# Marathon Supreme 29x2.0 is tiny....



## Slurry (Dec 23, 2008)

My Schwalbe Marathon Supreme HS382 (29x 2.00") only measure to ~1.770 inches (outer width) on a 19mm internal width rim. What gives? I understand there can be some variance in listed sizes versus actual sizes, but that's a huge difference!

I put one of them on my friends MTX33 29er rim (which i think is about 28mm internal width), and they were still well under 2 inches.

I fired off an email to Schwalbe, but I don't exactly know what they would do about my problem. My experience with newer Schwalbe MTB tires had led me to believe that Schwalbe was often a bit _over _their listed size, even when just measuring the sidewalls (not knob-to-knob)

And FWIW, they're still _really _nice tires, but I _really _wanted a 2" tire and the air volume to go with it.


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## manmythlegend (May 21, 2012)

What problem are you having besides inaccuracies of stated size?


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## Slurry (Dec 23, 2008)

manmythlegend said:


> What problem are you having besides inaccuracies of stated size?


I bought a tire labeled 2" because I wanted a 2" tire. The tire is not even close to two inches.

My reason for posting was to ask if anyone had an explanation, or similar experiences with this tire.


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## hunter006 (Jan 20, 2012)

That's no surprise. Surly mentioned this before with their blog that using a narrow rim like a 19mm rim tends to pull the mount points of the tire in, which in turn reduces the width of the tire. If you have a 19mm rim instead of a 26mm rim, you will get a different tire width. They made a big point of this when putting wider tires on the Krampus.

Schwalbe keep their tire dimensions chart here. If you check out their tech page, it has this underneath it, which coupled with the statement above, tells you why it can be so much less than the 2" you're measuring:

_*Why is it that tires are often actually narrower than the ETRTO tire section width?*

Standard tire widths are calculated using *fairly wide, standard rims*. Yet in practice, narrower rims are used more often, which in turn leads to tires becoming slightly narrower as well.

In order to ensure that tires have sufficient frame clearance, tire
manufacturers generally prefer to keep production closer to the lower end of the permitted tolerance (+/- 3 mm).

Carcass casing materials have become more and more sophisticated over time, that reduces the tire widening after the fitting. In order to correct this tire widening, over the past few years slightly wider carcasses have been used, so that the actual widths are now much closer to the standard widths._

FWIW, I notice the tire profile of Marathon Supreme's are a slightly narrower, taller tire than Big Apples, so I wasn't terribly surprised with it being slightly less than 2" on my bike - my 26mm rims measure it to be 1.92" wide, which is OK in my books.


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## rjedoaks (Aug 10, 2009)

I just installed a pair of 26x2 yesterday. 532 grms 1.77 on a 25mm OD rim. Smooth and quiet. How's the flat protection to anyone that has used the tire.


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## hunter006 (Jan 20, 2012)

I haven't had a flat since I switched to them over 4000 mi ago.


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## rjedoaks (Aug 10, 2009)

Good to hear. Is that all pavement use?


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## hunter006 (Jan 20, 2012)

Mostly pavement but I'm creative with my selection of routes when getting around. For example, we currently have construction on NE Points Dr. Everyone else takes the gravel path, which means you're stuck with the pedestrians. On the odd occasion I go through there, I like to take the path with rocks around the size of your fist, because I get through it faster than the slow people. Then there's light trail gravel, etc. nothing super crazy that I frequently use because people here have trouble with the concept of safe passing on paved trails (the shoulders are light trail gravel with the occasional surprise).

The pavement quality in Seattle is pretty low too... lots of broken pavement. I'm not gentle on the bike. They are pavement miles, but the pavement miles aren't great quality pavement.

I also ride a lot on the street, and most of those streets are only swept occasionally.


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