Raceworthy DH wheels
May 2, 2014
I’ve built quite a few Hope wheelsets lately. Here’s another set with my favorite brand of mountain rims — Stan’s. Shipped with Stan’s tape and valve stems installed.
I’ve built quite a few Hope wheelsets lately. Here’s another set with my favorite brand of mountain rims — Stan’s. Shipped with Stan’s tape and valve stems installed.
These are sweet 29er race wheels but great fun in general, especially on the climbs. The Hope hubs were the riders’s own and I supplied Stan’s Crest rims and Sapim Laser spokes. With aluminum nipples they add up to 1615g, that is 732g front and 883g rear (DT Swiss 240S hubs would push it under 1475g total). Because of the rim weight and resultant low tension ceiling, build quality is extra important on a wheelset like this. These wheels were built with tension balanced to ±7% or better. In getting there both wheels were stress relieved multiple times, which causes tension to relax so I can bring it up as much as possible. Lateral alignment is nearly perfect with a 0.1mm rise at the decals being the limiting factor.
I’ve built this make of rim before. I’m really happy with the quality. The nipple seats are reassuringly thick and the rims were round out of the box. The manufacturer makes carbon rims for a major league brand so production is mature. This particular model is 45mm deep with a hybrid toroidal shape, virtually identical to the Zipp 303. They lack the dimples found on Zipp Firecrests but sell for a fraction of the price.
The first wheelset is destined for a vintage mountain bike restoration project. Velocity Aeroheat rims offer a good strength-to-weight ratio and Shimano Ultegra hubs help manage the budget. It’s not easy finding sweet 26″ wheels for rim brakes and a 130mm rear end.
The next set is loaded touring wheels designed for journeys without limitation. They are based on White Industries MI5 hubs equipped with a titanium freehub body, Velocity Dyad rims and butted spokes. With 40 spokes each, these wheels are capable of carrying the kitchen sink.
Identical to a previous wheelset, these have more to offer than most OEM wheels. Their stiffness is excellent, the star-ratchet hubs are high quality at an affordable price, and spokes are butted. Butted spokes decrease weight and increase fatigue life. This set is 28h with alloy nipples — a recipe for durability with a nod to weight. These are nice parts and I like to think they’re put together as well as a wheel can be, which is an important determiner of maintenance requirements and lifespan.
My rims are shot so I’m looking for new rims and spokes. My hubs are going strong so I’d like to re-use them. This time I’d like to lace the front wheel radially…
It’s a pleasure to ride nice hubs and, as this rider knows, they can survive many sets of rims. But only re-use your hubs with the same lacing pattern used before. This is for safety. Changing from a cross pattern to radial is the most dangerous case and a notorious cause of hub flange cracks.
Campagnolo has always made nice hubs so I enjoyed overhauling and lacing these to Archetype rims. The rear hub needed help with pitted cones and sticky pawls but now it’s as good as new. The loose ball bearings were replaced on both hubs, which should be done as part of periodic maintenance. In the same way that regularly replacing your chain extends the life of cassettes and chainrings, replacing loose ball bearings saves your cups and cones. If you have nice hubs, take care of them and they will last forever. Good hubs can last through several sets of rims.
A cartridge bearing should have an interference fit with its hub bore. Some hubs hold their bearings firmly and others are too loose. At first glance a slip fit seems simpler for the DIY mechanic but a slip fit can allow slight play in the wheel. Play is no good because it’s your cue adjustment is lost or bearings are worn. Unnecessary play can damage hubs.
These hubs are a good example — out of the box I found the bearings slightly loose. In cases like this I re-install bearings with a thin layer of Loctite 641 applied to the outer races. Loctite makes a variety of industrial bearing retainer compounds but I use 641 because it’s a low viscosity formula that allows for thin applications. It’s the lowest strength sold, which means bearings can be pulled easily in the future.
A trend I’ve been watching is direct sales of carbon rims from China. It’s an idea with pros and cons. The main pro is price. When you buy direct you’re effectively a wholesale customer as they offer no better terms for dealers.
These rims were supplied by the rider. Weight is the focus with a Tune King 15 front hub, DT Swiss 240S rear and CX-Ray spokes. Total wheelset weight is 1470 grams (29er, 32h). Wow!
Heavier riders can be hard on wheels. Clydesdale/Athena riders need to look at a few factors when choosing wheels: get a strong rim, build with more spokes, select butted spokes and use brass nipples. I sometimes hear the suggestion that straight gauge spokes are better for these applications but untrue! Spokes break from fatigue and breakage usually occurs near the elbow. A butted spoke has a thinner middle section, which is more elastic. This redirects flex from the danger zone to a less risky part of the spoke. This means better durability even though weight may be lower.
Here’s a classic example: Velocity Deep V rims in 32f/36r, Shimano 105 hubs, and butted spokes.