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I recently got an IRC Mibro 26x2.25 tire. My stock tires are 16x2.00. I installed the new tire on the my bike, and inflated it. However, it doesn't look very much bigger at all compared to my stock one that was still on the bike. I was expecting more of a difference because I figured it was such a big size jump. Is something wrong?
 

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Bushwacker
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Interstingly, I just swapped in some IRC Trail Bears 2.25 for my Velociraptor's 2.1. The trail bears do look larger. The width is a larger but some of that is due to the large side wall knobs that stick out. The trail bear is a much fatter tire tho for sure. Anyways, it's just tenths of an inch difference so in most cases I suspect the difference won't be as dramatic as, say, upping the size of a car tire.
 

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local trails rider
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The widths that tire manufacturers give are not all that accurate.

Actual width depends on the rim too: Some time ago I had a 2.4" tire on rims with 7mm difference in width. There was a 4 or 5 mm (call it 3/16") difference in actual tire width too.
 

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I haven't used the Mibro, but tire sizing in general is rather inconsistent. A lot of tires run smaller than their stated size. I think the tire companies do this mainly to keep the weights down, so you're more likely to see it on race-type tires than the more aggressive tread tires (though that's not universally true). That's why the more aggressive Trail Bears (I've used those) run pretty close to true size even though they're also made my IRC.
 

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responsible zombie owner
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Yes, tyre companies often overstate the size so their tyre looks lighter than the equivalent from their competitors. Of course, when the companies all do this, you end up just having misleading tyre sizes all round.
 

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typo error?

cbwarrior23 said:
I recently got an IRC Mibro 26x2.25 tire. My stock tires are 16x2.00. I installed the new tire on the my bike, and inflated it. However, it doesn't look very much bigger at all compared to my stock one that was still on the bike. I was expecting more of a difference because I figured it was such a big size jump. Is something wrong?
is that really 16x2.00?
 

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Some tire makers lie about tire sizes to boost sales. Some are worse than others. So ignore the advertised size and go to Shiggy's site mtbtires.com to get actual dimensions, volumes, as well as some reviews. There are a number of tire dimensions to consider:

Casing width
Tread width, which can be wider than the casing
Tread height - how high the tread projects from the casing
Tire height (rim to top of tread)
Volume - how much space inside the casing. More volume = more cush.
And of course, weight

As mentioned in another post, the width of the rim can affect the mounted width and shape. Also, higher air pressure will make the tire bigger. Some people pump max air pressure and let the tire sit overnight to stretch it out a bit. This will happen also just from riding.

Just because some marketing hack misrepresents a tire size doesn't mean the tire is bad - just not as big as advertised. Case in point - WTB Weirwolf LT 29er, advertised as 2.55", but well known to be more like 2.35 or so. One of my favorite tires, big and balloony, deservedly loved by many riders.
 

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No good in rock gardens..
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Mibro's do run small. My 2.1's are more like 1.95's - still great tyres though.
 
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