Alto Velo R-Symmetric road bike hubs with oversized flange

It’s a fun idiom to say someone has reinvented the wheel. It’s even more fun when someone actually does, and that’s what friends Bobby Sweeting and Shawn Gravois, who both happen to be pro road cyclists and engineers, are looking to do.

“It’s been a year in the making, but it really started in college,” says Sweeting. “Both Shawn and I were racing professionally and would finish rides and have bearings failing, wheels flexing and just generally underwhelming experiences with the options available.”

It was December 6th, 2013, which happens to be Shawn’s birthday, and the two agreed that if they were ever going to make a go of it, that was the time.

“I pitched it to him as becoming a product manufacturing company, not a wheel company,” he said. “We didn’t want to come to market using just a bunch of open mold products with no real point of differentiation. So we took a hard look at what part we could design that would have the biggest impact, and have improvements or designs that we could patent.”

Their viewpoint was informed by more than just racing and an unrelated job in engineering – Sweeting was in rigid frame engineering at Cannondale, having designed the CAAD8, Trail SL and others, plus helping on the brakes for the Slice RS. And they had proximity to another cycling brand in Florida, where they went for winter training, that let them use machinery for prototyping. That shared equipment is what made it possible for them to get started on a shoestring budget while using advanced testing and research…

Alto Velo R-Symmetric road bike hubs with oversized flange

“The three main issues we’d continually run into as pro cyclists were: Durability (wheels falling out of true constantly and the frustration of hitting a pothole in a race and having to return to the team car to get a new wheel. It would ruin races), Lateral Flexibility (I’d stand up to sprint and have the tire hit the frame – not just the brake pads, but the frame!) and Bearing Wear (caused by imprecise tolerances that allow them to become slightly misaligned within the hub shell).”

The biggest question they had covered the basics of creating a better wheel: What is the best flange diameter, best flange spacing and best lacing pattern with regards to torque on the tire when sprinting and in corners? Shawn used Matlab to run an optimization problem that would relate the unknown hub geometry variables to lateral forces on the rim, an iterative process that would eventually yield optimal dimensions for the best possible wheel stiffness.

“Tom Frost, CEO of Datum, is big into cycling and was one of the first people we showed the design to,” said Sweeting. “This was February 2014 and we pitched him on investing and becoming a partner in the company, and when he said yes it allowed Shawn and I both to start doing this full time. We were prototyping at Sea Sucker in Florida, where our good friend Chuck let us use their machines, saving us a ton of money in the critical startup phase.”


Alto Velo R-Symmetric road bike hubs with oversized flange

To create a stiffer wheel, all of their data said they needed to make the spoke base wider to increase triangulation, but how to do that within the confines of existing frame and drivetrain designs?

“Others moved flanges around, even moving the non-drive side flange inward to make the wheel tension more even,” said Sweeting. “It seems like so many companies are just guessing or just buying something off the shelf rather than really optimizing the hub design as part of a full wheel system.”

Alto Velo R-Symmetric road bike hubs with oversized flange

Their solution? Widening the base of the triangle by making a wildly oversized drive side flange.

Flange width is 50.6, which they say is one of the widest in the industry. Amplifying that width is the oversized flange diameter, which is visually and functionally the most striking feature and effectively widens the triangle. The rear hub has a 109mm drive side flange diameter, spoke hole space diameter is 100mm. Non-drive flange is 38mm hole to hole (48.2 outside).

Tension is 120kgf on the drive side and 85kgf on the non-drive, where many wheels see about a 50% drop in spoke tension from drive to non-drive side. They could bring the non-drive flange in and even up the tension, but it would reduce the triangulation and make the wheel less laterally stiff. Getting the right balance between baseline width and spoke tension balance was the engineering problem they had to solve.

“Our R-Symmetric (stands for Right Symmetric) patent is really on the oversized drive side flange to optimize spoke tension on each side of the hub,” says Sweeting. “But there are so many other engineering decisions that make the hubs unique and better.”

Things like machined labyrinth seals so you don’t need plastic bearing covers and ultra tight tolerances to keep everything aligned.

