Assos iJ.bonKa.6 Cento fit jacket

What’s your view on climate change? Because, you know, in certain countries you may never need to wear this jacket. Indeed, if it lasts as long as I think it will, then even the Swiss may not be able to make use of it. The last proper winter down ‘sarf is fast becoming a decent memory and, as I write this, the number of days I’ve been able to wear this is in single figures. But those were cold days and very windy ones. If you’re reading this in Scotland or Northern England, this may well be the thing for you. You Europeans, yes. Us in the shandy drinking south of the UK, perhaps not so much. Anyhow, on with the review.

I’ve spelt all of that title correctly including the full stops and randomly capitalised letters. I blame Apple for that stuff. I can’t blame them for bonkers (sic) naming conventions though. The Bonka (and that’s how I’m spelling it) is arguably, on price alone, the world’s greatest winter cycling jacket. Is it bonkers good? Bonkers expensive? Or both? At an RRP of £330 can it ever be remotely justified?

The Bonka has been knocking around for a few years now, it was actually first released around 2011. What’s remarkable is that it still looks modern (in a way only Assos can pull off). A few details have been refreshed to keep it up to date. It replaced, at least in that the others were discontinued, the venerable Airjack 851 and Fugujack jackets. Assos don’t claim this as a direct replacement. I do. Both were superb jackets. Indeed, if you can find either of them at a reasonable price now they continue to push the boundaries. Arguably the 851 Airjack belongs in the pantheon of iconic winter jackets. As much an art form as a piece of cycle clothing. And the Fugujack? An Airjack on steroids. Suitable for only the very coldest of days. There’s no escaping the S&M look though. I had an Orange backed 851 and it was a very wonderful thing.

One of the (many) things that Assos do well is theatre. Even the lowliest of jerseys comes in a presentation wallet, the shorts in slip boxes and the Bonka in full on grand opening presentation mode. It’s not just a box, it’s a display containing all of the pertinent information about the product. This is no plastic bag. It’s an attention to detail that’s probably pretty cheap to pull off but elevates the product above its (chiefly Italian and British) competitors. You pay for it, naturally. Theatre is good.


The Bonka comes in two types of fit, the Cento (tested here) is for the more svelte athlete and the Mille for the larger bodied one. Many years ago I ordered the (XL) Mille and had to return it for the Cento in XL. That made me happy as, clearly, I am svelte (insert smiley). You get a more race fit with the Cento. At 39″ chest it’s spot on on me. I’d suggest it’s good for a maximum of 40-40.5 chest. I’ve not tried the L in Mille but I do think it’s worth trying them all on to get the right fit. The Mille seems to be in very short supply now so I wonder whether it’s being phased out.

The range comes in 4 different colours, each varying only the front colour. The red, pictured here, is my favourite. Then there’s a blue (not available in Cento) black and white Personally, I’d avoid the latter. It’s just one more white thing to keep clean and this is winter. There’s a 5th ‘colour’ as well, the Profblack version (only available in Cento). It’s all black losing the sleeve design but gaining a few subtle changes. I have to say that the current obsession with black from Assos and Rapha (to name a few) is a tad unsettling but it’s all about giving more choice. Visibility aside, it’s as good looking a black jacket as it’s possible to be.

20170210_100731A colleague once remarked to me that she thought that the sleeve contrast was very effective, she’d been following me in a car. I think that’s a fair point, the contrast of the shapes is something that catches the eye. The front zip is reflective as well. The front section is all ‘windstopper’ but, as you’d imagine, it’s all Assos’ own work consisting of a variety of proprietary fabrics. Assos described it as follows:

The iJ.bonKa.6 features 32 pattern pieces, 6 different textiles and 13 components. ASSOS technology TwinDeckFoiling in the chest and upper arm sections is a labor-intensive double-layer construction, a combination of strataGonUltra airBlock textile outside and RXQ fabric inside. Why? More effective insulation, better contouring fit. The chest and elbow areas feature an additional, in-between wind protection layer. – Inside the collar area, the iJ.bonKa.6 features an additional, ergonomically shaped inner layer.

I don’t propose to use Assos’s technical terms for each of their proprietary fabrics in this review but if you’d like to read about their claims for each of them then click here.

