Gyro_T

I am headed to Italy for three weeks in June. I am unsure about the availability of 29er (622 X 50) tires and tubes. Our bikes have the Schwalbe Marathon Mundial tires and presta valve tubes, and although they are suppose to be reliable tires, you just never know. I am looking for advice on carrying tires and possibly drilling out the rims for Schrader valves. We are flying with coupled bikes in cases so not having to carry a couple extra tires would be a benefit. We won't be in any large cities except for Florence. Thanks in advance

3speed

You'll find Plenty of 700c tubes in Italy("29er" is just the lame marketing term thought up by Trek for 700c MTBs). I would guess that they'll have tires available too, though I wouldn't count on needing an extra tire unless you're going on a Long tour. You'll also find Presta valves there. I could be completely wrong, but I think Schrader might have been an American thing and Presta originally European.

Ah, yes. I just checked, and it seems that the Presta is also known on a smaller scale as the "French valve."

fietsbob

all else you can arrange a mail drop along the way.. someone back home or one of the E Sellers that you use anyhow.

Chris Pringle

I've read in several magazines that the 29er craze never really caught on in continental Europe. Yes, you will indeed find lots of skinny 700c tubes used on road bikes, but the wider tubes for your 50mm Marathon Mondial tires might not be so readily available. So, I recommend to travel with a few spare tubes. In the rare case that you run out of tubes, any vendor from eBay.it will deliver new tubes (or tires) within 24 hours to an inn, etc. Use the keywords "camera d'aria 700".

Edit: I believe presta valves are the norm in Europe. I wouldn't drill the rims just yet. By the way, those schwalbe tires are super durables. I have the Marathon Racers and have NEVER had a flat with them here in Mexico after putting thousands of kilometers.

indyfabz

Yep. I used that term as a teen back in the late 70s.

3speed

Oh, yes, absolutely take spares. I didn't mean to advocate not taking spare tubes. Just saying that should the need arise, it wouldn't be a problem to pick up a few in Italy. Even if they didn't have any tubes that technically say "700x50c" on them, a 32, 38, whatever will work just fine as long as it's 700c. Hell, a lot of tubes even say they're for 27"/700c. Tubes aren't That particular.

Gyro_T

If you want to be technical, say "622" not 700c which like 29er, is a popularized approximation.

I will take a spare with me. I really appreciate everyones input.

3speed

I will have to look into the 622 thing. I have seen it on occasion and wondered what exactly that measurement referred to. I thought 700c was a measurement of something more specific. Perhaps I'm wrong. Again, I'll have to look into it. If 622 is indeed the proper size designation, I will definitely start using it. Thanks for the tip.

gorshkov

Tire sizes are weird. Sheldon Brown has a good explanation of how they work, but the 622 is the bead-seat diameter of the tire. I don't know what 700c actually refers to, but 26" and 29" refer to an approximate outer diameter of the inflated tire. One strange result of this is that a 27" wheel is actually slightly larger than a 29" wheel (which as 3speed pointed out is the same thing as 700c). From an engineering perspective, the BSD is a good way to specify a tire/wheel, but more cyclists (and bike shops) will recognize "700x40" than "622x40" if you tell them you need that size.

ekibayno

You're going to Italy for three weeks? Using Marathon Mondial? Presumably on sealed roads? Spare tyres will just be unnecessary weight and bulk. All you need is a couple of spare tubes and a patch kit each. It will be extremely unlikely that you use them.

djb

Pretty much sums it up.

cyccommute 

Don't blame Trek. They are just hangers-on and late adopters. An early 29er movement was around at the beginning but they could get a reliable tire source. The modern 29er movement can be laid at the feet of WTB when they made the 29er Nanoraptor.

The "700C", 29", 27", 26", etc designation on tires and wheels is based on the outside diameter of the mythical "normal" tire. A 26" rim, for example, is 559mm which is 22". If you put a 2" smooth balloon tire on the rim, the overall diameter is 26". A 622mm rim with a 35mm tire gets close enough to 700 to round up. A 622mm rim (24.5") with a 2.125" tire on it is around 29". If the tire has knobs, it's probably taller than 29" but a 29.465er just doesn't sound as cool.

3speed

Which early "29er" movement are you referring to? I know of the early 90s 622mm MTBs. Is that what you're referring to, or something before or after that? As far as I know, they never called them "29ers" in the early 90s. Maybe I'm wrong. Either way, I still think it's dumb and people should stop using dumb marketing terms, slang, and approximations. If everyone would just start using actual measurements, all of this stupid tire size confusion for new people, and need for everyone to know multiple different, all inaccurate descriptions for the same tire size would be eliminated.

Gyro_T

The Sheldon Brown article pretty well sums it up. Tire Sizing Systems It is frustrating because there is an international standard now in the ISO sizing, and manufacturers keep confusing it and going back to names like "29er" for commercial reasons. You just have to remember that the ISO measurement will likely be embossed in the side, so any "700C or 29er, either one will have 622 on the side, everything else that separates them is based on the next number (width) and the profile of the tire.

donalson

my last few MTBs have all been 29ers... if the shop doesn't have a proper sized 29x2.1 tube a 26x2.1 tube was fine... took a bit more work getting it in (had to make very sure the tube didn't get pinched bead and rim... but once I got that sorted it was just business as usual... and after the first install it was much easier the next time as the tube would stretch a bit

cyccommute 

You are correct that they didn't call them "29ers" but Charlie Kelly, Gary Fisher and Geoff Apps built a few bikes using Nokia Hakkapeliitta snow tires based around the 700C rim in 1981. They couldn't get a reliable supply of the tires, however. In the early 90s, the "hybrid" bike movement was a similar attempt to use 700C tires and rims for off-road but that didn't catch on. The "hybrid" term was supposed to be a bike that was equally at home on the road and on the trail but they really weren't.

I agree that the "29er" designation is dumb and confusing. Although I can usually translate from bike nerd speak to ISO/ERTRO, I would much prefer the latter. Less confusion.


This is the problem that 3speed was talking about. A 700C X 35 tube or 700X37 tube would have worked better. It would be stretched but the 26" tube is stretched too.

donalson

in the US at average shops i've run into far more issues looking for city bike/cross sized tubes than just a normal MTB 26er tube... but ya either would have worked OK

3speed

Cool. Sounds interesting. I'll have to read up on that.