Alto Velo R-Symmetric road bike hubs with oversized flange cutaway view

The hub shells are 6061, and the axles and endcaps are 7075. The way they come together serves to both protect the NSK non-contact bearings from the elements and prevent them from “leaning” under cornering pressure. The end caps thread onto the axle to let the user set the preload, then they’re locked into position with pinch bolts.

A labyrinth seal is created by having the shell overlap the endcaps by 0.5mm with just 0.15mm gap between the two. Sweeting says water would basically have to be coming at the end caps from a 90º sideways angle, which on a sideways rotating part is all but impossible.

“We spec really tight machining tolerances for the bearings, ensuring they’re firmly pressed in and held in alignment better,” Sweeting says. “It really came down to how the bearings are constrained, and our threaded axle endcaps come in and put the perfect amount of preload on the bearings to keep them in place without too much pressure to create drag but no looseness that could let them tilt.”

Alto Velo R-Symmetric road bike hubs with oversized flange cutaway view

“This creates a stiffer, more balanced wheel and really increased the overall durability. We’ve taken them over some really rough, nasty roads and they’ve been flawless. And it doesn’t just help forward momentum, but because you’re not losing so much energy to lateral flex, they’re more energy efficient, translating all of your power into forward movement.”

The front wheel uses normally sized flanges, but keeps the axle-and-end cap system, overlapping design and labyrinth sealing design.


Alto Velo R-Symmetric road bike hubs with oversized flange and custom carbon fiber rims

At launch, the hubs will mostly only be available on complete wheels, sold direct to consumer from their website and through shops. Standalone hubs will be available to select premium wheel builders that can build them up properly. All of their wheels are handbuilt to their specifications, using the right spokes, nipples, prep, lacing pattern and other considerations, which they say is critical to proper performance. And when they are built properly, Sweeting says you can completely loosen and remove one spoke and they’ll remain within a millimeter of perfectly true and strong enough to ride.

They’ll be laced to both carbon and alloy rims, both of which use existing rim designs, but the carbon models use a custom layup.

“We knew what we wanted for composites based on seeing the best practices used at (Cannondale),” says Sweeting, “but we had to find a manufacturing partner that could check all of the boxes we wanted, otherwise we were ready to open up our own tooling. Those requirements included building around an EPS foam core, allowing us complete control over the layup, a 25mm wide brake track that opens to 27.25mm wide section below it to create a toroidal aerodynamic shape.”

Alto Velo ended up at major Asian rim manufacturer that met those needs, which allowed them to save costs by using an existing mold while they specified the layup, which is what really dictates the ride quality. Sweeting said at some point they’ll likely open up their own tooling, but only to save on production costs and that it’ll keep the same exact shape.

The carbon rims will be offered in 40mm, 56mm and 86mm depths as both clinchers and tubulars. Claimed weights are (wheel / rim):

  • 40mm carbon tubular: 1268g / 377g
  • 40mm carbon clincher: 1471g / 478g
  • 56mm carbon tubular: 1349g / 417g
  • 56mm carbon clincher: 1566g / 526g
  • 86mm carbon tubular: 1672g / 579g
  • 86mm carbon clincher: 1875g / 680g

All wheels have a 20/24 spoke count with Sapim CX Ray. They’ll be laced radially on the drive side and 2-cross for the non-drive side. Retail will be $1,700 to $2,000 depending on model, with logo color options of green, grey, red, blue, yellow or orange.

Alto Velo R-Symmetric road bike hubs with oversized flange

Slotted and ramped spoke holes ease wheelbuilding and reduces stress on the spokes.

For alloy rims, they’re using a 24mm wide (18mm internal) and 26mm deep rim that’s clincher and tubeless ready. It’s going to be around 1,402g and come in at $1,150.

Between the public launch and actually cranking up final production, samples have been sent to Germany to be run through the gauntlet of tests, all from the same facility that performs testing for Cannondale and Tour Magazine.

“Late last year we finished the near-final prototypes and took our first rides. Shawn rode them first and was blown away. I’ve never been one to notice minute changes and differences, but during our first ride, when we swapped bikes, my mind was blown, too. It was awesome.”


They’re coming out with cyclocross and mountain bike specific wheels in 2015, which means that yes, they’re able to port this design to a disc brake hub. In fact, Sweeting says the models for those are done, they’re just launching the road wheels first.

