jrickards

In trying to find a local LBS that could supply me with a specific tire (pair) that I was looking for, I ran into what I believe to be a profound lack of understanding as to tire sizes.

I have a 29er bike that, in many ways, is just an MTB with larger rims. When I explained to the LBS staff and owners what I was looking for, they looked in the 29" section of their catalogs and when we didn't find them, I suggested that they look in the 700c section of the catalog at which point, (1) they questioned whether or not I had a 29er or a road bike and (2) told me that 700c tires wouldn't fit on a 29er rim. I tried to explain to them the ERTO code but all I got were blank expressions (including from the owners of the shops).

I recognize that most 29ers are built like MTB bikes for MTB-style riding so it makes sense that the 29er section of the tire catalog shows wider, knobby tire options but I have found that many popular tires are available in many widths such as the Marathon Plus, from 25-45mm and, for this reason, the LBS catalog may list the 25-32mm widths of this tire in the 700c category and the 35-45mm widths of this tire in the 29er catagory but, nevertheless, they all have the same ERTO code (at least the same 622 component of the code). The worst part of the quest was having an LBS owner tell me that the 622-47 (47mm = 1.85in) tire that I wanted would not fit on 29er rims (but they would sell them to me anyway) because the tires were listed in the 700c category of the catalog. Further compounding the situation was being told that MTB-style tires are measured in inches and 700c tires are measured in mms. I can't think of any road/touring bikes that could use 47mm wide tires and, I'm told that most hybrids top out at about 42mm (or less) so only something like a 29er would have the spacing for this width of tire.

It was frustrating trying to educate the LBS staff.

In the end, I agreed to buy the pair of tires from the LBS with the condition that they cannot be returned if they don't fit: I reluctantly agreed but I almost feel like (when they come in), offering the store a free training session whereby, for the cost (on their part) of a few minutes of their time, they are to install the tire on my front rim (at no cost to me) just so that they learn that 29er rims are the same diameter as 700c rims (not the same width but diameter). I'm not suggesting that I could use a 622-23 tire on my 29er rim, the rim might be too wide for the tire to be properly use. Alternatively, I'm not suggesting that a road bike could use a 622-54 tire because the tire dimensions would not allow it to be fit between the forks/stays/brakes of a road bike. In both cases, however, I believe that the tires could be installed on the "opposing" rims but not necessarily usable.

Please correct me if I'm wrong but I think I'm right about rim size, based on the fact that I took my 54mm Kenda Small Block 8 tires off last year and replaced them with Schwalbe Marathons, 32mm (622-32 or is it 32-622) and was perfectly fine with them. However, for my needs this year, these Schwalbes are too narrow so I've gone with a wider tire, Continental Country Plus, 47mm (622-47).

spivonious

Yes, 29er = 700c. They're both ISO 622.

Sounds like it's time to find a new bike shop.

tds101 

Yup! A 29er is just a 700c rim with a fatter tire.

mstraus

Sounds like the LBS is definitely a bit confused. 29er and 700c are the same diameter/circumference. The only difference that will impact what tires will fit what rim is the WIDTH of the tire and WIDTH of the rim. Many road bikes have narrow rims, somewhat limiting the max width of a tire you can put on them. Similarly most 29er rims are much wider, limiting how narrow of a tire you can put on. So maybe you can't (or shouldn't) put a 23 or 28mm tire on a "29er" rim due to width of the rim, Almost any 29er rim I have seen could easily handle a 47mm, and likely a 35mm tire.

There are charts that explain what width tire can go on what width rim online...maybe you should print it out and give it to the LBS?

acidfast7

ISO is written as 23-622.

That's also 700c (French/US/UK), 29er/29" (US/UK) and 28er/28-Zoll (German) if you are travelling!

mconlonx

Patronize a different LBS...

jrickards

Yes, that's what I meant when I said that the tires could be installed on "opposite" bikes (29er vs 700c road) but not usable (i.e., width issues) and to successfully install them would have been just to illustrate that the diameters of the rims were the same.

