mtnbke

With Schwalbe tires things get confusing and complicated. Listen every tire manufacturer gives an ISO tire size for their tire, but in reality the tire as mounted on the rim sometimes measures bigger or smaller. That can ABSOLUTELY have to do with the width of the rim, as assumedly the BSD (bead seat diameter) isn't going to be too far off.
A 700c rim should have a BSD of 622. A tire's ISO size might be 622-23 or 622-35, showing the rim size-tire width. Putting a given tire on a narrower or wider rim is going to change the profile of the tire as it sits, we can understand that.

Schwalbe gets interesting because when you go with one of their great Marathon tires that actually is a Marathon PLUS, the effective size of the tire actually ends up being bigger than the tire "actually" is per its size. What does this mean? It means if you buy a Schwalbe Marathon PLUS in say 700c that is 3 wide (which normally would be a 622-35) that believe it not Schwalbe marks the tire sidewall as 700x35 AND puts an ISO size on it as 622-37. Madness! How can it be both? That's Schwalbe's way of acknowledging that the extra flat protection of their Marathon PLUS actually ends up making their 700x35 actually measure out to about what would be a 37.

Many tire manufacturers actually misrepresent their tire sizes, to gain a competitive advantage for listed weights. Sad but true. Measure your tires with calipers as they sit on the rim inflated. As you wear through tires and try different manufacturers or tire models keep track of the effective tires size. Just because someone sells you a 700x23 or a 700x35 doesn't mean it "really" is. Not if they want to sell tires to all of us checking and comparing weights for a given "size." When they all cheat, which they more or less do to a degree, we end up with the madness we have.

I like that Schwalbe is honest in the other direction. Yes it "is" a 700x37 but the extra thickness in the flat protection of the PLUS makes it a porker, and it effectively gets wider, even though it is NOT a wider tire than the normal Marathon. Marathon Plus tires are a bit taller too.

Remember to recalibrate your cycling computers when changing tires for that reason. Many cycling computers let you enter the exact wheel dimension (circumference) of your rim/tire setup. To just arbitrarily assume that a given size wheel/tire combo is the same for all bikes gives just ballpark mph and distance metrics.

Once you understand the ISO size standards for tires some interesting things become evident:
559 (26")
584 (650b)
622 (700c)
630 (27")
635 (german 28", or rat rod rims)

The first is that the pejorative way we "judge" wheel sizes is just completely and totally arbitrary and capricious. The average professional mechanic will tell customers that "good" wheels are 700c and 27" wheels are only for cheap bikes. While it is true that a lot of bike boom bicycles in the US market were crap and sold with 27" wheels, there is no correlation to wheel size and quality. You can roll just as good of a rim in 622 as you can in 630 or even 635. For those like myself that find big old 68.5cm (27" frames) from that era it is frustrating how the lemmings in the collective cycling peloton have come to believe that 622 equates to good. In reality it is absurd to have one standard tire size for road bikes. Manufacturers want you to think everyone should be on the same size, distributers want you to think that everyone should be on the same size, shops want to only carry, stock, and sell one size. Its a logistics and inventory problem for them. However for the cyclist a 622 wheel on a 50cm bike rides differently for a five foot nothin' cyclist than a 622 wheel rides for a six foot nothin' cyclist on a 61cm. Those of us that are at either end of the spectrum say riding 49cm bikes and riding bikes over 63cm understand that one wheel size does NOT fit all.

I prefer to keep my big 68.5cm (27") bikes on 630 rims. Its only an 8mm difference from a 630 to a 622, but you can absolutely get quality touring tires from Continental and Schwalbe, plus the Panaracer Pasela and a host of others. You can even get road racing tires in 630 made by many. Its only a 4mm radius difference, as the 4mm above the hub doesn't really count effectively. That 4mm "upsize" matters on big bikes. Its hard to understand, but normal people need to ride a Dahon folding bicycle to understand how tiny wheels affect big people. The smaller the wheel size the less stable the bike is. Does that 8mm effectively matter or is it nuance? Let's just say that large bicycles are so inherently unstable that every little bit helps. Plus when you're running 205mm or 200mm cranks you want as high of a bottom bracket as you can get. In that vein you'll not give up the 4mm of extra clearance for anything.

The 650b fad wouldn't have fully HALF the momentum it has if it was simply referred to by its ISO size of 584. We love things to sound fancier than they are…700c, 650b, its part of the vanity of cycling. In reality there is nothing "better" about a 622 over a 630, just availability. Cyclists are lemmings they believe what they are told.

In reality there is just a 25mm difference between 559 and 584. Why the craze over 584 mountain bikes and touring bikes? The hilarity of it is that there is a 38mm difference between 584 and 622. Larger people wanting to convert to 650b are idiots in my mind. If they riding a 65cm or a 63cm bike, then proportionately their 622 rims are already "650b" size for their larger frames. What some people like with 584/650b is the relative proportion of wheel size to their frame size. How a wheel rides to one rider/frame is different relative to the size of the bike and the rider. Its all relative. There is nothing magical about the size, just the proportion.

Only cyclists are too ignorant to actually understand that, and people like Jan Heine perpetuate nonsense, and really they probably know better.