They’ve also got eyes on cockpit parts, frames and more, all inside a five year plan.

“Just like ENVE started out with a focus on making bad ass rims, we’re starting with a focus on making bad ass hubs. But it’s still a system. This company is about engineering and innovation,” he said, “and wheels are just the start. We will be a product engineering company, not just a wheel brand.”


The brand is launching on Kickstarter as this post goes live, check out the campaign here. It features some of their own internal deflection testing against well known wheels. The campaign has the usual schwag for smaller supporters, but it’ll also be your only chance to pick up a hubset on its own. Once the campaign ends, it’s complete wheels only. Hubs start at $500 for the pair, and complete wheels start with a $1,350 pledge.


  1. Andy on

    Seems a little short-sighted to launch the (shrinking) road non-disc market at those prices. But whatever, at least it’s something neat and new and the disc ones are coming soon. 😀

  2. Sevo on

    “At those prices?” $500 for a pair of hub isn’t all that bad. Quite a few at $400+ just for a rear. And discs on road bikes isn’t all that. Only as good as your contact patch when it comes to stopping. Many people will be just fine with non disc wheels….majority of the public actually. I’m big, always will be big even if I get skinny, but only going disc on my monster cross. Road? Buy the right brakes and I’m just fine.

  3. ShopMechanic on

    I don’t know how it took so long for this kind of design to happen, but I’m glad that someone finally addressed the obvious weakness of traditional hubs.

  4. Spring Forward on

    How innovative… another wheel company shilling Dengfu rims, and they want us to give them 30 grand?? No thanks, I’ll just buy the same rims for $150 from Dengfu.

    50.6mm flange to flange spacing is weak sauce. Even those crappy Bitex hubs have like 53mm

  5. Veganpotter on

    Neat story fellas. Unless you were pros riding the very very crappiest of wheels, I couldn’t imagine you having regular bearing failures. A decent hub can easily get close to or over 10,000 miles with nearly zero service. Well…maybe you are the type of rider that rides 10,000 miles per week;)

    I put in roughly 15,000 a year and I’ve only had bearing completely crap out on me once. Because I was dealing with Milwaukee salt on top of me being terrible negligent with caring for the wheels.

    Also, Mark Cavendish does pretty well without an insanely tall flange on his hub. This will make sense when 12 speed come around…assuming the hubs don’t go wider on road bikes

  6. Chris L on

    Having a hard time seeing how these hubs are doing anything new. Hi-lo flange hubs are nothing new – Campagnolo, Phil Wood and many others have offered Hi-lo designs for decades. Ditto for labyrinth seals. Maxi-Car hubs featured double labyrinth seals which allowed their bearings to last for decades. It’s a great design but one that went away because they cost quite a bit more to make than simple pressed in cartridge bearings or the traditional cup and cone design. These hubs may not be very original but it is good to see someone bringing these smart ideas back into production.

  7. F Almeida on

    As Jobst Brandt already noted all those years ago, tall flanges only increase lateral stiffness a bit for radial spoking. With crossed spokes, where the spokes typically leave the hub more or less tangentially, tall flanges have effectively no effect on the lateral stiffness of the wheel. Going back to the fourth picture from the top in this post, the shaded “stiffness triangle” is correctly depicted for spokes departing the flange radially, but for crossed spokes the triangle must be redrawn with its lower side near to the hub’s axis.
    Taller flanges increase the rotational stiffness or the wheel with crossed spoking.

    Best wishes for the AltoVelos start-up, may they build robust stuff.

  8. Slone on

    F Almeida- really good point- but looking at the CAD of the hub that shows the spoke ramps on the NDS it would appear that they may be thinking of radially lacing the DS- no ramps depicted in the CAD- or maybe its just all heads in on DS or they forgot to add the ramps. I just watched their video and saw some more anecdotal evidence of radial DS, or it may have been a rear wheel in the process of being built and the hub just wasn’t twisted.

  9. Bobby Sweeting on

    Thank you all for your comments and support! We are excited to bring the best engineering practices back into the wheel industry! For those of you with questions or concerns, I’d like to address any and all of them.

