First Look: Alchemy Bicycle Works ORC-UL Rear Hub

 

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…

orc-ul_build01

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.

orc-ul_weight

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

orc-ul_freehub

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

Comments

WannaBeSTi - 05/07/13 - 9:44am

First

gibbon - 05/07/13 - 9:46am

Are you 12?

Evan T - 05/07/13 - 9:50am

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.

Tom - 05/07/13 - 10:16am

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.

gringo - 05/07/13 - 11:38am

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’

Eyal - 05/07/13 - 11:49am

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!

Zach Overholt - 05/07/13 - 12:08pm

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.

Max - 05/07/13 - 12:14pm

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 ;)

Steve M - 05/07/13 - 1:17pm

About time someone put a ball bearing at the pawl pivot, lots of drag there- I think I am kidding.

Nakre Nakresson - 05/07/13 - 2:53pm

That is a beautiful hub! Form follow function, very nice.

Mindless - 05/07/13 - 6:02pm

Where are the disk brake tabs? Hub is useless without disk brakes.

Zach Overholt - 05/07/13 - 6:49pm

@mindless according to what Fair Wheel was told there will be a disc brake version available soon.

Craig - 05/07/13 - 7:49pm

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.

EM2 - 05/08/13 - 5:27am

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)

luis leon - 09/08/13 - 7:51pm

Am trying to find a freehub body to replace the campy freehub body on an Orc. Any help would be appreciated.

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