He was also looking for the last few seconds at the highest level 
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I’m sure there is some hyperbole in his statement….but he is absolutely correct that the vast majority of the gains are through position. If you put someone in a good TT position on a round-tuned bike and compared their time to aero TT frame but riding in a “road”position, they’ll be significantly faster on the round tubed bike.
But if you put them on identical positions on the two frames, they will be faster, but to a much smaller margin, on the TT frame.
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Yes, it’s all part of marginal gains and at the highest level, marginal gains can add up to something meaningful.
However, marginal gains can add up to net losses in average situations. If you have a 54-tooth chain ring for efficiency reasons, you reduce the number of usable gears in most situations, especially outside of race scenarios. (There are very few places where I live where I can safely (!) go beyond 70 km/h.) And you are limiting the number of climbing gears. Are 1–3 W saved in your gears worth grinding uphill? (Plus, most people don’t clean their drive trains sufficiently often, myself included. That’s often worth much more added friction.)
Ditto for running 28 mm instead of 32 mm tires. Having a more comfortable ride with more grip is another marginal gain that could be a net loss for many riders.
Personally, I think many performance-oriented people forget about the big gains amateurs can make: proper bike fit, proper body position (which includes e. g. working on your flexibility and your core), proper gearing so that you don’t grind uphill, working on bike handling, etc. Now pros are much closer to the theoretical optimum here than we are (than I am, I should probably say).
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Since one year I am using 28 mm conti 5000 tl.
And I love this smooth ride feel. When I began cycling we are on 19 mm
Full recommendation for 28 mm on the road.
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Ive been running wide tyres at low pressures since 2015 or so
Was commuting on 32c slicks then 40c slicks, so comfy, less punctures with the low pressures i was running too (35psi on 32s, and 30psi on 40s). Still commuting at 30kph+ whilst carrying a laptop, lunch and full change of clothes, so cant really say it made it heaps slower
When i started wanting to go fast i went to 28mms at about 60psi, no issues, now im on 25mm at 65psi, but they are on 24mm internal wheels, and measure more like 28mm
While this is true: even a lollipop (i.e. a wider tire on a deep rim) is better than a box shape it has to be regarded, that
a) in the Flo Tests the widest tire was 32 mm. That is definitely wider than the Pro Peloton rides for a normal road race but not overly wide if you are viewing tires in the width of 36, 40 and even wider.
b) they did a sweep analysis in their tests but only up to 20 degrees. That is rather conservative and only appropriate for really fast riding. It neglects the yaw angles which will be experienced more by slower rides and it is the stalling at yaw where the 105 % rule is most applicable. The more you hurt it the more you see negative effects on bigger yaw angles. A pure head wind isn’t as detrimental for a lollipop, but still.
Thus said, again, the overlying message is true: you still gain something from a deep rim if said rim doesn’t introduce other negative aspects for ride qualities you might seek. Very low weight or deflection properties (if e.g. you’d fancy those new moto style Zipp rims).
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I can see that happen, e. g. if people want to train on wider tires (perhaps in the off season) and ride narrower tires for races. Many aero road bikes will take surprisingly wide tires, a trend started with the 3T Strada (up to 30 mm) and continued with e. g. the Venge (33 mm, I believe is the max). I wouldn’t be surprised if road bikes by default allowed you to put in 35 mm tires in a few years.
I am/was/sorta running the rene herse bon jon’s 35mm on bonty aeolus 3V rims (pretty wide). I replaced the front wheel with a cont 5000 TL and I think it is a fair bit more aero…it matches the rim width pretty nicely. But I also put in vittoria tire liners front and rear.
So last week I was bombing down a semi-rough gravel road and got a sidewall puncture in my rear tire (the rene herse one). It went mostly flat before the sealant did it’s thing…but I was able to ride home without any rim strikes because of the tire insert. It had maybe 5psi in it when I got back. It felt really soft and wobbly in the (slow) corners but it wasn’t “terrible”…in fact, compared to swapping in a tube it was pretty awesome!I wasn’t at home (for tire replacement) so the next day I pumped it up a few times, sloshed the sealant around, got it to hold air, then rode for an hour w/o problems. It was totally flat later though.
Between the seeping of sealant thru the sidewalls (supposedly corrected now) and the fagility of the extra light bon jons I think I’m going conti 5000 TL on both ends for the future…but for now I’ll try to use up my one remaining bon jon tire.
