I think it also depends how fast you are going, it seems like a lot of the aero gains are insignificant <40 km/h. The gravel race I did last year I avg’d 23.4 km/h and that 9th on the Strava leaderboard for that annual race’s strava segment. Even on the flat I’m not spending much time >35 km/h.
The other thing is, I find in a lot of the testing and comparison people have a hard time showing measurable differences I think with a wide gravel tire its going to make it hard to get the aero gains of even a bad carbon road wheel and tire https://www.youtube.com/watch?v=ZXCUmt6bRo4
If I wasn’t limited by may current frame, I would run a 44-50c tire, not sure what they would blow up to on a 29mm internal but guessing it would be big enough to erase the advantage of the 40mm external. I think to optimize things you would have to run like a ~35c tire (blowing up to 38?). However, if you are averaging 25 km/h is there any gain? Wouldn’t having a tire that blows up to ~50c provide more advantage in decreased rolling resistance than the aero savings of a tire blowing up to 38c on a 40mm external wheel at 25 km/h?
I justified my purchase of my gravel wheels by saying I need an extra wheelset that I can leave set up with gravel tires so I don’t miss out on rides and the carbon is more durable than an alloy wheelset so I won’t need to get them trued as frequently. I doubt there will be any measurable performance gain over a set of DT GR 1600s though (although my Revives are ~400g lighter, probably 500-600g lighter than the current wheels I have my CX tires on currently).
There was a very good episode on Performance Process with someone from Swiss Side. According to him aero is actually more important for slower riders as you spend more time on the road. Going from memory here, but aero becomes less important for professionals at 7.–8 %, and at 4.5ish % for us mere mortals.
Well, not necessarily more “important”…but the time savings are bigger simply because, as you note, slower riders are on the road for a longer period of time.
The percentages you noted were for where aero becomes less of a factor going uphill, not the time savings. So us regular folk should look at weight if the a climb is above 4.5%, while for pros, the avergae needs to be above 8% before aero is not the primary concern.
But that is also if the ride finishes on a climb…once you factor in the aero savings across a whole ride, or if the ride continues on past a summit, the equation shifts back to aero being more important than weight.
So I’m not questioning that aero can provide a benefit and believe in aero gains over weight gains but I think even with a 40mm external, with a 44 to 53mm tire (44mm Thundero, 47 Pathfinder, 2.2 Race King) the aero benefit is either not going to be there or so small its not measurable due to falling within the margin of error.
As per Enve
’ Aerodynamics
With 28-32mm tires, the 3.4 is going to deliver a wattage savings of up to 10 watts at 20 mph over the G23 with the same tire. That doesn’t tell the entire story, however. As tire width increases beyond 32mm, the 3.4’s aero advantage diminishes. Going up to a 40mm tire, the two wheelsets would essentially be aerodynamically equal.’
I don’t think an aero profile wheel will help, I just think that the gains from wider tires ~50c are more likely to make you faster than the potential aero gain with a 40c and aero wheel and I suspect at >45c there isn’t going to be a measurable aero gain.
Don’t have the Discus 45 | 40, I have Terra CLX that weigh just a little under 1300g. Right now have 42c Pathfinders mounted that measure out to 47mm. Terra are 33mm external so nothing aero about the setup, but these wheels feel fantastic climbing or general riding and I’ve set some Strava PR / KOMs on them in 1-3 minute range (on gravel and road bikes). Not my first choice for a long ride if chasing aero gains but even in strong headwinds they feel fine on 100km rides and 28c to 32c road tires.
Have thought about chasing aero gains as I do a lot of road riding to get to gravel. Three things holding me back on the Discus 45 | 40 are the i) the hub (I want DT Swiss), ii) the weight (1665g Discus vs 1300g Terra), and how much money I’d have to spend chasing aero gains when these 2 year old Terra have been great.
Definitely the way to go, but I don’t think the 180 hubs are worth the extra cost for a few grams. Either way, Light Bicycles make fantastic “affordable” rims and wheels.
I was surprised as this is counter to what Enve says about to aero and wide gravel tires:
“ With 28-32mm tires, the 3.4 is going to deliver a wattage savings of up to 10 watts at 20 mph over the G23 with the same tire. That doesn’t tell the entire story, however. As tire width increases beyond 32mm, the 3.4’s aero advantage diminishes. Going up to a 40mm tire, the two wheelsets would essentially be aerodynamically equal.”
Alexey Vermeulen, who is an ENVE sponsored athlete, ran the ENVE 4.5s at Unbound last year. He was running a prototype Kenda gravel tire on them. I’m not certain how wide they were but suspect at least over 40. Alexey was trying to “aero-optimize” for Unbound last year and the comment made by ENVE was that because of the speeds he rides at there was an advantage to the 4.5s despite the added weight over a G23.
Funny you should mention those wheels. I‘m debating exactly this, and I think I’m coming down on the side of the g23’s. I won’t be moving anywhere near Alexi’s speed, so the aero advantage is minimal.
But there is another issue which is cross wind impact. The deeper dish wheels are much more impacted by cross winds. I recently did a fondo is a very windy area. Fighting the crosswinds all day was exhausting.
I also wonder which would hold more mud. I’m guessing the deeper dish wheels, but I don’t really know.
If you get to the point where mud has gone beyond the tires and onto the rim, you’ve got big, big problems. Not saying it’s not possible, but I’ve ridden in conditions that require constant dismounting and clearing of mud from tires, frame, chainrings, RD, etc., but I’ve never had to clear any mud off my rims.
