bc original Loamer MK2 Long-Term Test – Wheel K...
Product manager Chris rode with the Loamer over Canadian trails for 2 weeks in September and put it through its paces.
Is it worth building a custom wheelset for a road bike when there are so many good system wheels available? Absolutely! Read on to learn more.
The market for road bike wheels is dominated by system wheels, and there is a huge selection of very well-made wheels. However, there is only so much to choose from, and so there are good reasons to build your own custom wheelset. After all, you don’t want to waste energy while riding your road bike, and you also want optimal performance. However, the wheels on a road bike are subject to contradictory requirements. On the one hand, they are supposed to offer good aerodynamics to enable lightning-fast sprints on flat ground. On the other hand, they must be as light as possible in order to accelerate quickly and not impede propulsion in the hills or mountains. In addition to these aspects, there are of course demands in terms of durability, aesthetic preferences, your desire for certain technical features, your choice of tyres, the dimensions of your bike and the system weight of the bike, you and possibly your luggage. If all these parameters are to coordinate perfectly, then a custom-built wheel is your first choice.
Beyond all standards: With a self-built wheelset on your road bike, you can adjust all parameters perfectly to suit your needs. Our wheelset consists of the Chris King R45,
the stiff H+SON Formation Face aluminium rim
and CX-Ray spokes from Sapim.
Perfect lightweight construction is different for everyone
Complete wheels are designed by the manufacturer to suit the largest possible target group – and with a considerable margin of safety. That's why customising a road wheel is especially worthwhile if you're looking for a lightweight wheelset for riding in the mountains. This way, you can push the limits of what is physically possible while keeping a close eye on your weight and preferences.
Step-by-step to a customised wheel for your road bike
The best thing to do is to select the components for your wheel step-by-step. For road cycling, we recommend that you make your decisions in the following order:
Wheel size: 28", 622, 700C - three numbers, one size
With few exceptions, road bikes roll on 28-inch wheels with an ETRTO value of 622 (inner diameter in mm) and are designated as French size specification with 700C (approximate outer diameter in mm). 29” MTB wheels also have the same measurement in absolute terms. Nevertheless, these rims are unsuitable for the demands of a road bike, as MTB rims are optimised for stability on terrain and low air pressure in the tyre – the opposite requirements for a road racer.
Rim type: wired, tubular or tubeless
You’re not going to put an old tyre on brand new rims, are you? A new wheelset is a good opportunity to switch to contemporary tyres. For a long time, the tubular tyre was considered the measure of all things for ambitious road cyclists: lightweight, fast and comparatively puncture-proof in its heyday. Today this is changing, as there are now good alternatives to tubular tyres, which require special rims and must be completely disassembled in the event of a defect. Adhering it onto the rim also requires technical aptitude and time. In everyday training and life, the tubular tyre no longer really plays a role. However, it can still be found in competition and among professionals. Wired or folding tyres in combination with latex tubes are very popular with ambitious cyclists since they are very light and roll smoothly. The current star in the tyre world, however, is the tubeless system with a liquid sealant, which has been standard on mountain bikes for several years: it rolls easily, seals small holes while riding and still allows you to install a classic tube in the event of a defect.
Rim height: aerodynamics versus climbing ability
A high rim design makes wheels aerodynamic, e.g., particularly fast on flat ground and downhill runs. On the downside, taller rims are heavier and more susceptible to interference from crosswinds. If you are a rather heavy rider, then you have some advantages here: your bike will be less susceptible to wind and a higher wheel weight will have a relatively lower impact on the system weight. In this respect, you can opt for high rims. These are also stiffer as a rule, which affords you an additional advantage.
If you are more of a hill climber, on the other hand, then a little more restraint is called for when choosing the rim height. When in doubt, choose the flatter profile. It is usually lighter and less susceptible to wind interference, which works to your advantage.
The following applies regardless of ground conditions and weight: choosing a slightly higher rim at the rear than at the front brings stiffness to the rear wheel and improves aerodynamics without dramatically increasing wind susceptibility. Time trialists exploit this idea to the maximum degree: a disc wheel rotates at the rear, and the highest possible rim height rotates through the fork.