Being a windstopper type fabric it is also very water resistant. There’s no overt mention of a DWR treatment but the panels behave as if they’ve been treated in that manner, mostly. The red front, side panels and back arm sections all see rain run straight off. The patterned front of the arms tend to soak up water. I’ve no idea whether that’s because they are not treated or just the nature of the fabric. It does limit this to damp rather than wet conditions. That said, on my previous version, it laughed in the face of snow, hail and pestilence. I’m becoming a little undecided about full on water protection. If it’s that cold and that wet that you require something quite so hardcore you may want to stay inside. So I’m coming round to the idea that something warm that deals with some water is good. The Mossa.2 achieves that with aplomb, ditto the Castelli Alpha jacket. The Ale PRR range, yes to the warmth, no to the water. The Bonka is somewhere in between.

The cuffs are properly terminated and snug. There’s just enough space to squeeze a glove into the arm rather than over it if that’s what you want to do. There’s nothing awfully technical about the waist section other than the nature of Assos’ own fabric which is superbly stretchy. Silicone grippers keep everything in place around the back section.


You may be able to make out some indentations in the arm section above showing through. Most of the time I’d just show you what the inner fleece section of a winter jacket looks like. But not here. To appreciate how Assos achieve this warmth and the tech that goes into it you really need to see this thing inside out. Voila. I should add that if you ever forget what it’s made of you only have to look at the back label and the instruction booklet that runs down the inside of the zip (seriously).


The front panels are, in effect, double lined. Windstopper and thermal. They allow independent movement of each part. The dimpled approach of the sides, arms and shoulder sections lead hugely effective insulation. The inner arms a different material. And the back is a more jersey like material. This is not a full shell. That might surprise you, the approach taken by just about everyone else is that only a full shell will work in the harshest conditions. But Assos don’t take the approach that everyone else takes. Not only is this spectacularly warm, it’s also breathable. That said, when wearing the most heavyweight base layers I did notice a little bit of moisture build up in the arm section which is the only section where (two materials aside) it’s arguably all round shell. Where the Bonka succeeds over other jackets is that breathability. Snug, warm, protective, temperate.

You’ll also spy, top middle, the integrated neck/face warmer. It’s a neat touch.


Round the back we lose the colour entirely. There’s still some contrast with the white shoulders but it’s all black round here on all versions. That’s in contrast to the ij.habu5 jacket which goes all black at the front and takes the colour round the back. There are a plethora of pockets here, two bigger sides ones, a smaller middle and two zipped ones. Only the bottom strip is reflective.



You can see how all the various fabrics fit together here from the windstopper type in the shoulders to the more meshy roubaix type fabric in the back. The stitching here is Assos’ ‘rear stabilizer pattern design.’ I can’t say whether that structure is better than no stitching but can say that the back of this jersey works perfectly.


Warm? You bet. Assos say you can wear this at 0 degrees. I say you can wear it below that if you use a suitable base layer. A Craft wool one will do the job or you can get Assos’ own winter base layer. If you want to move up the temps slightly then a thinner base will still offer considerable protection. But don’t imagine that there’s much to be gained in wearing this above 6 degrees or so. It’s too warm for that. Yes, it breathes well. But that’s not what it’s for. It’s for the days when you need full bibtights, overshoes, gloves over gloves, the works. Is it warmer than the Mossa.2? They’re very similar overall. But it’s that breathability that clinches it for me.

Damp weather? Yeah, it’ll do that as well. Most of it, including the non windstopper parts, will shun rain effectively. But the front facing aspects of the sleeves don’t fare as well. So this isn’t as good as the Castelli Alpha/Espresso or Parentini Mossa.2 in that regard.

Crash? Yeah, they do that as well. So if you crash within a year of purchase then, if you can, they will repair it. I’ve used that when I came off in a CX race. Put a big hole in my Mille bibshorts. Off they went, they came back about 2 weeks later fully repaired. Not as good as new, it was the insertion of part of a new panel, but perfectly usable and not even noticeable unless you point it out. If you do find a defect with a product then Assos ask no questions. I’ve owned a lot of their kit. I have never, once, found a defect with any of it. I cannot say that about any other manufacturer I’m afraid.

But, let’s get down to it, £330. What did you expect? You’ll have read my review of the world’s most expensive cycling jersey. The only surprise, in this case, is that it’s not even more. And that’s a hell of a price. It’s two Castelli Espresso jackets. Well, that’s not fair, the Bonka is easy to find at £270, and that’s only a £100 more than the Espresso (review of that coming soon). It’s actually only a tenner apart from the Castelli Elemento 2 7X air. But, you know, there are many out there with £50 winter jackets that they swear by. It’s resolutely not worth buying now. Winter’s over guys, perhaps a cold shot in the next few weeks but it’s not the investment to be making now. Keep an eye on it though, I reckon you’ll see bargains by March and some stellar reductions come April. I’ve seen them drop under £200. Buy it in Spring, stick it in the loft till December. Stay off the pies.