    Spring Forward, we are manufacturing our rims in Taiwan with the best composite practices. The ideal cross sectional shape is well known in the industry and defined by the existing mold at the manufacturer. However, our proprietary laminate design (i.e. ply orientation) took many months of testing in order to perfect. It is this prototyping and testing process that we are in constant need of funds for. Regarding the rear hub flange spacing, we do have an extremely wide stance when compared to the industry average. But please remember, a wider stance does not equate to a stiffer wheel. It is a matter of balancing all of the hub geometry variables in order to optimize them for lateral wheel stiffness.

    Neil w, thank you for your interest in our patent. Please remember, a hub design is extremely complicated and it is not as simple as patenting an oversized flange. Our patent is regarding the flange geometry as it relates to the rest of the hub in order to create the most balanced system possible. If you have questions regarding the patent you are more than welcome to look it up, the serial number is 14/542,643.

    F Almeida, you are absolutely correct. We use a radial lacing pattern on the drive side of the rear wheel for exactly this reason. We couple it with a two-cross pattern on the non-drive side. As the spokes become more tangential to the hub shell, it requires more tension to dish the wheel the same horizontal distance, as compared to a radial spoke. This allows us to further equalize tension between the two sides.

    Thank you all! Shawn and I look forward to creating cool new designs in the wheel industry and elsewhere!

  10. chasejj on

    This is a fantastic idea.
    Need a disc version with a bulletproof freehub. with sizing for rear 142 and the new 148 that is coming soon. make a large flange version for MTB front wheels and have it convertible from 15 to 20mm.
    This with a 941 Ibis 29er rim and you will have one bombproof 29er wheelset.

  11. Bobby Sweeting on

    Thanks Chase! Shawn is actually hard at work on the disc wheel design now! Incorporating the R-Symmetric design into the disc is a complicated process, but it should create a very balanced wheel. A lot of great stuff coming soon!

  12. Prowheelbuilder on

    Solid idea however there is one major problem. Lacing the wheel. Using anything other than CX Ray, Aerolite of some other super thin / flexible spoke is going to be very challenging.

    To be clear lacing the non drive side flange one direction will be a cinch as they can pass though the drive side flange however putting the spokes in the other direction on the non drive side flange will require a sever pre bend of the spoke throughout its entire length which on certain spokes can prematurely weaken them. For those that might say that simply lacing the non drive side radially with heads in resolves that problem would be in correct as they designed the hubs to be two cross on the non drive side and radial on the drive side.

    The more intriguing part of there design is the labyrinth seal system. If done properly they could do away with the friction seal on the bearings and dramatically reduce drag.

    Good ideas just need to be refined.

  13. Espen Wettre on


    “This creates a stiffer, more balanced wheel and really increased the overall durability. We’ve taken them over some really rough, nasty roads and they’ve been flawless. And it doesn’t just help forward momentum, but because you’re not losing so much energy to lateral flex, they’re more energy efficient, translating all of your power into forward movement.”

    Give us some real measures and lab tests!

  14. Chris L on

    @ Prowheelbuilder:

    Labyrinth seals won’t “dramatically” reduce the drag. Maxi-Car hubs and SKF bottom brackets both use such seals and don’t have dramatically less drag than conventional cartridge bearings. The advantage is in durability. Maxi-Car hubs can go decades without service and SKF bottom brackets have a 10 year warranty.

  15. Bobby Sweeting on

    That’s a great point, Prowheelbuilder, and something that we noticed right away! That is why we notched every other hole on the rear non-drive flange. Every head-out spoke can be laced through smoothly and around the drive flange. It’s an important feature, as it means we do not have to bend the spokes at all! If you look closely you can see the notches in the second photo. Very good question, you are obviously a good wheel builder!

    Espen, we absolutely agree! We are excited to get the quantitative results back from Germany, and Bike Rumor will be the first to publish them! In the meantime, you can check out a video of a quick stiffness test that we did:

  16. Mike F. on

    Is radial lacing on the rear wheel really a good idea ?? The radial side can’t contribute much to power transfer. Seems like it’s more for looks than function.

  17. Roo Bay on

    Didn’t Zipp used to lace their wheels radial on the drive side and 2X on the drive side until the pros told them to cross the spokes on both sides?

