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Tire width; 28 vs. 30 or 32.

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Tire width; 28 vs. 30 or 32.

Old 10-28-20, 06:35 PM
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Ogsarg
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Tire width; 28 vs. 30 or 32.

My Roubaix came with 28 tires but will fit up to 32 safely. I ride on notoriously bad roads so always looking to improve the ride quality. My old bike (09 Roubaix) had 25's and the new bike is noticeably more comfortable but not sure how much of that is the tires vs. the bike itself.

I'm going to need tires soon and considering going wider. Is there a noticeable difference in ride quality between 28 and 30 or 32? And will I pay a price in rolling resistance going wider? My main use of the bike is rides in the 70-100 mile range on the weekends. Speed is not important but I don't want to feel like I've ridden an extra 10 miles at the end of a ride. Currently riding GP5000 TT but open to other suggestions as long as it's something that isn't super easy to puncture.
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Old 10-28-20, 06:37 PM
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My Domane came with 32's and I absolutely love them, buttery smooth. I went with the Bontrager R3 TLR's.
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Old 10-28-20, 06:45 PM
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They're consumables - just try them. If all else is the same, none of the jumps is going to be so bad that you'll want to toss them in the bin and go back immediately.

Having run 30s for a couple years, I do prefer 28s, but that's because a) the 28s on my wide rims are comfy enough and b) I like my bike to handle a little more to the agile/twitchy side. In terms of rolling resistance, there's no way that I could tell a difference.
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Old 10-28-20, 06:46 PM
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I have a Domane SL5 with 32s, and really like them. On the other hand, I didn’t like the 32s on my Sirrus 4.0, and went down to 28s which I find much more responsive and faster on that bike. My wife finds the 28s on her Roubaix much to her liking. I guess it depends on the actual tire and how they perform on the bike.
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Old 10-28-20, 08:27 PM
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Try latex tubes. My bikes max out at 700x25, so my only option for softening the ride on our increasingly rough chipsealed roads was to try latex tubes. Really helped. I'm not strong enough to notice any difference in speed due to reduced rolling resistance. But it's more comfortable, which matters on longer rides.

If you go this route, check out the tutorial videos by Silca. Very important for properly installing latex tubes to minimize problems. Since the Silca video was done they've begun pre-powdering tubes to ease installation with reduced risk of pinch-cuts against the rims. But I add a little of my own corn starch powder for subsequent uses. And be sure the rim tape adequately supports the tube -- some folks recommend tubeless rim tape rather than cloth or others.

So far my only puncture with latex tubes was user error -- I neglected to follow the advice to use tubeless tape and just used the Velox cloth tape that was already on the rims. There was a tiny bit of something sharp embedded in the cloth tape that punctured the tube on the rim-facing side. I was able to patch it using Lezyne self-sticking patches, which are very unusual -- they're paper thin, very soft and flexible, and the adhesive seems to get stronger and bond more securely with age. I used a Lezyne patch to repair the puncture and left it for a few days before riding. No problems since.

However I would advise carrying one or two spare butyl tubes for use on the road. Patching a powdered latex tube during a ride is a PITA. Quicker and easier to use a butyl tube, then patch the latex tube later. I usually carry super light Continental Race 28 Light tubes on my road bike seat bags, since I can carry two in the same space as one regular butyl tube. The Conti Race 28 Light tubes have been more durable than I'd expected, despite being so thin.

Tubeless is another option but I haven't tried it yet.
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Old 10-29-20, 12:51 AM
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Originally Posted by Ogsarg View Post
I'm going to need tires soon and considering going wider. Is there a noticeable difference in ride quality between 28 and 30 or 32?
There's a compliance benefit to pumping your tires squishier. The wider the tire, the squishier it can be pumped while remaining well-behaved.

If you increase width without reducing your pressure, the tires won't ride any comfier. (Actually, wider tires are a bit stiffer than narrower ones, when both are at the same PSI.)

And will I pay a price in rolling resistance going wider?
No.

"Rolling resistance" in bicycle tires on pavement has two main contributing factors.

