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Alto Cycling has updated their road and mountain bike offerings, coming fully modern with a hookless design for both, Boost hubs and XD options on MTB, and more colors for anodized hub shells and rim decals. We covered those last two cosmetic options before, but the road tubeless rims and mountain bike wheelsets are all new. Video above provides the run through, then read on for a little more techy chat about why they went hookless.

“It essentially came down to the profile of the tire bed and making that channel so that the air pressure wouldn’t be able to lift the tire over the sidewall,” says CEO Bobby Sweeting. “So it’s the height of the sidewall and the depth of that channel that the bead locks into so the pressure is pushing the tire outward against the sidewall and not upward over the sidewall.”

2018 Alto Cycling hookless carbon rims are designed for high pressure road bike tires

They test it up to 170psi in terms of yield strength testing so they know the composites will hold up, but limit real world use to 110psi to ensure the tire will stay on. They also tested as low as 20psi, trying to pull the tires off sideways…which means these are rated for cyclocross, too. Their recommended minimum psi depends on tire size, but for 28-40mm wide tires, they say running them down to 25psi should be no problem.

The new CCX52 is about 200g lighter per wheelset than the 2017 CCX56, and the disc-brake specific rim itself is 100g lighter than the rim-brake version of that same model. Sweeting says weight savings come from updated construction methods – ply orientation, number of plies, absence of a hook, and lack of high-temp resin and brake track materials. The sidewall itself is two plies thinner (look for more on that with future rim brake products, too…hint, hint). They also removed four plies from the spoke bed by replacing it with a small 3K woven section at each spoke hole rather than building up material around the entire rim.

He says, in general, once you take away the rim brake heat and pressure (from the pads, pushing inward) issues, you could theoretically get away with less expensive resins and manufacturing processes because there were several major stressors on the rim that no longer needed to be addressed. So, to improve margins or compete on price, cheaper rims may not made with the same proven methods and materials. So, Alto Cycling kept using steel molds and EPS mandrels, both of which cost more than alloy molds and bladder molding, but result in less deformation and more uniform heat transfer. He adds that most quality rims are using steel molds, so this isn’t unique to them, just trivia worth mentioning.

They went with 6-bolt rotor mounts because they could get the bearings a full centimeter wider, putting it directly under the rotor mount. With Center Lock, they had to run the bearing under the flange, much further inboard, which reduced stiffness by 12%. For folks really wanting the Shimano IceTech 40mm rotors, they recommend checking out the SwissStop rotors, which they’ve tested and shown to run cooler (their words). Scroll down for a complete spec and weight sheet.

2018 MOUNTAIN BIKE RIMS & WHEELS

2018 Alto Cycling carbon mountain bike wheels get wider rims with hookless bead walls

2018 Alto Cycling carbon mountain bike wheels get wider rims with hookless bead walls

For their mountain bike wheels, they’ve added wider rims to accommodate Plus-sized tires.

alto cycling boost mountain bike hubs with xd driver body for sram 12-speed eagle groups

alto cycling boost mountain bike hubs with xd driver body for sram 12-speed eagle groups

The bigger news is they now offer true Boost hubs with no adapters or spacers, and you can order their wheels with a SRAM XD Driver Body.

alto cycling boost mountain bike hubs cutaway internals

The hubs get an updated assembly method that puts the lock ring on the non-drive side, which threads tight until touching the bearing, then is locked down with an allen bolt. The design prevents any play without side-loading the bearings, so everything runs smooth and solid.

2018 ALTO CYCLING DISC BRAKE WHEEL SPECS

2018 Alto Cycling disc brake and tubeless wheel spec sheet with weights and dimensions

AltoCycling.com

JensonUSA end of season road cycling and mountain bike clothing sale offers deals on cycling gear and apparel

24 comments

    • Bobby Sweeting on

      The 2018 CC52 set comes in at 1581 grams. Our website is up to date regarding wheel specs, we simply haven’t done the official launch of our 2018 rim brake models. They’re shipping now, but we’re waiting to release the tech details for a few more weeks! BikeRumor and our social media pages will be the first to display all of the details.

