If you are interested in skating, you will have noticed that the offer of skate wheels is very large, so you may be wondering how to choose them. What advantages and disadvantages can a certain wheel model offer you? Will it be the right wheel to achieve the goals you have in mind?
Many guides have been written on this topic, most of them dedicated to the world of skateboards/longoboards. One of the best is the one created by Stokerideshop : if you are interested in taking a look, you can find it at this link . Quad skating is, however, a different sport : even if many general aspects have similarities, in our short guide on skating wheels we will highlight those that are peculiar to our sport, deepening some points of fundamental importance.
Let's start by saying that the parameters that we can take into consideration to choose a type of wheel for our skates are many: each contributes to define the behavior of the product considered and the possibility of using it with happened under a certain circumstance. We can say with reasonable certainty that there is no "universal wheel", suitable for all applications and styles: you must try to choose carefully, to avoid finding yourself with poorly performing skates, which can discourage even the most tenacious enthusiasts. These parameters are particularly important because the wheels are basically the interface between the skates and the surface on which you are training: their characteristics are able to determine grip, smoothness, comfort level and many others. aspects that, for a skater, are fundamental. Let's see them:
Diameter
It is normally expressed in millimeters: in quad skating, the diameter of the wheels is normally between 45 mm (for example: rink hockey goalkeeper wheels) to 64 mm (for example: wheels for the compulsory specialty of figure skating and wheels for road use)Hardness
The hardness of skating wheels is expressed as Shore hardness and is measured using a special instrument, the Shore durometer. It is a very important feature for a wheel, as it helps to determine its smoothness, grip and various other characteristics.Materials
The materials with which a wheel is made, both as regards the tread and the hub, are normally made up of plastic materials and synthetic elastomers, both thermoplastic and thermosetting. Their choice determines in a fundamental way some characteristics of the considered wheel, among which the grip and the rolling smoothness.Shape of the lip
The shape of the wheel's lip helps to establish whether it is capable of generating greater grip when cornering, or whether the propensity for lateral sliding (drifting) is greater. In the first case, the wheel will tend to have a sharp edge, in the second a more rounded edge.Width
The total width of a wheel, measured between the extreme points of the internal and external faces, in a direction parallel to the rotation axis, is a geometric parameter that must be verified to establish the compatibility of a wheel with a specific frame, together with other parameters, such as the position of the bearings (see below).Contact surface
The extension of the contact surface of the wheel considered with the track depends both on the total width of the wheel and on the shape of the edge, it has an influence on the grip generated: it generally increases if the contact surface is greater.Hub position
The position of the hub inside the wheel has an influence both on the grip generated, especially in the case of wheels of lower hardness, and on the wear profile. It is also an important parameter for establishing the compatibility of a wheel with a certain frame. To tell the truth, in the world of skating it is a parameter that does not offer many degrees of freedom.Diameter
The effects related to the choice of the diameter of the wheels of your skates are many, let's see which are the most important.- Speed: all other things being equal, larger diameter wheels allow you to reach higher speeds and are more efficient. This means that, with the same muscular effort, you will be able to cover a greater distance, or that - in short stretches - you will be able to reach higher peak speeds. This effect is in turn linked to several factors: for example, a larger wheel, with the same forward speed of the skater, rotates at a lower speed, dissipating less energy in the ball bearings. Furthermore, for the same weight of the skater and the materials used, a larger wheel undergoes less deformation during rolling, dissipating less energy within the elastomeric material.
- Overcoming obstacles: it is a known fact that a larger wheel allows you to overcome a certain obstacle with greater ease than a smaller wheel; this fact is completely general, and is therefore true both in the case of motor vehicles and - for example - in the case of bicycles. Roller skates are no exception: it is in fact a purely geometric issue. But what are the obstacles that the wheels of a skate are called to overcome? Generally, these are small objects that the wheel can encounter when rolling: pebbles and other small objects present - for example - on the road surface. In the case of very "dirty" surfaces, the use of larger diameter wheels offers the possibility of overcoming these small obstacles without jamming, making the tool more reliable and safe.
