Mountain Bike-Specific Design and Testing

One thing we knew for certain going into this project three years ago was that the industry standard impact test for carbon wheels wasn't going to cut it. That test, approved by the UCI, impacts both sides of a rim equally with a flat rubber pad without a tire mounted on the wheel. It's designed to replicate a pothole-type impact on the road. On a mountain bike, a rock is much more likely to only hit one side of the rim, so the rim beads have to be independently strong. We created a test in our lab that simulates one side of the rim landing directly on a square-edged rock from over 3 feet in the air with no suspension, and a lightweight tire inflated to 25psi. As we began to put some of the other rims on the market through this test, we broke a lot of them more or less like we expected to—on the bead—but we also found that a critical failure mode was the spoke nipples pulling through the rim due to the sudden increase in spoke tension as the wheel flexed on impact.

Material Where You Need It

This information in hand, we set about determining how we might design a rim to mitigate those failures, and part of the result is the square-shaped reinforcements you can see around the spoke holes. We made plates of different carbon spoke hole designs in our carbon lab in Santa Cruz, developed a test that mimics the sudden increase in pulling force associated with an impact, and spent a few months breaking bits of carbon, spokes, and nipples until we got to the point that we were breaking all spokes and nipples and no carbon.

We're far from the first company to reinforce high-stress areas with more material, but they're visible to ensure that the spoke hole drilling matches the reinforcement. Super-precise placement of these reinforcements allows us to use only the amount of material necessary to achieve the strength required, rather than reinforcing the entire rim. We then invest that extra material into the other common failure point of a rim—the bead.

The rim beads on the Reserve wheels are thick, relative to other rims on the market. As much as a millimeter thicker on either side, in some cases. The material we saved by optimizing the placement of the spoke hole reinforcements went directly into the bead, making it extremely strong without adding weight to the overall construction. The beads are hookless: this makes for a better fit with modern tires, but also simplifies manufacturing, which results in more consistent carbon compaction—the technical way to say stronger rim.

Watch the video below to see what this test looks like at full speed and in slow motion.

Then We Took Them for A Wee Day Out

As you saw with the recent hullabaloo surrounding 29er wheels on DH bikes we're big believers in putting prototypes under our athletes and asking them to push it as hard as they can.When it came to wheels, we couldn't think of anyone who would be harder on a prototype than Danny MacAskill. He started riding a pair of Reserve 30s (spec'd on the new Nomad) just before the filming of A Wee Day Out in the summer of 2016, and has yet to break one.

The Santa Cruz-SRAM Enduro Team have been racing on the Reserve 27 wheels since the first of the year, and our Factory racing team and various employees have been riding and racing all the models since June of 2016.

Never Miss A Ride

If you buy a set of our wheels, or they come as stock equipment on a bike you buy, they're covered by a lifetime warranty. If you break a rim, just fill out the warranty form, and we'll get a replacement headed your way within 24 hours. Simple as that. If you're on vacation, we can even ship a new wheel to wherever you're staying.

If you break a wheel through some momentary lapse of judgement, just get in touch with our warranty department and we'll still help you out. We stand behind our products, and we want you to be happy with your purchase. If you're ever unhappy, give us a call or shoot us an email and we'll try to make it right.

Make sure you take a minute to register for your warranty so that we can process your claim as quickly as possible if the need ever arises. We'll keep that image of your receipt on file so you never have to worry about proving that you're the original owner.

Manufactured for Wheelbuilders

We spent a lot of time making sure the rims were strong enough, light enough, and durable enough, but we also spent a lot of time making sure that our master wheelbuilders here in Santa Cruz would approve while turning rims into high-quality wheels. The spoke holes are asymmetric, which isn't an innovation on its own, but it does make for a very strong wheel build because the spoke tension is equal on both the drive and non-drive sides, front and rear. We also drilled the holes at a bit of an angle to allow the nipple to sit straight against the rim, which prevents uneven force from being applied to the carbon, and makes lacing easier. Our favorite feature? External, easily-accessible nipples so you don't have to break the bead or get sealant on your shorts just to make a small adjustment.

Standard, High Quality Components

We try to avoid proprietary designs in our bikes, so we were never going to use some double-threaded, straight pull spoke in our wheels. All of the wheels we spec on our bikes are built using standard J-bend spokes (DT Competition Race), mechanically-locking nipples (Sapim Secure Lock), and either the venerable DT Swiss 350 or the much-loved Industry Nine Torch hub. If you break a spoke anywhere in the world, you'll probably be able to replace it with parts available at the local bike shop.