From time to time the question arises: "What is the diameter of a bicycle?"
Most often, it pops up if a tire breaks through or if you need new tires on the wheel of an old bicycle. And the seller’s question “What wheel does your bike have?” Comes up with only one answer: “round”.
First of all, you need to determine the concept wheel diameter.
For most ordinary people, this is the diameter of the wheel along the outer (outer) border of the tire.
But there is still a concept rim fit Is the diameter of the rim or tire itself along the inner boundary.
Therefore, it would be nice to first understand the worldwide accepted tire labeling systems in order to speak the same language with the bike store seller. You can read about this in the article “Bicycle tires: sizes, types of marking and interchangeability” on our website.
For brevity, we present here a figure with explanations of what is measured in each marking system. Therefore, it is important to understand what we measure and what we want to find.
So, the methods for determining the diameter of a bicycle wheel in inches and millimeters:
- The simplest and most reliable. On an old tiremounted on a bicycle its diameter should be written in inches or millimeters.
When choosing a new rubber, focus on it. If there is no tire with exactly the same marking, look at the interchangeability table and select the desired size in a different marking.
If a new tire is needed a little wider or narrower, check the tire width and rim width chart.
If in doubt, talk to the seller. He will tell you whether it is suitable for you both in terms of size, and in terms of tread, riding style and which roads you want to ride.
This can be done by measuring the radius and multiplying it by two.
For younger students reading this article, I recall that one diameter consists of two radii.
Only need to measure strictly from the center of the sleeve, and not from its edges. When measuring, the bike should stand upright, and the tape measure, holding one end to the ground, keep the same strictly upright and not along the wheel spokes. Only such a measurement will give the correct value.
In the same way, you can immediately measure the diameter of the wheel itself. The main thing is to accurately determine its upper cut. To do this, you can take a level and attach it to the top of the tire, and, holding it strictly horizontally, determine the desired size from the tape measure.
After that, translate it from mm to inches. To do this, divide it by 25.4 (1 inch = 25.4 mm) and calculate the size in inches. The result can be rounded to standard inch wheel sizes.
For example, if the result of the measurements is 720 mm, divide by 25.4 and get 28.346 inches. So, most likely, the actual size of the wheel, taking into account the accuracy of calculations, is 28 ”.
In principle, the rim diameter can also be measured in the same way.
Just pay attention to the difference between what is measured by the tape measure outside and the fit size of the rim.
For those who are not looking for easy ways in life, you can calculate wheel diameter through its circumference. How to calculate the circumference of a bicycle wheel is described on our website in a separate article (Second method).
And knowing it, it is easy to calculate the diameter. To do this, the circumference in millimeters must be divided by the number "Pi" (3.14). Having received the diameter in mm, divide it by 25.4 and get the diameter in inches. Similarly to the previous paragraph, the result will have to be rounded to the nearest integer in inches. The more accurate all measurements, the more accurate the result and less rounding.
How to choose a bike? What should I look for when making a purchase decision? What types of bicycles are there? In order to answer these questions and not get lost in the huge assortment of cycle equipment, you need to understand the general structure of the bike and pay attention to the factors that make up its price. We offer you some consistent tips and hope that they will help you choose exactly the model you are dreaming of.
Choose the type of bike (mountain, road, BMX, children, etc.)
Depending on where, how, how often and extreme you are going to ride, you need a bike of a certain type. By clicking on the link located just below, you can familiarize yourself with various types of bicycles and find among them the best for yourself:
Typically, novice cyclists do not think long about how to choose a bicycle, and buy comfortable hardtail or amateur models. These are universal bicycles, riding on which allows you to understand what exactly attracts you the most: speed, conquering off-road, fast descents, jumping or a quiet ride without "bells and whistles". Then you can already attend to the acquisition of a more expensive and specialized model.
When choosing a bicycle, it is very important to choose the right size, i.e. frame size optimal for rider growth. Each bike model comes in several sizes, similar to how clothes are sewn in several sizes. Riding a bike whose size is small or large is not only uncomfortable, but also dangerous. Knowing the growth of a cyclist, it will not be difficult for you to choose the right size: just check the table in the tips on our website or consult our sellers.
Mode of use
The main thing in choosing a frame is the type of skating. How can I use a bike?
- Walking bike. Size, in fact, is not particularly important, because the loads will be rare and not very serious. You can leave additional space for convenience: the frame is lower, the steering wheel is higher so that it is easy to get off the bike.
- Racing and road riding are the exact opposite of walking. It is desirable for a rider to have the lowest possible steering wheel in order to use additional force when pedaling. The dimensions of the frames in this case must exactly correspond to the growth of the cyclist, universal changes will not be enough.
- Tourist or urban cross-country is a universal style, general recommendations are more or less suitable for it.
A universal rule is to test any bike before proceeding with testing different types of fit. The same rule will help you quickly choose the size of the frame.
So, you should stand above the frame of the bicycle so that the saddle rests on your back and relax. At this point, the distance between the upper tube of the frame and the crotch should be from 5 to 15 centimeters.
