Another Blinkin’ Tyre Width Thread

[Heltor Chasca]

Currently I run H SON PLUS Archetypes on my Audax bike. These 700 rims are 23mm wide and will accept tyres from 23-40mm according to literature.

Currently I run 32mm Schwalbe Duranos which have been super comfy, easy to change, fantastic in winter etc etc.

But in the spirit of all cyclists I have been thinking about fixing something that isn’t broken. Another rider suggested that I may make some marginal gains in the summer if I size down to a 23mm or 25mm Durano. Rolling resistance I am led to believe isn’t going to happen, but due to having less of a ‘bulge’ I may be more aero.

True or false? Comments welcome.

 

[T4tomo]

Very little to gain I would say, and plenty of comfort to lose. I wouldn’t go below 28mm for that reason, and certainly not 23mm. Maybe some lighter weight summer tyres in a 28mm could be worth trying, say Conti GP 4000s

 

[KneesUp]

This may be of interest

https://www.velonews.com/2014/12/bi...essure-width-affect-rolling-resistance_355085

 

[CXRAndy]

The consensus of opinion from so called experts, is that once you go above 28mm in width rolling resistance benefits start to be eroded by aero losses. I would look at a tubeless setup to improve rolling resistance in a 28mm tyre. Schwalbe/Continental do fast tubeless tyres.

I run schwalbe One Pro's in 25mm, but on a wider internal rim 21mm, this gives me a 28mm wide tyre profile and matches closely to the outside width of the rim, so my 30mm rims are actually deeper in aero terms.

The comments about how you cant convert a clincher rim to tubeless will appear, but I've done it many times with no problems. You just need a good clean of inside rim to adhere the Stans sealing tape and fit tubeless valve. Thats it.

 

[fossyant]

Duranos aren't the fastest rolling tyres, so switching to something else, eg 4 Seasons, mich pro race will see a gain. PS they don't come in tractor size width though.

I noticed a fair amount of drag switching from 23mm 4 Seasons to Duranos.

 

[12boy]

If you would like a different point of view check out the Bicycle Quarterly Blog, "Off the Beaten Path" by Jan Heine. His argument is wide tires with flexible sidewalls rib at lower pressures are faster than narrow high pressure ones in the real world. His company has worked with Panasonic to make these tires and I have read reviews that indicate they really are what he claims although flat protection and longevity are not their strong suit. If I remember correctly his method of testing tires involves using different tires on the same bike including wheels and rider and timing coasting runs down the same hill. This method is more accurate than a lab test using smooth rollers since uneven surfaces can increase rolling resistance in several ways. See what you think.

 

[rogerzilla]

Don't forget weight. A 23mm is MUCH lighter than a 32mm. A good supple 23mm tyre rides well enough. Something with a stiff sidewall will give a punishing ride.

 

[Ajax Bay]

Currently I run 32mm Schwalbe Duranos . . . Another rider suggested that I may make some marginal gains in the summer if I size down to a 23mm or 25mm Durano. Rolling resistance I am led to believe isn’t going to happen, but due to having less of a ‘bulge’ I may be more aero.

Your colocutor is talking BS.
You would make losses.
Rolling resistance of wider tyres is, ceteris paribus, lower, within reason (eg 28-).
And there's a plausible argument that the hysteric losses in the rider's body are less with wider tyres (wider ones, of course, come with a higher 'comfort quotient').
Read this comparison of 23, 25 and 28s of same make/model (which is by the way the acknowledged 'benchmark' clincher tyre for long riding):
https://www.bicyclerollingresistance.com/specials/conti-gp4000s-ii-23-25-28
Jan Heine's work referred to by @12boy also comes to this conclusion and he has exploited that to produce and sell wide high quality construction road tyres (Compass) but at a price.
There may be marginal losses from aero drag on a wider front tyre but for the distances (and therefore speeds) that you are targeting, these are outweighed by the poorer rolling resistance. See this article for insight to yaw angles (which suggests a well (width) matched tyre to a rim width has merit - also talks about 'trip' benefits of non-smoothness on the shoulders of tyres): https://road.cc/content/feature/213...heel-weight-doesnt-matter-and-how-wind-tunnel
Look at the Road Tyre reviews list in https://www.bicyclerollingresistance.com/
I'd support @fossyant 's advice. Balance the puncture protection you need against rolling resistance.
There are some 'fast rolling' tubeless tyres but I think the OP has considered and rejected the tubeless route.
Here's the comparison for Continental GP 4-season, Schwalbe-Durano and Michelin Pro4 Endurance v2.
Currently (on 15mm internal rim width wheels at 75/90psi) I have a 4 Season (a 28 but comes up narrower) on the front (which has done 11,000+ km) and a Michelin on the rear (a 25 but comes up wide). A pair of 4000s are waiting to go on in the late spring for my Easter Arrow (400+), 400, 600 and PBP.
For 25s at 100psi the rolling resistance difference between Duranos and 4000s is 5.8w (each tyre) or a gain of 11.6w. Over a 200km audax in under 9 hours rolling time that'd offer a time saving of about 20 minutes.
I've used http://bikecalculator.com/
Just be aware that Continental GP 4000SII come up wide, and on your rim width (H Plus Son Archetype rim 17.5mm internal width) I'd expect a 28-622 to measure 31+mm - best of both worlds: a fast tyre, wide for speed and comfort and pretty reasonable puncture protection.
I see one can get them for under £30. Restraint! Restraint!
HTH

 

[Ajax Bay]

Don't forget weight. A 23mm is MUCH lighter than a 32mm.

Forget weight (differential between tyres).
https://road.cc/content/feature/213...heel-weight-doesnt-matter-and-how-wind-tunnel
"Swiss Side feed aero and weight data into a model that crunches the numbers for different types of ride profile and length, and then spits out the likely speed and timing penalties based on a reference ride. One of their programs is a 120km rolling ride with 1200m of height gain. Their 'average' rider completes this parcours at exactly 30km/h (211.4W average power) . . . What difference would one hundred grams (from an 8kg bike to an 8.1kg bike, with a 75kg rider) do to the ride time?
"Well, it would increase it. By three seconds."

 

[Nebulous]

I've been using gp4000s for a while now. I ran 23s at 120psi back and 110 front on a carbon race bike. Moving to 25s at 110 / 100 gave a noticeable difference in comfort. I still managed to get nerve damage on a very long ride, in both feet, and one hand. It took 4-5 months to clear up completely. I now have a steel bike (genesis equilibrium) running 28s, at 90 / 80. That is as big as I can go with guards. Again I think there is a noticeable difference in comfort - yet to be tested on a long ride.

 

[Ming the Merciless]

The changes will be so marginal as not to be noticed outside racing. For the type of riding you do comfort is king. Become uncomfortable will significantly reduce your power output beyond any minor aero differences if a wheel. Remember around 85-90% of drag is you, not the bike.

 

[Venod]

I ran 25mm Michelin Lithion 2 with tubes on Archetype rims at 80psi rear 75psi front, very comfortable, no punctures, no slower than higher pressure. I believe some people run Archetype tubeless, this would be my choice if I was replacing tyres on these excellent rims

 

[FishFright]

Very little to gain I would say, and plenty of comfort to lose. I wouldn’t go below 28mm for that reason, and certainly not 23mm. Maybe some lighter weight summer tyres in a 28mm could be worth trying, say Conti GP 4000s

^ THIS ^

 

[DCBassman]

Whenever the tyres need changing on the Claud or the Trek, they're going to go to as big a set of slicks as I can fit. Currently at 40 and 50 respectively, will go to 60mm and lower pressure for armchair comfort!