Like any cyclist, I absolutely love a great set of race wheels. And like any cyclist looking to part with my hard earned, I like to research what wheelset delivers best bang for the buck. There are several key features to look for in a new wheelset which include weight, handling and brake type (disc v rim). Top of mind for most cyclists when buying a new wheelset is what wheels offer the most aerodynamic benefits to “buy some free speed”.
I’ll focus on road racing wheels here as time trial wheelsets are a different beast. For example, using a disc wheel in a road race is likely to get you blown off the road or crashing on a descent so the mid-depth wheels which balance aerodynamics and weight for optimal all-round performance are where the action is at. These wheels tend to have a rim depth of 50-65mm.
My observation has been that the speed or aero benefit of race wheels doesn’t seem to differ much between brands…. Despite the extensive marketing fluff each brand likes to throw at us. Deeper rims are more aero than shallow rims, but the difference in speed between two wheelsets of the same depth has never felt like an aero thing where one brand is faster. My experience is that the difference between wheelsets of the same depth is that a lighter rim accelerates faster and feels faster than a heavier one, but once up to speed there’s very little difference . And yes, I am aware that aero matters more than weight under most circumstances, but the point here is not being able to perceive an aero benefit when presented with two wheelsets of the same rim depth.
Enter the article I will share with you now:
As most of you who have read anything I publish will recognise, I like facts not marketing guff to support real world decisions. So, when deciding which wheelset to purchase, I wanted real data from testing mid-section road wheelsets that is independent of the brand selling them. The article above did just that – they used the slow speed wind tunnel at Silverstone (the British home for aero testing all things related to cycling) and it revealed some interesting data. Here are the wheelsets tested, all of which are in that 50-65mm rim depth category:
Shimano Dura-Ace C60 (R9200 series)
Roval CLX II 60mm
HED Vanquish RC6 Pro
Hunt 60 Limitless Aero Disc
Vision Metron 60 SL
Enve Foundation 65
Reserve 50/65
FFWD Ryot 55
Zipp 404 Firecrest (58mm)
DT Swiss Arc 1100 DiCut 62 DB
I’m sure there is a favourite brand in there for everyone. Here are the take home messages, and the results might just surprise you:
“The differences between the best and worst wheels in this test are very small. If you're able to average 40km/h, you're looking at fewer than four watts saved”
“A more typical road cyclist, riding alone and averaging 30km/h, will see even fewer watts saved; fewer than two watts between the best and worst here”
“Spending too much time worrying about the difference between the aero performance of two high-end wheelsets is a fool's errand”
“A racing road cyclist might still average 40km/h but that will almost certainly be in a bunch, and in that environment, you'll make much more than a four-watt difference to your result by working on your positioning and your race tactics, not to mention optimising your position on the bike and other equipment.”
So, if you are keen on a new race wheelset (and who isn’t - right!), then worrying about the aero differences when rim depth is the same is fool’s gold. Focus on other attributes like handling, durability, cost and weight.
And as the article also points out, there are other ways to make aero gains that cost far less including:
a bike fit,
clothing and helmet choices,
and a coach to help increase your power.
After all of that is done, it is always a great day when you get hold of a new set of race wheels!