      Reply
    • Bobby Sweeting on

      Thank you, Tyler, we certainly don’t want to be “just another” wheel company. And the more support we get from you guys, the more opportunities we have to create cool bike stuff! We appreciate it!

      Reply
    • Bobby Sweeting on

      Good eye, Jan! Our new molding technique gives us equivalent lateral stiffness with 2X/2X as we saw with radial/2X, with improved fatigue strength. It wasn’t mentioned in this article, but there will be more details to come in a few weeks!

      Reply
      • TheKaiser on

        Thanks for your answer to my below question re sidewall height Bobby. I also wanted to chime in here to 2nd Jan’s request for more info regarding the drive side lacing. Going radial on the drive side always seemed like a cool way to improve bracing angle. On the opposing view, I have seen some figures, I think on Sheldon Brown’s site, that imply there is a significant potential for radial drive side spokes to lead to the hub shell to winding up with drive torque before it is ultimately transferred through the non drive spokes, which always seemed like it could be problematic. So, basically, I’d love more detail from you guys on the pros and cons of those engineering decisions, given that you have done it both ways and thoroughly investigated the options.

        Reply
        • Bobby Sweeting on

          No problem at all! When it comes to a purely engineering decision, radial/2x is a better lacing pattern when just looking at the hub design. We found that if the material was sourced properly (i.e. not contaminated) then 99% of that torsional load was transferred to the non-drive flange. We saw no difference in torsional stiffness.

          That being said, we only did radial/2x because we saw improvement in lateral rim stiffness. We have changed the layup process of our rims, and it has essentially eliminated the difference between radial and 2x lacing on the drive side when it comes to lateral movement at the rim. I can’t divulge the details of the layup yet, but altering the ply orientation, resin, and processing in the composite drastically effects how particular lacing patterns effect rim stiffness. There is also a small improvement in the hub’s fatigue strength with a 2x pattern on the drive side. This isn’t so important when the factor of safety is high enough to keep the metal from failing either way, but why give up a little extra strength when we no longer see a difference in stiffness? That was essentially the reasoning that led us to make the change, and we’ll have more details on it in a few weeks!

          Reply
  1. TheKaiser on

    @Bobby, thanks for being so active and engaged in these comments! Quick question for you: When you went hookless on the road rims, did you have to make the internal sidewall height greater to improve the tire retention and provide enough safety margin to prevent blowoffs? Or is simply having a proper tire bed circumference and rigid tubeless bead sufficient? Some small hooked tubeless rims, like Stan’s, have a super low sidewall height of around 3.5mm, whereas I have seen some hookless rims direct out of China that have elevated sidewall heights of 5-6mm, which I have assumed is an attempt to compensate for the lack of a hook.

    Reply
    • Bobby Sweeting on

      That’s what I’m here for! An innovative new product is only going to work if it has people that stand behind it.

      The design is essentially an optimization problem that relates the depth of the tire bed channel, the height of the bead seat channel (the corner between the side wall and tire bed), and the height of the side wall. The tire bed channel has to be deep enough for easy tire installation, but not so much that the tire will not seat itself. Once it does seat, you want the tire to be as close to full-stretch as possible, with a factor of safety built into the sidewall height so that even the loosest tire will not have a chance to burp. It’s a challenge simply because tires are not standardized, so there are a lot of variables! We had to take an average of multiple different manufacturers, while ensuring that the outliers would also function perfectly.

      To answer your question more accurately, out side wall height is 5.5mm, which is not significantly different than our hooked models. The side wall height is important, but not as much as it’s relationship with the other two variables that I mentioned previously.

      Please let me know if you have any other questions at all!

      Reply
  2. Matt828 on

    I am confused by the tire size. Are you really saying that a 21.6 tire is ideal for everything from a 25mm tire through a MTB tire?

    I guess Stans was full of it with their Wide Right approach. It doesn’t matter what tire you are riding, 21.6 width is the way to go!!

