Bicycle spokes are far more complex than most people give them credit for being. There are several spoke patterns possible for different purposes. The most popular is called "cross 3" which is a good general purpose pattern giving reasonable strength-to-weight. Cross4 is typically used on higher load situations, such as heavy duty touring bikes. Lower cross patterns use shorter spokes, thus are lighter, and used for racing. You can even use a radial spoke pattern, but typically that would be used on a wheel with no torque (not the drive/rear wheel, and ideally no brakes).
All of the cross patterns are also woven, so they go over some spokes and under others. A single wheel can also mix patterns, such as Cross4 on the drive side of the rear wheel, and radial on the non-drive side. And on top of all of that, wheels have different numbers of spokes from roughly 20 to 48 or more, and on more modern race bikes the spokes are not necessarily spaced evenly. On wider rims, spoke nipples may also be offset from the center plane of the rim. In some wheels, all spokes might go to the inside or outside of the hub, but in average wheels, the spokes alternate inside, outside on each left and right flange.
Short answer is that if you are looking for a correct model of the spoking pattern on a bicycle, you will have to provide a lot of other information to get something specific. You can buy a book called The Bicycle Wheel written 30 some years ago by a guy named Jobst Brandt. It will answer some of your questions, and raise others.
When I used to assemble real bike wheels, I did it by taking adjacent spokes inserted into the hub from opposite directions, and separate them on the rim by a set number of holes. I don't remember any of this off the top of my head. I worked in a bike shop, and we had reference wheels and reference books for this. In the real world, spokes are work hardened stainless steel, and hubs are typically machined billet aluminum, so the final assembly and tensioning involves some deformation of the hubs.
Getting around to answering your question, I don't remember exactly how I did it in the example in the book, but I would probably mate a point on the rim to the axis of the spoke, and how you mate the spoke to the hub depends in part on if you modeled any straight area after the head of the spoke, which I would make concentric with the hole in the hub. You can't really hope to do this exactly in CAD since the assembly of spokes in a wheel definitely involves some permanent deformation of both hub and spoke.
If you are talking about the kids bike on the cover of the 2007 book, that was just taken from a photo somewhere. It's not an actual SW model. There is a bike used as an example in several chapters, and the wheels for that are correct for either cross3 or 4, and probably 36 spoke 26" wheels. I was a little lazy and did not weave the spokes, which would bend them slightly. It just didn't seem worth the time based on what I needed the example assembly to show. The spokes I used are butted spokes, but I have forgotten what gage.
Just as an interesting aside, how is the stress distributed in a bicycle wheel when you apply a load at the axle, with the tire against the ground?
Whoa, excellent reply. I used to bend my wheels every hour or so when I was learning proper trials techniques on my mountain bike (used to be a fairly technical rider), so I knew how to true a wheel quickly with spoke wrenches. Never built a wheel, though.
As to the question, from what I understand, the spokes are tension devices and not compression. So, supposing weight is applied to the wheels from a rider on the bicycle, the spokes generally pointing up from the hub are pulled on to keep the hub from falling, so the tension is in the generally vertical spokes above the hub. Other factors would change this (such as jumping off large ledges and landing on the ground, harsh braking or other acceleration, or slapping a soccer ball with the front wheel) to whichever spokes would best absorb tension energy as applied from the rim to the hub.
Once our snow melts, I'm eager to (attempt) riding my old non-suspension, super-light Bridgestone MB-1 again--at 9,000 feet. Lots of ways to achieve oxygen deprivation around here.
Is there anything Matt doesn't know about?! I'm impressed, Matt, simply because I'm a cyclist/tinker and have built several sets of wheels. Brandt's book is still a classic, it sits on my cycling shelf with several others just on wheels.
To the topic at hand, how to do a spoke in SW? As one poster said, what do you want to do with it? I've created them in-context, with a hub & wheel assy. I've also created them as part features, where the wheel assy is a single part. In any case, you have to ask 'Why am I modeling this?' That will tell you how much detail to use, and how important it is to be 100% accurate in your depiction. Are you modeling the spoke head? What about the nipple? The hole in the wheel, is it riveted? What about spoke holes in the hubs? Radiused or chamferred?
If you just want to show a 'spoke pattern', make it as simple as possible with in-context point-to-point creation & no mates. Then you can resize your hub & wheel, and the spoke will resize. If it was only that easy on a real bike wheel!!
P.S. You don't have to cross spokes if you don't want to... theoretically ... I figured I'd better add a disclaimer before someone gets hurt after reading my post and looking at my wheel lacing. BTW, that's a front wheel. I'd NEVER do that to a rear wheel.
There are plenty of things I don't know, and only a few that I do. Like Bluegrass, Bicycles, trombones, a fair amount of classical music, and classic literature. I don't know how to get to the local walmart, how to set up my own FTP site on my local computer, how to bake anything I can't see, or anything electrical. Also, I'm the world's most dangerous skier - I can make 'em go, but I can't stop. I can't match my shirt and pants, and I seem to be incapable of ironing.
Anyway, I've never seen spokes done that way. I would assume it would twist the hub. I stopped keeping up with cycling about 10 years ago, so there are plenty of new things I haven't seen. The world was just getting 8 speeds when I stopped. The new shifting and brake systems are all new to me.
By the way, those wheels are my old Bullseye hubs, Avocet slick tires, and some Matrix (Trek brand) narrow mt bike rim. Bullseye hubs are the greatest.
There's more than one speed on a bicycle?
Perhaps you should start by telling us whether you are modelling for manufacture, presentation or simulation. Until we know what you want to achieve, we can only recount our tales of our misspent youth.
Now the real question remains:
All things being equal, did you learn more from this thread than your entire semester in class?
Yes I did! most definately. You all are very nice and helpful...and I'd say a bit playful.
Not a remedial question at all..... There was just a bit more nuance to the subject of modeling wheel spokes then you realized. :-)
Context is everything when designing. The end goal will affect the process up front.
Great question, I actually learned a lot that I did not know about wheels and spokes myself.
ok we figured it out....we needed to change the configuration of the spoke part...Front in vs front out....
Congrats! Way to stick to it & not give up!
I was just about to stop working and take on this challenge myself. Thanks for posting the files, I'll still have to look at it now, ya know.
Enjoy your class!
Here is a bicycle front wheel I created with SolidWorks some years ago.
The reason why I did that was to find out how the spokes are arranged in a common wheel.
Some internal details, like ball bearings, are missing.
Here is a bicycle wheel I created for a project. I made it as a series of revolves, and I made the sopkes circular arrays. it is not correct, but it serves my purpose. I hope it gives you a idea of how to start.
3X spoke pattern, 2mm DT spokes and nipples, Shimano deore disc hub, mavic F519/XM719 rim, hayes disc rotor.
To model one correctly, you've first got to understand how to lace them correctly.
There are four seed spokes, the rest are patterned off these. You need to mate these four, rotate the rim or hub until the spokes protrude into the nipples the same in leading/trailing then lock it down and create the pattern.
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