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11/01/2021
Stop calling them bicycles

E-Bike

 

A market, cultural, social and, not least, economic phenomenon. E-bikes, or electrified bicycles, are the link between man-powered and motorised traction. Tires included, obviously

Duilio Damiani

When it comes to electrified mobility on two wheels, we need to make a few distinctions. Not all electric bicycles are the same. Some are referred to as pedelecs or EPACs (Electric Pedal Assisted Cycle), with a maximum speed in pedal-assisted mode of 25 km/h, which are more or less traditional bicycles equipped with an auxiliary electric motor - and batteries - with a maximum power of 250 watts that kicks into action as soon as the pedal starts moving, progressively reducing its action stopping when the set speed of 25 km/h is reached. In Italy these are treated in the same way as traditional bicycles (Art. 50 of the Highway Code), so helmet, number plate or insurance are not compulsory. One level up we find the more powerful Speed Pedelecs, or S-Pedelecs, which are more similar to electrically driven mopeds, especially in their more powerful versions. Some of them do not even require the rider to pedal in order to get the boost from the auxiliary motor, and they can be driven at speeds of up to 45 km/h (if not more, following questionable if not illegal tuning). In this case there are two regulatory levels: L1e-A standard for S-Pedelecs with a motor output of up to 1 kW and a maximum assisted speed of 25 km/h, and L1e-B, up to 4.5 kW (well over 5hp) and a speed of 45 km/h, both of which are subject to registration (European directive 2002/24), and must feature lights, mirrors, number plates, compulsory insurance, as well as the AM licence, just like a moped. In Italy, the bicycle market is not as successful as it is with our Central European cousins, but it still represents a volume of 1.5 million units delivered in 2019 alone (+ 7% compared to the previous year), 200,000 of which were pedelecs, up 13% compared to sales in 2018. It is therefore clear that, with the help of government subsidies and grants - such as the recent mobility bonus - we will likely see pedelecs becoming increasingly popular.

 

Tailor-made tires

Cycling holidays, road, mountain, competition and even riding around town are the main fields of use, both amateur and professional, where e-bikes are used in all their forms. It is therefore clear how important it is to have specially designed tires able to respond adequately to the increased workload: higher weight due to the motor, equipment and battery, as well as the stress dictated by higher speeds and acceleration.

Turning our attention to the wheels, one of the characteristics we need to pay attention to, as on a traditional bicycle wheel, is the structural density of the tire, expressed in TPI (Threads per Inch), i.e. the weave, which usually varies from 25 to 300 threads and substantially determines the type of use. Low values means the casing will be soft and flexible able to adapt to the ground for greater traction, while high values, on the other hand, guarantee greater stiffness and strength, especially on the sides ensuring adequate resistance to impacts on the ground, perhaps when landing after a jump, as well as abrasions, rocks and bumps. Equally crucial is the material used to make the casings: cotton, polyester, nylon or a combination of these as well as the more advanced aramid, Kevlar and other synthetic materials. The same goes for the compounds made up of mixtures of rubbers and sophisticated additives, used individually or in multiple combinations, overlapping in different areas to offer advanced characteristics. Last but not least, energy saving and mileage, is an additional vital element, which needs tires able to offer low rolling resistance in order to maximise the charge (usually limited to a few dozen kilometres) offered by the on-board batteries.

Now we need to turn our attention to “reading” and understanding the size: measurements can be expressed according to different parameters. The English standard is expressed in inches, usually used for mountain bikes and children’s bicycles, for example, 27.5 x 2.40, which means the outer diameter is 27.5" and the tire width is 2.40". The French standard, which can be found on road and racing bicycles, refers to the metric system and also in this case expresses the external diameter and width in mm, for example 650 x 38B, where the letter B identifies the diameter of the rim to be used. The ETRTO (European Tire and Rim Technical Organization) system, again expressed in millimetres, represents an attempt to standardise the matter, but in this case identifying the internal diameter and the width of the tire and even the internal width of the rim channel, which must not be confused with the width of the tire. For example, a 40-584 tire will have a width of 40 mm, an internal diameter - corresponding to that of the rim - of 584 mm, while the wheel will be marked with the number 584-19, where 19 mm indicates the width of the channel. A brief overview will guide us through the proposals of the main brands in the sector (many more are worthy of note), which are particularly attentive to the rapid growth of the e-bike tire segment. While pedelecs can also be fitted with conventional, non-specific tires, S-Pedelecs require ECE R-75 approved tires.

