Carbon 27.5 wheelset is for all those who appreciate the highest performance and advanced technological solutions. Their first choice would be carbon wheels. Their low weight allows for higher speeds and better riding performance.
- Part 1: Beginning: Overview of Carbon 27.5 Wheelset
- Part 2: Advantages And Disadvantages
- Part 3: Precautions for Mountain Bike Riding
Part 1: Beginning: Overview of Carbon 27.5 Wheelset
Carbon 27.5 Mtb wheel rims can be found on mountain bikes. They are the perfect compromise between the smaller 26″ and the more gigantic 29″ rims. The medium size is ideal for some MTB disciplines where you need freedom of speed, better control, bump absorption, and braking at critical points along the trail.
While 27.5-inch wheels are relatively new, they immediately gained traction in the mountain bike world, promising to be an adequate middle ground between the old 26-inch standard and much larger 29ers. Bike manufacturers assured riders that they would be just as efficient and easy to ride as smaller-wheeled bikes while retaining the rollover characteristics of the 29er. It certainly has its advantages, but unfortunately, it’s not the holy grail of wheel sizes. We’re still looking for that – and it comes with some inherent compromises. The proper carbon structure and DT Swiss expertise guarantee high resistance to mechanical damage and excellent shock absorption properties when absorbing vibrations.MTB carbon wheels meet high-quality requirements, being a safe choice for the most demanding users
There was a lack of a golden mean for a few years – either 26 or 29 and period. Not always, with the correct frame size, effectively put someone on big wheels. The market response had to happen. The rumors emerged some time ago, but it wasn’t until the 2014 season that an unequivocal answer appeared – bikes on 27.5-inch wheels. The new site is supposed to be the golden mean, a miracle cure for MTB, ending the age-old dispute between the two camps – lovers of small (26) and large (29) wheels.
The Birth of Carbon 27.5 Wheelset
Manufacturers have believed in the new size so much that they have slowed down the production of new bikes on 26″ wheels – lower-end models are available, while it is increasingly difficult to find a well-equipped motorcycle on a small wheel. Let’s take a closer look at the new trend and assess whether the wheel size problem has indeed been solved! At the outset, it should be emphasized that 27.5 does not lie perfectly in the middle of 26 and 29, and this is an ideal combination. 27.5 carbon wheelset Mtb are closer to the 26 wheels than the most oversized wheels. Therefore, many painstaking testing and comparison are required to get the differences right.
From the above data and numerous tests, it appears that indeed the new wheel size may be the golden mean. It combines the maneuverability, agility, stiffness, and low weight of the 26 wheels while improving grip, speed performance, and softness over off-road obstacles. Concerns about parts availability, which were still prevalent in 2012, are no longer valid – the current market offers a full range of parts and components, from tires and shocks to rims, spokes, frames, and everything else you need to build a bike on a 27.5-inch wheel (for the record, it’s worth mentioning that the correct name for the new wheel size should be 650B, so don’t be surprised if you come across that term).
The total weight of a carbon 27.5 wheelset (including wheel, tire, and tube) is only 5% more than an identically constructed 26″ wheel. Compare this to the 12% increase in weight of a 29″ wheel, and you can see how even a one-and-a-half-inch increase in wheel diameter makes a difference to wheel weight and, therefore, performance when climbing or accelerating.
More lively acceleration and reduced angle of attack for a smooth and agile ride
An increased wheel diameter results in a reduced angle of attack (the angle at which a circular object rubs against an object perpendicular to itself). This is a great advantage. A 29″ wheel overcomes a 6cm obstacle with sharp edges 14% more effectively than a 26″ wheel. A 27.5″ wheel overcomes the same obstacle 9.8% more effectively than a 26″ wheel.
If we assume the angle of attack for a 26″ wheel is X˚, for a 27.5″ wheel, it’s X˚-4˚, and for a 29″ wheel, it’s X˚-6˚.
Probably the most essential advantage of 27.5 wheelset carbon over 29″ wheels are the ability to accelerate faster. It’s all about that “spurt” that a cyclist feels when pressing the pedals harder. At this point, not only the overall static weight acts but also the distribution of weight across the wheel. The further the weight is from the center of the hub, the slower the bike’s acceleration.
The key to breakaway acceleration is to minimize the weight of the outermost wheel components (rim, nipples, spokes, tire, and tube). Therefore, a 1000-gram 29″ wheel accelerates slower than a wheel of similar design, same weight, but 26″ diameter, because the larger diameter rim and longer spokes place the importance further from the hub. As you can see, a 27.5″ wheel achieves only 1.5% slower acceleration than a similarly constructed 26″ wheel. In contrast, a 29″ reel is 3.6% slower than an again built 26″ wheel.
