I've made a video to explain the counter-intuitive fact that thinner (especially swagged) spokes are often more durable (if not technically stronger):
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How to prevent your spokes from breaking?
- Thread starter BikeGremlin
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A follow-up video offering a brief overview of what does, and what doesn't make sense when building (and designing) wheels:
A longer video explaining the reasons why that is so:
A longer video explaining the reasons why that is so:
Hello. Thanks for the wheel videos explaining how spokes work and don't break. I see many modern disk roads bike 11sp 12sp with 24 crossed spoke in 2:1 configuration. So for example 16 spoke 2x drive side and 8 spoke 1x non drive side. My bike has this arrangement with carbon rim and steel spoke. I have 25,000 km and no issues with wheels and never adjusted tension. Now I am interested to know if claims of bike wheel manufacturers about 2:1 is really better. And if it is better why is it not the
industry standard. I used your concepts, trigonometry and some basic engineering calculations and seems like 2:1 is better because it simply puts more spokes on the side that benefits most from more spokes. Am I missing something.
You mention in video about spoke breaking to use thicker spoke on drive side. That's seems similar to just add more spokes from non drive side.
industry standard. I used your concepts, trigonometry and some basic engineering calculations and seems like 2:1 is better because it simply puts more spokes on the side that benefits most from more spokes. Am I missing something.
You mention in video about spoke breaking to use thicker spoke on drive side. That's seems similar to just add more spokes from non drive side.
Hi,
Good, reasonable questions and points. Thank you.
Technically, generally:
Let me discuss radial lacing, along with using fewer non-drive-side (NDS) spokes - the two are interlaced.
Radial lacing on the non-drive-side (NDS) reduces the risk of NDS spokes getting loose. How and why?
On rear wheels, leading spokes lose tension when you pedal. NDS spokes have a lot lower tension to begin with on most modern highly dished rear wheels, so there can be a risk of their nipples starting to unscrew. Radially laced spokes always gain tension (and twist, which is bad) when you pedal.
However, with a rim that is deep and strong enough, each spoke can be tightened to a higher tension, so even cross-laced NDS spokes on the rear wheel won't run the risk of getting loose. That's even easier to acheive if you use one (or several) of the following:
All the above-listed designs have their pros and cons. However, if your goal is to have a strong and reliable wheel, any option that relies on fewer spokes (either in total or "just" on the NDS) results in a weaker wheel). The same goes for radial lacing.
Now, to address, the 8 NDS spokes laced 1x compared to 16 DS spokes laced 2x:
This is simply a matter of angles. With fewer spokes, you use fewer crosses to achieve the same angle relative to the hub and the rim. See the optimal number of crosses for more details.
Plainly put (my opinion):
Such a design has more to do with trends and marketing (hype) than it has with engineering. It may make some sense for riders who are racing and wish to reduce air drag as much as possible.
Modern spokes (and strong, stiff rims) can let wheel builders and designers get away with a lot of nonsense. I saw a fully radially laced front disc brake wheel - and its spokes weren't breaking, even with a tall, strong and heavy rider. Poorly designed and poorly built wheels don't fail right away if you use high-quality rims and spokes (they still don't last as long, aren't as strong, durable, robust etc.).
To use an analogy:
Automobile wheels could be held with 3 bolts only, but they usually have 4 or more as a safety feature in case any of the bolts fails. You could design and run a car with 3 bolts on wheels (in fact, some French manufacturer did just that for some lighter, cheaper models), but that would be considered unsafe by todays standards.
I believe my two paragraphs above can apply to this question. I'd just add that cycling industry is driven by marketing, not by engineering. It's like making toys. Automobiles and motorcycles have hundreds of horsepower and kilograms, and go hundreds of kilometres per hour, so no toying around there - but with bikes you can get away with anything, and the "pro peleton" riders will take their money and ride whatever the sponsors tell them to.
Based on my measuring, modern hubs transfer loads to the NDS spokes.
Still, if our aim was to go with a minimum possible number of spokes (for aero benefits, the needed extra rim and hub flange thickness would negate any weight savings gained by using fewer spokes), I suppose it would make some sense to use fewer spokes on the NDS.
Yes, exactly. The main downside of trying to achieve that using fewer (NDS or in total) spokes is that you lose redundancy in case of a spoke failure or other imperfection.
Relja
Good, reasonable questions and points. Thank you.
Technically, generally:
Let me discuss radial lacing, along with using fewer non-drive-side (NDS) spokes - the two are interlaced.
Radial lacing on the non-drive-side (NDS) reduces the risk of NDS spokes getting loose. How and why?
