How wide is too wide?

Back in my day, we raced on 21s. Now get off my lawn.

Unfortunately a lot of 'older' bikes don't come with the clearence to fit 30mm tyres - so going wider comes with the little pricetag of a new bike 😢😅

It's impressive how consistent you guys are repeating the wattage down to the watt!

Maybe do this test again using only 32c tires but different rim widths, would be interesting to see how that affects things.

At 1st i tried 23mm. Very rough ride. And i switch to 28mm. Very comfortable

As wide as your frame can take in they back. 105% external rim width rule on the front. Comfy and fast.

The difference between the 32s and 34s is well within the margin of error. I ride 35 gravel king slicks for road riding on my gravel bike. I don’t see much of a difference between these and the 28mm Conti 5000 on my second set of wheels. Larger is less rolling resistance but if you you get too large the weight and aerodynamic penalty will set in. The question is, How large is that. For a recreational rider, I think comfort is king. At the end of the day you’ll be happier!😊

It's cool to see the results are very similar on both tests. This is probably one of the most useful comparison videos I've seen you do, simply because most people can afford almost any tire. Awesome video!

It would be interesting to see the Strava segment "compare" view of the different runs/sizes given the varying terrain of the course. In other words, did the wider tires gain their time steadily throughout the course or were they significantly faster in certain sections and potentially slower in others, etc. Might shed some additional light on their strengths.

Jeff I love all the race recaps and Alviso videos, but I really love seeing these science-based videos. You inspire me a lot and I’ve always been a fan since I first learned about you, keep up all the great work and thanks for the videos!

Matching the profile of your rim is going to give you the fastest times unless the roads are terrible. You can see in the face-on images that the 32mm tire best matches up with the rim profile for this test which is why it was the fastest and why it was a bigger advantage for Will as aerodynamics became a bigger factor at the higher speed.

Sweet vid. I liked how the different watts graph mirrored each other. I've been on 30mm since 2013, my butt doesn't lie!

A problem with comparing tires of different width is that normally you only have one wheelset to mount them on when you want to test back to back. Because of the aerodynamic interface with the rim, this means that both rolling resistance and aerodynamic drag will be different for each size. That's not to say that the comparison in the video is invalid, but I guess matching rim to tire would be ideal to really see if there is any significant trend!

Great video! It would also be interesting to do a test on mixed tire sizes. I saw in a bike check video that some pros had narrower tires up front, and wider in the rear. Either for better aerodynamics and comfort, or to trick their opponents.

For the the effort here, the algo and my envy my old Trek 5200 can't see these optimal sizes. Great work guys: direct, analytical and super work. :text-green-game-over: Subscribed

Seems like it has been like 3 years or so where we've jumped from calling 25mm tires wide but maybe not so fast to having to decide between various 30+ mm sizes which are both more comfy and faster. Love cycling. P.s. this is an awesome test. Short, concise, no BS. Keep it up. P.p.s I'll be ordering 30mm gp5000 for my sl7 to replace the 26mm turbos.

Thanks for doing the testing for us! Very helpful!

Love this kind of stuff. Keep it up!

It's great to see this excellent test... Thanks for this.

NO BS, spot on, I love you guys! That's just what I want to do but without the time and resource! Plus there might be another plus for bigger tyres, there's no strong evidence, just my own feeling, that the bigger tyres feels a lot more grippier in the corner than slimmer ones. If that is true, then bigger tyres would have another plus for maybe more cornering speed, which could translates to faster descent or less race time for some guys, or a more stable "safer" downhill feeling for other less racey guys. Hope you guys could do some experiment with this. It will be interesting to see if this is really a thing.