One is energy lost to tire deformation.
A bicycle tire inflates to a round-ish cross section, but at the contact patch where it's pressed against the road surface, the shape is flattened out somewhat. As a bicycle rolls along, when a section of a tire gets to the contact patch, energy is spent deforming it against the road surface. When that section of the tire leaves the contact patch, it "springs back" to a round shape. When it springs back, some of the energy is returned to forward motion, but not all: some of it is lost to internal frictions within the material of the tire, becoming heat.
Wide tires don't have to become any more deformed at the riding surface than narrow tires do, so they aren't really disadvantaged here.
An effective way to reduce this effect is to use performance-oriented tires that have less internal frictions. A beefy tire like a Marathon Plus has durable sidewalls, a long tread life, and extremely effective protection against punctures, but in order to accomplish this, they are very stiff and lose a lot of energy when they deform against the riding surface.
Another way to reduce this effect is to pump the tires stiffer. A stiffer tire deforms less at the contact patch, so less energy is lost to deformation.

BUT

The caveat to pumping a tire stiff is that the tire won't be as compliant on road surface irregularities. This isn't just a source of discomfort: it's also the other major contributing factor to rolling resistance. When a road tire is deflecting off of surface irregularities instead of deforming smoothly around them, it's vibrating the bike+rider. Vibrating the bike+rider costs energy, which is stolen from your forward motion. This is a decent article on the subject.

The costs from the latter effect can be significant. If your current tire width is preventing you from running adequately-low pressures, going wider might actually let you reduce your rolling resistance.

My main use of the bike is rides in the 70-100 mile range on the weekends. Speed is not important but I don't want to feel like I've ridden an extra 10 miles at the end of a ride.
Wider tires do generally have more aerodynamic drag, and weigh more. However, I think that most people dramatically overestimate the consequences of tire width: the tire just isn't a very physically large part of the bike+rider system.

Here's my gravel bike, with 2.1" Rat Trap Pass EL tires, which are built like performance-oriented road tires except super wide:



Here's my Emonda, on some 25mm Bontrager R3s, a road racing tire:



On most paved road riding, I maybe go around a kph slower on the gravel bike. This is a VERY significant difference from the point of view of anybody shopping for fancy road racing bikes, but we're talking about feeling like having done a few extra miles on a century. And this is with a comically large difference in tire width, blasting straight past the wildest illogical conclusions of the question that you're asking. If you're worried about "feeling like you've ridden 10 extra miles", 32mm versus 28mm isn't in the same universe as anything that you should be worrying about.

If you think that going 28mm -> 32mm might offer some benefit for your rough roads, I'd say go for it.
-BUT-
At the same time, the really important thing for compliance is appropriate inflation. Are you sure that you're not overinflating your current 28mm tires? What's your bike+rider weight, and what PSI do you usually run?

Currently riding GP5000 TT but open to other suggestions as long as it's something that isn't super easy to puncture.
GP5000s are already pretty flimsy, as road tires go. If the durability isn't currently bothering you, you probably don't need to worry much about tire beefiness (and maybe shouldn't, since using beefy tires can be a significant performance cost). If you like your current tires, the 32mm GP5000 wouldn't be a bad choice.

//================================

If you're currently running butyl inner tubes, I'll also echo canklecat 's suggestion of latex tubes. You have to be more careful when installing them than butyl, but on the road, if anything they seem less prone to punctures and whatnot. And their benefits are real.
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Old 10-29-20, 04:04 AM
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Originally Posted by Ogsarg View Post
I'm going to need tires soon and considering going wider. Is there a noticeable difference in ride quality between 28 and 30 or 32? And will I pay a price in rolling resistance going wider? My main use of the bike is rides in the 70-100 mile range on the weekends. Speed is not important but I don't want to feel like I've ridden an extra 10 miles at the end of a ride. Currently riding GP5000 TT but open to other suggestions as long as it's something that isn't super easy to puncture.
If you are riding at the rivet in a competitive setting, you will feel the difference in RR. However, if you are riding at endurance pace, it isnt a big deal. I ride 37mm slicks on my weekend endurance group rides and dont have any issues. Maybe I am slightly higher in Z2 - big deal. You are looking at maybe a few minutes difference in total time - and it wont be anything you really notice. So yeah, go ahead and get the 32s. (That said, for my race bike, I am not going wider than 27-28mm measured width).

FWIW, I really like the Panaracer Gravel King slicks - they are light, they have been holding up very well so far (knock wood) and they roll surprisingly well for nominal 35c. I am getting more of those (and I say this as someone who rides race tires all the time).
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Old 10-29-20, 04:27 AM
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While more comfy, wide tires are slow as a dog on climbs. I need all the help I can get in that area, so I always run the narrowest tire I can get by with. Not a big devotee of the "wider is always better" cult. YMMV.
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Old 10-29-20, 06:46 AM
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Originally Posted by Ogsarg View Post
My Roubaix came with 28 tires but will fit up to 32 safely. I ride on notoriously bad roads so always looking to improve the ride quality. My old bike (09 Roubaix) had 25's and the new bike is noticeably more comfortable but not sure how much of that is the tires vs. the bike itself.