    Reply
    • Bobby Sweeting on

      We designed the rim for tire sizes from 25c to 38c. That’s really the sweet spot. However, you can run a 60c tire without any issues, which gives the wheel a lot of versatility when it comes to road and off-road options.

      If you’re looking for a wheel that is a more dedicated gravel option, I’d recommend our CMX29 and CMX275 sets. They’re slightly wider and better suited for larger tires than our CCX line, but do not have the ability to run high pressure road tires. We have rim designs for every need, it just comes down to where/how you like to ride!

      Reply
    • Bobby Sweeting on

      Good question. There are three main benefits: First is obviously weight. It’s much lighter than a hooked rim, and it’s all rotational weight. For something like ‘cross where you are constantly accelerating, that gives you a huge performance benefit.

      Second, increased tire volume. With more air in the tire you can run lower pressure, get improved ride quality, and see a drop in rolling resistance at the contact patch between the tire and the road.

      Third, tire stiffness. I know that sounds strange, but think about any shape in torsion — A round down tube on a road bike will always give you better BB stiffness than an aero profile. This is because the tube is in direct torsion, and an aero shape is trying to warp itself into a circle (the most ideal shape under torsion). Engineers have to pile on more material in that area to offset this reality, which is why aero bikes are heavier. Anyways… For a standard clincher tire, the tire is compromised as it bends around the hook. When you corner, the tire is attempting to warp and become a perfect half-circle, which causes it to feel a bit softer. With a hookless profile, the tire is pressed uniformly against the sidewall, and is already in a perfect shape to resist torsion from cornering loads. So you will see a significant benefit in the handling of the bike, simply because of the shape that the tire will take inside of the rim.

      Reply
      • Timoshenko on

        Bobby, would you mind explaining your third point more? I’m just a simple country mechanical engineer, so I don’t follow your claim that an aero cross-section “tries to warp itself into a circle” under torsion. For example, the sides of a square tube under torsion tend to distort from flat to concave. In other words, it becomes less circular under torsion, not more so. The extra material in an aero downtube isn’t there to resist strain normal to the tube wall, but rather to increase the area moment of inertia where it’s lowest.

        And that’s just for isotropic materials; anisotropic materials like carbon laminates couple shear and bending moment, so torsional behavior is further dependent on the laminate schedule. Given your background, you surely know this, so I’m confused about why you wrote what you did.

        Similarly, your tire example doesn’t make sense. Surely you know that a thin-walled pressure vessel with trivial bending stiffness (like a tire) automatically assumes a circular profile. Aside from the contact patch, the portion of the tire not touching the rim is already a perfectly circular arc, hooks or no. I mean, we agree that a circular cross-section is best for resisting torsional loads, but the tire’s arc is already circular. How does a hookless bead make a circle more circular?

        And even if bike tires didn’t have circular cross-sections (e.g., if their casings were as stiff as those used for motorcycle tires) torsional loads wouldn’t distort it into a circle. Internal pressure would tend to do this, but not torsion.

        Are you perhaps thinking of Prandtl’s torsion/membrane stress function analogy?

        Reply
        • Bobby Sweeting on

          You have a lot of great points, and I appreciate the email as well! We can definitely get into a detailed discussion here or through email, depending on how nerdy Tyler wants his forum to be, haha.

          Regarding down tubes, of course you are correct that some areas are in tension while other are in compression. That’s true for any shape, and this causes different failure modes in different areas of the cross section. However, the load path itself is circular in nature, which I why I chose the phrasing that I did. It also keeps things simple to understand, since a circle is always the strongest shape in torsion. However, that point has been a hot topic of debate, especially with Cervelo’s “Squoval” shape and other methods of increasing the amount of material away from the centerline of the tube. But we always saw better results at Cannondale from the good ole’ circle, both in testing and on paper. And of course all of this is effected by the layup schedule of the frame (or rim, or whatever you’re making), but I highly doubt people want to talk about the matrix math and eigenvalues resultant from our layup calculations, haha. If you want to get into layups we can certainly do it via email.

