Bicycles guide: wheels, tire size, rims, spokes explained
After the frame material and construction, the design, purpose and make-up of your wheels is probably the biggest factor in deciding the speed, efficiency and feel of your bike. Bicycle wheels are a group of components that are assembled. Including bike tire, rim and spokes etc.
Bike wheel size mainly has 700c(about 28in), 26-inch, 27.5-inch(650b) and 29in(29er).
- 700C is the dominant wheel size in the modern bike world, and the biggest of the top three. Almost all road bicycles have wheels that are 622mm diameter – referred to as 700c tyres on the tyre wall. It rolls fast, and handles well.
- 26in wheels (559mm diameter) used to be the standard on mountain bikes, lighter for serious and competitive mountain bikers, cutting the smallest excess weight and being able to maintain an ability to control the bike is a big deal. But handling steep descends at higher speed on a 26” wheel is not for the fainthearted and will require you to have some skills. So have now been somewhat superseded by 29er and 650b wheels.
- 27.5in (650b) wheels offer a great balance of fast rolling and control on difficult terrain, is slightly larger wheel that offers a more comfortable riding experience than a 26″ and more stiffness and durability than a 29″ mountain bike wheel size.
- 29in wheels feel stable and roll fast over rough terrain. On the downside, short riders might not feel at home on a 29er. A 29 inch mountain bike wheel is the same diameter as 700c.
In general, commuting bicycles will with the 700C wheels. But, on a hybrid you can just choose road or mountain bike wheels in the right size, with your ride style. Note, adult bicycle size refers to the frame.
Narrower tires give you less rolling resistance for the smooth asphalt. Wider tires allow for better handling in gravel or dirt and lessen the likelihood of getting a flat. Generally speaking, the wider the tire, the cushier the ride. The main disadvantage to wider tires is weight.
The most common width for road bike tires is 23mm. As a custom, race bikes have 23mm widths while training has 25mm widths and a mixture of hard and rough roads have 28mm widths.
A much wider tire between 2.0 to 2.5-inches is typically used for mountain biking. Hybrid bike tires are somewhere in the middle, typically runs between 28mm to 47mm– which is just under 2-inches.
Rims are typically made out of aluminum, carbon fiber, or a combination of aluminum and carbon fiber. All well built rims provide the structure necessary to allow a wheel to support the bicycle and rider weight over many miles.
- Wheels with aluminum rims for the most part are very reliable. Aluminum rims are much simpler than carbon, thus their lower cost.
- Carbon rims perform in the same fashion as a well-built aluminum rim. The strength of carbon is better than that of aluminum.
- Top-level race wheels can be built from carbon as well as aluminium. The aluminum is used to provide the structure of the wheel and the carbon fiber is used to improve the aerodynamics.
Spokes provide support to the rim and distribute pressure evenly around the bike wheel structure. Low spoke counts to help decrease weight and make their wheels seem more exotic, but they are also making the wheel less efficient, especially for larger riders.
Heavier riders need more spokes, with means a stronger wheel, the load is distributed over more spokes, therefore the cyclic stress per spoke is lower. Also, for a wheel to be stable you need a certain amount of tension, this greatly increases the longevity of the rim.
Below is a general guideline for the ideal spoke counts. These are not set in stone and they may vary with part selection.
- less than 100 lbs (<45 kg) -- 20/20 (front/rear)
- 100 lbs-150lbs (45kg-68kg) — 20/24
- 150lbs-185lbs (68kg-84kg) — 20/28 or 24/28
- 185lbs-215lbs (84kg-98kg) — 24/28 or 24/32
- more than 215lbs (>100kg) — 28/32 or 32/32