Alloy Wheel Durability
by John Neugent
John Neugent probably knows more about bicycle wheels than anyone else alive. Maybe more about bikes as well. He's spent his life in the bike business, at every level. He now owns Neugent Cycling, a firm devoted to delivering world-class equipment at the lowest possible price. If you are in the market for a set of wheels, please, check out John's site. He really knows his stuff. —Chairman Bill
So you want a strong set of wheels that need to be as light as possible. Most people don’t know where to begin when it comes to wheel durability. An understanding of how wheels fail, and how easy and affordable is it to fix them when if they do fail would give you insight into their durability.
This article is for people who race or who like a light, fast, bike – not someone interested in touring or low speed riding where performance isn’t as big an issue
First, let’s go over a little bit of recent wheel history. In the old days of the 80’s most wheels came with very strong cup and cone bearings and lots of spokes - in most cases 32 spokes or more. The problem is that cup and cone wheels tend to be heavy, and so are lots of spokes – especially when, in the old days, people used mostly brass nipples. The spokes also act like egg beaters so they are not very aerodynamic.
Mavic started introducing low spoke wheels in the late 80’s and initially had quite a few problems with durability. Spoke makers, for example, who were supplying spokes for 32 and 36 spoke wheels didn’t need to make them strong enough for 20 and 24 spoke (or even less) wheels.
Cup and cone hubs gave way, at the high end and for the most part, to cartridge bearing hubs. The bearings for cartridge bearing hubs are made by the millions for mostly non bicycle products. Electric machines use lots of them. They can be made to very high tolerances and very inexpensively.
A front hub is, for the most part, a cylinder with a bearing on either end. A rear hub is the same but with a driving body (the cassette body) which is a cylinder with two bearings in it. It also has pawls that engage a drive ring in the hub shell to power the wheel. These are not difficult parts to make extremely well so many factories in Asia are now producing very good hubs.
In the last 10 years or so I have sold about 30,000 sets of wheels. There are probably less than 10 and certainly less than 20 hubs that have broken (outside of the occasional broken hub flange). Unless you get a pretty inexpensive set of wheels, hubs are not going to give you a problem. Even at the low end, hubs tend to be overbuilt and heavy, but strong.
So good hubs are not difficult to come by. That leaves you with spokes and rims.
Alloy wheels are have come a long way in the last few years
I would personally stay away from any wheels which require a unique spoke. They may be excellent wheels but if you break a spoke it may, or may not, be difficult to find a replacement. Even the very best spokes occasionally break. In fact, spoke breakage, even among top quality wheels, is the most common problem. That’s not to say it happens a lot – it doesn’t – but it happens. The famous mountain stage of the TDF that paved the way for Floyd Landis’ win (for a week or two) also saw him replace a wheel because of a broken spoke. So it happens.
Luckily there are a number of spoke makers who make spokes far better than the old days so going with lower spoke count wheels is generally not a problem. Spoke gauge and count do have an influence on wheels stiffness so most of the pros opt for a minimum of 24 spokes in the back wheel so they don’t rub their brakes while climbing.
The second most common problem with wheels, and this is really just a matter of wear as much as anything, are spoke hole cracks in the rim on the rear of the drive side spoke nipples. Although some people get far more mileage, it’s not uncommon for rear rims to wear out between 5,000 – 10,000 miles. That’s a pretty normal life span. It’s the price you pay for light and fast wheels. Surprisingly, or not, I have not seen this failure mode in the modern carbon wheels.
In the old days, with 32 or 36 spokes, wheels normally didn’t fail this way. The spoke and hub would often wear out before the rims did. People are now often surprised with rim cracks but the fact is that’s how modern wheels fail because both the hubs and spokes are much better and wheels are using less spokes.
So my recommendation is to go with wheels with 24 spokes in the back (18 or 20 is fine for the front) and expect to replace rims every once in awhile, In my opinion, spending a lot of money on expensive hubs…while it made sense in the old days….no longer is as important as it once was.
If you weigh more than 220-230 pounds, or are hard on wheels, get more spokes in the rear wheel. Most likely 28 will be enough but a few people could use even more.
John Neugent was was one of the first to establish quality hand building in Taiwan around the turn of the century. He now owns Neugent Cycling, a firm devoted to delivering world-class equipment at the lowest possible price.