I wouldn’t consider anything smaller than 28 mm at this point. If you stick to 28 mm, I don’t think you are any slower than on 25s in terms of rolling resistance. Wider tires allow you to ride ride at lower pressures, though. I think you can easily go 30 mm without sacrificing much in terms of speed.
Offseason I’d go 32–35 mm, depending on what the frame allows. If you want something faster, I’d think about your priorities. When it is wet or there are leaves and debris on the road, I always err on the side of traction and comfort.
Yes, narrower tires have an aero advantage, but is that what is really important? In most situations, I’d take a tire with more traction and comfort.
My weapon of choice is a 3T Strada, an aero road bike with 3T aero wheels. On the box my tires claim to be 26 mm wide, but my 3T wheels have an internal width of 25 mm and I know they are wider than that. I reckon 28–29 mm, which is perfect for the frame.
Good info here on the rolling resistance vs aerodynamics of smaller and larger volume tires. IMO, you should also factor in comfort.
Dear Brad,
Very good question. As you’re probably aware, the aerodynamic data put forth by Hed and Zipp in support of wider rims for improved aerodynamics shows that it definitely depends on the rim. In general, if you ride very fast, the aerodynamic drag of the fatter tires will cost you more in speed than the rolling resistance benefit will gain you.
In general, if you ride very fast, the aerodynamic drag of the fatter tires will cost you more in speed than the rolling resistance benefit will gain you.
On 23mm rim width, a 25mm tire sounds narrow to me, especially if you’re considering tubeless. A wider tire, with lower pressure, is also more reliable tubeless. I would not go below 28mm on such a rim.
Thanks - right now I’m in the same camp and pretty much exclusively riding my summer bike with 28s on 19mm rims. I can’t go any wider due to the rim brakes sadly and my super lightweight climbing bike will only fit 25’s between the chainstays anyway…
After a couple of winters of fairly big mileage on the G One Spped 30’s I’ve sworn many times I’d never buy a frame that couldnt run at least 30s as the increased comfort and the way the bike just seems to glide over the horrendous tarmac we have all around here, is just incredible.
I have my eye on a titanium Enigma Evoke frame that says it will take 32 max, so maybe some wide rims with 28 or 30’s will give that cushioning and minimise the aero losses as well, albeit there is very little that is particularly aero focused on a titanium frame really.
Thanks again everyone for all the info. I was able to find some tires at a bike shop (sort of) locally, so I ended up going with GP5000 TL in a 28mm up front and 32mm in the back. The ride is super plush. The 28 measures to 30.4mm on my 31mm external rims…it doesn’t hit the 105 rule but I feel very confident riding on these. I even hit a Strava PR on my first ride!
I probably could have gone with 25mm up front and 28mm out back, but I’m not sure how much more efficiency I’d get considering my bike and fork aren’t terribly aerodynamic.
And, most importantly, the tires look great on the bike
Lot’s of things to consider when switching to tubeless these days with all of the new carbon rims available. Many of those considerations are covered in this link to the guy who runs In The Know Cycling, THE BEST TUBELESS TIRES - In The Know Cycling. Best of luck.
