“Bartime” sounds like a pretty generic bike component manufacturer’s name, doesn’t it? I mean, it almost sounds like someone got the translation dictionary out and chose the first two bicycle-related words they saw and glued them together. But actually the “Bar” in “Bartime” is not in fact the kind of bar, like a handlebar, that you hang onto while riding, it refers to the kind of bar you lean on with a beverage in hand. Bartime – as in, time at the bar/pub. The company say that is where many of their best brainstorming ideas have come from. I like that, it displays a passion for life that I can identify with.
Sometimes I get excited about reviews, and sometimes I don’t. Testing the very best of the best can be difficult because the product has to work perfectly – anything short of perfection then, is a disappointment. On the flip-side, cheap and cheerful gear can be quite interesting to review, but then sometimes it’s hard to be positive about an inferior product even if it is cheap (and we tell the brands we publish honest reviews).
Today though, I’m excited as I get to tell you about the Bartime CW45-CL carbon wheelset. What makes this exciting is that it’s not an ordinary review. You can’t buy these wheels… yet. Bartime are in a rapid expansion phase, introducing a new line of hubs and wheelsets to cover a wide range of applications. So when we were given the opportunity to try out their new 45mm Wide-Rim (Full) Carbon Clinchers, we jumped at the chance. Just like when BNA reviewed the Bartime BW38 wheelset, we had the opportunity to see how these products are developed through the design phase, and give feedback that would actually be used to improve the final product.
The CW45 rims are full carbon clinchers with a special coated braking surface that were originally designed to allow you to use both carbon and standard brake pads (more on that later). In addition, the rims are a wide-profile (24mm) U-shaped design. Like the BW38’s improvements, they include bite guards on the freehub to ensure hub longevity and stop your cassette from getting stuck. They use a high-flange rear hub drive-side (more on that, too), and yet weigh in at just over 1.5kg per pair (excluding skewers, etc.)
Let’s talk about Aerodynamics
The fact is, short of hiring a wind tunnel, all we have to rely on in this regard is the manufacturer’s claims. I truly believe that the margin for error is far too big for most reviewers to be able to accurately pinpoint the aerodynamic difference between one manufacturer’s 45mm carbon rim and another’s. There are so many things that can go wrong; slight changes in the conditions, accidentally riding in a different position, even the placebo effect – all of these can introduce a greater margin for error than the difference we’re trying to measure.
What I can do for this review is restrict my comments to the measurable. My opinion of the research to hand is that a wider rim is actually more aerodynamic, at least over the real world range of yaw-angles. In this case, the CW45 have a wider rim. Is their cross-section better or worse than say Zipp’s Firecrest cross section? The difference is likely to be relatively small. Your mileage may vary.
Finally, I really like the 45mm depth. I ride every day on 50mm rims and, while I like them, there are times when I would prefer something more low-profile. Compared to 50mm rims, I see the 45mm rim as quite a versatile size having over 10% less surface area when viewed from the side (improving stability in crosswinds) but having less than 1.5% longer spokes (which increases aerodynamic drag). Of course, that spoke length is at the end where it travels fastest, but suffice it to say that in my mind there are real merits to this rim depth. Not quite enough for me personally to invest in a brand new wheelset for that small improvement, but enough to think about if you’re looking to buy something in that region.
Do you think you know about Stiffness?
This is one of my pet topics. I will spare you from my rant, but point out that wheels are not “flexy” when you’re doing a time trial, or climbing a mountain. Unless you’re climbing at 1,000 Watts, you’re coming nowhere near the levels of flex required to see a power-transmission loss. Even in a sprint, stiff wheels are more about stability than power transmission.
It may seem that I’m setting you up to say that these wheels are flexy, but don’t worry, the reality is quite the opposite in fact. I gave these wheels an almost 1400 Watt pounding over and over again. My main criteria is that the wheels don’t flex enough to rub the brakes or frame, and despite being 24mm wide, these rims didn’t. My second criteria is that they still “feel” stiff under that power. Again, this is more about my perception of comfort and stability than anything else, but in my view, they performed excellently.