My view is that this is a labour of love. It’s the best balanced between warmth and breathability. It’s good in the damp but not as good as others. It is the best fit and it’s easily the best made. It should be, given the price. It’s probably not necessary to own this in the UK now, you’ll be lucky to get more than 2 weeks out of it a year. But, let’s put it this way, it’ll still be as good as new in 2030…………….if we’re still here because, you know, uranium……bad things……


15 thoughts on “Assos iJ.bonKa.6 Cento fit jacket

  1. Bought one on sale (less than 200 pounds without VAT) to replace a decade old 851 Airjack (completely agree with your comments, magnificent piece of kit…and I once saw an orange version, perfect deep winter jacket right there – perhaps you should review THAT jacket!). I still have a white 851 (with matching 851 gloves!) for dry days…..just so good….Assos perfected the pockets with that one.

    Back to the Bonka; Temperatures between -5 and 8 are possible (depends on tempo of riding as well)…but it manages the temperatures so well, at 0 degrees I roll out the door and feel invulnerable to the cold (I initially would worry about being over dressed) then within 10 minutes the cold air has started to cool the chest area….then another 5 or 10 after that the jacket is back to being perfect again with the rise in body heat. Then it doesn’t seem to matter what happens to the tempo of the ride, I can ride at 90% and still not get cold/hot or clammy. I can stop dead to fix a flat and it still won’t let me sweat or get a chill.

    Quite simply, if Harry Potter was a cyclist and rode in the dead of winter – this would be his jacket! (it’s a bit magic, no muggles allowed).

    So keep an eye on those sales, you may only use it 10 or 20 days a year – but you’ll be very happy you had it on those days!

    Liked by 1 person

  2. I’ll see if I can find an 851. No one does retro tech reviews. Perhaps that’s a way forward! Both are magnificent because they take that different approach, the thicker jersey back. Flawless pieces of kit, other than the price. Look out for some more reviews of the habu, tiburu (jersey) and tiburu shorts. Need to find some knee warmers to go with the latter as the Assos ones aren’t highly regarded. But my OCD may overlook that.


    1. isn’t it ironic that a company like Assos can’t seem to make a kneewarmer – super technical seems to be where they excel. Something that seems basic they cannot get it right. They now make a simple warmer which is a good basis, could use a more complex shaping pattern and some DWR but at least they got the bottom and top grippers correct which is a 1st in over a decade. Leg warmers are different yet again – the S7 and previous Roubaix are fantastic! (would love to try the new S7 with DWR)

      The Habu and Tiburu shorts are very impressive garments. Both have massive acceptable operating temperature ranges that really make them great for autumn & spring days were it starts out cold and ends in mid range.

      The Tiburu jersey – strange animal and I don’t know what it does better than an Intermediate – so why does it exist? It does do one thing really well, it fits and feels amazing, I know a couple of guys who also own it and we all think it is an amazing fitting jacket but I think the Intermediates have handled that temperature range better with the multiple fabrics in the chest/shoulder/arm area than the Tiburu does – especially cold winds.


      1. Absolutely agree with you Spider. I have owned an intermediate for years and it’s the most versatile longsleeve maillot I have ever had. I got a Tiburu this year and as you say: excelent fit & look. I like the thicker clothing in the arms area but…. chest fabric in the intermediate is way better, holds on better the wind. I bought the Tiburu as a heavy duty version of the Intermediate but they happen to be 2 different garmets. I use the Tiburu on non windy days o even with the Intermediate below it. If I had to choose just one garmet I’ll go for the intermediate.


  3. Great review again!

    NB. As you are interested/obsessed with ASSOS lingo:
    bonKa = good thing (bon=french for good & Ka=egyptian/general for entity) … Fine Young Cannibals must have been on the ASSOS R&D playlist.

    Got myself one early this fall and yes….. it hurts the moment you pay, but from then on… it is a bliss.

    Liked by 1 person

  4. looking to buy an ij Bonka jacket, I already own various bits of Assos kit and they
    are all superb. But where can I buy a Bonka Jacket for £270.00?
    The best price I’ve seen is £315.00 HELP PLEASE!! Mike


      1. I’ll be very interested to read the winter jacket review you mention below, as there is no way I can see myself squeezing into the Cento Bonka (yet, their Cento s7 bibshorts fit me just fine, so I’m not sure they are consistent in their use of the Cento and Mille monikers) yet the Mille Bonka is starting to appear online with discounts.


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