The aluminium rim is not dead, not by a long shot. For people who are hard on equipment, on a restricted budget, worry about carbon, and for a variety of other reasons – the aluminium rim is the way to go. But carbon is the new black (and yes, it is very black too).
There are so many carbon rimmed wheels on the market in Australia now that just on sheer space limitation alone we could make the argument about a carbon-only buyer’s guide.
Buying New Carbon Wheels
As much progress as we’ve seen with carbon bike parts, particularly on price, there is still some way to go before carbon rims can be considered entry-level. Yet prices get more competitive all the time and it is possible to find good quality carbon rims (or whole wheels built around them – the focus of this article) for not substantially more money than a good quality aluminium one might cost. Of course, it is also possible to spend vastly more money on fancy carbon wheels.
How Much Should I spend?
Which brings us to the subject of budget. Most, perhaps all, readers of this magazine will start from the premise “this is what I can afford to spend on my new wheels” and then look for the best wheel for them within that limit. If that limit isn’t somewhere above $1500 dollars, then you will have a really difficult time in finding carbon wheels.
Second hand might be an option for you, but that is outside the scope for this article. On the high end, the most expensive wheels I have seen approach the 5-figure mark (that is, $10,000) without quite touching it. That is more than a lot of nice bicycles cost, so part of this article will explain why it is that two very similar items (carbon wheels in this case) can vary so much in price.
Smaller Brands, Lower Cost?
If you look at our buyer’s guide, you will see that for the most part the lower cost wheels come from small brands. There are reasons for this. The big companies like Shimano, Trek, SRAM and Specialized develop their own wheels (labelled Shimano, Bontrager, Zipp and Roval respectively) from a blank sheet of paper.
The development costs are high for carbon products. One mould costs thousands of dollars. Some small companies rent time in an “open” mould offered by a carbon production specialist. In these cases, you might find the identical rim offered under several company names – but they aren’t necessarily identical in layup or carbon fabric, only in shape.
A Word On Design
To develop your own rim shape properly requires lots of time by a specialist engineer on a computer running design software [employing acronyms such as FEA (finite element analysis – structural strength and stiffness) and CFD (computational fluid dynamics – aerodynamics of a shape)] through countless iterations of their design idea. Then the digital model has to be turned into a physical prototype that can be tested in a wind tunnel. There may be several rounds of computer design and prototype testing. Eventually they get to a shape that fulfils their design brief and they cut a mould to produce that rim. That fixes the shape.
Then they consider which carbon fabrics to use, in which quantities and by what layup schedule (in other words how much carbon to put in each part of the rim structure). Once the process is determined, the actual production might be done in-house or it might be farmed out to carbon specialists. Western production inevitably costs more than Asian production as the Western workers get a higher wage. As an example, Cervélo bikes introduced a US-produced variant of one bike frame a few years ago which, by virtue of its more careful construction with higher grade carbon, was both marginally lighter and substantially more expensive than a visually identical Asian produced frame.
Once we get past development and production costs, remember that the price of the other components (the hubs and spokes) can vary by well over ten-fold between the economy option and the trick option. A plain spoke is well under one dollar. Mini-blades (such as DT Aerolight and Sapim CX-Ray) are up towards the ten dollar mark. I have seen even higher prices for the proprietary spokes used in some wheels (at least when purchased in small quantities for maintenance purposes). Hubs are similar, with the difference between a basic pair of hubs and some boutique hubs being well over the 10:1 ratio.
Big Brand Or Boutique?
Those large companies tend to advertise more – which costs money. They sponsor professional cycling teams and top triathletes – which costs more money. Finally we get to testing. The top brands, particularly if they sell in the litigious USA, will invest lots of money on testing. That testing might be as simple as putting the wheels under a lot of riders and watching how they work out (one of the marked benefits of working with pro riders is that they ride a lot of kilometres in a short period of time).
Or it can be a lab-based testing regime that takes the products past the failure point in order to know exactly where that sits. If you purchase a big name wheel you know that hundreds of people rode it thousands of kilometres before it even came to market. That peace of mind costs money.
Time To Go Shopping?
With a budget in mind and an understanding of what it can buy, it is time to consider which wheels of the hundreds out there are the best ones for you. I divide wheels into three general categories: the climbing wheel has rim depth up to 40 mm; the flat-course wheel has rim depths over 55 mm; in between lays the all-around wheels. For most people and most riding the first choice should be an all-around wheel.
Light enough to climb well (probably lighter than the wheels you are replacing), aerodynamic enough to go fast on the descents (modern aero wheels are markedly better in every way than even the wheels of a few years ago – their wide profile makes them ride better and behave better in crosswinds).
