The question is about the size of the donut, not the donut hole.

ETRTO specifically measures tyre width (number before the dash) mounted on a comparable rim.

The often differs from the classic x 2.5 or x 2.1 or 1.5 designation and precisely measures mounted width (which I check when I first mount tyres.)

Perhaps, I have foolishly anticipated that everyone was in know about ETRTO.

Here's a synopsis.

https://en.m.wikipedia.org/wiki/ISO_5775

Michelin used to make car tires that only fit on metric sized rims (TRX was the designation), and their car tires were harder to mount since they were just a little smaller than the other brands. You could tell by the louder noise they made when the bead settled in place. It wouldn't surprise me if their bicycle tires were a little off too.

The tire bead size is usually very accurate, but the tire width, which the OP is primarily concerned with, and the tire height, can vary based on tire design, manufacturing tolerances and rim width/design. The OP is asking a question that is really not answerable, as none of the variables are known.

Awww...come on! Guess! :D

The rim width is the biggest factor in how wide a tire mounts. The thinner the rim, the thinner the inflated tire width. So that's a big variable.

But some manufactures don't even get close. (Continental, I'm looking at you. Great tires...but you guys don't know how to use a ruler to save your lives)

I'll back that up. My Michelin Proteks are listed as a 35mm tire

They mount as a 37mm tire. It's so well know that Bike Tires Direct has warning labels on Michelin products saying that they are wider than advertised.

But the bead is smaller than it should be. They are the hardest tire I have ever mounted. I mean they are a FIGHT to mount on a 700C wheel. The same 700C wheel I mounted the Continentals I tried out (the ones that were much thinner than advertised) without using a tire lever. Just pushed it on with my hands like it was nothing.

So yes...your experience with Michelin car tires is my experience with Michelin bike tires.

This article may help. Even if not, it’s interesting.

https://bikerumor.com/2016/08/12/tec...-best-results/

Bikes are complicated.

But yes that was interesting.

From the article:

Something else to noodle on – Schwalbe says many tires are intentionally manufactured on the narrow side of the allowed tolerances because they’ll likely stretch a few millimeters during your first several rides.

I thought he claimed to be 6'3" and 239lbs :innocent:

Interesting tire but no personal experience with them. Also, 700X38 may be a hair too wide. Great price, 66% off.

Vittoria Revolution 700X38 PlanetX

https://cimg2.ibsrv.net/gimg/bikefor...e7d5b61cd4.jpg
Vittoria's take on the one-bike tyre, perfect on and offroad. Includes their PRB 2.0 breaker puncture protection and a superb tread pattern that clears water fast to offer maximum grip in wet conditions. The Revolution is perfect for all types of bikes and riding and it's destined to become a commuter and gravel bike legend.

I was just looking at those. Small world.

Maybe I'll just take the darn fenders off and slap some 42mm tires on there. I try not to ride in the rain. And if it's really raining...I'm getting wet no matter what.

The fenders were more or less for wet roads after a rain so keep the slight spray from getting all over my tail light and killing it. But maybe I just don't need them.

Bike looks cooler without them anyway.

So here's a fresh data point - I just went out to my trike and measured the right front 40-406 Marathon GG. It's 1.54 in wide on my dial caliper, which is 38.5 mm. I've got no idea though what the rim width is, other than it's about right, nor what the pressure is today, since I haven't done that in 2 weeks at least.

I'm still open to being convinced that treads do something. Bike tires may not hydroplane but neither do you when you slip in the shower. That's why you have fingerprints. But many things in this world are designed by engineers but hidden under things designed by artists. This looks like the latter.

They do a lot when you leave the pavement.

I often take a shortcut up this grassy hill. If I'm on slicks...nope. Not gonna happen. With even a little tread...right up it.

Please don't post my nude photos on-line without permission.

Wow, did this one spin outta control there for a bit. It looks like I’m the only guy around with actual experience with both tires. Well, not EXACTLY the HS 420 but the full (5mm) thickness Marathon Plus.

First, my experience with Conti is that their cheaper tires run undersized. In fact, I would buy one size larger just to get close to the size I actually wanted. But, the Contact II’s are true to size as measured by my calipers. I have mounted both 37’s and 42’s on rims with 22mm and 24mm internal. Now, it kinda depends on how firmly one squeezes the micrometer, but the tires measure out true to a variance of no more than 1mm. I have a set of 47’s but I’ve never measured them — they’re fat and that’s all I need to know.