A deep rim design makes wheels more aerodynamic, but also more susceptible to wind. Which rim you choose should therefore be based on your discipline. © bc GmbH
Rim width is determined by tyre choice
For the road dynamics of the tyre, the inner rim width, also called the jaw width, is the relevant dimension. The right combination of jaw width and tyre width allows the inflated tyre to form its ideal cross-section. If the rim is too narrow, the tyre sits vertically oval on the rim and is very sensitive to insufficient air pressure; the road behaviour then quickly becomes spongy. Conversely, if the inner width of the rim is too wide compared to the tyre, it flattens the inflated tyre considerably, and this worsens the tyre's cornering ability – it literally makes it square. Therefore, rim selection begins with determining the tyre’s width. Tyre manufacturers provide specifications for the appropriate rim width for each tyre model and its width. These are your guidelines for deciding on a suitable rim width. The tyre clearance of the rear triangle and fork defines the maximum tyre width you can choose. Many manufacturers list these in their documentation for the frame. If you are building a new wheelset for your old bike, you can also take measurements on the frame directly. The tyre should be at least 3 mm away from the frame in each direction. This applies to both chain and seat stays. With short rear frames and time trial or triathlon bikes, you should look at the complete passage in the frame along the seat tube. The same applies to the fork.
Rim material: competition or daily life?
In terms of performance, carbon is the ideal material: free shaping, low weight and load-specific fibre alignment make carbon rims the first choice for athletes and their competition wheels. Rim profiles higher than 40 mm are in fact only available in carbon. If you have speed in mind, carbon is your material.
On the other hand, if you ride year-round and your bike is equipped with rim brakes, aluminium rims are a good choice: they have proven to be more robust in certain situations, such as when stones are trapped in the brake pads, and their braking behaviour is more predictable, especially in wet weather. The fact that aluminium rims are usually significantly less expensive than carbon models naturally add to their appeal.
Lasting performance: selecting hubs and rims
The interplay between frames and hubs has evolved greatly in recent years. In this respect, it is worth having some foresight when choosing a hub, especially if your bike has already got a few years under its belt: if you currently need a quick release, there are a number of manufacturers such as DT Swiss who offer corresponding adapters for contemporary thru-axle hubs. This way, your wheelset remains usable when you eventually switch to a new frame with modern axle mounts. By the way, the same applies to brake rotor mounts: corresponding hubs are only insignificantly heavier, and they can of course also be combined with a rim with a brake flank, and the unused brake rotor mount on rim brakes is negligible in terms of aerodynamics. A 142 x 12 mm thru-axle at the rear and 100 x 12 mm thru-axle at the fork are currently cutting-edge for road bikes and can serve as a guide. For the front hub, there are manufacturer-independent axle adapters from SON. For the rear wheel hub, you have to rely on model-specific adapters from the manufacturer. It also pays to have foresight when it comes to rims: if you want to ride with wired tyres, choose a tubeless-compatible rim, even if you still want to ride with inner tubes.
Although this guide is primarily about wheels, we would be remiss not to mention it: weight and puncture resistance are important factors, and a lot has been accomplished in the realm of inner tubes. The Schwalbe Aerothane and tubes from tubolito offer the chance to depress the weight of the rotating mass while also improving puncture resistance.
Weight optimisation on the tube: Schwalbe Aerothan tubes weigh only between 40 and 60 g, but promise a good amount of puncture protection. © bc GmbH
Even lighter and also made of TPU are the REVOLOOP.race ultra tubes: at just 25 g, they push the weight of the rotating mass down significantly. © bc GmbH
Spoke Choice 1: the ideal number of spokes
The number of spokes, commonly referred to as “standard," has steadily decreased over the past decades. From 36 spokes in the 1990s to 32 in the 2000s and down to 28 spokes today may be considered "normal" on a classic wheel. This also applies up to a rider weight of 80 kg when using disc brakes, which mean increased stress on spokes and fork legs or rear triangle. If you are very light, you can reduce the number of spokes. Many rims and hubs are also available in 20- or 24-hole versions. Using four spokes less at the front than at the rear is a proven way to save weight. The design and stiffness of the rim also influence the appropriate number of spokes. As a rule of thumb, the higher the rim, the more likely it is that the number of spokes can be reduced. However, the decisive factor is not the “visual height”, but the position of the spoke nipple in the rim and therefore the real spoke length. The same applies to the hubs: the larger the flange diameter and the flange distance, the stiffer the later wheel will be.
Spoke Choice 2: Design
High-quality spokes for road bikes have an aerodynamically flat cross-section, also known as “bladed spokes". These follow two design principles: those with “blades” so long that the spoke holes of the hubs must have a corresponding slot for assembly, and those that fit through the ordinary spoke holes of the hubs. In this respect, the latter allow you more flexibility when it comes to choosing a hub. If you want to maximise lightweight construction, then you should use heavily end-reinforced spokes. However, these are often not available as bladed spokes.
The straight pull spoke is another variant. Its proponents hope that it will provide greater protection against broken spokes. The downside: you need hubs specially designed for them.
