922g of heaven…

As you certainly noticed, I’ve not been very active on the website lately. I’ve a workplacement in the bike french magasine « L’Acheteur Cycliste » and so the free time to work here is very limited.
Today is a day off and so I’ve the time to present what has been, since almost a decade, the lightest and stiffest wheels ever.
We had a visit in Lightweight factory during the Eurobike, I hope you enjoied this article that is still online from this link: The secret of Lightweight wheels! (available from the main page too). We think some of you could have been slightly frustrated not to see a lot of pictures of Lightweight wheels. But , we unfortunately couldn’t show every pictures because of the process secret…
That’s why, we’re happy this time to show a lot of pictures of these wheels. This set will be tested in laboratory and on the road for a great report in the magasine very soon. Stay tuned!

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The set is the Generation II of the Obermayer Lightweight wheels (see here). The overall look of these wheels remains unchanged since the first version of them. Only the internals mechanisms and structure have changed so far. Thus, originnaly a set of Lightweight wheels was close to 1250g with a Dura-Ace or a Record mechanism and 20/20 spokes. Now, the maximal weight of the Obermayer II, the version with TUNE internal rear hub mechanism, and 12/20 spokes is 960g… Our set came in with a mere 922g! (408g front, 514g rear)

We think the « war » between Lew Racing, making the PRO VT1 at 880 / 920g (Shima/Campa), and Carbon-Sports, owner of Lightweight wheels, might have hurt the « ego » of the german company that feels forced to push even more the limits of its wheels! Of course this competition between the companies is very good for the final customer since the products get better and better for cheaper.

Stefan Behrens, at the head of CarbonSports has been very reactive to get us a set for the test in the magasine. It was just a question of days, very good. We give them a big thump up!
On the other side, we are still waiting for some others high-end sets from two other companies. It seems like the others companies can’t make enough wheels yet to send us a set. We really hope this situation will end soon.

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The height of the rims is 53mm for 19.5mm width. The rims skeleton is foam that brings stiffness and resistance to compression. For the generation 2, a new foam is used. It is the one used in A380 wings, it is lighter and stiffer. The carbon fiber used is the famous 3K one, it is pretty thin and is composed of 3000 carbon fibers per weave. The aesthetic aspect is really very good even through we can notice some voids at very close range.
The inner tip of the rim is flat. This is a particularity we didn’t really expect from a wheelset claimed to be aerodynamical, therefore fast. We think there is still a good improvement to bring to the rims here.  A flat part isn’t really fast and it certainly explains the relative bad aero result of the front wheel to the TOUR magasine test. You can see it here, the Lightweight front wheel absorbs 24,8W and is not among the fastest wheels despite its deep rim.

A special shape hole is moulded for the valve extender, it is very well done but was slightly larger than our extender. It means we will have to block the extender to prevent the « tic-tic-tic » noise while riding. Nothing to complain about though. We thought about using some electrician tape around the extender for that. Another possibility is to cut a small piece of butyl from an old air tube to block the valve extender.
But, as a perfectionist brand, Carbon-Sports offers two tiny seals to prevent the valve extenders from entering in contact with the rim hole. This is with these small details we recognize the best brands!

A magnet is laminated inside the rim so there is no need of a big/ugly one on the spokes. Good point!

About the brake track, it is normal carbon and it requires special brake pads. Carbon-Sports advise the Swissstop Race 2000 Lightweight (see here) modified compound for them.

As the rims, the hubs are made out of 3K carbon. The look is as nice and is matched. We can notice again some voids in the carbon, this is really common for lightweight high-end bike parts and this is definitely not a problem for the suitability and reliability. But we could be waiting for more from such pricey products! No need to complain that much either, it remains a detail!

Front hub

Rear hub

The voids in the carbon

The spokes are made out of carbon and kevlar fibers. They can hold up to 1200kg of tension with no significant increase in length. Their shape is almost bladed. The dimensions differ with the process but, generally the thickness is close to 2mm and the width is close to 5mm. As comparizon, the Cx-ray stainless steel bladed spokes are 0.9mm thick and 2.3mm width.

Regarding the process, basically, the spokes, rims and hubs are laminated as one piece, forming a very solid and stiff component.  The spokes are wrapped around the hub at 140/160° (depends on the spoke count) and goes to the brake track. They are glued then a carbon cap is glued as well over it to bring some stiffness and integrity. Some glue is sometimes visible around the hub/spokes. It is the red one, as you can see on an old picture of a process below.

Ok we’re not specialized in the process so we leave it to the experts… but fundamentally, this is how it’s done. We can notice some foam as well around the spokes. No idea what it’s used for though.

Click to enlarge.	Click to enlarge.

Once again, as the rims and the hubs, the finish of the spokes is not perfect. Some kevlar fibers remained uncut or not well « cooked ». The crafty aspect of the wheels is definitely obvious! We do like this kind of small aesthetic issue, it shows how far the hand-made and technology sides of the process are!

The rear spokes are tied, just like what we do on handbuilt wheels. It increases the lateral stiffness of the wheel and makes a fictive bigger flange diameter. Obviously, the front spokes are not tied, they cross each other inside the hub flange.

The differences in Lightweight wheels range are mainly related to the bearings and the internal mechanisms. Both the Standard and the Obermayer front wheels versions use GRW bearings, custom made for Lightweight front hubs.
The main difference between the two version Carbon-Sports offers is related to the rear hub. The Standard version spins around a rear hub DTSwiss mechanism with its patented ratchet system. While the Obermayer uses the TUNE mechanism with its patented custom double bearing and the traditionnal three titanium engagement pawls. Both mechanisms are very reliable but the TUNE one uses a carbon axle and is way lighter.

The precision
Regarding the trueness, the roundness and the dish, Lightweight wheels aren’t perfect. They are more out of true than standard hand-made wheels that have been trued and dished for a long time. This is caused by the cooking process, the wheel shape is almost done when it leaves the oven and it has to be slightly adjusted by hand then. However, this doesn’t have any negative impact on the functionning and the braking because it is still very low. Yes, there is no need to worry about the trueness and the roundness. But about the dish, it is a bit more worrying since it could affect a little the balance of the bike.
Regarding the bearings smoothness, the front wheel spins forever… you can see it spinning for hours. It’s awesome, definitely awesome! The rear one is not of the same level. It is tighter and needs some kilometers to be broken in. This is common on some carbon axle TUNE rear hubs and of course the Obermayer 2 follows the same rule.

We are impatient to test ride them and to have the results of the laboratory!
Yes this is real, although I could ride a lot of good wheels I built, I can’t wait to ride the Obermayer 2 and I hope to enjoy the ride. Actually, I don’t see why I would not enjoy it. Riding a 922g wheelset is something very special, something only a few people can afford and I’m happy I can do it for a few rides. A full report and match with two other high-end wheelsets will be published in the magasine I work at. I do think I will report on RouesArtisanales.com a similar article to this one about both others wheelsets as soon as we get them.
Carbon-Sports was the fastest company to provide us a wheelset, this is at this date the only company able to provide wheels for the test. This is an important point and it shows how confident they are in their product.