So why do the other wheels exist? Choices are good. Some people are decidedly a “type” themselves on the bike. Some lighter riders are dedicated climbers. Perhaps they want matching wheels. Then a shallow rim with moderate aerodynamics but impressive weight savings suits their needs. Or maybe they want to compensate for their lower power outputs as much as possible, and choose to go with a 55 mm deep rim that is still quite light but also very aero.
On the other end are the heavy riders. Some are sprinters and some are time trial specialists – some are neither but are simply forced to drag along extra kilograms by virtue of being larger than average. Large riders tend to hold speed well on the flats, and so a very aero deep rim is a complement. The choice of a climbing wheel might be made to compensate, as much as possible, for that extra mass every time the road points upwards.
Mostly the specialist wheels should be second or third wheelsets in the well-equipped cyclist’s quiver. That is how the pro teams do it. All-around wheels for most riding, climbing wheels for the big mountains and deep wheels for the flatter races and for time trials.
Is There A Perfect Wheel?
Also note that you need to vary this a bit for the size, experience and local terrain of the rider shopping. A typical female cyclist, being both shorter of stature and lighter in weight than the average male cyclist, will struggle much of the time to retain control of a 60 mm (or deeper) rim. A novice rider should probably avoid deep rims completely until they get to grips with the finer points of riding a bike – it really is no fun to get blown off the side of the road while riding deep-section rims.
A heavy rider, just due to the extra mass, will find controlling a deeper rim easier, even in the wind. Shallow rims might feel too flexible for a big cyclist. On a technical mountain descent I would never choose a deep rim. The extra speed it can provide on parts of the descent is not enough to compensate for the difficulty in manoeuvring with really deep rims at high speeds on steep descents. At 80+ kmh it is quite scary to get even a tiny crosswind moving the front wheel; if that wheel is a deep one it is going to happen (even with the modern rims that are relatively insensitive to crosswinds!).
Putting Your Choice to Use
Once you purchase your carbon wheels, should you reserve them for good days (races, gran fondos and Saturday morning rides with the gang – that sort of thing) or leave them on the bike and use them every ride? A very good question!
On the “save them” side of the argument the main benefit is that tossing good wheels into the bike makes it feel special (faster and lighter) for the first ride or two before it just feels normal. It also spares the expensive wheels from the daily grind of training or commuting.
On the ‘leave them’ side are several compelling issues. If your everyday wheels are alloy, swapping wheels over means swapping brake pads – which makes the process that much more involved. If those everyday rims (even carbon ones) aren’t the same width as the good wheels then the brakes require adjustment too – it is approaching “too hard” for last minute swaps. Two sets of wheels mean either maintaining two cassettes or swapping one across each time. It means two pairs of tyres in use (which is actually the most persuasive positive reason for me to consider having two sets of wheels). Hving just one good set of wheels and riding them all the time is so easy, and your bike always rides the same.
Discs & Durability
Durability might be a concern for someone spending several thousand dollars on a pair of wheels. Alloy rims wear down from braking – very fast in wet climates. Carbon rims do wear from braking but considerably slower than alloy ones. If you choose to run disc brakes then this isn’t a concern at all for any rim material. Any decent hub – and all the hubs built into carbon rims should fall into this category – will last virtually forever with appropriate maintenance. So really there is no reason not to ride a carbon rim every day.
Wrapping It Up
My own experience with carbon wheels might be a useful example at this point. I had the opportunity to review several carbon wheels during 2014. Based on that experience I decided to purchase some 58mm deep carbon wheels and use them as my daily hoops. These are quite deep for regular use.
Despite my size (193cm tall, 95kg) and experience (racing for 30 years) I have had three occasions where the wheels were too much – all of them at high speeds in mid-descent with gusty wind. These wheels were the same weight as the alloy rims I removed, meaning climbing was unaffected. But with 35mm extra depth I gained approximately two kmh.
Braking (with the manufacturer’s brake pads) has been good enough – not quite aluminium quality and actually quite poor in the rain, but good enough. If I was going to do it again I would choose something a little shallower. If I could have two sets I would go even deeper with one set and much shallower with the other.
As a final note I will offer that the cheapest way to purchase carbon wheels is as part of a new bike. At the manufacturer level the addition of carbon wheels is partly offset by the exclusion of the alloy ones and helped by the volume purchasing. It is almost impossible to quantify exactly how much you are paying for the wheels in a new bike because they seldom offer the identical bike with different wheels, but if you shop across brands and models you’ll see that sometimes there is little or no difference.
Perhaps the biggest question is; do you need carbon wheels? The answer is a definitive no, especially if you do not race. But should you want carbon wheels? That is a lot more ambiguous. Riding is a pleasurable experience and many people enjoy it more with nice wheels – the nicest wheels I have ridden all happen to be carbon.
Zipp 303 NSW CCL
Zipp 808 NSW CCL
Zipp 404 CCL Disc Brake V2
Zipp 454 NSW CCL