Aerodynamics and colour accents: You have a lot of choice when it comes to spokes and nipples, which you can also use to give your wheel a unique look. © bc GmbH
Spoke nipples: weight, colour and form fit
There are nipples made of brass or aluminium. Aluminium nipples are significantly lighter and therefore your first choice. The second advantage is that they come in various anodised colours. They not only deliver a pop of colour but are also potentially useful: a different nipple colour to the right and left of the valve hole makes it easier to find the valve when fitting the tube or inflating.
Wheels outside of the norm
Are your starts legendary, are you fit and able to keep up the pace, but is your stature a bit on the heftier side? Then you probably fall outside of the norm of many system wheel suppliers. A lot of really fast wheels often have very sporty weight limits, sometimes under 100 kg for the system weight. In this case, it is worth building an individual wheelset for your requirements: hubs with large flange diameters and large flange spacing in combination with aerodynamic high-profile rims and an additional pair of four spokes give your wheel unimaginable stiffness. Here it is particularly worthwhile to pay attention to good models: the CX-Ray spokes from Sapim are legendary. They are lightweight, aerodynamic and stable. However, there is no need to worry about aluminium nipples if they are installed carefully and looked after properly. If you want maximum safety reserves, then take heed of our explanations on gravel wheel building, which naturally focus on increased stability.
Style: wheels as individual as you are
As we all know, visual appeal is also a factor, so the reason behind building a customised wheelset for your road bike can also be purely aesthetic: do you want your wheelset to match the orange colour of your frame decals or the colours of your sports club? Do you want to colour-coordinate your brand new Open road bike with your car? No problem: various hub manufacturers have a wide range of colours to choose from. Chris King, Hope and tune lead in terms of variety. We also offer plenty of choice when it comes to aluminium nipples: you can choose from a total of eight colours. Rim décor offers further possibilities to set colour accents.
For bikepacking & randonneuring: the hub dynamo wheel
Are bikepacking or long-distance races your thing? Then you may already have flirted with the idea of a hub dynamo. It not only supplies your bike lighting with power, but also allows you to use chargers such as the E-Werk from busch+müller or the Plug5 Pure, or Plug5 Plus from cinq while riding. The Plug5 Plus from cinq charges your power bank, smartphone, GPS and more while riding. This makes you more independent, more flexible and ultimately faster in competitions such as the Transcontinental Race. A hub dynamo wheel that is precisely matched to your bike, your riding style and your cruising speed is hard to find right off the shelf. With a race-ready high-profile rim on the outside and an electric powerhouse on the inside, in between – sparingly counted – aero spokes, your “rando wheel” is ready to roll. However, the devil is in the details: the selection of hub dynamos with small numbers of holes is manageable. There are also few hub dynamos with approval for radial lacing, and by no means is every hub dynamo compatible with aero spokes. For the lacing itself, the combination of a high-profile rim and a high flange hub dynamo can make for quite short spoke lengths. They require more care during assembly to avoid scratches on the hub and rim.
For bikepacking or brevet: a hub dynamo provides light and power for charging smartphones or GPS devices. © bc GmbH
Time travel: old frame – old standards
The golden age of steel frames was certainly at the end of the 1980s, where high-quality craftsmanship was met the finest steel alloys. The riding feel of these racers coupled with their sleek lines have given them cult status among many bike aficionados. If you need a new wheelset for such a racer, then a custom build is the best way to go. There are two approaches to this:
Vintage: classics are rarely available off the shelf
Theoretically, you can also choose to repurpose old parts. It is important that you have the “standards” of the different components in mind: the rim width and rim flange shape should match the tyres. The spoke hole diameters of the hub should match the spoke thicknesses. If the spoke holes of your old hubs have already widened somewhat over the years, you should thread a suitable washer between the heads of the new spokes and the hub. It increases the form fit and thus reduces material stress. In addition to the hub’s over locknut dimensions (which must fit the fork and rear triangle), you should also pay attention to the freehub body: old bikes with five to nine gears need a narrower freehub body or a spacer, which you put on the freehub before mounting the sprocket set.
Combining old frames with modern wheels
Of course, you can also take the opportunity to treat your beloved road bike to a state-of-the-art wheelset. For example, you can install modern rims that allow you to ride tubeless. When updating tyre widths on road bikes, however, be careful: from the mid-1970s to the 2000s, road cyclists preferred tyres between 18 and 23 mm, and only in rare cases 25 millimetres or wider. Therefore, the tyre clearance on many of these road frames is very narrow. In this respect, you should measure very precisely before you decide on a wider rim and a wider tyre for the new wheelset. Apart from that, new wheels on a classic bike are an invitation for stylistic crossover. The fixie scene shows that this can work out very well: classic steel frames and modern aero rims have been combined very successfully for quite some time, bold colour accents included.
Product manager Chris rode with the Loamer over Canadian trails for 2 weeks in September and put it through its paces.
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