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Tire Width (I don't get it)
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splain me this. and tell me if i've got a problem with my reasoning.

1. 25mm is testing better than 23mm in most rolling resistance tests.
2. in the limited amount of testing i've seen, isn't 28mm outrolling 25mm?
3. wider tires are also likely to be more comfortable (lower pressures).

but...

4. almost 6 in 10 are choosing 23mm or thinner.

yes, there are aerodynamics to consider as well. is this your argument? or is there something wrong with my chain of reasoning above?


Dan Empfield
aka Slowman
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Re: Tire Width (I don't get it) [Slowman] [ In reply to ]
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Fit.

I don't think anything wider than a 23 on my Flo 30's will fit on my bike.
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Re: Tire Width (I don't get it) [Slowman] [ In reply to ]
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The results you got are likely heavily influenced by you being so specific - race wheels on your tri bike. Most low crr 23mm tires test faster than 25mm tires when aero is factored in. Plus, many frames still do not fit wide rims with 25mm tires.

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Re: Tire Width (I don't get it) [Slowman] [ In reply to ]
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For myself (n=1), it comes down to aerodynamics, what wheels I'm running, and what fits in the bike frame I'm riding. On my old TT bike, a 25mm tire was the widest I could comfortably run in the rear, and this was a 25mm tubular. I'm not sure my current Jet Plus disc with a 23mm Corsa Speed which measures > 26mm on the rim would fit on that bike.

My current wheel setup is a HED 3+ front and a HED Jet Plus Disc. I have a Conti SS 20mm on the HED 3+ which measures around 24mm and a Corsa Speed 23mm on the Jet Plus Disc which measures > 26mm. On my tubular wheel set, I have a 23mm front tire and 25mm rear tire, which more than likely measure narrower than the clincher setup I'm currently running.

For training I run wider tires, but for racing it's balancing aerodynamics, wheel/tire interaction, and rolling resistance.
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Re: Tire Width (I don't get it) [Slowman] [ In reply to ]
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Fit for me, too. I can't get anything wider than a 23 GP4000 on my bike with FLO 30s.
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Re: Tire Width (I don't get it) [Slowman] [ In reply to ]
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Also, probably a good chunk of the people who responded with 23mm are using 4000s, which are really almost 25mm on wider rims (limit for many frames).

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Re: Tire Width (I don't get it) [Slowman] [ In reply to ]
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23mm GP4000s on my Flos measure just over 26mm, my 2 main bikes can't handle anything larger.



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Re: Tire Width (I don't get it) [Slowman] [ In reply to ]
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Slowman wrote:
splain me this. and tell me if i've got a problem with my reasoning.

1. 25mm is testing better than 23mm in most rolling resistance tests.
2. in the limited amount of testing i've seen, isn't 28mm outrolling 25mm?
3. wider tires are also likely to be more comfortable (lower pressures).

but...

4. almost 6 in 10 are choosing 23mm or thinner.

yes, there are aerodynamics to consider as well. is this your argument? or is there something wrong with my chain of reasoning above?


One thing to consider is that wide-rim clinchers increase the effective tire size. For example, a 25mm-wide (external) / 21mm-wide (internal) Hed Plus rim makes a tire labeled 23mm inflate to about 25-26mm actual. So - is the poll asking about labeled size, or measured size when inflated?

And, frame fit is an issue. I have a custom tri bike that can fit 30mm tires. But it's an extremely rare bird. It was outstanding when I used to live in Michigan, with their abysmal road quality. I never understood how people rode 23mm tires at 100psi or more in that state. Newer tri bikes are slowly accepting wider tires, but it's often capped at about 25mm actual/inflated size.
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Re: Tire Width (I don't get it) [Bonesbrigade] [ In reply to ]
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Bonesbrigade wrote:
Most low crr 23mm tires test faster than 25mm tires when aero is factored in. Plus, many frames still do not fit wide rims with 25mm tires.

i'm not disputing you, but do you know this? how many tires have been tested on how many wheels? seems like there must be a lot of aero testing left undone in order to make a broad claim like this. if the 25mm tires on balance outroll their 23mm siblings, then the 23mm tires MUST perform better aerodynamically just to get back to even.


Dan Empfield
aka Slowman
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Re: Tire Width (I don't get it) [Slowman] [ In reply to ]
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Aero + fitment.
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Re: Tire Width (I don't get it) [Slowman] [ In reply to ]
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In my case, they simply came with my bike. When it's time to replace, I'll consider 25s. Edited to say, my current tires are pretty nice (Schwalbe One, tubeless)... so can't really see ripping them off till they're done.

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Last edited by: surroundhound: Jun 27, 17 13:28
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Re: Tire Width (I don't get it) [Slowman] [ In reply to ]
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I'm on 23mm GP4000 on SRAM S60/S80.

If anything happened to this wheelset I'd get a wide rim wheelset and 25mm tires, if the tires could clear the frame. But not going to go out of my way to change the wheels for a few seconds over 40Km.

On my road bike running 25mm on a Mavic Ksyrium wheelset. Whole different game there. Frame clearance is better, brakes open to allow wider tires, and rear brake isn't hidden behind the BB making wheel swap a pain in the ass.
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Re: Tire Width (I don't get it) [Slowman] [ In reply to ]
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Old HED3 front. Which means a 20c. Some things don't change.

