Impressions of Velocity A23 and A23 O/C Rims
When I wrote about my newest wheelset earlier this year, I said relatively little about the rims. Now that I have done about 2000 kilometres on a variety of roads in different countries, I have a much better appreciation for the Velocity A23 rims and the A23 O/C in particular. In short, I am really fond of them. I think they are great all-rounders.
There are inherent difficulties in isolating the qualities that are attributable directly to a specific component like a rim rather than, for example, an entire wheel. Furthermore, the perceived characteristics tend to be assessed relative to other comparable parts or set ups used in the past that tend not to be directly comparable because, as in this instance, the rim is not the only thing that is different whilst all other components remained constant. The A23s are the third wheelset to be used with this frame, but the set up has been very different for each wheelset (8 speed, fixed and now 11 speed). For the current incarnation, absolutely everything including the fork was changed; only the frame remained. With that in mind, these are my impressions.
First, there are aspects on which I have no opinions. The rims are tubeless ready, but I have not tried them with tubeless tyres. I am usually amongst the last to try new things, so until that day comes in about a decade or two, I have no thoughts on the tubeless aspect.
The other is the aerodynamics of the rim. The fashionable theory these days is that wider rims are more aerodynamic because it disrupts the flow of longitudinal air less than narrower rims do. It makes me wonder what the ‘performance’ rim makers have been doing in the wind tunnel all these years when they were pushing narrower rims, but I have no way of measuring or even perceiving the aerodynamic performance of the A23s, other than to say that they are surprisingly indifferent to violent cross winds.
The 23 mm width of A23s are said to make the clincher tyre sit on the rim with a profile that is similar to tubular tyres, that is, rounder in section, and therefore roll more like tubs than clinchers. When I was reading up on the A23 prior to the purchase, a part of me thought that it made sense and wanted to believe it. Another part of me suspected that it was probably just a gimmick and a vacuous claim. I have had Continental Grand Prix 4Season installed most of the time, particularly in these winter months. They are very robust tyres that have been made with durability as the first priority. Therefore, the ride quality is a bit harsh and slow compared to tyres that prioritise speed. However, they roll noticeably better (more comfortable, smoother) than on another wheelset with slightly narrower rims.
For a couple of weeks in autumn, I installed Michelin Pro4 Service Course on the A23s. The ride quality was divine. Since I have no experience rolling on tubular tyres, I don’t have an actual frame of reference to say whether it approaches the way tubs roll, but the Pro4s rolled nothing like they do on my other rims. I think the way to describe it in the presence of Mother-in-Law is buttery. The more natural version would be rated 18 or NC-17 if it were a film. If you are of a Catholic persuasion, then you might think that there is something utterly sinful about the feel of Pro4 + A23 coming through the perineum. Well, not to worry, you’ll go to hell anyway, so take pleasure in it whilst you can.
In comparison to the claim made about the width, I was easily persuaded by the benefits of an off centre rim. That is, it was easy to see the long term benefits, as echoed by my favourite wheel builder Gilbert Cattoir, but I had not expected to actually see or feel the difference in the daily use of A23 O/C.
This week I spotted this video clip in which the advantages of A23 O/C are explained in a more quantitative manner, to delight all the physics nerds amongst the cyclists. Caveat: the video contains proper nerdiness.
It is difficult to say whether it is directly attributable to the A23 O/C, but the general feeling I get from my rear wheel is that it is more efficient. Acceleration seems easier in the sense that it feels as though more of the power transferred to the pedal goes directly into rotating the rear wheel. Of course, the drivetrain may have something to do with this, and my legs may have become slightly stronger. However, there is something very noticeable when riding over cobbles.
When riding over longer stretches of cobblestones, I always sensed that the rear wheel, with spoke counts of either 32 or 36 and varying rim profiles but all with centre drilling, was doing something that I would rather not have it doing, namely, wasting energy through flexing that does not contribute to propelling me forward or increasing ride comfort. It is a little difficult to describe as it is really just an interpretation of the feedback coming through the entire bike. With the A23 O/C, I do not really sense this. Instead, it feels like it is focussed on doing just one thing, rolling forward. As I mentioned above, it feels noticeably more efficient. Once I watched the video above, I understood that I was not just imagining the way in which A23 O/C rolls over cobbles; it all makes sense. So, yes, the nerdy quantitative stuff is noticeable in daily use.
The only negative thing that I found about the A23 and A23 O/C is the Velocity decal. It is a poor quality decal that starts to crack and deteriorate relatively quickly, particularly if you are not just a fair weather cyclist. I happen to prefer having minimal logos, so I was happy enough to get rid of them once they started to look a bit tatty.
Other than that inconsequential detail, the Velocity A23 (24 holes) and A23 O/C (28 holes) rims laced by Gilbert Cattoir to Chris King R45 hubs using Sapim spokes are ace. Very pleased.
For an update, read this.