icemilkcoffee 

It seems like a good solution to a long standing problem. How come OC rims never became industry standard?

cyccommute 

‘Tis a puzzle! It can’t be cost, since the Velocity A23 OC cost $106 vs the A23’s cost of $102. It could be a patent thing. It could also may be part of the inherent conservatism of bicyclists. While we seem to like some new technology, there is some that we just won’t embrace.

Wheels tend to fall into the very conservative well of bicyclists. Triple butted spokes are a very good idea but mentioning using them can start a flame war almost as vehement as chain lube. I’ve had cause to review wheel building calculations for various hubs lately and the topic of off-center rims came up. It’s somewhat surprising how much the off-center rim changes the spoke tension differential. For a 135mm hub, changing from a center drilled rim to an off-center drilled rim decreases the drive side/nondrive side tension from 51% in the former to 70% in the later. I don’t know why people don’t take advantage of that improvement.

Troul 

OC rim with a tall flanged hub could be something to invest in for durability. Maybe OC is limited by how narrow it can be positioned before it becomes a fatigue concern?

seypat

Pardon my ignorance, but can it be used with a standard brake caliper? We're in the disc era now, so it might catch on.

njkayaker

Yes. The brake tracks are in the same place as centered rims. It's the arc between the parallel brake surfaces that is off center.

cyccommute 

It can absolutely be used with a standard brake caliper. The A23 OC is rim brake rim. It can be used with disc, of course, but it is primarily for use with rim brakes. Ritchey which kind of pioneered the OC rim in modern times, was making them before disc brakes became a thing. Oddly, Ritchey doesn’t make the OC rim anymore.

njkayaker

More expensive to manufacture and stock/distribute.

With centered rims, you only need to make one part. With off-centered rims, you need to make (and stock/distribute) two parts.

icemilkcoffee 

Most mid to high end bikes run a rear rim with more spokes than the front. So you already have two different parts by necessity.

masi61

When I had some 32 x 32 used Dura Ace 7900 hubs built up with Velocity A223 rims, I tried to get the rear in OC but could not obtain one in the polished finish that I wanted so I went with the symmetrical A23's both front and rear.
I have since built up a second similar set this one with 28 spoke Dura Ace 7850 rear and an 24 spoke Dura Ace 7800 front but this time using Velocity Quill rims. The rear is symetrical and not offset.

I would have liked to have spec'd the offset versions but these just did not seem to be available.

njkayaker

Err. Yeah.

I wonder if some rims will the higher-count "rear" wheel for the front (and use an even higher count for the rear).

It still might be significantly cheaper not to also produce the off-centered feature.

There must be a fairly strong disincentive not to produce OC rims as the norm (enough to offset the benefit).

I doubt it's because cyclists are "conservative". You'd have to really look closely to notice the off centered aspect.

Shimagnolo

I have 4 bikes.
3 of them have been running Velocity O/C rims for years, on wheels I built myself.
(The 4th one is rarely ridden has has some of them thar store-bought wheels).
I swear by O/C rims.

pdlamb

So a combination of reducing SKU for big bike OEMs and low available + low demand for aftermarket (replacement) wheels?

Iride01 

Perhaps it was a solution for a problem that didn't affect most users.

Darth Lefty 

I think that the #1 problem with inexpensive wheels is almost completely solved for most people by the DB spokes found on slightly better wheels, and extra things like OC rims and triple butted spokes are just not necessary enough on top of that.

I had a Diamondback MTB that came with oc rims about five years ago. This caused some problems with tubeless setup, because they put the depression in the rim on-center with the spoke holes and not centered between the sidewalls, and it had a hard time sealing up on the "short" side because there was no "shelf" to start the bead sliding into its channel. I have not seen other rims made this way nor can I think why they did it. It was a strangely unique problem.

njkayaker

Because this difference doesn't end up mattering much in the real world.

There doesn't seem much conservatism in mountain bikers. If OC rims had a significant useful real world advantage, they would be the norm (or common) on mountain bikes. Kind of like how disk brakes came to be.

OC rims should also be more common for wheels that mostly serve the secondary market.

Kapusta

The mountain bike I bought recently (Ibis Ripley AF) came stock with off-center rims.

njkayaker

Sure, OC rims exist. How common are they on mountain bikes? Maybe, they are already the norm there. If OC had a big advantage, they should already be common on mountain bikes.

Kapusta

I don’t know how common they are. it’s not something I really pay much attention to. I did not even realize these rims were off-center until I had had the bike for about a week.

cyccommute 

Based on the few offerings around, they don’t appear to be significantly more expensive. $4 more from Velocity and about $10 for Kinlin.

Some disc wheel manufacturers are offering OC rims for front wheels since those didn’t need to be dished before discs.

JohnDThompson 

I'm sure that's part of it. Until the mid-70s, standard wheels on British bikes were 32 hole front, 40 hole rear. Bean counters and the bike boom supply chain issues contributed to simplifying inventory by using 36 holes both front and rear.

cyccommute 

That’s a very significant difference even in the real world. Heavier riders…who suffer more broken spokes…can really benefit from them. The whole boost idea is an attempt to solve the tension difference on dished wheels by making the dish superfluous. 157mm hubs are basically dishless.


There is some. There are also mountain bikes that come with OC rims as OEM. Not many but there are some.

rosefarts

I’ve built with them. No issues. They came stock on my mountain bike too.

The Kinlin rims I bought from bike hub store were offset and not advertised that way. Seems possible that a lot more out there are doing it, just not talking about it.

Seems that a lot of wider 30+mm mountain bike rims are offset until you get into the fat range.

I’ve never seen a road rim offset. I’ve heard of their existence.

urbanknight

I figured it was a matter of aerodynamics with the deeper carbon rims getting so popular, but you can still get OC rims for sure.

icemilkcoffee 

Kinlin, Ritchey, Velocity, Shimano, DT Swiss all make or made road OC rims.

genejockey 

I've got Fulcrum wheels on 2 bikes. The Fulcrum Racing 5s are OCR, while the more expensive Racing 4s are not. *shrug*