elcruxio

Shape is more important than wall thickness. A taller rim is going to be stronger and resist deformation than a shallower rim that has the extra material put to wall thickness. That isn't to say that wall thickness doesn't matter because it obviously does. However it is less important a consideration than shape.

Typically your average strong touring rim is going to have a pretty high profile. Of course then there's deep V's which probably wouldn't be a bad choice overall.

Of course then there are reinforced spoke beds like the ryde andra line of rims, but that doesn't directly affect the stiffness of the rim. Then again there's also added wall thickness in the andra rims overall so they're pretty beefy and indestructible. My tourer has andra 321 with 36 DT Swiss alpine 3's. Those are pretty strong wheels.

Now that all would be true if all factors were equal. But they aren't are they? There aren't any steel rims with the same profile and wall thicknesses of aluminum rims. Steel rims typically have pretty squat profiles and they lack the double wall construction of aluminum rims as well as the material uniformity and wall thickness variability you get with extrusion. If you've got a solid block of material or a piece that's a bunch of folded sheets, the solid block is going to be stiffer.

There's probably a lot of truth to that. that's one of the reasons why I'm looking into rope wheels. Dyneema wheels can get crazy light and the rope material is much better at handling detensionings than steel. And since it's multiple strands there's no material uniformity to worry about.

One of the reasons why wheels can go with lower spoke counts is higher rim profiles. Once high profile carbon rims entered the foray, you could effectively build "smaller" wheels with shorter spokes and with the added benefit of a rim that exhibits practically zero deformation in any direction.

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.

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.

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.


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.

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.

My wheels with Dyad or A23 rims or even the slightly heavier Deep V are equally strong but weigh significantly less.

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.

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.

Russ Roth

I've seen penny farthing wheels built like this and have heard that it was common on early wheels. There is a tool for doing this but they aren't made for spokes anymore, you have to buy a tool for installing the bend in the metal end of a pullcord, it puts in a bend that matches the hub and won't pull out even when built to proper tension.

Shape matters a lot and you sort of contradict yourself here. You mention no extra material is needed except the material needed to make the shape but that's still more material which would increase stiffness. Further, shape by itself changes stiffness. Take all the metal of an I-beam and lay it out flat and it won't handle anywhere near the load of the same metal in I-beam shape. It isn't just the amount of metal that matters but the shape as well.
Although I believe spoke metallurgy and design have changed the strength, so has similar changes in material and design of the rim. Older rims were easy to flex by hand vs newer rims in general.

But spoke breakage isn't necessarily a reflection of wheel strength vs spoke strength, picking the right components for the job is important. But wheel strength is more the ability of the wheel to resist deformation and maintain its shape. Proper spoke tension is important to this point as is the rim material.

The stronger the wheel as a unit, and the better the tension is maintained, the better every part of the system will hold up. Rolf as an example didn't use stronger spokes then what was available at the time they first came out and he attributed the strength to rim design and profile. Giving all credit to the spokes ignores the system and the biggest improvements there have been the rims.

elcruxio

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.

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.

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.

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.

Luckily, I’ve never broken a spoke. My wife has and those wheels went to the trash soon after that.

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.

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.

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.

cyccommute 

The issue as I see it is the material used for the rim construction. Aluminum isn’t a stiff material. Adding additional aluminum doesn’t really do that much to increase the stiffness of the rim, especially if a similar wall thickness is used and the overall width of the rim is increased. Any aluminum rim…or even steel one or carbon for that matter…is going to deflect upwards when the weight of the system is at its highest over a particular section of rim. The spokes in that area are going to decrease tension and the spokes elsewhere are going to increase tension in response. This flexes the spoke heads and leads to fatigue.

Shape of the rim has little to do with this flexing of the rim. The difference in the shape just isn’t different enough to make that much difference.

Yes, there has been better design and metallurgy for the rim but the rims never really suffered that much from failure. Again, I’ve not experienced that many rim failures outside of a few worn out braking surfaces and some cracks. Rims don’t fail catastrophically like spokes do.

Everyone assumes that spoke tension is bad whenever this is discussed. Let’s assume that the spoke tension is “proper”. Spokes still break. Additionally, everyone starts from the assumption that a strong rim makes for a strong wheel. Why? What does the rim do that adds to wheel strength? If the rim were directly attached to the spokes like a wagon wheel or a car wheel, you’d have a valid argument. But the rim has no connection to the spokes. It is allowed to float on the spoke. The rim is always undergoing deformation as long as the bike is under load. The spokes are what resist the rim’s natural tendency to fold up when either vertical or lateral pressure is put on the rim.

I agree that care should be taken when picking components for a wheel. Spokes are on of the components of the wheel. But, all too often, spokes are an afterthought. Even here on the Bike Forums, there are endless questions about which hub to pick and which “strong” rim to pick but very few people even consider which spoke to use. If the problem is broken spokes, the solutions is not a different rim.