On rear wheels, leading spokes lose tension when you pedal. NDS spokes have a lot lower tension to begin with on most modern highly dished rear wheels, so there can be a risk of their nipples starting to unscrew. Radially laced spokes always gain tension (and twist, which is bad) when you pedal.
However, with a rim that is deep and strong enough, each spoke can be tightened to a higher tension, so even cross-laced NDS spokes on the rear wheel won't run the risk of getting loose. That's even easier to acheive if you use one (or several) of the following:
- Stronger, stiffer rim.
As already mentioned - that allows a greater total aggregate spoke tension. - Swagged (NDS) spokes.
They elongate more at a given tension, so will be less likely to get too loose when a rim compresses or (micro)rotates relative to the hub. - Thinner NDS spokes.
Thinner NDS spokes (compared to DS ones) will let the thicker, stronger, and less elastic DS spokes take more load, reducing the risk of the NDS spokes taking too much load by losing tension (and having the nipples loosening). - Using fewer spokes in total.
With a given rim strength and a maximum individual and total, aggregate spoke tension, having fewer spokes mean you can (and usually must) use higher tension for all the spokes, including the NDS spokes, thus reducing the risk of them unscrewing (36 spokes at 100 kgf is the same total tension as 24 spokes at 150 kgf). - Using fewer NDS spokes.
Similarly to the previous point, using fewer NDS spokes will allow each of them to use a higher tension, thus reducing the risk of it coming loose. - Radially lacing the NDS spokes.
As discussed above, radially laced spokes don't lose tension when you pedal (or brake using a disc brake for that matter), they twist and gain some tension.
All the above-listed designs have their pros and cons. However, if your goal is to have a strong and reliable wheel, any option that relies on fewer spokes (either in total or "just" on the NDS) results in a weaker wheel). The same goes for radial lacing.
Now, to address, the 8 NDS spokes laced 1x compared to 16 DS spokes laced 2x:
This is simply a matter of angles. With fewer spokes, you use fewer crosses to achieve the same angle relative to the hub and the rim. See the optimal number of crosses for more details.
Plainly put (my opinion):
Such a design has more to do with trends and marketing (hype) than it has with engineering. It may make some sense for riders who are racing and wish to reduce air drag as much as possible.
Modern spokes (and strong, stiff rims) can let wheel builders and designers get away with a lot of nonsense. I saw a fully radially laced front disc brake wheel - and its spokes weren't breaking, even with a tall, strong and heavy rider. Poorly designed and poorly built wheels don't fail right away if you use high-quality rims and spokes (they still don't last as long, aren't as strong, durable, robust etc.).
To use an analogy:
Automobile wheels could be held with 3 bolts only, but they usually have 4 or more as a safety feature in case any of the bolts fails. You could design and run a car with 3 bolts on wheels (in fact, some French manufacturer did just that for some lighter, cheaper models), but that would be considered unsafe by todays standards.
I believe my two paragraphs above can apply to this question. I'd just add that cycling industry is driven by marketing, not by engineering. It's like making toys. Automobiles and motorcycles have hundreds of horsepower and kilograms, and go hundreds of kilometres per hour, so no toying around there - but with bikes you can get away with anything, and the "pro peleton" riders will take their money and ride whatever the sponsors tell them to.
Based on my measuring, modern hubs transfer loads to the NDS spokes.
Still, if our aim was to go with a minimum possible number of spokes (for aero benefits, the needed extra rim and hub flange thickness would negate any weight savings gained by using fewer spokes), I suppose it would make some sense to use fewer spokes on the NDS.
Yes, exactly. The main downside of trying to achieve that using fewer (NDS or in total) spokes is that you lose redundancy in case of a spoke failure or other imperfection.
Relja
Thanks for the response. For additional information my wheel is 45mm deep. Spokes are steel sapin cx ray. Based on geometry I worked out the angles of DS and NDS spoke hub to rim. The ratio of the Sine of the spoke angles worked out to very close to 2. So I can see why 2:1 is designed so that tension on DS and NDS can be similar and high at same time. The 2:1 arrangement resolve problem of 1:1 arrangement where NDS spoke tension should about half of DS to balance lateral force on rim. I was wondering if there is some compromise of stiffness with 2:1 and when looking in radial direction but seems to be better because more spokes on DS with steeper angle. Lateral stiffness is better because more spokes on DS to compensate for weaker DS again due to angle. Torsion from pedal drive there is same number of pulling spokes 12 across DS and NDS.Hi,
Good, reasonable questions and points. Thank you.
Technically, generally:
Let me discuss radial lacing, along with using fewer non-drive-side (NDS) spokes - the two are interlaced.
Radial lacing on the non-drive-side (NDS) reduces the risk of NDS spokes getting loose. How and why?