    Sure, this may be marginally stiffer, but what about torque?

  18. Prowheelbuilder on

    Regarding the radial pattern on rear wheels, there is a measurable loss of power in the way of torque. This was demonstrated back when we would build PowerTap’s with radial patterns on the non drive side. Although PowerTap fixed the dramatic power fluctuations by having builders no longer use radial patterns on the Torque Tube reading side the empirical evidence still was apparent. Radial patterns do not resist Torque.
    As for the demonstration that is supposed demonstrate the amount of deflection the more symmetrically built wheel is supposed to eliminate, there are several variables that may skew the results such as how tight the stand is tightened against the hub, the gauge of spokes, the tension the wheel was built to, and the rims integrity.

    All that being said, I believe there design warrants credence as the methodology is sound and will result in a laterally stiffer wheel. By how much is the question.

  19. Bobby Sweeting on

    Prowheelbuilder: Thank you for the input, we are always happy to hear about people’s past experiences. Our extensive Matlab programming showed little to no loss of radial power transfer under acceleration for a radial/two-cross system, when compared to a two/two system. However, the increased tension asymmetry of the two/two system did create a much more flexible wheel in general, particularly at 90 degrees to the rim. In our opinion, this loss of power due to lateral flex drastically outweighs any compromise one would see in torque transfer values. This was the driving force behind our design choice.

    Regarding our own testing: we did our best to control every variable, but realized that it would be tough to convince everyone of its accuracy when it was performed by us. That is why we are seeking independent results from Zedler. That being said, the wheels were all built to mfg specifications, had similarly gauged DT Swiss or CX Ray spokes, and rims that were all in great condition. It was precise and repeatable, but we understand that it wasn’t done in a laboratory!

    Thank you for the engaging posts, it’s always cool to get into the more technical aspects of wheel design theory!

  20. Prowheelbuilder on

    Bobby Sweeting

    I too enjoyed the conversation. Regardless of how much I know I always gleam insight from these types of conversations.

    Best of luck and keep us in mind when you start to offer hubs only.

  21. Bobby Sweeting on


    The reason for the “mostly” terminology in the article is because we will be offering hubs sales immediately, but only to select and qualified builders like yourself. The reason is because we realize the importance of the build process, and have spent a lot of time ensuring that our wheels are built in the correct manner. We simply don’t want the average shop to build them up only to have an unsatisfied customer with an improper build. If you would like to order the hubs you will be able to do so in February as an OEM partner. Please email me at for more info! Thank you!

  22. Zarathustra on

    Nice to see someone trying to engineer something better. A couple of things though:

    1) Using radial lacing on one side means that the tension variation on the other side is greatly increased, which leads to premature fatigue failures[1].

    2) If you want to equalize spoke tension, why not use an offset spoke bed rim? They have much more effect on spoke angle than PCD does.

    3) If you really want a stiffer wheel, then just use more and thicker spokes.


  23. Tom on

    Great idea. Just great. These may be my next 29er wheels when offered in the (somewhat hated due to lack of availability) Boost 148 format. For gosh sakes, please don’t make them either ridiculously narrow OR wide.

    I may have missed it, but are there any details available on the freehub portion of the design? Not typically a huge deal on the road bike, but very important on mtbs.

  24. What? on

    How is this different then A-Symetrical wheels on my Cannondale FS-i, looks to be an identical pattern. My wheels are Mavic.

    “Our Ai design shifts the drivetrain and rear triangle to the right by 6mm. This creates an ultra stiff rear wheel by reducing dish, and delivers the shortest chainstays on the market, dual chainring compatibility, tons of mud clearance, and a super responsive rear end.” Cannondale

  25. Trendy on

    WHAT? How is it different from you A-Symmetric wheels?

    Well if you bothered to read the information, you would know that the hub is in fact R-Symmetric! What is hard to understand?

  26. James S on

    What if you just built wheels with 32 spokes using quality hubs? For instance, try lacing up some White Industries hubs with DT Swiss spokes, laced 3x to Mavic Open Pro rims or whatever rims you like. I bet those wheels would be practically bombproof and really smooth. Oh wait, they would be a tiny bit heavier than these wimpy wheels that you guys say are failing. Hmmm. Never mind, I can never understand racer boys. I just like to ride. You guys do it your way and I’ll stick to stuff that actually works.

