3 ms·
> 559mm "26 inch" > 584mm "27.5 inch" > 622mm "29 inch" > 630mm "27 inch" I've done no actual unit conversions myself, but just reading this, I'm highly con
by hunter2_ 5y ago
> 559mm "26 inch"
> 584mm "27.5 inch"
> 622mm "29 inch"
> 630mm "27 inch"
I've done no actual unit conversions myself, but just reading this, I'm highly confused. Quotes sorted by mm. Why is 27 not between 26 and 27.5?
- pythonaut 5y agoThe mm widths refer to exact rim diameter while the inch measurements refer to rim+tire diameter and are not exact.
- mauvehaus 5y agoThis nails it. The nominal sizes are mostly (for some insane reason) based on the outside diameter of the wheel and tire. 27" road tires would have a 30mm tire size, whereas 27.5" mountain bike tires are probably running close to 60mm these days (haven't been keeping track of what's in vogue). ETRTO is based on the bead seat diameter, which is what matters when you're buying a tire.
- walrus01 5y agoactual "27" is very old standard you might see such as if you discover an unused road bike from the early 1980s deep in somebody's garage. It's quite rare these days. 27.5 is used for mountain bikes so the rim profile and tire widths are a completely different thing than old "27"
- zwog 5y agoNot to forget: 29" wheels have the same rim diameter as 28" wheels used in road bikes (622mm). Obviously. (The reason: mountain bikes use lager tires than road bikes, so the complete wheel is larger )