I'm going to need tires soon and considering going wider. Is there a noticeable difference in ride quality between 28 and 30 or 32? And will I pay a price in rolling resistance going wider? My main use of the bike is rides in the 70-100 mile range on the weekends. Speed is not important but I don't want to feel like I've ridden an extra 10 miles at the end of a ride. Currently riding GP5000 TT but open to other suggestions as long as it's something that isn't super easy to puncture.
Depends on several factors (personal preference being one of them). My new TCR came with 25mms even if they can now run up to 32mms. I'll be upgrading to 28mm once the OEM ones will be worn out and see if I like it.

Did you consider the Schwalbe Pro Ones with the Addix compound? Also, what kind of usage are you doing?

Last edited by eduskator; 10-29-20 at 06:50 AM.
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Old 10-29-20, 06:56 AM
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Originally Posted by Lemond1985 View Post
While more comfy, wide tires are slow as a dog on climbs. I need all the help I can get in that area, so I always run the narrowest tire I can get by with. Not a big devotee of the "wider is always better" cult. YMMV.
I think you have this backwards. Rolling resistance goes DOWN as you go wider on tires, although I certainly agree that there is such a thing as too wide. What goes up with wider tires is aerodynamic drag.

See the below rolling resistance test of GP5000 tires at various widths. Rolling resistance decreased from 10 watts to 9 watts when comparing a 25mm to a 32mm. In other words, the wider tire rolls easier. Unless there is some aspect of wider tires and climbing that I’m missing.

GP5000 tire width rolling resistance test
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Old 10-29-20, 07:45 AM
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I’m running 32mm GP5000TLs on my Roubaix and my Creo. I really like them. I’ve also run them in 28mm on both bikes and much prefer the 32s.
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Old 10-29-20, 07:52 AM
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Originally Posted by drewtk View Post
I think you have this backwards. Rolling resistance goes DOWN as you go wider on tires, although I certainly agree that there is such a thing as too wide. What goes up with wider tires is aerodynamic drag.

See the below rolling resistance test of GP5000 tires at various widths. Rolling resistance decreased from 10 watts to 9 watts when comparing a 25mm to a 32mm. In other words, the wider tire rolls easier. Unless there is some aspect of wider tires and climbing that I’m missing.

GP5000 tire width rolling resistance test
Yeah, but at what speed?

I think he meant wider tires = heavier tires. At low speed (climb), I'm not sure how significant is the reduced rolling resistance gain.
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Old 10-29-20, 07:53 AM
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Originally Posted by drewtk View Post
I think you have this backwards. Rolling resistance goes DOWN as you go wider on tires, although I certainly agree that there is such a thing as too wide. What goes up with wider tires is aerodynamic drag.

See the below rolling resistance test of GP5000 tires at various widths. Rolling resistance decreased from 10 watts to 9 watts when comparing a 25mm to a 32mm. In other words, the wider tire rolls easier. Unless there is some aspect of wider tires and climbing that I’m missing.

GP5000 tire width rolling resistance test
That struck me as odd, so I clicked through and looked at the pressures they were running.
That test shows that the rolling resistance goes down only if the two tyres are at the same pressure. But that it goes up the wider you get if use the recommended pressure which results in a 15% drop of the tyre when loaded:

Look at the part that says:

Rolling Resistance at Recommended Air Pressures (15% tire drop)
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Old 10-29-20, 09:07 AM
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32mm GP5000 TL's are awesome.
I switched from tubed 28 GP5000s to these, and have been very happy. I wouldn't say the difference between them is dramatic, but the 32s definitely don't feel any slower and I can run them at lower pressure which makes for a more comfortable ride on rough stuff.

