More information about the Alchemy UL rear hub.

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mythical
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by mythical

Maybe I can shed a bit of light on this, having owned a few Mavic Ksyriums over a decade ago as well as exchanged ideas with Jeremy about hub constructions incorporated into his ORC-UL.

For many of their road wheels, Mavic commonly uses a ratchet system called FTS with 2 pawls on the inside of the hub shell diameter underneath the splines. The ORC-UL ratchet mechanism sits in the driveside flange and its cassette body has a cartridge bearing supported by the axle where Mavic FTS has its pawls.

Mavic FTS-L ratchet system
Image

Both Mavic FTS hubs and ORC-ULs have a bushing between the cassette body and hubshell right at the driveside flange. Mavic has also used bearings here before. Now comes the interesting part.

On both hub designs, there are 2 bearings right at the dropout end, one to enable rotation for the cassette body for coasting and one for the hubshell to spin on its axle. With Mavic, both these bearings spin on the same axle. With the ORC-UL however, Jeremy has devised a construction where both bearing and bushing inside the cassette body body rotate on the hubshell and not the hub axle.

The brilliance in this is that the ORC-UL cassette body body rotates independently and isolated from the axle, whereas with all Mavic's ratchet systems both the drive-side hubshell and cassette body body bearings are always both mounted on the axle. In other words, the ORC-UL hubshell has a wider bearing spacing either end of the hub. The bearing and bushing for rotating the cassette body body are only engaged during coasting, thereby saving wear. Additionally, Jeremy has specified the hubshell with larger load capacity bearings than commonly used to increase durability and, because the axle barely gets loaded, he was able to reduce its diameter as well as weight.

All this resulted in a stronger and stiffer yet lighter hub than the previous ORC, despite the heavier but higher load capacity hubshell bearings.

OP Ergott shows a ORC-UL without cassette body. A Mavic hub could not be ridden without its at least the drive-side bearing of the cassette body. @Ergott, could you maybe photograph an exploded view of the ORC-UL including the order that the bearings and bushing sit in? I think this will help greatly for people to understand the differences between most hubs and the ORC-UL's construction.
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WMW
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by WMW

Thanks for the info!

I talked to Jeremy about this yesterday, and will try relay his thoughts... although I haven't taken either the UL or Mavic apart or seen a good diagram. He mentioned that the Maillard Helicomatic was the inspiration for his hub, but that hasn't proved helpful since I can't find a diagram of it either.

The Mavic hub (shown below) has a "nose" that sticks out of the hub body. There are two pawls attached to the middle of this, and a bearing in the end that rides on the axle. The freehub has a bearing on the outboard side that rides on the axle and a plastic bushing on the inboard side that rides on part of the aluminum hubshell.

Image


The OrcUL's equivalent of the "nose" is a piece that screws into the hubshell (from the DS side). Unlike the Mavic this extends to the DS end of the hub and contains the outer most bearing. The freehub is supported by I think a 17-28mm bearing on the DS side that is supported on the "nose" rather than the axle. On the inboard side there is a plastic bushing that rides on a stainless steel collar pressed onto the "nose".

For persons concerned about the UL bushing being a problem, there are a few difference compared to Mavic's. For one the freehub doesn't ride on the axle, so it won't misaligned by axle loads. Another is that the 3 pawls+springs of the UL are directly over the bushing and would tend to keep it concentric when freewheeling. The Mavic has only two pawls which is not very good for keeping things concentric. And an important difference is that the UL bushing ride on a stainless collar, which is much more durable than aluminum... and it's replaceable. The bushing itself is very easy to replace if it's needed.

The main bearings in the OrcUL are 6901s... which I wouldn't call high capacity. About the same as 6803s that are used in a lot of hubs. They have the advantage of lower friction though (smaller seals) and when power is applied only the two outer bearings are turning.
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by Weenie


hobe
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by hobe

Here's some information about the Maillard Helicomatic:
http://www.borgercompagnie.com/helicomatic/history.html

This is probably the part of the design that Jeremy was talking about:
The Helicomatic system also had the axle ball bearings in the hub under the outside edge of the freewheel rather than near the flange. This meant axles were better and more evenly supported.


