Originally Posted by
cyccommute
There is only a slight difference due to rim shape and the rims that are marketed as being “stronger” are typically wider, flatter models like the
Velocity NoBS (620g in 700C) or
Atlas (620g) or
Cliff Hanger (675g). They are heavier and wider so the
must be stronger, right? Even the high profile rims like the
Deep V (580g) only offer marginal compressional strength over something like a
A23 (450g). The Deep V is far narrower as well so it doesn’t offer much lateral stiffness as
Dyad (535g) or A23 do. Both of those are significantly wider. The Deep V does offer a shorter spoke length which is something of a plus.
I’m not entirely sure the added weight isn’t going to additional wall thickness in the rims you outlined. The Atlas for example isn’t particularly tall nor wide but still it is incredibly heavy. That weight must be somewhere. The Cliffhanger is wide for wider tires and that adds weight. But it also seems to have a reinforced spoke bed which allows for higher build tensions. The Atlas seems to have that too, but it’s not as obvious from the profile. The NoBS product description states that it has extra thick sidewalls and 15 % thicker spoke bed, which would account for the extra weight.
Mind you, different companies have different philosophies regarding how to make a rim durable. The DT Swiss TK540 is not particularly heavy at 540g, but it is one of the most durable touring rims out there. It has a relatively high profile and double eyelets (which DT Swiss seems to believe to work).
Ryde on the other hand makes some of the heaviest rims on the market and that weight is put directly towards the extra thick spoke bed, allowing for really high build tensions as well as added wall thickness. And of course the wider Andra models are particularly wide. The Andra line is also relatively high profile compared to squat road or MTB rims.
The common theme with touring rims is that they are typically both relatively wide to accept wider tires as well as tall for added vertical stiffness. Road rims are often high profile but quite narrow (though with the more common use of wide road tires that’s changing fast). MTB rims are often wide but quite low profile to save weight. You could say touring rims combine the best of both worlds.
Lateral stiffness is something I don’t consider to be at all important as the spokes are supposed to handle that aspect of the wheel.
Full disclosure: I do have Deep Vs on my touring bike. I don’t have them because of the strength and some would question using a rim with a 14mm internal width with 32 to 38mm tires. I don’t have a problem with the tires but others might. I don’t find them any different from any other rim I currently use, however. I still build with triple butted spokes because that’s where the strength is needed…not in the rim.
Deep V probably isn’t a bad rim for touring purposes but as you outlined, it is a bit narrow. That would be an issue for me but then again I like to dabble with the idea of some day mounting 45mm or even 47mm tires on my tourer.
All things considered, however, I’d have no issue touring on an A23. It’s stiff enough and strong enough for touring. It’s also the only rim in the Velocity line that offers off-center drilling which goes a very long way in terms of wheel strength by significantly reducing the drive side/nondrive side tension imbalance.
Now that asymmetric thing should definitely be more common! Sadly there aren’t many asymmetric rims ticking enough boxes. But perhaps that’ll change too in time.
Are broken rims a common problem? I’ve built, used, and destroyed a lot of wheels as well as rebuilt a lot of those destroyed wheels. I’ve worn out only a handful of rim brake rims in 40+ years of riding and building. I’ve cracked quite a few more rims. But I’ve, by far, broken far more spokes. A worn out or cracked rim can be relatively easily replaced as long as the rim is the same or has the same ERD without changing out the spokes. The wheel is just as strong as it was before.
Cracked spoke beds aren’t exactly uncommon. Too little material and too much tension or constant load will do that to a rim. It’s understandable to want a little extra reserve for the NDS spokes and crank up the DS near or slightly above the rated tension limit. I’ve done that before but luckily haven’t cracked a rim yet. Perhaps the eyelets do work.
I chose the Andra rim with the reinforced spoke bed because I knew I was going to be putting some intense loads on the wheels. I’ve mentioned before elsewhere that my latest touring system load was around 200kg. Some of it was on a trailer and thus not constantly loading the bike. However, when you brake all that weight is going to be transferred to the wheels. Add a bouncy gravel descent and I’m glad I chose beefy.
Oh, and the andra 321’s were cheap. They were something like 20 euros a pop. The reason I avoid Velocity is that they are way too pricey in the EU. I can get welded DT Swiss for cheaper.
I prefer not to break a rim because getting a new one with the same ERD on tour can be a serious Via Dolorosa even in the EU. It will likely require the shipping of a new rim to the destination we are at the time of rim failure. Next day deliveries are a thing if said rim is in stock at a vendor that provides such service.
However, the common wisdom for spokes is that once you’ve broken a few of them…estimate range from 2 to 5…the wheel needs to be rebuilt with brand new spokes. The reason for that is that the other spokes tend to get stressed with a spoke breaks and can ultimately fail as other spokes break. In other words, a broke rim is a fairly minor repair. A broke spoke is far more serious and more likely to result in needing a new wheel.
Luckily, I’ve never broken a spoke. My wife has and those wheels went to the trash soon after that.
My wheels with Dyad or A23 rims or even the slightly heavier Deep V are equally strong but weigh significantly less.
Now if you mean to say that the wheels you have with the Dyads, A23’s or Deep V’s are equally strong as the wheelset I described, they aren’t. The rim does matter. Well, if the A23’s are asymmetric that wheelset might well be stronger for less weight. Actually, maybe the Deep V’s too. But those are narrow so not a good fit for my use case. Dyads? Definitely not.
Aluminum rims need the double wall construction to make them stiff enough for use in a wheel. Single wall aluminum rims are around and they aren’t all that strong nor stiff. My point with steel rims is that even with a single wall, they are very stiff and strong but they aren’t any less prone to breaking spokes than aluminum is.
And my point is that a double walled extruded aluminum rim is a homogenous piece of metal with varying thicknesses. Those properties are going to make the rim stiffer than a steel rim which is just folded sheet metal. Those folds move about, and the underlying steel is still very thin. The spoke beds are thin and give more than an aluminum spoke bed in an aluminum rim. If you could extrude steel to a rim shape you could get a stronger stiffer rim, but it would also be far heavier.
While we are at it, one other interesting point about stiffness is that wall thickness matters more than the material. Steel is three times stiffer than aluminum. However, an aluminum sheet that’s three times thicker than a steel sheet is going to be much stiffer than the steel sheet.
Comparing steel rims to aluminum rims is apples and oranges.
Again, you are giving credit where it isn’t due. High profile rims have been available for a very long time. Bad spokes aren’t less likely to break just because of the rim’s profile. The improvement in materials of the spoke has more to do with the wheel strength and ability to use few spokes. As a large rider carrying heavy loads and riding in tough conditions, I still wouldn’t trust a low spoke wheel to stand up to the rigors that I put my wheels through. But I also realize that I don’t need to drag around hundreds of more grams of wheel weight than I need to if I use a better spoke.
High profile rims may have existed for a long time, but they haven’t been commonly used for a long time at all. Back in the day if you wanted an 80mm high rim, you’d pay it with an insane weight penalty. These days you can get an 80mm rim that weighs less than your average touring rim. High profile carbon rims are approachable because they do not weigh a ton. And they make a wheel stronger by shortening the spokes and making the rim stiffer than any touring rim every built.
Wheel durability has likely increased due to all the relevant factors improving incrementally. There are better spokes, there are better rims and there are better hubs.