I'm around 165 and run my tubeless 32s at about 55-60psi on a 19mm internal rim.
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Old 10-29-20, 10:27 AM
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Originally Posted by CargoDane View Post
That struck me as odd, so I clicked through and looked at the pressures they were running.
That test shows that the rolling resistance goes down only if the two tyres are at the same pressure. But that it goes up the wider you get if use the recommended pressure which results in a 15% drop of the tyre when loaded:

Look at the part that says:
When adjusted for drop the Rolling Resistance is virtually the same (within .1 of a watt) however the RR calculations are flawed because they do not take real-world road conditions into account. The irregularities and imperfections in our roads skew the advantage substantially in a wider tires advantage. Also not taken into account the energy which our bodies must absorb from a narrow high-pressure tire, there are numerous studies including a famous one from the US Army on the fatigue effects of vibration on Tank Crews.
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Old 10-29-20, 10:41 AM
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Originally Posted by velopig View Post
When adjusted for drop the Rolling Resistance is virtually the same (within .1 of a watt) however the RR calculations are flawed because they do not take real-world road conditions into account. The irregularities and imperfections in our roads skew the advantage substantially in a wider tires advantage. Also not taken into account the energy which our bodies must absorb from a narrow high-pressure tire, there are numerous studies including a famous one from the US Army on the fatigue effects of vibration on Tank Crews.
I wasn't saying the test was perfect or that narrow or wide tyres are better or worse. I wasn't value judging at all.

All I did was correcting a misunderstanding with the referred test. It did not, in fact, show that rolling resistance dropped the wider tyre you have unless the tyres were pumped to the same bar/psi.
Personally, I much prefer wider tyres (within reason) myself. But that's mostly a preference and certainly not based on rolling resistance (well, within reason).

Add:
There's a .6 watt difference between the 28 and 32mm. That really doesn't matter, but it's not lower in that particular test.
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Old 10-29-20, 11:31 AM
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Originally Posted by velopig View Post
When adjusted for drop the Rolling Resistance is virtually the same (within .1 of a watt) however the RR calculations are flawed because they do not take real-world road conditions into account. The irregularities and imperfections in our roads skew the advantage substantially in a wider tires advantage. Also not taken into account the energy which our bodies must absorb from a narrow high-pressure tire, there are numerous studies including a famous one from the US Army on the fatigue effects of vibration on Tank Crews.
Fatigue and vibration (and suspension losses) are results of overinflated tires, for the tire width, your body weight and the road surface, and not a necessary consequence of narrow tires. Wider is not automatically more comfortable. At the same pressure, the narrower tire will deform more so unless you drop the pressure the suspension losses will be higher. This is trivial to test. You can take a 42mm tire and pump it up to 80psi or whatever the maximum is. The ride will be much harsher than a 28mm at 80 psi which will feel very plush and especially than a 23mm tire at 80 psi which feels ridiculously (too) soft.
​​​
The idea that larger tires roll better because they perform better in RR tests at the same pressure (which is comfort and suspension wise equivalent to inflating the narrower tire to a higher pressure still) and because they have lower suspension losses because they can be inflated to lower pressure is like having your cake and eating it too. Either you have one or the other.

Personally, if i'm going on one of the bumpier roads, I just inflate my tires a bit less. Latex tubes made a felt difference, even at higher pressures it is very comfortable.

​​​​​​

Last edited by Branko D; 10-29-20 at 11:35 AM.
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Old 10-29-20, 12:23 PM
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Originally Posted by Branko D View Post
The idea that larger tires roll better because they perform better in RR tests at the same pressure (which is comfort and suspension wise equivalent to inflating the narrower tire to a higher pressure still) and because they have lower suspension losses because they can be inflated to lower pressure is like having your cake and eating it too. Either you have one or the other.​​​​​​
Maybe. The complicating factor is that the spring rate of a tire looks different depending on the curvature of the thing that's pressing into it. If the static observations hold in the dynamic case of riding, then the effect that increasing width has on reducing compliance is less significant than the effect that it has on tire drop (and, potentially, hysteresis losses).

Unfortunately, I haven't seen any real efforts to quantify the significance of this. The oft-cited BicycleRollingResistance article just assumes that equal absolute drop implies equal compliance with respect to surface irregularities.
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Old 10-30-20, 06:59 AM
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Originally Posted by Lemond1985 View Post
While more comfy, wide tires are slow as a dog on climbs. I need all the help I can get in that area, so I always run the narrowest tire I can get by with. Not a big devotee of the "wider is always better" cult. YMMV.
100% agree. if i'm rocking '25's or '28's on big climbs, i'm going at a glacial pace vs a dripping honey slow. gimm(i)e shelter and the '23's. and i definitely need the help as well.
the '23's force me to pay better attention vs zoning out. kinda like a manual transmission/stick vs automatic transmission.

that said, if i'm in ogsargville/central ca land where the pavement can be a serious issue (as per dozens of pics and personal experience), i'm likely rocking '25's on the rollers and flats.
i'll just suck it up and go slower on steep hills/mtn climbs on '23's. if there is any dirt involved, it's '28's. if i'm doing multiple rides involving different terrain, i'll bring another compatible wheelset and
the applicable tires.