And, there it is again. No one gives credit to spokes at all. All of the credit goes to the rim strength. It’s misplaced credit.

cyccommute 

Well none of the Velocity rims are heavy when compared to the Ryde Andras. The Atlas and NoBS rims have that extra void running down both sides of the rim which adds significantly to the amount of material used. The Cliffhanger and A23 only have the single void. Yes, there is a thicker spoke bed on the NoBS but I question if that is really necessary or if it contributes anything. Tension might be able to run a little higher but like I said above, aluminum is a soft material and adding a little bit more doesn’t necessarily have a huge effect.

What do you mean by “durable”? Again, broken rims isn’t that much of an issue. I’ve cracked a number a number of rims over the years. They are about equally split between supposedly heavy duty rims and supposedly light duty rims. That includes Mavic A119 which cracked around the eyelets. I haven’t noticed a significant issue with the lighter (supposedly weaker) rims as compared to the heavier (supposedly stronger) rims. That’s partly what has lead me to basically ignore the conventional “wisdom” that heavy rims are needed for a durable wheel.

Yea, I was very surprised when I looked at the weight of those rims. Uff! I can’t figure out why the Andra 30 disc rim is about 50g heavier than the already massively heavy 786g rim brake rim. Nor can I figure out why they would need to be that heavy. The Andra 40 disc weighs in at a whopping 935g compared to the already heavy Cliff Hanger at 675g. That a full half a kilogram of weight for a pair of rims and almost a kilogram heavier than the A23. I really don’t see why the extra weight is needed.

Not an idea I subscribe to. People want wide tires for vertical stiffness and then run them flat because the ride is too jarring. I have no problem cornering nor any issues with running my pressures way higher than is the current fashion with wide tires on narrow rims. My mountain bikes all have 17mm rims with 55mm tires. I run narrow rims to save weight

And if the spokes are stronger they handle that lateral stiffness far better. They also handle the vertical stiffness better because they can handle the loading/unloading cycle of the spoke as the wheel rolls better.

The only…ONLY…reason I use Deep Vs is for vanity reasons. I could get them in red and that matched the color scheme of my bike. As a rim, they are “meh” but that’s the way I feel about most any rim. As long as the rim is light, it really doesn’t matter to me what the profile or supposed strength is. I’ve found it really doesn’t matter.

Yes, but like triple butted spokes, people consider them to be too weird. When my Deep Vs are gone, I’ll be using the asymmetric A23…if it is still around

That’s exactly what I’m saying. I’m living proof. This bike with me, bike, and touring load is around 145 kg (bike, luggage, and me). I’ve had zero issues with the wheels and spokes in thousands of miles of touring.


This one is carrying a load of close to 140 kg but is subjected to far more demanding riding. The other bike gets ridden on most smooth roads. This one is ridden on unpaved roads where the term “road” is somewhat nebulous. It’s using Aeroheats which are similar to the Dyad.




Have you ever had to break down a rim for scraping? Without spokes, you can clamp an aluminum rim in a vise and fold it over by hand. You can’t do that with a steel rim. Steel rims have to be cut down with a grinder if you want to reduce the size. You can also push down on an aluminum rim and deform it significantly. A steel rim won’t bend nor deform even with my weight.

That’s not how that works. An aluminum sheet that is 3 times the thickness of a steel sheet is going to have about the same stiffness as the steel sheet. Bicycle frames have been using this difference for years. Aluminum tubing has…and has to have…a thicker wall than steel tubing. There were bicycles made back in the 70s (Alan?) that used the same tube diameter as steel but with thicker walls. They were noodles.

Cheese to chalk, please. Science has shown that apples and oranges are, indeed, comparable. But for the purposes of rim stiffness, steel rims are significantly stiffer…even in a flat profile…than aluminum ones are. If you want a strong rim, there is nothing quite as strong as a steel rim. A steel wheel built with light spokes isn’t stronger than an aluminum rim built with strong spokes.

I don’t disagree, however, as I pointed out in post 30, far too many people concentrate on the hub and rim and treat spokes as an afterthought. If anything, the rim should be treated as the afterthought. Get a good rim, of course, but you don’t have to get an overly heavy one to build a strong wheel…if you consider the spokes that you are using in addition to the other components.

djb

hey Cycco, sort of off topic, but on my Troll I have a set of those same XC 717 rims, narrow internal diameter, probably exactly the same as yours. They have been on the bike now for all kinds of trips, and I've been pleasantly surprised by how well they have held up. The rear rim even got a slight ding in it six years ago and has been fine since, didn't even break a spoke.
I found it interesting that a rim designed for XC mountain biking has performed so well touring, but I do realize that me and even the heaviest of my touring loads is probably less than a lot of much heavier riders with no luggage at all, so being a lightweight has its advantages with regarding rim choice and what will work.

I just got some DT swiss touring or e bike rims to one day replace the 717s.

cyccommute 

XC mountain biking is probably more demanding than touring when it comes to wheels. I’ve been using the 717s for a long time on mountain bikes. Never had much of a problem with them. I’ve more recently used Velocity because they come in 26” 36 hole rim brake sizes.

djb

My 717s are 32 spoke, and I really did wonder how they would be on the rough roads sometimes on my Latin American trips, but they performed really quite well.
But again, I'm only 135 so a lot of leeway.