- Acceleration: smaller diameter wheels, having a mass and a moment of inertia minor, allow to obtain burning accelerations.
- Agility: smaller diameter wheels give the skate greater agility: ability to make faster changes of direction, tighter turns and even higher jumps, thanks to the lower weight. However, the stability of the shoe, for example at high forward speeds, will be less.
- Based on what has been said, it should be natural to choose the ideal diameter of your wheels, depending on the specialty that interests you most. For example, in "distance" street skating, neither great acceleration nor great agility are required: it is therefore preferable to move towards larger diameter wheels (63-64 mm). Conversely, if you play as a goalkeeper in roller hockey, you need small wheels, which allow you to make lightning-fast shots and sudden changes of direction. The wheels used in figure skating, on the other hand, cover a wide range of diameters: medium-small in the "free" specialty, in which jumps and spins are performed, larger in the "dance" and "compulsory" specialties, in which it is preferred smoothness and stability. By the way, have you ever wondered why the maximum diameter of a quad skate wheel is around 64mm? The reason lies in the fact that when making a curve, the movement of the steering brings the wheels of the internal threads to approach the sole of the shoe: wheels that are too large could touch the sole itself, causing it to block and the skater to fall. For this (and for other reasons as well), quad skates will never be as efficient as inline skates over long distances. But they have other characteristics in which they excel!
Hardness
The hardness of a skate wheel means, of course, that of the part in contact with the track, which generally consists of a synthetic elastomer (natural rubber was used in the past, but being less durable and more expensive than the synthetic counterparts , has been abandoned for this application; previously wood was also used). The hardness of an elastomer, as already mentioned, is measured in Shore degrees: it is basically a matter of evaluating the ability of a certain elastomeric material to oppose the deformation generated by a well-defined tip, pushed against the surface of the material with a predetermined strength. The elastomeric materials used to make wheels for skates have a hardness that is normally evaluated using a Shore scale: either the "Shore A", for the softer compounds, or the "Shore D", for the harder ones (the Shore D is also suitable for measuring the hardness of rigid plastics). It is therefore possible to find, for example, a hardness "95A" or "46D" indicated on a wheel, where the letter indicates the type of scale used and the number the actual hardness value in that specific scale. Although there is no formula for the direct conversion between the two scales, there are experimental graphs and tables that can be used to get an idea (however, they must be taken with some caution). For example, the following table, taken from the company website Americule, allows you to make comparisons between wheels made of polyurethane elastomers.
On the market there are wheels made with hardnesses from super-soft (eg 78A), up to extra-hard (eg 60A, used in figure skating). To orient yourself, what is the criterion of choice? To define it, let's see what are the effects of the hardness of the elastomer used on the operational characteristics of the wheel:
- Smoothness (efficiency) : the smoothness of a wheel is evaluated by skating on a smooth and clean surface. A smoother wheel makes you consume less energy to keep the forward speed constant, or - equivalently - makes you go further, once you have exhausted a thrust, before you stop. Normally, harder wheels are smoother: this means that - all other things being equal - they dissipate less energy to move forward, while softer wheels dissipate more energy when moving forward due to the friction inside the material and what is generated on the surface of the wheel. wheel-track contact. Therefore they can be considered For example, if your goal is to reach high speeds, the use of harder wheels is better.
- Grip : the grip of a wheel is the ability to effectively generate static friction forces with the surface on which they roll. A wheel with high grip will give you greater confidence and will allow you to push more intensely and effectively. Conversely, a wheel with low grip will allow you to drift and facilitate the braking technique with the wheels of the skate (even if it will be less intense). Normally, with the same material used from a chemical point of view, a softer wheel offers greater grip. It should be taken into consideration that the grip can be strongly influenced by the track conditions, which can modify the state of the surface of the wheels (for example due to the presence of dust) or generate lubrication phenomena (for example in the case of a wet track). . From this point of view, the old natural rubber wheels were, in reality, much safer and more performing, so much so that even today in certain applications, such as for example in automotive tires, it has not been possible to completely replace this material.
