Choosing a Mountain Bike Wheel
ENVE’s carbon fiber mountain bike wheel line, the M-series, is comprised of four fundamentally different wheels, each designed with its respective purpose in mind. Understanding the differences in each rim will help narrow down the choices. There are a number of different options to consider when selecting a wheel set – from the basics all the way down to nuances of the shape and layup. Let’s get started…
The Basics of Mountain Bike Wheels:
The first step in choosing a wheel is identifying the wheel size, axle configuration and rotor type of your application. We can’t think of any topic that has been more controversial these days in mountain biking than wheel size. The last 5 years has seen a flurry of activity from 26” to 29” to 27.5”. There has been much written about what size wheel is right for you, so no need to rehash what has been done well. As Bike Radar explains:
26 Inch Wheels:
- Can be made lighter, stiffer and stronger than other sizes
- Loads of existing 26in wheels, tires, forks and bikes makes spares cheap and easy to find
- Feels lumpier and stalls easier than bigger wheels on rough terrain
27.5 Inch Wheels (650b):
- Faster accelerating, stronger, stiffer and more agile than 29in but noticeably smoother than 26in
- Handling and wheel placement feels a lot more natural than 29er wheels
29 Inch Wheels:
- Smoother, grippier and more stable for better control on rough terrain
- Slower to get moving but hold their speed better once rolling
- Can feel awkward on tighter, slower trails and harder to sync with long suspension or short riders
There are a few different axle standards that you will find on mountain bikes that range from traditional quick release skewers to thru axles. However, fork manufacturers have been consolidating around 15mm x 100mm on the front for trail use, and 20mm x 110mm for downhill use. As you would expect, Downhill bikes just need a burlier axle.
Front axle configuration is dictated by your fork, not your frame. You can look it up like this:
FOX Racing Shox
ENVE’s M50, M60, and M70 all come standard with a 15x100mm front hub and a 12x142mm rear hub. The M90 comes standard with a 20x110mm front hub and a 12x150mm or 12x157mm rear hub. Unlike the front hub, the rear hub is dictated by your frame. Here are some examples:
Santa Cruz Bronson
As you can see, both of these bikes are 142mm x 12mm which is becoming quite common. Although these are the most frequently seen axle dimensions for frames and forks, both hub options offered from ENVE (Chris King and DT Swiss) are retrofit-able with adapters for use with quick release skewers, thru bolts, and other thru axle dimensions. Chris King and DT Swiss also both offer a hub that is compatible with the Cannondale Lefty fork, another hub option offered by ENVE in DT Swiss only. Axle standards continue to change in order to suit the needs of new technology, so in many cases ENVE is willing to accommodate custom builds.
The next step in choosing a wheel is to determine the correct rotor type. There are two options with the rotor configuration – CenterLock and 6-Bolt. CenterLock was designed as part of Shimano’s brake system and mounts similar to a cassette where the rotor carrier slides on to machined splines and a lock ring is used to secure the rotor to the hub, as shown below:
6-bolt is the International Standard for the rotor mount and as the name suggests, this standard uses 6 bolts to secure the rotor to the hub. 6-bolt rotors can be used on a CenterLock hub with an adapter; however, CenterLock rotors cannot be used on a 6-Bolt Hub. The CenterLock option is only available with DT Swiss Hubs.
Choosing the correct freehub body is a matter of understanding the drivetrain components featured on your bike. There are two options for freehub bodies with mountain bike wheels – XD compatible and Shimano 10-speed compatible. The XD compatible freehub body is only used for SRAM’s XX1, XO1, and X1 1×11 drivetrains in order to accommodate the proprietary 11-speed cassette. The more common Shimano 10-speed freehub is compatible with most 8, 9, and 10 speed cassettes as well as Shimano’s new 11-speed XTR.
An ENVE wheelset is more than just the hand-made carbon rim, which is why we partner with the best hub manufacturers to complete the build. We offer DT Swiss and Chris King hubs as part of the premium ENVE wheel build to provide our customers with a personal customization. Both DT Swiss and Chris King hubs are convertible to accommodate most of the current axle sizes that exist on the market with adapters. Both manufacturers offer a 6-bolt rotor configuration; however, DT Swiss is the only hub manufacturer that offers a CenterLock compatible hub. When choosing a hub set, there are a few differentiating factors between the two choices.
Chris King hubs are highly serviceable and can last for years without having to replace any parts. However, the process is slightly more involved and in some cases requires special tools and mechanic assistance. DT Swiss hubs are also highly serviceable, and the general process is slightly less complicated, but the cartridge bearings are not serviceable and require special tools and mechanic assistance to replace. There are two offerings from DT Swiss available as part of an ENVE build – the 180 and 240s. The 180 is the cream of the crop featuring ceramic ball bearing cartridges, but is only available in CenterLock and not adaptable for a 20mm thru axle. The 240 is the enthusiast performance price point option from DT Swiss. All of these hub options are considered to be the most reliable, durable, and fastest hubs around. There is a small weight penalty for the Chris King option but the extra grams have a very negligible effect on the overall performance of the wheel. ENVE believes both hubs to be perfect companions to our hand-made rims.
Spoke Hole Count
ENVE offers our mountain bike wheels in 28 or 32 spoke hole counts. The M50 is only available in 28 hole, the M60 and M70 are available in both, and the M90 is only available in 32 hole. Each spoke hole count has its own advantages, with the 28 hole offering a slightly lighter build and the 32 hole offering a slightly more laterally stiff wheel. Both builds yield exactly the same results in terms of durability, so having two options accommodates the range of hub offerings on the market. When choosing a spoke hole count for the M60 or M70 wheel, a lighter weight rider will be better suited with a 28 hole wheel and a heavier rider will be better suited with a 32 hole wheel. Because the durability is not affected the choice is more personal and subject to hub availability. For more information on ENVE’s wheel building philosophy, check out our recently published journal article on building a faster wheel.