 

Continental

Several Continental tires have been approved for pedal assistance up to 50 km/h with the all-rounder Contact Plus guaranteeing high freedom of movement. Designed for road and off-road e-bikes, Contact Plus features a flexible casing reinforced by SafetySystem Breaker technology, three layers of 180 TPI Nylon, resistant to punctures and lateral cuts (protection level 7), also available as Contact Plus Travel version, more road-going and longer life span, and Contact Plus City, comfortable and flexible ideal for riding around town. The size range is rather wide, depending on the model, ranging from 28-622 mm to 42-635 mm.

At the top of the amateur road range, we find the renewed Top Contact II, a multi-range product characterised by a 180 TPI casing made using Vectran technology, inserting a lightweight high-tech synthetic fibre into the weave to improves resistance to tearing while maintaining high flexibility. Marked E50 (like the rest of Continental's Speed Pedelec range), the Top Contact II covers a size range for 28" wheels between 28-622 and 47-622 mm.

 

Cst Tires

One of the youngest and liveliest players on the market, the Asian company CST Tires (Cheng Shin Tire) is devoting a great deal of attention to the e-mtb sector as evidenced by a dedicated range featuring solutions designed for different uses.

The renewed 2020 catalogue includes models such as the Rock Hawk / C-1844, approved up to 50 km/h and ideal for tackling tough terrains, from all mountain to enduro, with a TPI 60 casing, a tread featuring wide, widely spaced single-compound tread blocks, an EPS (Exceptional Puncture Safety) puncture protection system with protection level 4, and two sizes: 27.5 x 2.25 and 29 x 2.25 (ETRTO 57-584 and 57-622 respectively).  The Gripper / C-1879 is a more versatile on-off road profile, suitable on both tar and dirt roads, and features the same TPI 60 casing structure with EPS technology, approval up to 50 km/h and the same two sizes as the previous model. Following a common thread the Patrol / C-1846 offers an off-road design, suitable for a wide variety of terrains, from soft terrains to gravel, with smaller tread blocks to guarantee smoothness and grip. TPI 60, level 3 puncture protection, single compound and approval up to 25 km/h, for four sizes available, 27.5 x 2.60, 27.5 x 2.80, 29 x 2.60 and 29 x 2.80. Next, the Brooklin / C-1996 displays a decidedly urban tread pattern, low rolling resistance and long life to be used in a predominantly urban environment, approved up to 50 km/h, reflective stripes on the sidewalls makes it easier to spot them in traffic, TPI 27 and a single compound, in sizes 27.5 x 2.00 and 29 x 2.00. Finally, the road-going Tournée C3039 range, in four variants, Free - Dynamic - Sport - Prestige, in sizes 28x15/8x13/8 or 28x1.50 and single compound, approved up to 25 km/h and for 50 km/h according to the versions. Concluding the offer we find the Xpedium Ampero C1880, also for road use, in size 28x15/8x13/8 or 28x1.50, a high level tire suitable for speeds up to 50 km/h.

 

Maxxis

The comprehensive Maxxis catalogue, with its range of e-bike tires reinforced with Maxxshield K2 technology, i.e. casings strengthened by an additional layer of Kevlar fibre going from bead to bead and capable of supporting the greater load required by motorised traction. Among these, Rekon deserves to be mentioned, a tire suitable for the most demanding cross-country use, with a tread pattern featuring large tread blocks as well as lateral blocks to ensure high grip also when turning or leaning. TPI 60 or 120, depending on the version, also available with Exo and Exo+ technology, i.e. additional anti-puncture protection under the tread on two levels (and weights) according to specific needs. Downhill enthusiasts will no doubt appreciate the Assegai range, a tire that features high resistance to stress and equipped with a tread shaped to maintain grip even on dust and dirt, with a 120 TPI casing. Designed for the rear wheel only, the Dissector is shaped to maintain control and stability at higher speeds, using a tread pattern clearly inspired by the Rekon and Minon models, with grooved blocks to increase flexibility and support when braking, ideal on dry and fast terrain. TPI 60 or 120, depending on the size, characterise a flexible and sturdy structure. The size range, for all, goes from 27.5 x 2.40 to 29 x 2.60.

 

Michelin

Michelin’s entry in the e-mtb sector means that the French tire maker will use all its know how to prepare a new range of tires dedicated to assisted traction on mountain bikes, the new E-Wild. Inspired by the current line of enduro and downhill tires for traditional mountain bikes, the E-Wild Rear, specifically designed for the rear wheel, is equipped with a reinforced casing that stems from racing models, to allow superior power transmission to the ground and greater resistance to the stress imposed by greater torque given by the electric motor. The E-Wild Front, on the other hand, uses the same structure as traditional enduro tires, optimised to offer a combination of strength and grip when changing direction. The development of special compounds has resulted in the latest generation of E-GumX, which guarantees the best compromise between traction and longer tread life. The Michelin E-Wild in its two variants is available in sizes 27.5 x 2.60, 27.5 x 2.80 and 29 x 2.60 inches. The Michelin Energy Performance Line city/trekking range is a high-energy efficiency tire, thanks to its e-bike-specific compound that combines grip with low resistance, on top of a structure reinforced by an HD Protection system, which offers anti-puncture properties without compromising smoothness. The only size currently available is 47-559 mm.