Just like with cars, one size tire does not fit all. However, manufacturers, distributers, and shops don't want you to know that. They'd have an inventory and logistic nightmare. In reality there should be AT LEAST five different wheel sizes covering the ground between a 49cm frame and a 68cm frame, to keep things minimally proportional. The wheel size needed for the BIG bikes don't even exist. True Clydesdale cyclists are riding around on clown sized wheels.

mtnbke

I like the Pasela and the Tourguard version, however in the tandem community there have been a LOT of sidewall failures on Paselas. Now Paselas are a very lightweight tire that is a great touring tire. It is not a bombproof sidewall like a Marathon or Marathon Plus (same sidewall) or Continental Touring tire. When you double the load with two cyclists on the same two tires bad things did happen. For a single I love the Pasela tires. I don't like them on tandems though many teams still do. They are so lightweight the attraction is clear.

A Panaracer Pasela Tourguard in 700x32 is only 330g! A Schwalbe Marathon Plus in 700x32 is 810g! That's insane. BOTH Paselas weigh less than a single Marathon Plus, and buy a long shot 660g to 810g. If you're doing loaded touring in third world countries you don't use a Pasela Tourguard. If you want a go fast tire with some touring capability for credit card touring, I love the Panaracer Pasela. I use them as road tires on my "racing" singles because I'm so heavy.

non-fixie 

I would ride the tires you've got, but keep an eye on the valve stem angles. The one time I did encounter a serious problem with my tires was when I had mounted 32mm tires on narrow rims. I'm still not sure what role the size played exactly, but replacing an inner tube twice a day gets boring pretty quickly. Check out this post.

verktyg 

@non-fixie I ran into valve stem problems on several tire/rim combinations. I was trying to mount 700x32c and in one case, 700x28c tires on some narrow 20mm x 13mm rims.

Figured out that the beads on the tires were very thick and kept the valve stems from seating down in the rim. On some tubes, the base of the stem where it joins with the tube is too wide/large to fit below the tire bead so it stays inside the tire above the bead.

In another case the distance between the bead lips and the rim floor was too short!

This will eventually cause the tube to bulge enough to blowout.

The only solution I came up with short of going with wider rims was to go to thinner tubes, ones made for 18-23mm or 20-25mm size tires.

verktyg

Chas.

ver

non-fixie 

Thanks, Chas. I'm still trying to find the courage to mount those Grifos on another set of rims.

What happened is that under downhill braking the tire would shift ever so slightly on the rim, taking the inner tube with it. In the picture below you can actually see the rear valve stem already being askew (I'm sure I didn't mount it that way). It sheared off later that morning for the first time. Solutions that were suggested were a) glueing one side of the tire to the rim and b) applying a liberal dose of talc powder to the inner tube so it won't be dragged along with the tire.

verktyg 

Challenge Grifos are cyclocross tires made in both clincher and tubular versions.

The clinchers have folding Aramid beads. Folding bead tires can be very difficult to install on some rims. There's a possibility that they could fit too loose on other rims???

Here's a scenario... Say the Grifo tires fit loose on the rims they're mounted on. The knobby tread pattern can tend to grip the pavement unevenly - they can repeatedly grab and let go especially when braking hard downhill.

The tires get gradually pulled backwards causing the valve stem to pull backwards in the rim too putting stress on the tube???

Question... why do you run cyclocross tires? Off road ridding? Gravel grinding?

I stopped using knobbies on paved surfaces years ago because they're noisy and create a lot of vibrations that get transmitted into my hands, feet and other areas.


BTW, I use talc in all of my clinchers. It helps in preventing pinching during installation plus the tubes settle into the tires better. I keep my spare tubes in baggies with a little talc too.

Regardless of what Jobst Brandt had to say about talc covered tubes, it's been used in all types of pneumatic tires for over 100 years!


verktyg

Chas.

verktyg 

The tires that I recently had problems with were a set of Challenge 700x32c Paris-Roubax (not Parigi-Roubaix) clinchers on Super Champion Mod 58 rims. They're 23mm wide on the outside and 16mm on the inside so I didn't expect any problems with them??? The height is only about 13mm



The Michelin A2 tubes made for 28mm-32mm tires wouldn't work. I had to switch to the smaller A1 18mm-25mm tubes.

verktyg

Chas.

KonAaron Snake 

Except for Vittoria hyper Randonneurs, which measure 2-3mm wider!

nlerner

You inspired me to go measure. My 32mm x 700c Vittoria Hyper Randos measure 32mm on an Araya RC-540 rim. My 37mm x 700c Vittoria Hyper Randos measure 36.5mm on a Sun CR-18. Where do your figures come from?

KonAaron Snake 

I measured the 35mms at 38.2 on a Mavic tandem rim. Maybe they made an error and marked the size incorrectly.

nlerner

Could be. Too bad I don't have any 35mm VHRs to compare it to (or maybe I do--need to check the bin!).

non-fixie 

They're actually Grifo XS tires, which Challenge call 'Gravel Open Tubulars'. They're in between road and CX tires. Road treads in the middle and knobbly bits on the sides. I stumbled upon them in a bike shop. Reasonably priced, good-looking and light. And at 32mm I thought they'd be just the thing for L'Eroica. Needless to say I decided not to use them after that first test and opt for 28mm Pasela's instead for Tuscany.

Apart from the flats, they do ride nicely, though, and I will use them again. If only because I have the Paris-Roubaix 27mm 'open tubulars' on my Champion Mondial semi-race, and I really like the way they feel too:

eschlwc

verktyg 

OH! That's bad....


verktyg

Chas.
On the edge of your seat movie from 1976.