Riding style will ultimately provide you with the answer to the wheel you are looking for, so we recommend keeping your riding style in the back of your mind as you navigate the different options. In some cases, a bike’s design, ride characteristics, and component specs will fall outside the generalization of category which is why it’s important to consider your personal riding style.
Your riding style can be defined by many different factors including, but not limited to:
- The terrain you like to ride. Do you enjoy the rough terrain or do you prefer fast smooth singletrack?
- Uphill or Downhill? Do you enjoy the hard work and determination of climbing, pushing the limits on each and every rocky descent, or a balance of both worlds?
- Are you hard on equipment or do your bikes and equipment seem to last longer than your riding buddies?
- How often do your wheels leave the ground?
Consider the application of the bike you are riding, in most cases a mountain bike will fall into one of these four categories: Cross Country Race, Cross Country/Trail, Trail/All-Mountain, and Downhill/ Freeride. The bike’s axle configuration, rim diameter, and brake rotor type will all initially narrow down the choices as well. For example a 20mm front thru axle will not likely be found on bikes that fall under the Cross Country categories because for that application the added strength and stiffness of a 20mm thru axle is not as applicable.
M50, M60, M70, or M90?
ENVE’s M-Series rims are all designed to be a premium blend of stiffness, durability, and light weight, for a faster, more reliable carbon wheelset. All of these factors play a part in the wheel’s ride characteristics and the emphasis of each characteristic is defined by the application. At ENVE, our first priority is quality. All of our rims are handmade in the US which allows us to deliver the highest quality product possible. Quality is a characteristic that defines ENVE wheels all the way from the design, to the finishing touches of a hand built wheel. The quality to redefine your ride with the most responsive carbon fiber mountain bike wheels in the world and the durability you demand from a premium wheelset.
ENVE’s M50 rim is an everyday, race ready wheelset. We designed the M50 to be the most responsive wheelset on the XC World Cup and meet the demand of everyday abuse. Our focus was to make a lightweight, race-ready rim with a wider profile and increased impact resistance. The M50 proved to be the most durable XC race wheel to come out of the test lab while simultaneously improving lateral stiffness for optimal power transfer. The M50 features a well-balanced 21mm internal width creating an ideal profile for tires in the 1.9”-2.25” range. ENVE’s M50 wheel is available in 27.5” and 29” with 28 hole spoke count.
The M60 is a very unique rim in its design. Being the first carbon wheel to define the xc/trail category, the M60 is a XC race wheel, a light enduro race wheel, an adventurer’s wheel; it is a mountain biker’s wheel. The design behind the M60 is achieving a new level of durability without compromising weight. A slightly deeper shape and 23mm internal rim width, give the M60 a unique blend of unrivaled impact resistance and optimized tire profile for tires ranging from 2.1”-2.3.” The M60 is versatile in character, with an emphasis on impact damping qualities at XC race weights; the M60 is a desirable choice for bikes in the 100-150mm travel range. The M60 is available in 27.5” and 29” with spoke hole counts of 28 and 32 hole.
The M70 redefines the wheel in the trail and all-mountain category. 160-180mm travel bikes have come a long ways, rivaling the descending capability of the modern downhill bike, yet transforming their personality on the uphills into a well-balanced climbing machine. The M70 is the perfect match for full force enduro racing and bike park riding. With its robust 34mm deep shape and 25mm internal width the M70 optimizes the profile of tires in the 2.3”- 2.4” range. The M70 surpassed our expectations with its highly impact resistant and lightweight form making it a great choice for riders who are hard on their equipment, but still want the responsive and precise feel on an ENVE carbon wheel. Coming in three sizes 26”, 27.5” and 29” and 28 or 32 spoke hole count, the M70 is the perfect match for any high performance trail and all mountain bike.
ENVE paved the way for carbon wheels in the Downhill World Cup, but our M90 has once again raised the bar. The ultimate in durability now tubeless compatible, the M90 demands to be pushed harder. With a 34mm deep rim and unique layup, the M90 exceeded even the lofty expectations set by the Santa Cruz Syndicate. While world cup teams piled up damaged wheels at the UCI World Cup in Windham, NY, the Syndicate came away from the weekend without a single damaged wheel. The M90 is the wheel designed to keep up with the demands of the modern downhill bike and proves itself on the steeps day in and day out. Featuring an internal rim width of 25mm the rim shape is ideal for 2.3” to 2.5’ tires. ENVE offers the M90 in 26” and 27.5” sizes with a 32 spoke hole count.
Buying your Mountain Bike Wheels
Yes. ENVE, among others, make it really difficult to select wheels to buy. With seemingly endless permutations and arcane abbreviations, its a complicated world. Let’s run it down to see what we learned. I have a new Yeti SB5c with 27.5 inch wheels, XX1 drivetrain and XTR brakes. What wheel do I need?
The Fox front fork is a 15mm x 100mm, and the frame has a 12mm x 142mm rear axle. I chose the M60 Forty because I want to climb well and descend aggressively. My brakes have CenterLock (CL) rotors. I chose the DT 240 CL hubs with 28 spokes as I’m a bit on the lighter side. In total, it may look like this in a wheel catalog or online: 27.5″ 60/40 28H WS DT 240 XX1 15mm Front 12×142 Rear CL
Now we know. Get your wheels and get out riding.