arrived but of course you’ll never repack it that neatly yourself again, and if you like the svelte, form-fitting silhouette of the Bonka you won’t like it looking as if it has a stowaway sock down the back.

However, we’ve found that if it’s cold enough to wear the Bonka jacket it’s generally also cold enough to wear the buff. Of course a simple but drastic solution for buff-haters is take a pair of scissors to it and separate it from the jacket.

We’ve found that the Assos iJ.Bonka.6 is warm enough with just a base layer for the coldest UK days but the super breathability means you don’t overheat up to the high single digits (but not beyond unless you’re really pottering) and you don’t need to take an additional rain jacket if the forecast is iffy. Whereas many brands’ softshell winter jackets are only water resistant, the Bonka goes a long way towards being actually waterproof.


It’s got more fabrics and more tech than its rivals’ winter jackets; even down to having two zipped valuables pockets instead of one. Assos has gone the extra mile – but of course it costs.

Assos garments are designed to give several years of service and in our experience they do, so with that in mind although £330 is a lot of money if the Assos iJ.Bonka.6 lasts five years it’s worth it. And fortunately Assos has a crash replacement policy.

Simon Smythe
Simon Smythe

Simon Smythe is Cycling Weekly's senior tech writer and has been in various roles at CW since 2003. His first job was as a sub editor on the magazine following an MA in online journalism (yes, it was just after the dot-com bubble burst).

In his cycling career Simon has mostly focused on time trialling with a national medal, a few open wins and his club's 30-mile record in his palmares. These days he spends a bit more time testing road bikes, or on a tandem doing the school run with his younger son.

What's in the stable? There's a Colnago Master Olympic, a Hotta TT700, an ex-Castorama lo-pro that was ridden in the 1993 Tour de France, a Pinarello Montello, an Independent Fabrication Club Racer, a Shorter fixed winter bike and a renovated Roberts with a modern Campag groupset.

And the vital statistics:

Age: 52
Height: 178cm

Weight: 69kg