My Marathon experience is limited to a couple of sets, years ago. As I recall, they were slightly oversized, but damn were they heavy. Now, as a Clyde I don’t really give a damn about weight except when it comes to tires. That’s the one area where weight means anything to me because of the effect it has on acceleration and handling. And Marathons are heavy to spin up and you feel every gram in the handling. Once spinning, they carry momentum well, but for stop & go commuting they’re tough to live with. I see why they’re a great choice for touring with their tough, heavy design, but for everyday riding I find them to be overkill.

I spent a lot of miles on Specialized Armadillos. They offer OUTSTANDING flat protection and for years I overlooked their punishing ride in favor of the protection. Armadillos wear like iron and are tough as nails, but they are definitely not plush. If only there was a tire that offered excellent flat protection, a comfortable ride, and didn’t weight half a ton apiece — enter the Conti Top Contact II.

Early last year after wearing out another set of Armadillos I was dreading the thought of mounting up another set. I considered the Marathon Supreme, but they’re pricey and I lose a tire every once in a while to a major catastrophe and I don’t wanna spend $80 bucks only to ruin one with a gash to the sidewall. The Conti’s use the same Vectran belt flat protection design as the Supreme and do it cheaper so I figured WTH I’ll give them a try.

As I already mentioned, the Conti’s run true to size. They ride very plush (but honestly, compared to the Armadillos anything is plush) and have excellent grip. They’re wearing out evenly and appropriately, without any weird bulges or patterns. I have about 3k miles on the 42’s with zero flats (in Oakland California, the Broken Glass Capital of The World) but my guess is that they will not wear as long as the ‘Dillos. I never wore out the Marathons but then again, I didn’t want to make the effort.

I hope you get something out of this.



-Kedosto

There are specific inflationary pressures that are employed with ETRTO and specific rim widths to be employed (not suggested as per the OP).

In addition, the standard measures tyre width, which is exactly what the OP is after.

To me, the question of the OP is facetious, because when mounted on the correct rim width and inflated to the proper pressure,the tyre width is printed on the size of the tyre. I'm slightly befuddled as to why this isn't common knowledge.

Also, 1.54" is 39.11mm, which would probably go to 40mm at the middle of the inflationary range.

I would wager that if you're on the correct rim width and inflate to middle of the range listed on the side of the tyre, you'd be bang on the written width.

That's what I'd say as a reviewer and request that in the revisions of the manuscript.

My eyes! ouch HAHA thank you for the laugh... :roflmao:

Now THIS is how you answer a tire question!

Thank you, brother. That is EXTREMELY helpful. I never thought about the Conti tires form India having all different sizing specs than the Conti tires from Germany.

Those are a folding tire with a kevlar bead if I'm not mistaken. Are they hard to put on the rim or do they cooperate?

As [MENTION=24941]StanSeven[/MENTION] requested, please stay on topic. Much of the content in this thread has been bantering between a small number of users. Please do your best to stay on topic and not dilute the meaningful content of this thread. Thank you.

Also I pulled the fenders off last night. I definitely like the look of a bike without fenders better.

As for the ride...I managed to survive without fenders on this dry day with no mud or puddles to splash through. It's a miracle, but I survived.

The Top Contact II's mount with ease. They are folding bead tires, so they can be a bit floppy with the first mount but with subsequent remounts they hold their shape. I've always found wider tires much easier to mount than the skinny ones anyway. I have mounted the Conti's on Ryno Lites, DT Swiss 545D, Velocity Dyad, and generic Specialized stock rims (probably Alex).

Both the Marathons and Top Contact II's are high quality tires. For me, the decision came down to flat protection. I can do it the heavy way with a thick extra layer of rubber, or I can do it the lighter way with a thin layer of high-tech fabric. I suppose the Marathons probably are better at flat protection but if the Conti's already exceed my needs, why bother? I just feel like when when the level of flat protection is already so high, there's no need for me to go to the extreme. My real world experience with the Armadillos has proven valid and they use a special weave of Kevlar which is supposed to be weaker than Vectran. I probably would still be rolling Armadillos if they didn't ride so harsh.

The Conti's are plush, smooth rolling, flat resistant, lightweight (for their size), grippy, durable, high quality tires. I'm happy.


-Kedosto

?? With a history of 11K posts, you should be able to see that this thread is like 75th percentile for staying on topic.

Anyways, Kedosto yes, thanks for the excellent writeup. Any idea whether the Contis claim tubeless-ready, or might hold sealant even if not? Do the sidewalls seem like they might be porous?