alchemy_orc_ul_rear_hubsWhen it was time for Alchemy Bicycle Works to redesign their ORC rear hub, making it lighter was important, but making it stiffer and more efficient even more so.

Thanks to clever hub shell design and bearing placement, the ORC-UL is 30 grams lighter than the previous hub while increasing rigidity. The crew at Fair Wheel Bikes took apart one of their first production samples to photo and weigh, and sent over the details on the new hub.

Tech breakdown and actual weight coming right up…


In order to increase the stiffness of the hub rather than adding material, Alchemy looked at the bearing placement. Specifically, the drive side bearing that supports the end of the hub shell by the freehub. Typically on many hubs, this bearing is flush with the hub shell. That’s about 42mm from the drive side dropout. In the ORC-UL, the hub shell extends inside the freehub, placing the drive side bearing 11.7mm from the dropout, significantly reducing the amount of unsupported axle.


It is because of this design that a 193g hub can be stronger and more efficient than the previous 222g version.


The Freehub features three spring loaded pawls, for a total of 36 engagement points on the hub shell drive ring. In order to keep the cassette from digging into the freehub body, the surface is hard anodized. Currently, the ORC-SL is available in Shimano 10 and 11 speed versions which was a crucial upgrade from the original ORC which is not 11 speed compatible – and the new freehub design means they are not retrofittable. Drillings are limited to 24h and 28h hubs at the moment.

Apparently Alchemy had thought about releasing a Campagnolo ORC-UL, but have decided to delay its availability offering this explanation:

We have decided to delay the release of a Campy specific hub. However, there is a viable option. I recently tested the use of a Shimano 11sp cassette with a Campy drive train and I discovered that, by using three micro shims placed roughly equally throughout the stack, a Shimano 11sp stack will shift perfectly with a Campy drive train.

Currently, the ORC-UL is available in S10 and S11 versions.  To address the needs of Campy users, I am now offering a modified version of the S11 that will include spacers for Campy 11. The modified S11 hub (O-UL-SC-11) will include the spacers and instructions on where to place them in the Shimano 11sp stack to achieve perfect shifting with a C11 drive train. I have tested this and the shifting is excellent.

At this time, we do not have a target release date for a Campy specific hub.

~ Alchemy Bicycle Works


  1. Minor edit (please pardon my anal-retentiveness): I believe it’s “30” grams of weight savings, not “3o” as in the letter, not the arabic numeral which appears in the second sentence, first paragraph. I quote:

    “Thanks to some clever hub shell design and bearing placement, the ORC-UL is 3o grams lighter than the previous hub while increasing rigidity. ”

    otherwise, interesting read.

    • Thanks Evan, I had actually tried to fix it as I noticed last night. The problem is 0 and o show up exactly the same on the editing side, but show differently on the site. No excuse, just frustrating.

  2. I appreciate Alchemy’s attention to detail with bearing placement and hub geometry to maximize stiffness. Good to see them really pushing this even further with the new version of the ORC!

    Personally, I just can’t see a Campagnolo person wanting this hub badly enough to want to run a shimmed Shimano cassette with the rest of their Campagnolo groupset, seems like a weak solution? Hopefully they release a Campagnolo specific hub like the original ORC.

  3. Aaaaand once more we have proof that a lack of Industrial Design is one sure fire way to save weight.

    round and straight saves weight.

    not hatin’, just sayin’

  4. I have Tune Mag 170 which is Campy compatible and lighter, and doesn’t require proprietary tools to work, still silky smooth after 10K miles!

  5. The claim, that they had increased the rigidity while they are using an axle which has 12mm or up to 15mm? Increasing the axle to 17mm diameter will boost the rigidity to an level you cant afford with any other trick of construction.

    PS: Gringo hits the point 😉

  6. Actually Max you are not quite correct. As a hub designer I understand what Alchemy has done and it completely makes sense (nor is it entirely new but a clever variation on what has been done before). Anytime a load point is moved further from center it will have significant effects on stiffness. The point of leverage is essentially the tire contact on the ground. By moving the bearing further out from center, as he has done by extending the hub shell underneath the freehub body, the triangle formed from the tire contact, to the center of the hub shell, out to the bearing, from a mathematical standpoint, will result in a huge increase in WHEEL stiffness. While increasing an axle diameter will increase the axle stiffness, and arguably to a degree pawl/ratchet ring alignment under drive torque, the overall affect on wheel stiffness will be minor compared to what Alchemy has done. The downside is I suspect that he would have to resort to an extremely small bearing size to accommodate the deeper splines of a Campag compatible freehub. Shimano hubs use a small diameter axle but their freehub is a structural load bearing component of the hub itself, this makes the hubs very stiff (and strong) but even if Shimano wanted to, due to the design they would never be able to make a Campag compatible version. Pull apart a high end Mavic hub and look at how it is constructed, similar concept to Alchemy although different in its execution.

  7. do we like the 3 bearing design ?

    the weight saving is not from the shell but from a missing bearing at the freehub body !!!?

    instead of second bearing in the freehub body they use a plastic ring (teflon or P.T.F.E.) that actually in high pedaling strees will contact the shell (just contact no rubbing) so this will not affect rolling or power loss.

    clever ? YES
    but who knows for sure that the MR1728 bearing can handle all that stress or for how long ?

    do i want one ? YES (posser mode ON)

  8. These hubs finally seem to have found a new (and stable?) home with Wheels Manufacturing in Louisville, CO, and are no longer called ORC-UL but simply “hubs” (not very sexy but what’s in a name?). My understanding is that they’ve been available for about 18mos. now and have begun to sell “well” (whatever that means). Anyway can anyone report on their real life experiences (i.e., riding, servicing, durability) with this reincarnation of a beloved (in small circles) hub?

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