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Re: Tire Width (I don't get it) [Slowman] [ In reply to ]
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Brake clearance on the rear brake of my Felt prevents anything wider than the 23.
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Re: Tire Width (I don't get it) [Slowman] [ In reply to ]
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Fit and ease of use. I tried 25s and experienced frame rubbing, brake rubbing, etc. Cervelo p3c.

Switched back to 23s (4000s) and no issues.

Your reasoning may be fine, but it's incomplete in terms of gauging factors relevant to consumers.
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Re: Tire Width (I don't get it) [Bonesbrigade] [ In reply to ]
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+1

on my Flo 60/90 wheels, 23 Conti GP4000 SII are far wider than 23... 25+ and there is just enough clearance on my 2015 Felt B series.
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Re: Tire Width (I don't get it) [Slowman] [ In reply to ]
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6 in 10 of us are too poor/cheap to have a wheel/frame setup to take advantage of anything wider than 23. In the big scheme of things, there aren't that many rims with internal widths of more than 17mm (though this isn't much of an issue if you are buying new).

Other factors include the Corsa TLR only being available in 23, up until very recently, some of the TT crowd are still running SS 20s on HED/Specialized Trispokes, and wheels like the Flo 30s being really fat with a 23.
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Re: Tire Width (I don't get it) [Slowman] [ In reply to ]
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Dan,

For me, it depends on the wheel and the bike. Shiv with RZR92s - 23 (Vittoria tubulars) as manufacturer recommended. With Hed C+, 25 IRCs which measure 30+. With Eurus, 23 Michelins. Reynolds Assaults (old) 23, Enve 3.4s, 23 (measure 26 and 25). Flo 60s, 23 (measure 25).

I was in my LBS the other day. A 25 Conti 4000s2 on Hed Jet 6+, Pinarello FP Quatro was rubbing on the brake. New tire and it was too big. Sadly there were rub marks on the chains stays where the previous 23 had rubbed, too.

What I wonder about all the width testing is, how specifically is it tied to nominal tire width?
Last edited by: FatandSlow: Jun 27, 17 14:03
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Re: Tire Width (I don't get it) [Slowman] [ In reply to ]
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25's barely fit on my bike as it is. Its uncomfortably close.
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Re: Tire Width (I don't get it) [Slowman] [ In reply to ]
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For me it's about bike fit; my B16 from 2012 doesn't fit 25mm tires.
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Re: Tire Width (I don't get it) [Slowman] [ In reply to ]
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Are there tires that are comparable (i.e., as fast as) to the conti supersonics in casing/tread suppleness in 25mm or 28mm? If yes, let me know.

I think that bottom line is that there is a serious dearth of public data on where exactly the tire/rim width crossover point is for modern bikes and modern wheels and modern super fast tires.

In other words, when exactly does the excess tire/rim width mean an increase in aero drag that exceeds the very small improvement in rolling resistance? I don't know. But my guess is that you can't go that wide without a speed penalty.

And, when people don't know, usually they stick with what they have.

I think that might be the answer to your question.

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Re: Tire Width (I don't get it) [Slowman] [ In reply to ]
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Slowman wrote:
Bonesbrigade wrote:
Most low crr 23mm tires test faster than 25mm tires when aero is factored in. Plus, many frames still do not fit wide rims with 25mm tires.

i'm not disputing you, but do you know this? how many tires have been tested on how many wheels? seems like there must be a lot of aero testing left undone in order to make a broad claim like this. if the 25mm tires on balance outroll their 23mm siblings, then the 23mm tires MUST perform better aerodynamically just to get back to even.

The general rule of thumb - based on the results from others, is aero takes a good hit when rim widths are less than 105% of tire widths. I don't think the Crr benefit from wider tires makes up for that.

BUT, I think we will see wider rims paired with wider tires, but we also need more clearance on bikes to accomode this. This is happening though......Flo is going this way for their gravel rim.

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Re: Tire Width (I don't get it) [Slowman] [ In reply to ]
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The great Walter Benjamin discussed how and why products have an aura created around them and how that aura becomes the authentic 'thing' and not the product itself. Light reading for your recovery days.

People will go with the first narrative they've created (or agreed with) concerning a product. Judgements about information after that simply serve to justify the opinion.

And when it comes to numbers, people just aren't smart - please believe me, I don't mean that to be condescending. But, Agent K said it best "a person is smart but people are dumb." Read up on why A&W's 1/3 lb burger failed and you'll begin to crack the code of the wider tire. Opinions about tire width, like most things cycling, have nothing to do with the actual thing itself.
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Re: Tire Width (I don't get it) [PennBen] [ In reply to ]
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i can see now i asked the wrong question. the question i SHOULD have asked is what tire width you feel your next bike should accommodate. i will ask that in the next poll


Dan Empfield
aka Slowman
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Re: Tire Width (I don't get it) [Slowman] [ In reply to ]
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But, if speed is the goal, how are we to know what is the optimal tire width that our next frame should accommodate?

Especially when there is no good data.

Now Available: the High-Capacity Speedpack 915/915D Series. Advanced Aero Storage, made in the USA.
DarkSpeedWorks.com......Reviews......Instagram......Facebook

"Why would you want to be the last man alive on a sinking ship?" -- Elon Musk on why Tesla Motors shares its patents with competitors.
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