Why is there different wheel sizes, what are their usages purposes, how they
have historically evolved in cycling, why so many confusing dimensions for
tyres!......
Like all beginners I have also gone through these questions and have
eventually come to understand the following:.
26" wheel cycle: since the center of gravity is low and resultant control,
they are better suited for trail riding, stunts, City bikes which can turn
easily in the small bylanes etc, due to low turning radius.
Moreover 26" was the standard size in all MTBs when mountain biking started
off initially. So we can easily get cost effective tyres and wheels in this
size. ആദ്യ കാലങ്ങളിൽ ഈ size Tyre ധാരാളം മാർക്കറ്റിൽ വന്നിരുന്ന കാരണം ഇപ്പോഴും
ഏറ്റവും വില കുറച്ച് കിട്ടുന്ന tyres and wheels ഈ സൈസിൽ ആണ്.
29" is for Downhill etc where rolling is the key while being off-road capable
27.5" is the midway option where more rolling is needed along with having
maneuverability
That is to say that 27.5 inch sized tyre is an in between option when
maneuverability(26 wheel is more maneuverable than 27.5 due to its smaller
diameter and hence smaller turning radius) is needed as well as good rolling
speed (29 inches diameter wheel has more rolling speed due to its higher
diameter).
Selection of the wheel size depends upon the nature of ride planned, whether
it's off road trail involving twists and turns where control, stability and
precision turning is important (smaller diameter wheel is needed in these type
of rides, 26" would be preferred if speed is not that important but control
is, 27.5 would be preferred if speed is important but the trail involves not
much of curves and turns at high speeds, 29" will be preferred if it's just
Downhill and speed is important, not involving any serious curves).
Also 29" MTB is not meant for long rides on tarmac, for that a hybrid or road
bike (depending on the condition of the road and speed required) with a 700mm
diameter Tyre would be better.
See the explanation of Tyre sizes below, basically different places(for
example the 700c nomenclature is due to the French standards) different
ways/standards of mentioning Tyre sizes, some mention in inches some mention
in inches (in India we have both!
The more accurate way of noting Tyre sizes are using the ISO standards
or the ETRTO (European Tire and Rim Technical Organization) standards as explained in this video:
For more reading on the historical standards of tyres and wheels, click here
https://www.centurycycles.com/tips/tech-talk-know-your-tire-size-pg1275.htm#:~:text=700C%20is%20used%20to%20refer,diameter%20of%20over%2029%20inches
Excerpt from the link above: 700C is used to refer to any tire, rim, or wheel
with a 622mm BSD (Bead Seat Diameter) , but it could be on a skinny-tired road bike where the wheel
has an actual diameter of only 660mm (which is actually a little LESS than 26
inches!), or a mountain bike with a wheel diameter of over 29 inches.
Read more at: WHAT IS THE BEST WHEEL SIZE FOR A MOUNTAIN BIKE?
Want to know the pros and cons of each wheel size and what might work best for you? Read all about them here.