  27. Kernel Flickitov on

    There is no real mind blowing tech in the industry for years now and I don’t see anything special here. Wheels need the equivalent of a clipless or STI moment, like a lightweight race worthy internally geared hub. That’s something I would happily crowdfund. In the meantime my King R45’s work superbly.

  28. Trendy on

    @James S – Open Pro and Bomb proof in the same sentence, seriously? I’m 140lbs and have split 2 pairs of open pro rims with that same “Bomb Proof” set up.

  29. Jake on

    Alright, I’ve been racing a while now and I can really appreciate a very light, very stiff wheel. Of all the wheels I have seen come out lately, I am the most excited about these. I want a set…badly.

  30. Icycle_Bay on

    @Bobby Sweeting “Regarding our own testing: we did our best to control every variable, but realized that it would be tough to convince everyone of its accuracy when it was performed by us.”

    The issue is not that the test was performed by you, but that it has way too many variables unaccounted for. As Prowheelbuilder mentioned, the spoke gauge, lacing pattern and spoke tension all come into play, but furthermore, the method you are using is effectively testing rim stiffness just as much as (if not more than) hub or spoke stiffness. Aside from using a tipped-over truing stand and the host of variables that represents in itself, each different hub should have been laced to an identical rim in exactly the same spoke pattern, tension, number etc. for your test to have held any significance. We aren’t faulting you for conducting your own test, but for conducting a poorly conceived experiment.

    All of my ranting aside, are you concerned with the later flex of the DS hub flange as the spokes try to pull it inwards towards the center of the hub? Will there be any axial triangulation/bracing of the hub flange itself?

  31. Bobby Sweeting on

    Thank you all for the questions, I’m happy to see all of the interest in the new products! I will do my best to address each of them!

    To Zarathustra: Regarding your first point, you are correct that a radial/2-cross pattern causes an increase in spoke tension on the crossed side. That is done purposely in order to further balance the drive and non-drive tensions. Regarding offset rims: Off center rims create a similar effect in terms of the spoke pull angle, but our design focuses on the virtual bracing angle of the spoke where it attaches to the hub. By effectively widening the base of the triangle (as opposed to moving the top of it over a bit) has a much greater effect on spoke tension and, in turn, wheel stiffness. In our experience, off center rims also cause an innate stress riser in the corner of the shortened wall, which is a design flaw that we did not want to incorporate into our wheels. To your third point, we chose not to incorporate thicker spokes (or more spokes) as it created a very hard ride that we found to be too stiff. We were also focused on keeping weight to a minimum.

    To Tom: Very good questions. For the road models, we are using a freehub system with a 4-pawl leaf spring system and internal ratchet ring. Each pawl has three individual teeth machined into it for 12 total points of engagement. The free hubs will be anodized black, mostly for surface hardness purposes but all because it looks cool 🙂 The mountain bike hubs are still being designed and we do not have a finalized free hub body yet, but I assure you it will be very robust with excellent engagement.

    To Greg: The slots in the non-drive flange are designed to run a 2x pattern, so it is not recommended that you run 3x as the slot orientation would not be optimal. It would technically be possible to run a 2x pattern on the drive side, but this would increase the tension on the drive spokes and create a more imbalanced system. We recommend sticking the with radial/2x pattern.

    To What?: Please give me more information on your wheelset and I would be happy to discuss them with you. I am not sure what set you are referring to.

    To James S: We don’t believe that an overbuilt wheel will make it bomb proof. Is a poorly built steel frame more secure than a properly design carbon frame? We don’t think so. The Alto Velo wheel design is based on best engineering practices and geometry optimization. These specifications make for a more robust and durable wheelset than a lower end product with more spokes.

    To Kernel: We have created a wheelset with the perfect hub geometry, after so many brands have guessed for so many years. We personally believe that, in a sport of marginal gains, that this is a significant contribution!

    To Robert W: That is a good question regarding off-center rims, thank you for the question. Please see our response to Zarathustra above.

