Pulling and Pushing Spokes
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- Опубліковано 30 лис 2024
- Explains the difference between so-called "pushing" and "pulling" spokes in a bicycle wheel. Wheel builders use these terms to distinguish between orientations of spokes in a bicycle wheel, but all spokes are really pulling spokes that are under tension. This short video is easy to understand and also shows how torque is transmitted through the drivetrain from the pedals to the wheels.
Wow, what a great teacher, and spectacular graphics! I will have to watch this several times before really "getting it". You are very generous sharing your expert knowledge with those of us who love bikes but don't entirely get what's going on.
Bill moulds presentations are training center level!
Hello mr. Bill, not only did I enjoy watching your video, but I also learned a lot and helped me claarify many doubts I had about how the spokes of a bicycle wheel work. Me I really like building bicycle wheels. Thank you mr. Bill, regards from México City.
Cesar, thank you very much for the nice comment. Bill
Wow! Thank you for putting so much effort into this!! 👋👋👋
A few of my cycle wheel's spokes had become lose, and I wondered how even is wheel not falling apart. You have very nicely presented how the spokes work. Thank you. But I still do not understand how load is balanced in this mechanism. Also please keep making more educational content as this, it was a pleasure watching.
Thank you, sir
I have wondered about this for years. Good presentation, thank you!
Thank you for the clear explanation it really helped me understand the physics behind this. Very good video!
Thank you, Allan
Great video, I was looking for an answer to this question and this explained it in a very understandable way
Thank you, Grant
I have no doubt that this explains long-known bike vernacular & engineering.
Yet, I've long wondered if the physics of spoked bike wheels "mirrored" the theory behind "suspension bridges"..? Means: is the entire weight of bike plus rider "hanging" on the spokes above the hub?
Just for fun...
Yes, and on a bike with a disc/hub braked 32 spoke front wheel under brakes the bike and rider are supported by just 4 pulling spokes in the top half of the wheel.
Quite a stressed tensegrity.
Thank you for this well made vid - I relly didn't understand this pulling/pushing (especially the pushing part) until now.
Sarah, thanks for your nice comment. Bill
@@BillMouldWheels poop
Great video , thank you for the explanation 👍
Unstated, at least by 2:00, is that wagon wheel hubs/axles rely on "compression" of the downward-pointing spokes, whereas the bicycle wheel's hub hangs from the upward-pointing spokes, which are under "tension".
You are correct that wagon wheels work under compression, but I didn't talk about that because I was differentiating between pushing and pulling spokes on a bicycle wheel. All spokes in a bicycle wheel are under tension. Perhaps surprisingly, the wheel doesn't really hang from the upward spokes. In the load bearing zone, spoke tension goes down, but it goes up rather evenly on all the others, even those on the sides. I have mounds of data that show that. I find the term "hang" to be misleading.
Great explanation. THX!
Nice presentation
Intentioned thick spokes is half the story.
A wagon wheel has compression spokes, essentially chunky spokes.
Thanks, Bill! Never knew I needed to know this
Thank you, amazing!
Wow great video. Would the forces be opposite when applying disc brake pressure on the wheel? The tension on the red counterclockwise pulling spoke would increase? Also would you consider the red counterclockwise pulling stroke the "leading" spoke or "trailing" spoke? I'm asking because Shimano recommends to install spokes in a very specific manner regarding elbows in vs elbows out depending on the drive side vs brake side. This makes sense that under acceleration the green spoke is under greater tension therefore Shimano sets these as elbows out maybe because the spoke gets more support from the flange with elbows out and/or is in a wider position (increased bracing angle?). For the disc brake side, Shimano recommends the red spoke counterclockwise pulling (leading?) be placed with elbows out. It seems most wheel manufacturers don't pay attention to this detail and lace them opposite of Shimano recommendations. My DT Swiss straight pull hub wheels use the outside position in place of elbows out, which still seems to follow Shimano recommendations.
Thanks great video
N thank you for teaching sir
Great content, thank you very much!
Thanks, great video! What factor decides which wheel type (wagon or bicycle type) is best suited for a given application (bicycle, car, train, etc...). Is it just the total weight?
Tension spoke are efficent only when you have to carry low weight and the dimension of the weel is not too small. In fact in cars is used flanged whells and spoke well was used rarely and for aesthetics reasons meanly
Bill.....you are likely aware of the extremely light BERD fabric/cord spokes.....Not that i intend to use them yet but it seems obvious that these cannot work as push spokes but only as pull spokes. So what advantage remains for these to be laced as 2 or 3 cross?
Graydon, actually, all spokes are pulling. "Pushing" spokes are what wheel builders refer to, but no spoke can actually push in the sense of applying a compressive force. When you accelerate, some spokes pull more in a CW direction, and others pull more weakly in a CCW direction. Thus, the resultant CW torque. You and I should have a long conversation.
@@BillMouldWheels - sounds good. The term “push” is counter-intuitive so i had to think harder.....the “push” spokes are simply under less tension relative to the “pull” spokes. Tension trumps compression for all spokes....
Hi Bill, thank you for all the extremely explanatory videos you post, can tell that you are an educator at heart. I have a question, something I've been after for a while but I cannot figure it out. Let's say I have a 18/8 Stainless steel, 14G spoke that can take a max tension of 3300 N before it snaps. What would be the max tension a 45# Steel, 14G spoke before it breaks? I guess it's lower, but I might be wrong. Curious about what you'd say. Cheers
Ruben, I would have to know the tensile strength of the steel in question. Your estimate of 3300 N for a 14G stainless steel spoke looks about right.
@@BillMouldWheels well you got me there. What I meant to say is that if you have a carbon steel, cheap, made in china kind of spoke, what would be, in average, its max tension? Close to those 3300N for inox spoke or way below that number? Cheers
@@cbitwchilebrointaiwan872 Likely less than 3300N, but it wouldn't be hard to test. Don't forget that max tension is one thing and the yield point is another. Spokes experience a permanent stretching, i.e., increase in strain, long before they neck down and fracture. It is important that spoke tension stay within the elastic region of the spoke.
@@BillMouldWheels Legend! Thanks again, Bill.
How to insert 16 holes hub to 32 holes rim
Kudos for your very informative videos, sir!
Right now I'm trying to build my first set of wheels. But accidentally, I laced the CW pulling (some called it trailing) spokes at rear freewheel side, with head position outside the flange. Now it gets me thinking if I'm lacing it wrong since another bike of mine laced in other way...
When I'm checking on some bike forums, seems debates over decades... Is there any mechanical purpose to lacing it in such way? Or does it really matter?
Thank you very much for the nice comment. It is not that important, and I certainly would not disassemble the wheel you have already built.
Well done and very thorough. Radial spokes miss the mark...
Thank you, sir. Bill
I've live my life thinking bicycle wheels worked like wagon wheels
Don't beat yourself up. Lots of people think that and are still happy.