On rear wheels, leading spokes lose tension when you pedal. NDS spokes have a lot lower tension to begin with on most modern highly dished rear wheels, so there can be a risk of their nipples starting to unscrew. Radially laced spokes always gain tension (and twist, which is bad) when you pedal.
However, with a rim that is deep and strong enough, each spoke can be tightened to a higher tension, so even cross-laced NDS spokes on the rear wheel won't run the risk of getting loose. That's even easier to acheive if you use one (or several) of the following:
- Stronger, stiffer rim.
As already mentioned - that allows a greater total aggregate spoke tension.- Swagged (NDS) spokes.
They elongate more at a given tension, so will be less likely to get too loose when a rim compresses or (micro)rotates relative to the hub.- Thinner NDS spokes.
Thinner NDS spokes (compared to DS ones) will let the thicker, stronger, and less elastic DS spokes take more load, reducing the risk of the NDS spokes taking too much load by losing tension (and having the nipples loosening).- Using fewer spokes in total.
With a given rim strength and a maximum individual and total, aggregate spoke tension, having fewer spokes mean you can (and usually must) use higher tension for all the spokes, including the NDS spokes, thus reducing the risk of them unscrewing (36 spokes at 100 kgf is the same total tension as 24 spokes at 150 kgf).- Using fewer NDS spokes.
Similarly to the previous point, using fewer NDS spokes will allow each of them to use a higher tension, thus reducing the risk of it coming loose.- Radially lacing the NDS spokes.
As discussed above, radially laced spokes don't lose tension when you pedal (or brake using a disc brake for that matter), they twist and gain some tension.
All the above-listed designs have their pros and cons. However, if your goal is to have a strong and reliable wheel, any option that relies on fewer spokes (either in total or "just" on the NDS) results in a weaker wheel). The same goes for radial lacing.
Now, to address, the 8 NDS spokes laced 1x compared to 16 DS spokes laced 2x:
This is simply a matter of angles. With fewer spokes, you use fewer crosses to achieve the same angle relative to the hub and the rim. See the optimal number of crosses for more details.
Plainly put (my opinion):
Such a design has more to do with trends and marketing (hype) than it has with engineering. It may make some sense for riders who are racing and wish to reduce air drag as much as possible.
Modern spokes (and strong, stiff rims) can let wheel builders and designers get away with a lot of nonsense. I saw a fully radially laced front disc brake wheel - and its spokes weren't breaking, even with a tall, strong and heavy rider. Poorly designed and poorly built wheels don't fail right away if you use high-quality rims and spokes (they still don't last as long, aren't as strong, durable, robust etc.).
To use an analogy:
Automobile wheels could be held with 3 bolts only, but they usually have 4 or more as a safety feature in case any of the bolts fails. You could design and run a car with 3 bolts on wheels (in fact, some French manufacturer did just that for some lighter, cheaper models), but that would be considered unsafe by todays standards.
I believe my two paragraphs above can apply to this question. I'd just add that cycling industry is driven by marketing, not by engineering. It's like making toys. Automobiles and motorcycles have hundreds of horsepower and kilograms, and go hundreds of kilometres per hour, so no toying around there - but with bikes you can get away with anything, and the "pro peleton" riders will take their money and ride whatever the sponsors tell them to.
Based on my measuring, modern hubs transfer loads to the NDS spokes.
Still, if our aim was to go with a minimum possible number of spokes (for aero benefits, the needed extra rim and hub flange thickness would negate any weight savings gained by using fewer spokes), I suppose it would make some sense to use fewer spokes on the NDS.
Yes, exactly. The main downside of trying to achieve that using fewer (NDS or in total) spokes is that you lose redundancy in case of a spoke failure or other imperfection.
Relja
Example 24 spoke 1:1. Arrangement has DS 120kgf x 12 = 1440kgf total tension. NDS has 60kgf x 12 = 720kgf. Total tension 2160kgf. Now for 2:1. DS 90kgf x 16 = 1440kgf. NDS 90kgf x 8 = 720kgf. Total tension is same 2160kgf but is similar in all spokes. Why is this not better to have more uniform tension in spoke?
I understand that if materials are strong enough then design arrangements can be made less optimum for strength and consumer isn't affected In this case it seems like 2:1 has actual technical advantages. I can't see the disadvantage except as you describe the redundancy safety of fewer spokes on NDS. If one NDS spoke breaks while riding I don't think the wheel will collapse and buckle. Ok, maybe some puts a stick in the spokes while going 50kph but then you have other problems. I am getting another set of carbon wheels but these will have 24 spoke 2x 1:1 arrangement so that's what got me thinking about 2:1 vs 1:1. I have many years of good use from the 2:1 wheels and since it's very popular design now I was questioning why some similar wheels still are 1:1.