Too much distance will reduce the stability of the bike on the track and, most likely, corresponds to too short a base, and too small will create inconvenience and a greater likelihood of injury.
If you approach from a professional side, then to determine the size of the frame is not enough just to measure one of the pipes, ETT is used - the abbreviation stands for "effective bike length". ETT is calculated as the length of the segment parallel to the earth drawn from the top edge of the steering tube to the continuation of the straight podsitelnoy pipe (which itself is called ST).
Relying on a particular manufacturer of bicycle frames is not worth it, even the dimensions given in the documents sometimes turn out to be erroneous. Measurements should be made independently.
Features of frame types
What should I look for when choosing a bike? Consider the recommendations for the type of frame.
- Universal cross country. Direct and clear frame makes this type of reference. When choosing, we use the universal rule and carefully look at the steering wheel and the configuration of the saddle. They can be of "unexpected" size and seriously change the configuration.
- The frames of a road bike should fit perfectly, since every centimeter of the lever of a moving body directly affects power and speed. It is important to pay attention not only to the configuration and length, but also to the steering wheel, which takes on a very large load corresponding to the weight of the athlete.
- For downhill and mountain bike frames, it is especially important to leave safety distances both under the saddle and at the steering wheel level - it makes no sense to choose a configuration that will interfere with a sudden fall or full operation of the fork.
- Cruisers The main thing is convenience. Pay attention to the position of the saddle and hands. There is no point in looking at the nominal sizes, since even within the model line of one manufacturer they can differ.
Each table of sizes below will help determine the range of models of interest, but the main thing to know is that no size can be determined exactly. 18 or 24 inches is the manufacturer’s assessment of a very specific distance — for example, the length of a feed tube, or the distance from the center of the carriage to the connection point between the extensions of the upper tube and the steering column — there can be many measurements!
Therefore, it is very dangerous to buy a bicycle via the Internet or “by eye” - any bike should be tested in practice, sit on it, feel the maximum distance from the seat to the pedals.
Usually, buyers of such bicycles know what model and size they need, but everything happens for the first time, and even professionals should learn standard sizes.
Of course, the child does not care what size the frame is, and on any frame it will not be convenient for him in six months, but buying bikes “for growth” is still not worth it if the joint health of the baby is expensive.
We give a table for BMX bicycles - it is approximate, as professionals, perhaps, begin to select a bike not for the growth of a rider, but for the planned tricks and their acrobatic level. And injuries from prolonged loads in stunt sports are far from as likely as falls and unexpected blows.
Depending on the gender and age of the rider, choose the optimal model
Are you looking for a bike for an adult man? Looking for a female model? Or maybe you need a bike for a teenager or a baby? Depending on gender and age, there are different recommendations on how to choose a bike. We bring to your attention thematic article-tips:
- Pick up a bike
- Pick up a bike
- Pick up a bike
for a child
Each bike can be divided into two components: a frame and attachments (wheels, fork, pedals, chains, speed switches, etc.). The level of quality and price of the frame depends on the materials of which it is made (steel, high-tensile steel, chromium-molybdenum, aluminum, magnesium, titanium, carbon), as well as strength, weight and other operational characteristics. The price of attachments is usually two to three times higher than the price of the frame.
Do not forget to buy everything you need
- Bike computers
- Cycling gloves
- Backpacks and bags
Do not forget to pick up accessories for your bike - useful things that you should have with you while riding. This is about protecting the rider (helmets, bicycle gloves), in addition, we recommend paying attention to cycle computers - devices that display speed and mileage, pumps, bike locks, wings, bags and many other necessary devices.
We make a purchase
- In the catalog of our site, all models are sorted by brands, sections and types. If you are looking for a bike with certain characteristics, then use the advanced search service or contact our consultants by e-mail or by phone: +7 (812) 309-82-27. After choosing a bicycle, click on the “Add to Cart” button, and the order will go to your personal basket. The number of items that you can put in your basket is unlimited. The bikes you have chosen remain in the basket for one week. If after a week the order is not completed, the basket will automatically be emptied. Then go to the "Your Cart" section. View its contents. Here you can familiarize yourself with the final purchase price, including taking into account delivery, change the number of bicycles or delete individual positions. After changing the contents of the basket, do not forget to click the “Recalculate” button. Having finally decided on your purchases, click the "Place an order" button. After you click the "Place an order" button, you will be prompted to enter your email address and password (if you are not a registered user on the site, you can register here). Then, in the process of registration or authorization (entering E-mail and password), specify your personal data (name, address, phone number, etc.) that will be used to deliver the order. Further, our manager will contact you by phone and send the necessary documents by e-mail.
If you have any difficulties in making a purchase, you can ask us your questions or make a purchase by e-mail or by phone: +7 (812) 309-82-27
Each bike model is a kind of balance between cost, durability, speed and maneuverability. Each bike is good on its track and in its riding mode, so it is very important to consult a professional before buying. You can get competent advice, as well as clarify the color or frame size of a particular model, by contacting our managers!