Increased tire contact area, increased stiffness, and optimized frame geometry improve traction, braking, and handling. The larger the wheel size, the harder it is to optimize the geometry, especially on smaller frames. The smaller the frame, the higher the head tube (relative to saddle height). This is not a significant problem for 26″ or 27.5″ frames. However, creating a bike with a petite frame and 29″ wheels with ideal geometry is not easy.
The greater the diameter of the wheel, the greater the area of contact between the tire and the ground. More contact area means better traction, which improves acceleration, braking, and hard cornering. As you can see below, a carbon 27.5 wheelset has a similar contact patch to a 29″ wheel.
Wheel size can also affect the lateral stiffness of the frame. A longer frame length is necessary to accommodate larger wheels in a frame. This is why a medium-sized frame on a 29″ bike has more lateral rigidity (bottom bracket and head tube) than a medium-sized frame on a 27.5″ or 26″ bike. This lower stiffness negatively affects the bike’s steering when there is a lot of pressure on the pedals or when cornering hard.
The diversity of Mtb disciplines is the primary determinant of mountain bikes. Among the features that divide them, there is the size of bicycle wheels. Some prefer the popular 29″ rims, but there are also enthusiasts who choose slightly smaller 27.5″ Mtb wheels, which have been well accepted on the market. It is the second variant preferred by the followers of gravity sports, like enduro or downhill, as it helps to maneuver the bike on more challenging trails. It is also recommended for shorter people, so they can discover the charms of real Mtb!
It is becoming more and more popular in special downhill bikes to have a solution with different rim sizes, the so-called mullet configuration, where the 29″ version is on the front, and the other user is a 27.5 Mtb carbon wheelset on the rear. Mtb with such a bike becomes even more interesting, as such an option provides a perfect balance between stability and maneuverability.
Part 2: Advantages And Disadvantages
Because of their smaller diameter, carbon 27.5 wheelsets are easier to handle in tight and challenging trails. They are more responsive to the rider’s commands, especially for smaller riders who would otherwise have difficulty controlling a larger (and generally heavier) 29er. All other things equal, bikes with 27.5-inch wheels usually are more accessible to ride than their 29-inch counterparts.
Even more, because of their lighter weight, 27.5-inch wheels tend to provide a more efficient and energetic ride. You’re likely to hear riders describe them as more “fun” because they can quickly change direction, jumping from one side of the trail with less effort.
27.5-inches are nimble and accelerate quickly. For riders who don’t want to reach for 29-inch wheels, 27.5-inch wheels are a great choice if you wish for the most agile ride.
Mtb carbon wheel set 27.5 works well with extended travel frames, forks, and aggressive trail bikes.
Bikes with 27.5-inch wheels seem to be nimble and easier to maneuver than larger bikes. So for tight, technical trails or trails that require a lot of suspensions, 27.5-inch wheels are a good choice.
Availability of parts. Most serious is related not so much to wheels but to wholesalers. In the case of spoke replacement, we will not be able to fit any Sapim or DT in most cases. You will need a specific spare part dedicated to a particular model.
Distributors often do not care about it, resulting in a long wait for parts from abroad. In the case of older or less popular models, it is often impossible to get spokes or bearings.
This is also a severe disadvantage if you want to use the bike on trips and do not want to bring spare spokes with you. In addition, many system wheels require special centering tools, which not every service center has.
If something is for everything, it means it’s for nothing. I agree with this adage, but the versatility of system wheels means they won’t meet specialized requirements. If you know what you want (e.g., you care more about weight than durability or vice versa), nothing can replace traditional braiding. Especially since manufacturers of some of the top hubs and rims don’t make whole wheels.
Part 3: Precautions for Mountain Bike Riding
Many cyclists pay attention to the size of bicycle wheels because it is a component that influences the quality of riding. There are as many as three sizes in mountain sports, which have their advantages and disadvantages.
Products made of carbon fiber have always been shrouded in myths. Fortunately for us, carbon is becoming so popular that its production costs are steadily decreasing, allowing a growing number of users to enjoy the highest quality equipment without ruining the household budget.
On the one hand, it means greater variety in the choice and adaptation of the component to your preferences. For some, however, it is a conundrum as to what will work best with the chosen riding style.
There is often a view that finally, you can match your bike to your height with more than just a frame size, and this is true! Shorter people will often choose 26 or 27,5. Since 29 will remain in the circle of interest of tall people, although there are many low supporters. An example of them is our Maja Włoszczowska, whose Scott Scale on a 15″ frame and 29″ wheel looks at least strange.
As I mentioned earlier, such a crop can only be good for the further development of the market. The stores have a big challenge ahead of them, as they have to find space for new bikes. The salesmen have to learn how to recommend the right wheels to individual customers.