In some specialties, skates set up with a mix of wheels of different hardness are used, to modulate the grip according to specific needs. For example, in figure skating, a free specialty, the performance of certain spins requires the use of softer wheels in correspondence with the rotation axis, to ensure safe positioning and harder wheels in the outermost positions, to guarantee a less friction in contact with the track. - Overcoming obstacles : considering the small obstacles that can normally be found on a track or road, we can say that softer wheels are more forgiving and allow you to overcome them with greater peace of mind. In fact, if the wheel should encounter a small object, a low hardness would allow it to "sink" inside the elastomer in a reversible way, making it easier to overcome from the geometric point of view.
- Comfort : a softer wheel is more comfortable, as it is able to reduce the intensity of the vibrations transmitted to the foot, generated by contact with the surface of the track on which is skating. This is a point to be particularly taken into consideration, for example, in street skating.
Materials for skate wheel
The materials with which the wheels for skates are made can be divided into two broad categories: thermoplastic elastomers and thermosetting elastomers. The first are the materials that are used to make the hubless wheels, produced by the injection molding process.
The latter consists in introducing the elastomer into a metal mold: this is made possible by the fact that the thermoplastic materials can be brought to the molten state by heating. After waiting the time necessary for cooling, the wheels are extracted from the mold and subjected to a finishing process, which consists in turning the external surface and the edge. This last step is essential to obtain a wheel with a perfect profile, considering that the production process used involves quite high geometric tolerances.
As far as thermosetting materials are concerned, these are essentially polyurethane elastomers, produced starting from two components, which are mixed hot (50-70 ° C) and cast in a metal mold. The wheels produced with this process, called hot-cast, are the most valuable, as they are more resistant to abrasion and more resilient. The resilience of an elastomer is its ability to efficiently return the accumulated deformation energy, or - in other words - to "bounce more". This feature is sought to make the wheels more efficient, i.e. to dissipate less energy provided by the skater. A further advantage of polyurethane elastomer wheels is the very wide range of hardnesses obtainable, which covers the entire range indicated (and beyond). If you are curious to know how wheels of this type are produced, you can take a look at this video, made by a famous skateboard wheel brand, Eulogy:
As you can see, this type of wheels is also turned, but for another reason: the main objective is to eliminate the excess parts deriving from the casting process (called sprues). The polyurethane elastomer wheels also have another particular characteristic: for the same hardness they have a greater grip than those in thermoplastic elastomer. In some cases, this can be an advantage, in others not: it depends on the needs of the skater. Finally, two other observations: polyurethane elastomer wheels always need a plastic hub, and their cost is much higher than that of injection-molded wheels.
Shape of the lip
The shape of the lip of a skate wheel has a significant influence on cornering grip: a non-rounded edge allows you to obtain the maximum possible grip, while an edge with a large connection facilitates lateral movement when cornering (skidding). Furthermore, the thickness of the material near the edge has a certain influence on the ability of the steering to return to the center at the end of a curve: greater thicknesses make the system stiffer and more self-centering. Normally, in street skating, wheels with higher corner radii are used, while in specialties where high precision of the trajectories is required (for example in figure skating), the connection radius is reduced, or is replaced by one bevel.
Width
The wheel width of a skate is limited by geometric compatibility issues with axles and crossbeams. This parameter is therefore relevant, for the performance of the wheel, if considered together with the shape of the lip, discussed above, as these two parameters determine the contact width.
