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After fitting a set of Bonty XR4 team issue 2.2 to my Fuel Ex I've had to remove the rear one as it was wearing a small groove in the chainstay 🙁 - it came with a Bonty 2.2 to begin with so why are they so different?
I've just fitted a Maxxis High Roller 2.1 LUST and it looks positively weedy compared to the Bonty.
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the XR4 was rubbing lightly here when the wheel flexed - only a couple of mm clearance
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I think the 2.1 refers to the height of the tyre. Some manufacturers include the tread height in that, some don't.
its the width of the tread
Think of a number,any number.....
Ian
Any advance on width or height?
Width.
So why is a 2.2 Rubber Queen wider than a 2.4 Mountain King from the same manufacturer?
Ian
Indeed, the bonty 2.2's I had were leagues apart in size
The number refers to the width but there doesn't seem to be a standard way of measuring it.
You need to look at what other people have got on their bikes to see how they size up really.
They just make it up in most cases. Maxxis have had a change of carcass sizing so the newer designs size up bigger than the old ones, which is why the 2.1 highroller is so laughably small. Conti have no standard at all evidently, the 2.4 RQ is genuinely a 2.4, the 2.4 MKs I had were about 2.1. Some say that the older Contis are measured round the circumference of the tread rather than the actual width.
So far Kenda have been the only tyres I've used that have been consistently accurate.
Perhaps dirt or singletrack. Could enquire and make a small feature on it?
Just to further complicate matters the same tyres can give quite different profiles depending on what rim they are fitted to.
"Just to further complicate matters the same tyres can give quite different profiles depending on what rim they are fitted to."
Well. In practice it doesn't make that much difference, not within the constraints of the wheels that are available. If you stick a mtb tyre on a vast rim then sure, but the difference between a skinny XC rim and a fat DH rim, or a tall rim and a short rim, doesn't make such a vast difference, all you're really doing there is increasing the circumference of the cross-section by a few mm at most which translates into a pretty small difference of width at the contact points.
do manufactures include the spread (as it were) of the tread, or do they only measure the carcass width of the tyre?
and why are inches the standard measurement of tyres?
The only reliable way to measure a tyre size is to measure it bead to bead laid flat before you mount it. Still some variation with regards tyre profile/ height but much more accurate than any manufacturers numbers.
Had some funny looks from bike shop staff when I've asked for a tape measure and headed for the tyre section, but what do they know eh?
So why is a 2.2 Rubber Queen wider than a 2.4 Mountain King from the same manufacturer?
THE
The MK's have knobbles sticking out of the side of the carcass, which is included in the measurement. The RQ doesn't.
Likewise my Race King 2.2 has a bigger (as big as) carcass as the 2.4 MK.
Apparently, they just guess.