Thanks all.

jrickards

Thanks @acidfast7, the 28er explains why Schwalbe sometimes identifies some 29er tires as (for example) 28"x1.9".

I wonder, is 29" in the US equal to 28" in Germany? If so, is it because of different languages or time zones?

I-Like-To-Bike

Schwalbe Marathons are marked with both designations

I-Like-To-Bike

Germany has considered 622mm tires/wheels as 28" for a long time. Note that 27" tires/wheels actually have a larger diameter 630 mm than 28" tires/wheels with a 622mm diameter. But just to add more confusion 28" tires wheels used on older Raleigh Tourist bikes have a 635mm diameter, I believe that size was also used in India and Africa and perhaps China too.

The 29'' designation is just a marketing gimmick trying to create a new market for bikes with fatter tires.

ragnar.jensen 

Schwalbe Marathon tire on Crank Brothers Cobalt wheel.

--
Ragnar

fietsbob

the rim for a 622-23 tire would be different than if for a 622-60 tire , but thats width, not Bead-seat-diameter (that is what the 622 measures.)

acidfast7

No problem! You should always read the Schwalbe page in German as they have other options that aren't always in the English versions.

In the US market, 29er came from MTB tires, which is roughly 29 inches with a knobby tire.

In the German market, 28er came from trekkingfahrdäder (trekking bikes, kinda like an easy trail version of a US touring bike ... think a US "road" bike with mostly road components plus a trekking/MTB triple up front and flat bars). In this case, there was only a need for international "inches" and this was without the knobbies and called 28er/28-Zoll.

Null66

I have 48's on my Disc Trucker right now.

I have a custom wheel set though.
PH Tandem disc hub with Velocity chukker rim (some have described this are a 29' er rim.)

I think one possible distinction of 700c vs. 29'er is the width of the rim itself.

irwin7638

29er is just another meaningless marketing gimmick which has nor real relevance. Like the terms 700c, 650b, 26er and 28", it has nothing to do with the real tire or the rim. I wish the industry would stop, but a catchy phrase is an easier upcharge, put drop bars and brifters on a hybrid trail bike to sell it as a cyclocross racing bike.

Marc

alan s 

Refer them to Sheldon Brown for a free education. Sheldon Brown-Bicycle Technical Information

dynaryder

You're both wrong. Originally,'29er' was the term used to differentiate very wide 700c MTB tires(2"+). The intent was to make MTB's with larger diameter wheels so they would roll over obstacles easier than bikes with smaller 26" wheels. The term was later watered down by companies using it as a buzz word to describe bikes with wide(38mm+) tires. But there are advantages(and disadvantages) to 29ers over 26ers,which is why they're so prevalent.

I do agree they're getting a bit silly in marketing odd sizes like 650 to recreational riders,but the pros do have their preferences.

Rootman

I remember riding a bike with 29" tires 45 years ago, 29" is simply the older imperial measurement that used to be in use before 700c became the more common designation.

I also have a bike I ride today that has 700c wheel that has 40mm tires on it, so your second point has no merit either. There are skinnier tires designated 29" and fatter tires designated 700c, there is overlap in the sizes and widths.

irwin7638

My point is the 29er tires are actually 622-54. It would be nice and less confusing to use the actual tire size than the marketing nicknames and archaic designation.

Marc

jrickards

I like the idea of 650 (also marketed as 27.5") wheels for small (generally) women so as to keep the frame proportions good but generally, I don't see the need. But then, for men who are very tall, should there be a 750?

acidfast7

FYI, the width is always first ... 54-622.

benda18

You should've made a friendly wager. ISO 622.

irwin7638

It's nice to know that somebody does know what I'm talking about. We should hire you to educate the LBS crews.

dramiscram

You educated me as well, I didn't know that.

Thanks form the lesson

unterhausen

a lot of 29'er mtb tires will actually run ok on a 19mm rim even though it's not recommended -- used to be fairly common, now less so. And rather obviously, you can use road tires on 29'er rims. I am running 700c x 38mm Marathon cross tires on my 29'er wheels, not sure what the actual designation of the rims is, but they are wide