    To Michalis: I’m not sure what you are asking…

    To Icycle_Bay: We were not comparing hub stiffness, we were comparing wheel stiffness. That means using wheels with the spokes, rims, hubs, and lacing patterns that they are generally built with and spec’d to by the manufacturer. For Enve, that meant Chris King and DT Swiss. The Zipp with a Zipp hub, etc, etc. We designed the system, not just the hub, and that is what we set out to test. The truing stand was obviously not the prettiest setup, but the fact that the test was precise and repeatable showed us that it didn’t present any sort of inconsistencies with the results or create more unwanted variables. Outside of the testing parameters, you bring us a great question regarding the DS flange and the forces acting upon it. At 120kgf per spoke, and 12 spokes, you end up with approximately 500 pounds of horizontal force acting on the flange. That’s a lot! Our initial design was minimally built and we did see some flex in the flange. We went back to the computer model to more accurately represent the forces on the flange, and optimized the shape to prevent this bend and provide a factor of safety greater than 6 (required to prevent yielding in cyclically loaded parts). The final design, as you can see in some of the photos, includes a tapered wall as it reaches the root of the flange. That change, along with increase fillet radii to the inner surface, prevented all bending and passed the FE analysis with flying colors (no pun intended). Great question!

    Thank you all for the questions and support. We can’t wait to hear your feedback after getting to ride the wheels!

  32. Bobby Sweeting on

    Thesteve: We are absolutely claiming that is is optimized within our system, which includes the spokes and rims. Minute changes such as spoke elasticity and rim deflection (from different laminate designs) can disrupt this balance slightly. But we worked on Matlab for many months to create an iterative program that would balance flange width, flange diameter, spoke gauge, spoke number, spoke lacing pattern, and rim stiffness in order to provide optimal later stiffness between 60 and 90 degrees. It is not an easy problem to solve, but it is what we set out to achieve and we believe that our results will speak for themselves!

  33. Darryl on

    My Back of the napkin design calculations say that the large flange, radial spoked, will suffer from premature failure if using off the shelf alloys.
    And I’m not buying any low spoke count wheel with j bend spokes.
    Your preload design also suffers from variances due to skewer tightness variations.

  34. ginsu on

    “Our extensive Matlab programming showed little to no loss of radial power transfer under acceleration for a radial/two-cross system, when compared to a two/two system.”

    FAIL…..BAD ENGINEERING. Wilbur and Orville Wright did not have Matlab…you should NOT be looking at Matlab for *real world* data. Do a real test, on a real wheel, with real gauges and verify results, and repeat, ad infinitum! Only then can you actually start talking about your mathematical model having any degree of validity.

    Yes, I am an Mech. Engr.

  35. ginsu on

    Yeah, really. You haven’t answered the simplest question. Why are you using a radial lacing to transfer ‘torsional’ loads to the drive side hub flange? They don’t work!

    That is ENGR 101 stuff! AFAIK, there’s no reason the drive side should be laced radially….the wheel will not benefit from it. I just don’t get it really. Scratching my head.

    *Searching for Jobs Brandt book*

  36. ginsu on

    From Sheldon Brown:

    “Wheels with hub brakes and drive wheels should never be radially spoked. Due to the near-perpendicular angle of the spoke to the hub’s tangent, any torque applied at the hub of a radial-spoked wheel will result in a very great increase in spoke tension, almost certainly causing hub or spoke failure.”

  37. ginsu on

    Nevermind. Answered both my questions with good ‘ole Jobst Brandt’s book:

    “In a high-low hub the larger diameter of the right flange can help balance
    tension by about five percent, but only if the spokes are radial. With tangential
    spoking, no improvement is achieved by the high flange because its spokes have
    the same length and leave the hub from the same lateral position as the ones from
    the small flange. The large-flange, however, makes spoke insertion on the low
    side difficult. High-lows cannot reduce vertical loads, the principal cause of
    spoke failures. Torque loads have so little effect on fatigue that high-low hubs
    offer no improvement over conventional hubs.”

  38. A1A racer on

    Thanks for posting that info from Sheldon Brown’s website, there’s a lot of good stuff in there.

    Bobby, can you explain how increased spoke tension and better tension balance makes a stiffer wheel?