Contact width
The contact width represents the part of the skate wheel actually in contact with the track. Normally, the grip of a wheel tends to increase as contact width increases, and agility to decrease. For this reason, in some specialties (eg the dance specialty of figure skating), the use of wheels with reduced contact width is preferred. The surface of the wheel in contact with the track needs a period of use (break-in) to develop the optimal frictional forces: this is because the roughness of the wheel given by the mold and/or by the turning operations is not the final one. , which the same wheel will acquire after a certain period of use. Furthermore, the molds are often coated with release agents, which can be partially transferred to the surface of the wheels, reducing the coefficient of friction. Our advice is, therefore, in case of buying new wheels, to use them for at least a couple of weeks before important occasions (races, events, etc.). The use of wheels with a "ribbed" contact surface, contrary to what one might believe, does not bring substantial advantages in the case of dry contact surfaces (we strongly advise against skating on wet tracks), it is only an aesthetic factor.
Core position
You will have noticed that, in many cases, the wheel hub is not centered, in the axial direction, with respect to the wheel itself. This choice of the manufacturer, in the case of wheels for skates, is essentially linked to reasons of geometric compatibility with the cruises. Therefore, in quad skating, there are practically only wheels with "offset" or "sideset" configuration. As known to those who have skated for a while, this fact leads to uneven wear of the wheel itself, the outer part of which tends to take on a conical shape over time, changing the grip characteristics of the wheel itself. An aggravating factor is the type of use made of the skates: spins or other exercises that are strongly asymmetrical for the wheels themselves, tend to wear some wheels more than others. Therefore, we recommend that you at least "cross" the wheels periodically, in order to increase their duration.In the following image you can see the section of a quad skate wheel on its cross: you can see the hub (the white part) in the "sideset" position, and the bearings.
To help you choose the right wheels for your needs, we have created a web app dedicated to figure skating athletes: you can find it at this link . If you are looking for high quality wheels for other disciplines (eg roller derby, street skating, etc.), you can take a look at dedicated section of our store. We have selected for you the best wheels available on the market!
Tips
- Figure skating: Your coach knows the rink you train on and your technical needs. Ask him for advice, or possibly use our web app . You will probably need several sets of wheels to be able to compete smoothly on different surfaces than you are used to: it is convenient to organize your wheels using a wheel holder. Furthermore, it is good that all your wheels are already equipped with bearings(clean), for a quick reconfiguration of your skates, as needed: the grip offered by a track can change over the course of a day, due to -for example- variations in humidity: be prepared! Alternatively, you can equip yourself with a bearing puller; consider that it is still a good investment, because you will need it in any case, for example to clean the bearings. If your wheels need cleaning, use only water and a detergent, such as washing-up liquid. Do not use solvents, they can damage the wheels and compromise smoothness and grip. If necessary, you can carefully sand the contact surface of the wheels, with a medium-fine paper (grain 240-320), being careful not to insist too much, so as not to change the profile of the wheel. In any case, we advise you not to clean your wheels immediately before a race: the behavior of a clean wheel can be different than that of a slightly dirty wheel, and this could throw you off!
- Street skating: we recommend using wheels designed specifically for this specialty, in our store you will find different types, for example the Energy from Riedell are very good. You will easily recognize them: the diameter is usually among the highest, the edges are well rounded, the hardness is generally medium-low, and the hub has a small diameter, so that the greatest amount of elastomer present can act as a shock absorber. Don't choose a wheel just for its attractive aesthetic! You risk skating with reduced comfort and with wheels that will not last long, because you are not designed specifically for this application. In any case, we advise against skating if the road is wet: the wheels for road use are made of polyurethane elastomers, which have a very high dry and very low wet grip, creating the ideal conditions to cause falls and accidents in the event of the presence of water.
- Other specialties: in general, choose wheels suitable for the surface on which you skate (indoor/outdoor, concrete/tiles/parquet/etc.), so that the grip that develops is neither too high nor too low. You must feel safe and comfortable: this will allow you to obtain maximum performance and avoid injuries. For this reason, to meet all needs, it is important to have wheels of at least 2 or 3 different hardnesses available.
Conclusions
In this short guide we have tried to summarize the main parameters that can guide the choice of skate wheels, according to your favorite specialty and your level of preparation. We have also tried to give you some useful tips to use them to the fullest, both for leisure and for competing. If you need more information or clarifications, please contact us!Greetings from your Skateguru, see you next time!