Here you can kinda make out how far out the bearings are under the freehub:
http://www.angryredplanet.org/log/2009/05/15/trek-helicomatic-bearings/

It also shows a nice picture of the cone destroyed by an exploded bearing.

senator52
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by senator52

Slightly off topic, I see the ORC-UL is offered in both 10 speed and 11 speed versions, but I've also seen them listed as 10 and 11 speed compatible. Are these hubs convertible? (ie. I currently have 10 speed and I will likely upgrade to 11 speed in 18 months) Will I need to buy a new rear hub if I upgrade to 11 speed or can I convert the current hub through use of spacers or another method.

Thanks.

Zigmeister
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by Zigmeister

What kind of lacing pattern and spokes to build a good aero stiff build with this hub? Wide aero rim will be used in 40mm depth clincher.

Thx

ryker
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by ryker

senator52 wrote:Slightly off topic, I see the ORC-UL is offered in both 10 speed and 11 speed versions, but I've also seen them listed as 10 and 11 speed compatible. Are these hubs convertible? (ie. I currently have 10 speed and I will likely upgrade to 11 speed in 18 months) Will I need to buy a new rear hub if I upgrade to 11 speed or can I convert the current hub through use of spacers or another method.


You can run the 11sp hub as 10sp with a spacer behind the cassette. The 10sp hub has no upgrade path to 11sp but naturally builds a stronger wheel.

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WMW
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by WMW

Zigmeister wrote:What kind of lacing pattern and spokes to build a good aero stiff build with this hub? Wide aero rim will be used in 40mm depth clincher.


Not a big deal and not enough info to go on, but I'd probably go 2x DS (24h or less) and radial heads-out NDS.
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JN2Wheels
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by JN2Wheels

Mythical and WMW offer up fantastic info! thanks, guys. The main difference between the Mavic design and Jeremy's is clear; the outer bearing of Mavic's free hub rides on the axle, whereas Jeremy's rides on an extension of the hub shell, allowing the greatest possible bearing stance width, and completely isolating the free hub from any structural role.

However, according to MWM, the main DS bearing doesn't actually sit in the hubshell, but rather an extension that threads into the hubshell "nose" (the silver piece pictured threaded into the black extension). Unless there is a 3rd bearing that supports the hubshell (black extension) proper, this puts some crazy bending stress on a mechanical connection??! I must be missing something. A diagram would be worth at least 1,000 words.

JN2Wheels
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by JN2Wheels

Huhhmm. The more I think about it, this extension piece seems very similar to the threaded bearing cup of an outboard BB. Seems like it may be installed with a 10mm Allen or so, and it flares at the end to hold the biggest possible bearing size. Then the free hub bearing rests on it. Installation order would be hubshell with axle, slide free hub onto hubshell with bushing, then slide bearing cup onto axle and tighten into threaded hubshell. The flared bearing cup should capture the free hub such that it won't move laterally. Lastly there would be an axle end piece threaded into the axle with loctite to set the preload. Can't wait to see a complete tear down. And I still don't know if I'm sold on having the outer main bearing mechanically connected to the hubshell proper.

JN2Wheels
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by JN2Wheels

Ok. Last post here about this. Found the image at Bike Rumor, which helps clarify. http://www.bikerumor.com/2013/05/07/fir ... -rear-hub/" onclick="window.open(this.href);return false;" onclick="window.open(this.href);return false;

Looks like there is a threaded sleeve pressed into the hubshell (which also becomes the bearing seat for the freehub bearing) The main bearing cup threads into that sleeve very deeply in the hubshell extension, creating three layers of material overlap for the whole length of the extension. That may be strong enough. If I've got this right, Jeremy sure thinks so!