  39. Gruntled Hintrap on

    To everyone yipping about radial spoking the drive side, look at the Mavic Ksyrium wheels. They’re radial drive and they pedal pretty darn well. I’ve got thousands of miles on my set and haven’t had issues with tension or spoke breakage. (6’1″ 210lbs)

    That being said, seriously dude, don’t take this the wrong way, but you sound like a third year engineering student blathering about “best practices” and “our well iterated MatLab simulations tell us…” Repeating those phrases doesn’t make them more impressive.

  40. greg on

    there is no physical problem with transferring torque using only the left hub flange. many, many very successful bike wheels have used this design well.
    i hope you are testing rear derailleur clearances on a bike, with different cassettes mounted. some come extremely close to the right spokes when in the easiest gear.
    bearing preload should be adjustable when on the bike to account for qr compression.
    torsional stiffness takes a pretty big hit with your layout. although it does not lose energy, it negatively affects the “feel” of the wheel, enough that pros made Zipp change back. also, the extra torsional movement allows for a lot of spoke head movement at the flange, as well as rubbing movement and noise at the left spoke crossing points. i would at least consider making the left flange a little taller.
    what about 2:1 lacing, if youre building these as a system? as long as the rim is stiff (carbon or deep aluminum), this does provide the best of all worlds.

  41. Magnetic Wheel Co. on

    @Bobby Sweeting and Alto Velo,

    Bit late to the party here, just wanted to say I really appreciate you guys’ efforts. Things like optimizing hub design is an often overlooked element in wheels and feel that too many hub manufactures rest on their laurels, afraid to get out of their comfort zone. Thanks for pushing envelopes, buttons, and shaking things up a bit. Big fan of the high/low design. Hopefully IWB’s like me can get a hold of a set sometime soon.


    Steven Pamlényi
    Magnetic Wheel Co.

  42. Wheel Fan on

    Just saw on Facebook that Holloway and the Athlete Octane team just got Auto Velo as the new title sponsor.

    Thanks pretty crazy that Bobby is asking us for 30 thousand to help him get started with production, yet he commits the money for a title sponsorship of a pro team.

    I was going to help him out a bit on the kickstarter page until I saw that.

  43. Non-HTR on

    Hey Ginsu
    “Mech Engr” do you mean ME. Are you really…. BTW testing at infinitum nothing would ever be released. Your posts were passionate but exaggeration ruins the credibility you probably really don’t deserve anyway. Seems like these guys have masters degrees and rare professional racers more experience/better/faster than both of us unless you are really Taylor Phinney. If you are hope the leg is better and can I get your autograph. Seems like a pretty cool product dread building another set of awesome hoops with the same old….

  44. Tom Frost on

    Wheel Fan: My name is Tom Frost, I backed the team on behalf of Alto Velo. Can promise you these guys are seriously boot strapping it. Was able to ride the prototype wheels and I knew that Dan and Chad winning races on the wheels would really prove out the concept. I am slow weekend warrior CAT 4 that races on the rare occasion but have had the money to buy every wheel worth riding and thought the ride feel was better than anything else I have ever ridden. This is a huge help to Bobby and Shawn.

  45. ginsu on

    @Non-HTR Yes, an ME is short for Mechanical Engineer. I graduated in 2011. I was part of a 3-Time World Championship winning FSAE Formula Race Team. I worked on the suspension team as part of my Senior Design Project at Oregon State.

    I don’t have to defend myself, I brought credible reference material. If you are arguing with me you are arguing with Jobst Brandt (I recommend you look into his credentials especially if you need to believe a Ph.D is necessary to know something about bicycles).

  46. ginsu on

    @Shaun – Thanks for the posted info.

    As far as I could see, the stiffest wheel in that list is:

    72. Matrix ISO-C (not C-II) 28 spoke front. Built radially (elbows in) using DT flat blades on a Hi-E old style front hub. 862g / 19.2w x 21.4d mm

    Lateral Deflection:1.09mm

    All they have to do is get some results that meet or beat that result, and I will be convinced they may be onto something.

  47. Mickael Zen Dittlau on

    Hello Nice wheels you make, i Will like to import Them in Dennark , Will Alto Velo

    Make wheels for the new Zcappa breake system keramisk / Carbon model


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