Wheel blog
The wheels are next - I will add pics in a future post. The rear is done, the front is waiting on a lefty hub, but I have the rims, spokes, and nips.
I decided to try Stan's Olympic rims. I have been using - and happy with - Stan's system since the days of strapping and electrical tape. The newest Olymics are disc only, perfect. They are designed to not need the usual rubber strip, but rather some new tape, weighing only 5g per wheel, and a 7g valve. When I ordered them over the web, I got a call back from Stan. He explained that the Olympics were out of stock, but he had an "OEM" version Cannondale (!!!) was evaluating. They are about 10g each heavier, and the 10g added strength and durability over the standard Olympic rim. So I went for those. They weighed in at about 360g each, not bad, within a couple of grams of Stan's claims. They are eyeletless and have kind of a messy weld at the seam. The weld is no big - at least they ARE welded, and these are disc only, so who cares about the brake track. As for eyeletless - well, yes that saves weight, but durability will be another issue. I have used a lot of eyeletless rims, and my experience has been that as long as you tension the spokes properly - meaning you don't overtighten - they are fine. Plus, without the eyelets, the wheels are totally blacked out, which looks great. Combine the low weight of the rims and the 14g strip/valve combo over the normal rimstrip of about 60g, and you have some serious weight savings, great if they prove durable. They also have a lightweight rimstrip option - about 35g - that I am trying not to use.
At Stan's suggestion, I am using the newest DT Supercomp spokes, which seem like a good weight compromise for a real world bike. They fall between DT revolution (revos, as I call them) 2.0/1.5 and Competition 2.0/1.8. They are 2.0 at the hub end, with a longer section of 2.0 than the revos. Then they narrow to 1.7, and at the rim end they widen to only 1.8, and with a very short butted section. Nice design. The 2.0 section at the hub is where it belongs, able to protect the wheel from chain drops (depending on hub flange height, of course), which the 2.0 butting on the revos too short for. The chain inevitably lands on the 1.5 section. There is no need for a bigger 2.0 butting at the rim either, so the 1.8 is fine. The end result is only 320g, between the weight of the revos and the competitions, closer to the revo. Another good choice, I think.
The rear hub I am using is the latest American Classic disc rear hub - the kind with the thread off disc mounts, an amazing 227g weight. The non drive side flange has been moved in to eliminate dish so spoke tension is the same on the drive side, and there is no need for asymmetric rims to achieve this. Also, when paired with the front hubs I am not using, all 4 spoke lengths (F&R, R&L) are equal lengths. Very clever, it allows you to buy a box of 72 spokes to build a wheel. The downside is that the flange spacing is very narrow in the rear - narrower than the front. According to AmClassic, equal spoke tension and zero dish more than offsets the narrowness.
Stan does not like the combination I am using - the new AmClassic rear hub with his rims, and he does not offer that combination at his web site. He pointed out the narrowness and the zero dish design of the rear hub, and correctly concluded that spoke tension will be equal drive and non drive side. Most rims in the world should be tensioned to about 100kg, which I measure with a tensionometer. With a non-dished wheel that means spokes are tensioned to 100kg on each side. On a dished wheel, the spokes that are closer to the center of the hub are tensioned to 100kg and the spokes on the other side are tensioned less, whatever is needed to make the wheel dish properly, and that is where the reduced strength of a dished wheel manifests itself. Stan, however, did not like the idea that both sides should be tensioned to 100kg, and insisted that even though his rims are rated for about 100kg, the total of both sides should be added up and total about 160kg, so spoke tension should be about 80kg per side, which would make for a very weak wheel. That makes no sense as far as I am concerned, I have already built up the rear wheel with 100kg on each side.
I have installed a Conti Explorer Pro onto the rim, and the rims are interesting. They are not hook beaded, but they curve around to match the shape of the tire bead. The bead seats with a series of loud scary pops or cracks, but it assures me the bead has set with authority. Indeed, removing the bead from these rims takes considerable pressure, I have great confidence that they will hold securely on the trail.
