Originally Posted by
Milton Keynes
Me too. Like, where/how does the 27.5" come into play? I thought 700c was also known as a 29'er since it's 29 inches
Originally Posted by
IGH_Only
I was just confused much like Milton Keynes because they call it a 29er but it's really not and so forth.
The 'Traditonal' names came from a size designation based on the outside diameter of the wheel/tire. 700A, 700B, and 700C all measured (nominally) 700mm in diameter, with A being the widest tire, and C the narrowest, but they all had different diameter rims, in order for the wheel/tire combination to have a 700mm outside diameter. Same goes for the 26" 'fractional' 3-speed wheels and 26" 'decimal' MTB rims.
Also, countries and individual mfgrs had wheels of different dimensions, but all locally given the same 'size', though none were the same.
Since modern bike manufacturing has really coalesced in the later part of the 20th century, a more common international standard was developed, based on the bead seat diameter (BSD) of the wheel rim (also referred to as ERTO) The 700C size, with it's 622mm BSD became 'the' standard road bike wheel size, so that any tire that fit a 622 rim is referred to a a 700C- ##, regardless of tire width, and overall outside diameter.
'29er' MTB wheels are also 622mm BSD, although usually only the wider offroad oriented tires and rims. (30mm+ rims and 45+mm tires) Narrower road / hybrid stuff is called '700c'
The 29er name was to differentiate it from the older (80s-00s) generation 26" MTBs (559mm BSD)
Confusing things, the "27-five" MTB (584mm BSD) doesn't have anything to do with being twenty-seven and a half inches anywhere, it is just in between the 26er and 29er sizes. It also happens to be the same BSD as the 650B that's starting to make inroads in the gravel / audax segments.
Still don't have a clue as to why the OP question, unless he's trying to Rinko it.