 

Pirelli

Scorpion is synonymous with performance, and the Italian brand's range dedicated to pedelecs is no exception, with the Scorpion E-Mtb for electrified mountain bikes, launched in 2020. Advanced structure technology, with HyperWall reinforced bead and sidewalls, anti-puncture rubber insert, coupled with a textile loop around the bead, thus increasing resistance to major stress. The advanced SmartGrip+ compound, with lignin additive - a component of natural origin - provides greater grip on dry and wet surfaces, even at higher speeds. Three treads are available, all tubeless ready: M (mixed terrain) for trail and all-mountain riding on mixed terrain; R (rear specific), a natural complement to M, provides greater traction to the rear wheel; S (soft terrain) specifically designed for softer, more yielding terrain. For all of them, the dimensions currently available are 27.5 and 29 inch diameters, with a width of 2.6". The Pirelli range also includes four urban tires, made with a dual-compound tread, a puncture-proof base and a top compound for better grip: the Downtown (DT) is also offered in a Sport version, ideal for city use, the Granturismo (GT) suitable for extended use, the Crossterrain (XT) suitable for mixed use, both on the road and light gravel roads, and the Winter (WT) for roads made slippery by bad weather and low temperatures. There is a wide range of sizes on offer, with over twenty references between 54-559 and 50-622.

 

Schwalbe

Schwalbe, a German company famous in the biking world, has an extensive catalogue dedicated to pedelecs and S-Pedelecs, both on and off-road. The Marathon E-Plus is the trekking and touring tire defined as "puncture-proof", based on Dual-Smart Guard technology, i.e. a protective belt supported by two layers of fabric, barriers that prevent air from escaping in the event of a puncture. The Addix-E compound, specially designed for this use, combines smoothness and grip even at high speeds, while the anti-ageing sidewalls are able to withstand heavy loads over a long period of time without cracking at the sides. There are six main sizes ranging from 50-584 to 55-622. A motocross-inspired design characterises the Eddy Current, the enduro and all-mountain tread, available as Front and Rear options, the former featuring a high grip especially when braking and the latter characterized by its traction qualities when tackling the steepest climbs. Addix Soft compound for greater grip and four sizes for 27.5 ( x 2.60 / x 2.80) and 29 inches (x 2.40 / x 2.60). Super Moto is the road tire that leaves no room for interpretation, with a tread pattern clearly inspired by motorcycling, thin grooves and large blocks right across the tread, again in Addix compound, offering great grip and cornering at high speed. Three sizes are available 62-584, 50-622 and 62-622 mm.

 

Vittoria

An established player with around 8 million tires produced each year, the Italian company Vittoria, through its Thai subsidiary Lion Tires - where most of the production takes place - holds the technological leadership for the use of graphene, a high-performance synthetic material.

The catalogue includes four enduro tires: E-Mazza, with 120 TPI Nylon casing, well-defined blocks and graphene 2.0 compound to reduce wear and consumption. Two sizes are available: 27.5", x 2.4 and x 2.6 respectively, and as many for 29" wheels, with a unit weight of between 1,160 and 1,400 grams. More aggressive and suitable for a wide range of rough terrains, the E-Martello features a motocross-inspired design with spaced blocks and 4C technology with four overlapping compounds. Sizes and weights are similar to the previous series. Combining XC and enduro characteristics, the E-Agarro range was designed for trail riders, with uniform grip in all conditions, the same 120 TPI Nylon construction technique, offered in three sizes (27.5 x 2.6 - 29 x 2.35 - 29 x 2.6) and very low weights, between 850 and 970 g. Maximum performance also for e-mtb cross country bikes thanks to E-Barzo tires. Traction and speed is guaranteed even in bends thanks to alternating blocks, three sizes all for 29" wheels (x 2.25 - x 2.35 and x 2.6). For urban riding, Victoria offers its E-Randonneur, 33 TPI Nylon with reinforced puncture-resistant sidewalls, low-resistance compound and reflective stripe for greater safety at night. Four sizes (ETRTO): 47-584, 37-622, 42-622, 50-622.

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