          I have to disagree regarding your assumptions of tire shape. For the sake of time, I’ll reference people to the cross sectional drawing that Enve made of their hookless rims and how the tires are seated. It will show what I mean, as the hook will always cause a stress riser in the tire regardless of internal pressure. While a hookless model (assuming the correct tire size) will create a perfect dome shape that allows the tire to resist those loads more efficiently. This isn’t proprietary to us, and has been proven experimental and theoretically. The point where the tire’s sidewall meets the rim acts as a cantilever beam (with a lot of simplification, of course), and the stress from the hook will always cause more deflection at the tire than you’d see with a hookless model.

          I hope that helps to clarify some of my points! I’m hoping to keep everything clear and understandable regardless of whether someone has an ME degree or not!

          Reply
          • TheKaiser on

            That is an interesting point you fellows have brought up, regarding the effect (or lack thereof) that a hookless rim will have on tire profile and performance. It sounds like, from what Bobby is saying, a rim with a 22mm inner width that is hookless will offer different (and in this case better) tire performance, than a 22mm inner width hooked rim, due to the reduction in the acute bend in the casing at the outer rim edge. That is a point that I have wondered about for a while, as it isn’t totally clear cut to me. As Timoshenko pointed out, casing stiffness is a trivial component of most tires, so they will all tend to assume the same circular cross section on a given width rim. What happens below the rim edge (which is where the difference between hooked and hookless occurs) isn’t obviously important on first glance.

            If “increased tire volume” (which is normally discussed as if it were universally beneficial) were truly better, then the 22mm hooked rim would actually have the edge in that regard as it would have greater volume below the hooks. Granted, a straighter path for the casing on hookless may also offer some structural advantage, which would counterbalance the increased volume of hooked to some degree, but my point is that most people will attribute increased volume as a benefit of hookless, when really what they mean is increased volume is a benefit of a wider internal width rim, regardless of how that is achieved.

            Separate but related to the hooked vs. hookless discussion, I would like an engineer to address the supposed “tire volume” advantage. I am of the opinion that tire volume above the rim is advantageous to the extent that it allows for more tire “suspension travel” before bottoming the rim on a obstacle, but it is not as clear to me how additional volume below the rim edge is of benefit. In fact, quite the opposite, as it seems that tires have an excessively linear rate, to borrow another term from suspension design, which forces the rider to choose between rim protection and supple compliance. Imagine an extreme example with a disc wheel, where the whole interior of the disc is part of the tubeless tire air volume. Would that ride better than a standard setup? If so, why? Juxtapose that with one of the new tire insert systems that are popping up everywhere for MTBs where a foam insert acts in the opposite manner, reducing tire volume, and providing a supplementary spring, which ramps up the tire spring rate dramatically, allowing low starting pressures but also reducing rim bottoming. Which would offer better performance?

            Reply
  3. jamz_on on

    Check out that awesome pre-load in the video!
    Simply, slide the axle through, press this cap into place, install an O-ring, adjust until you feel pressure, consult page 32 of our manual, finish this Rubix Cube, call the 1-800 number for support, start drinking heavily, and there you have it. 18 minutes later you’ll never want to ride your bike again, so your bearings will last forever!!

    Reply
  4. haute_1995 on

    Every hub!

    Literally every single hub. . . ever!

    Is more convenient to work on. It took 6 minutes for you to properly set up the pre-load. And the video was full of warnings about doing it incorrectly.

    Truing a carbon tubular wheel with internal nipples is about as convenient as that rear hub.

    Reply
    • Bobby Sweeting on

      I’m genuinely shocked that anyone could feel that way, as it takes roughly 30 seconds to disassemble or reassemble one hub and only requires two 5mm allen wrenches. Of course in the video we have to describe the steps in extreme detail and cover anything that someone could do incorrectly. We try to be as thorough as possible so that our customers have all of the details, and we certainly weren’t trying to race through the video in order to prove a point.

      Reply

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