The large drive-side flange appears to contribute to the overall stiffness. If I’m looking at wheel-hubs, I like ’em big. The bigger the better. The CW45’s cut down on weight by having an asymmetrical rear hub. This adds significant stiffness to the drive side, while maintaining a lower weight. I think this is a great design.
Given the wide rim profile, you can also run a lower pressure if you so decide and thus offset any additional vertical stiffness you may perceive. For the record, I did find them to ride a little harder than average, but most of the time I ran them around 10 psi lower, which more than offset this.
There’s not much to say here. I think 1514 grams is quite good. Again, I’m a bit of a skeptic when it comes to weight. Especially when it comes to claims about “rotating mass.” Even still, I really enjoyed the “feel” of these rims. They are light enough for me to notice the difference while accelerating, and even when making small adjustments in line.
This is where the story gets interesting. Bartime have created a special laminated braking track with a kind of cross-hatched texture to it. Originally, we understood it was designed to allow either carbon or regular brake pads to be used. Of course, this was nothing short of ground-breaking, so we were intrigued.
I had some concerns with the braking. Usually the brand-own or brand preferred brake pads are provided with new carbon fiber wheels, however in this case they were not. We checked which pads we could use and settled on SwissStop Black Prince pads, which are usually top performing brake pads for carbon fiber wheelsets.
Unfortunately, I found the braking very vague and seemed to fade quickly. I wasn’t too keen on taking them down any serious descents until I had reliable and solid braking.
Next I went to standard pads for alloy rims, and this time the initial bite was much stronger. Unfortunately it came on a little bit too strong and they made quite a racket too. It’s no wonder, the rubber pads were getting some serious friction against the textured braking surface. This didn’t seem like it was what the manufacturers envisaged – despite the stronger braking, they were too “grabby” to be reliable. After just one ride, the pads were already starting to get shredded. Not a good start.
So we went back to the manufacturer for their feedback. They sent us a new set of carbon-specific pads direct from the Bartime factory and said they were confident these would do the trick. Thankfully they did, and although not on par with the best I’ve seen, the brakes now responded the way I’d seen most other carbon wheelsets respond. The upfront bite is pretty good, and while there is a little bit of softness through the middle, they are predictable enough to become quite comfortable with.
Bartime also advised us that these pads will now be matched to these wheels and will be sent out with each wheelset sold.
For me, the 45mm depth, along with the wide profile, are a very practical choice. As well as the aero benefits, you are able to run lower pressures for the same rolling resistance and thus achieve a much nicer ride. Be warned though, that some frames may not be able to accommodate the wider profile – such as the Orbea Orca.
I can’t think of many situations where I’d wish I had a different wheelset in. These are a good middle ground which will be suitable to a (comparatively) large range of conditions.
The rear hub is quite nicely designed, with the (larger) star shape hub on the drive side reducing spoke length (and increasing stiffness under power) while the longer left-side spokes allow for lower weight and more give. And I recognise, of course, that those things probably make only a small real-world impact, however it’s nice to see design based on function, rather than decisions made for aesthetics only.
All in all, these are exactly the kind of wheels I like. They are like a Hyundai with lots of cool features but without the ostentatiousness of a BMW. I like how they have all the good features without the pricey name tag. There is some great technology built into them at a reasonable price point and they are also very versatile. Sure I could buy something similar from another manufacturer and get something that’s probably had more time in the wind-tunnel, but the CW45’s seem to tick all the right boxes – and for that, the cost saving is worth it.
Where can you get some, and for how much?
While I’ve talked about the proposed retail price for these wheels, the importer, Keith Louis Eichmann Innovations, notes that the final price and availability is not yet confirmed. To be the first to know, email or call the importer on [mobile] 0406 614 044. Technical specifications for the Bartime CW45 are available on the Bartime Website.