The insert works though…I’m going to carry a plug, a CO2, and skip the tube going forwards.
FWIW!
Joe
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The high-end Tarmac SL7 comes with Roval Rapide CLX which are wide rims:
- 35mm front / 51mm deep
- 30mm rear / 60mm deep
and come with 28x622 tires. My lower-spec SL7 has a 32x622 Conti 5000 TL tire on the rear wheel, measures out to ~34mm, and there is about 5-6mm clearance to the chainstays (well within 4mm European safety spec). Not that I’m interested in going with even bigger tires, just saying its possible.
On the road its really hard to tell the difference between my 32mm wide Aeolus Pro 3Vs wheels and 29mm front / 28mm rear Enve 5.6 disc (except in strong winds). Someday, probably in Feb/Mar, I’m going to try staggered wheels/brands with a wider/shallower Aeolus on front and narrower/deeper Enve on rear.
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Finally got around to swapping out tires…I have a bonty R3 hardcase lite that came on the bike in decent shape so decided to throw that on.
Man, I didn’t realize how difficult getting the tire off is with those tire inserts! I mean…super tough! I needed to bust out the gas pliers for a little gentle persuasion (I’m sure the vittoria tool would have worked better). I couldn’t push the bead off of the shelf (I think) due to the tightness, the insert, and a little sticky sealant in there. Putting the bonty tire on was about the same as the 5000TL and a bit harder than the bon jon FWIW.
But if you are going tire inserts on your wider tire setup…I’m not sure putting in a tube is possible in the field, I’m thinking you either ride it home flat (which you can definitely do) or call for a ride. I’m pulling my spare tube out, keeping the tire plug and Co2 in the kit so I have one shot at fixing a big puncture.
Joe
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Did you remove 32x622 5000 TL tires on your Aeolus 3V wheels?
Thats what I’m currently running with Vittoria inserts. It wasn’t that bad putting them on, much easier than putting 25x622 TLs on Enve 5.6 disc (without an insert).
Glad to hear about some real-world experience with this!
I’ve been considering it for mountain biking. Would simplify my setup, and would allow for either a “quick on-trail fix” or “limping home”… especially good for marathon MTB…
No I haven’t tried to get the 5000tls off but I’m not looking forward to it. It’s on the front….I hope it lasts 10000 miles!
What’s the logic of a wider front tire and narrower rear? Always assumed the other way around would make more sense - narrower at the front where aero is more important, wider at the back where aero is less important and where more of your weight sits so you could use some extra volume for comfort and grip. With those external rim widths I guess the Rivals are optimised for something like a 32mm front and 28m rear tire?
I dunno, never looked into aerodynamics… But the LBS manager is studying aerospace engineering, and his analogy was to think of my rear wheel like a TT disk wheel. I don’t have access to a wind tunnel, and to be honest am pretty darn happy running 32c Conti 5000 TLs on the Bonti Aeolus 3Vs.
Going back to the Rapide and its wider front, narrower rear wheel you can read the marketing blurb here:
and in this article:
you see this data from Hunt:
which under Hunt’s test conditions (Pro One 28 tires), puts the Rapide CLX on par with my Enve 5.6 disc.
I’m guessing the Enve might be faster with 25c or 26c, but with our rough roads and at 90+kg I really don’t like running narrower tires. Thinking of selling my Enve, they simply aren’t being used although I’m still thinking of swapping them on for Wed worlds in the Spring.
Bmxers and mtbers sometimes have bigger tires on the front wheel for better handling. They have the back tire a little smaller for less drag/ surface area to go faster. Don’t know any aero studies or any studies at all making this claim true. It’s probably just bro-science but that was what I heard/ do and seems to work for trails.
Agree with the above. Unless perhaps you were seeking a larger contact patch and greater grip on the front?
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Argue in the abstract with Specialized?
The best Tarmacs have:
- front wheels 35mm wide and 51mm deep
- rear wheels 30mm wide and 60mm deep
Tires are another discussion.
Experimenting is the basis of science.
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Tyres do stretch over time too, my old bike would take a new 25mm GP4000, but after a few months it would rub, so needed to run 23mm tyres on it.
Most likely grip. Although then I’d run a symmetric setup, aerodynamics is less important in the rear anyway.