tFUnK

Same rim, just different drilling.

njkayaker

There are all sorts of really-noticeable odd (not very conservative) things that change all the time about mountain bikes that OC rims wouldn't even register. "Conservatism" isn't a big deal for the mountain bike market (your "some" is negligible).

OC rims would barely register on road bikes. There are also many examples of odd looking wheels (much more noticeable than OC rims) on stock bikes over many years.
And there are lots of odd looking wheels (especially after market ones) for road bikes too (not many appear to use OC rims).

If there was that strong a benefit/cost ratio, OC rims would be common on mountain bikes.

Then, they really should be already common on mountain bikes. Or after-market wheels.

It's possible that the extra cost (even as small as it is) is enough to discourage manufacturers from using OC rims on stock bikes. It might be that the advantages are a "hard sell" to customers (unlike disk brakes, which are a fairly easy sell).

The public is generally convinced of the benefits of disk brakes (and doesn't mind spending more for them). The benefits of OC rims might be too hard for the public to understand (and they might not see even a small increase in cost as worth it).

prj71

Asymmetric. Another word for OC.

I have these on my mountain bike.

https://btlos.com/mountain-bike/coat...arbon-wheelset

2old

I ride MTB exclusively, and have had a few OC-wheels over many, many years. To me, and as stated above already, maybe it's an answer to a question nobody asked. I've never encountered a situation where it made a difference AFAICT.

njkayaker

If OC is so great, why did they stop making them?

(There have been all sorts of odd wheel configurations that were tried and abandoned.)

I'm not saying there isn't an advantage to OC rims. It just doesn't seem there that big of an advantage (otherwise, they'd be much more common). It could be they aren't common because the general public doesn't understand the advantages (so, it isn't worth the extra manufacturing costs). Still, it would seem that they'd be the norm for higher-end mountain bikes (the purchasers of those might be more technically savy).

cyccommute 

There isn’t a benefit to the manufacturer but there is a benefit to the user. Part of the problem is that broken spokes aren’t a concern of the manufacturer. Most all broken spokes are replaced at cost to the user, the manufacturer doesn’t know or care about them. The user probably won’t even blame the manufacturer for the spoke failure and will assume that is is something they did. Most people have no clue that there is a design flaw in the way the wheel is built.

njkayaker

I said that already (basically). I think this makes more sense. Disk brakes don't have a benefit to the manufacturer either but the user is clear bout the advantages (the benefits of OC rims isn't as clear). Put another way, disk brakes make it easier to sell bicycles (for more money, even) and OC rims don't make it easier (so, they don't warrant the extra small cost).

It's still odd OC rims don't seem to be standard on higher-end mountain bikes (maybe, they are?).

KerryIrons

Pretty much sums it up.

79pmooney

I ride both 7 and 9-speed hubs and fix gear hubs with no or very little dish. I can definitely feel the difference on corners. The fix gear wheels feel more solid despite using the lightest spokes I can get on both sides. (DT Revolutions when available.) The dished wheels feel less secure on bumpy hard corners.

Granted, part of this is my engineering brain. Triangulating structures is so basic a concept. And wide base triangles are far stronger. So a wheel that takes advantage of the (pre-disc) simple and elegant front wheel geometry in the far more demanding rear wheel application just feels right. Compromising that base, just wrong.

Haven't yet used OC rims. But now that I am in new wheel mode (swapping al my good bikes over to tubular), I should look into it. (Did OC and shallow tubular rims ever cross paths?)

njkayaker

Maybe, they aren't as aerodynamic. Though, that shouldn't matter for mountain biking.

alcjphil

I have a set of Campagnolo Neutron wheels. The rear rim is offset

TiHabanero

OC rims are not a solution to low quality parts. A well built wheel using quality parts will go the distance. I've seen it and experienced it.

KerryIrons

It is indisputable that OC rims build stronger wheels. I have used them for more than a decade and been very satisfied. Whether you need that stronger wheel is an open question that can't be universally stated. My current rear wheel (32 spoke, Velocity A23 OC) has 75,000 miles on it.

TiHabanero

KerryIrons, you and others have raised a valid point. Is the extra strength needed. My point of view falls on the "no" side of the equation. I'm a 235 pound guy that is less than graceful on a mountain bike and have never folded a wheel or broken a spoke on one. My road bikes have lots and lots of miles, with one of them using wheels that I built over 30 years ago and have at least 50,000 miles on them. Zero issues with those wheels.
On my ti bike the wheels are newer, 4 seasons old and only 7000 miles on them, but they have yet to require any truing or tensioning. My son rides like I used to ride, 4-5 thousand miles a year and he has zero issues with traditional rims as long as he is using quality parts.
I say most people do not need the additional spoke tension that an OC rim provides on the non-drive side spokes. If a clod like me doesn't need it, then I earnestly doubt anyone else will.

Steve B.

Bontrager made an OC touring rim about 20 years ago, I've a rear wheel with one, built up by Rivendell on a Deore 135mm hub. Needless to say its a bombproof wheel, I've never had to fix truing issues. Not made anymore, I doubt Bontrager still makes this rim.

cyccommute 

Why does everyone assume that wheels are built poorly or that the parts are substandard? All things being equal, OC rims make for better triangulated spokes with less of a spoke tension differential between the drive and nondrive sides. A well built wheel with an OC rim (and triple butted spokes) will go beyond the distance.

On of the most frequent posts on these forums and one of the most common problems in bike shops is broken spokes. Just because you haven’t broken one doesn’t mean that spoke breakage is not a problem for others. A quick google search of “how common are broken spokes” returns nearly 42 million hits. If they were never a problem, we wouldn’t need procedures on how to replace them.

There are other benefits of the OC rim as well. The increased triangulation makes for a stiffer wheel. The need for a stiffer wheel…and the gradual increase in hub width…is especially important in 29ers, more so when you carve out the extra space needed for a disc brake.

The bottom line is that off-center drilled rims and stronger spokes make for stronger, more durable wheels than wheels that are built without them. Many people can benefit from these improvements.

tomato coupe

A quick Google search of "Are lizard people real?" returns 28 million hits.

cyccommute 

Non sequitur much? A very large proportion of those hits are saying “no, they aren’t”. There aren’t a lot of people saying that spokes don’t break.

tomato coupe

Your statement implied a large number of Google hits supported the idea that broken spokes are a problem. The number of hits is meaningless.

unterhausen

I definitely like OC rims, but I generally don't bother buying them. Didn't a couple of companies have problems with them early on?

tkamd73 

I don’t know, it’s caught on with me, since my sources for nos vintage Campy rims have dried out. Have used the Velocity A23 OC on my last 5 builds, also have 2 more builds in progress that will use them.
Tim



91 Schwinn Traveler

91 Series 5 PDG Paramount

cyccommute 

No. Go do the search yourself and look at just some of the results or just pay attention on the Bike Forums. It is a frequent topic and a very common problem.

njkayaker

We still have no idea how much OC rims would reduce the frequency of that problem.

Kapusta

I know plenty of people who have broken spokes, but none who believe in Lizard People.

Of course, Lizard People have not come up in conversation, much. I’ll have to dig a little deeper on that one.