Last edited by ooga-booga; 10-30-20 at 07:12 AM.
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Old 10-30-20, 07:25 AM
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Originally Posted by velopig View Post
When adjusted for drop the Rolling Resistance is virtually the same (within .1 of a watt) however the RR calculations are flawed because they do not take real-world road conditions into account. The irregularities and imperfections in our roads skew the advantage substantially in a wider tires advantage. Also not taken into account the energy which our bodies must absorb from a narrow high-pressure tire, there are numerous studies including a famous one from the US Army on the fatigue effects of vibration on Tank Crews.
This. There are so many ''real world'' factors and other relevant factors to consider. For instance, air resistance: Wider tire = increased resistance. Mass: Narrow tire = lighter = faster acceleration when needed.

Research may have shown that wider equals less RR, but it's not the only thing to consider if your goal is to shave a few seconds off your century trip.
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Old 10-30-20, 08:22 AM
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Originally Posted by eduskator View Post
This. There are so many ''real world'' factors and other relevant factors to consider. For instance, air resistance: Wider tire = increased resistance. Mass: Narrow tire = lighter = faster acceleration when needed.

Research may have shown that wider equals less RR, but it's not the only thing to consider if your goal is to shave a few seconds off your century trip.
Perhaps this is not only about shaving a few seconds off a century ride comfort plays a huge role in speed. That said virtually all long-distance riders are in the wider is faster camp. Regarding air resistance, tire width is a minor contributor in that area, body shape, body position and other factors play a much larger role. Lighter is faster may have a point once all other weight factors have been removed, and only in an acceleration and climbing area.
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Old 10-30-20, 10:10 AM
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Originally Posted by eduskator View Post
I think he meant wider tires = heavier tires. At low speed (climb), I'm not sure how significant is the reduced rolling resistance gain.
The 200gm additional weight of wider tires is pretty much irrelevant for climbing - or anything else, for that matter.

And re the aero part - what little you lose in aero, you probably gain in reduced vibration losses. Silca has a really good article explaining that - worth checking out. And if you have a modern wheel, what little aero disadvantage you have at 0 yaw gets offset by better handling at yaw. Eg, Roval Rapides.

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Old 10-30-20, 10:13 AM
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Originally Posted by CargoDane View Post
That struck me as odd, so I clicked through and looked at the pressures they were running.
That test shows that the rolling resistance goes down only if the two tyres are at the same pressure. But that it goes up the wider you get if use the recommended pressure which results in a 15% drop of the tyre when loaded:
You lose about 1-1.5W of rolling resistance for dropping the tire pressure by 10psi. That's not going really significant, and as mentioned, you probably gain that back with reduced vibration losses.

Last edited by guadzilla; 10-30-20 at 10:17 AM.
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Old 10-30-20, 11:25 AM
  #24  
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Originally Posted by eduskator View Post
This. There are so many ''real world'' factors and other relevant factors to consider. For instance, air resistance: Wider tire = increased resistance. Mass: Narrow tire = lighter = faster acceleration when needed.

Research may have shown that wider equals less RR, but it's not the only thing to consider if your goal is to shave a few seconds off your century trip.
This. There's reasons we don't ride fat bikes in crits.

OP - 25.

We used to consider 25's wide. Not it's not wide until you're over 32 apparently. That's ridiculous. I know a lot of really fast guys that rode 28's even back in the day who now feel like they've been validated but let's be real: It's a bit like saying some day recumbent riders will be validated for having the faster bikes.

At some point we have to stop putting monster truck tires on supercars.

You guys have fun on your Barcaloungers though. I'll be waiting for the kids to bring back narrower tires, triples, smaller cogs, bigger chainrings, rim brakes, etc. It's not like we haven't covered all of this multiple times in the ~140 years of bicycle development, manufacturing and use.

OP - seriously just pick a tire size. In that range you're not missing anything even remotely ground breaking or life changing in either direction.
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Old 10-30-20, 12:01 PM
  #25  
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We've already got this thread:

https://www.bikeforums.net/general-c...l#post21767943

Maybe it's time for a "Heavy Tires Are Better!" thread as well.
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