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WMW
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by WMW

JN2Wheels wrote:Huhhmm. The more I think about it, this extension piece seems very similar to the threaded bearing cup of an outboard BB. Seems like it may be installed with a 10mm Allen or so, and it flares at the end to hold the biggest possible bearing size. Then the free hub bearing rests on it. Installation order would be hubshell with axle, slide free hub onto hubshell with bushing, then slide bearing cup onto axle and tighten into threaded hubshell. The flared bearing cup should capture the free hub such that it won't move laterally. Lastly there would be an axle end piece threaded into the axle with loctite to set the preload. Can't wait to see a complete tear down. And I still don't know if I'm sold on having the outer main bearing mechanically connected to the hubshell proper.


A 7/16" allen is used to remove the extension.
The axle bearings are both 6901s.
Disassembly: Use two 5mm allens to remove axle and cap, use bearing extractor to remove DS axle bearing, use 7/16" allen to remove the extension. Then the freehub bearing and bushing, and the NDS axle bearing can be easily removed/ replaced.

BTW... I haven't taken one apart yet.

I can't give you any intelligent info about the hub loads going through a threaded fitting... except that I'm pretty sure that Jeremy considered this. I'm guessing that the extension isn't just cantilevered where the threads end, but rather the threads are recessed a bit and there is an tight fit between the inner surface of the hub shell and the outer surface of the extension. This would greatly increase the strength of the connection. (Edit... shit... missed your last sentence... looks like we reached the same conclusion. Hopefully someone will chime in who really knows).

One more addition. I think one of the important differences between this hub and the Mavic design is that the Alchemy bushing rides on a stainless ring (which should be very durable), while the Mavic bushing rides on the aluminum hubshell. When abrasion wears down the hubshell, then even replacing the bushing doesn't work... and formerly the hub had to be tossed. Luckily the aftermarket has come to the rescue and now provides bushings with a smaller inner diameter to take up the space.

Image
formerly rruff...

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ergott
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by ergott

I've taken the hub apart. The order mentioned above is correct: remove axle, remover outer bearing, use 7/16" hex to remove cup and the freehub will come off. 7/16" hex can be ordered from any automotive or tool shop so I don't consider that a "special" tool. Anyone that removes bearings from any hub should have a proper bearing puller like the one Wheelsmith makes. I have the whole kit in my shop.

http://wheelsmfg.com/sealed-bearing-extractor.html

After that anyone that cares to properly install bearings (especially high precision bearings) should use a proper press. Here's the one I use.

http://wheelsmfg.com/rear-hub-sealed-bearing-press.html

If you don't do your own work I recommend you check to see if the shop that does your work uses the proper tools. They are universal so I consider them worth the investment if you maintain your own bike and anything else with cartridge bearings.

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ergott
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by ergott

Another update.

I've been sending out wheels to Campagnolo customers with a Shimano cassette. The cassette is supplied with the required micro shims to make the spacing compatible with Campagnolo. I personally run this on my SR 11 bike and the shifting is excellent.

A few added bonus points about this.

Cassettes are less expensive now that Ultegra 11 is out. Even with 10 speed, the cassettes are cheaper than the equivalent Campagnolo. 9000 cassette and Record are almost the same weight for a given ratio.

Since you are using a Shimano cassette, you can easily swap the wheel to an Shimano or Sram equipped bike by removing the micro shims from the cassette. That way if you spend a lot of money on a set of wheels like Enve Smarts or the like you can swap them around other bikes. Also makes selling the wheels in the future easier.

JN2Wheels
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by JN2Wheels

Great additional info. It's a bit off putting to know that the DS bearing has to be pulled and pressed in order to lube/service the drive pawls. I hope they're well sealed. Or is there a dust seal that pops off without free hub removal?

Pretty cool to hear about the microshim approach. I guess this works for any shimano 11s freehub? If campy would just come out with their internal battery, athena eps would give 6870 a run for its money!

Zigmeister
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by Zigmeister

I can't believe that what you say is correct. To service and lube the pawls which should be a five minute job on any wheel, requires the hub shell with bearing to be pulled with tools to accomplish?!?!

This would be a big oversight and design fail. If this is actually true, then the wheels I'm about to build are not going to get these hubs. This would be one of the silliest designs in the business if true.

Someone clarify please.

by Weenie


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