What kind of spokes give the strongest wheel strength? I notice most wheels have spokes that are just rods extending radially from the center. Is this generally as strong as it gets, or is this bc of fabrication limitations? What about arched spokes?
Any suggestions or pointers as how I should get started in analyzing the strength of a wheel mathematically?
2007-01-11 08:20:41 · 3 answers · asked by Johan S 1 in Science & Mathematics ➔ Engineering
RE to Amy B: What do you mean by "give"? Also, why is there no force acting on the bottom of the wheel?
2007-01-11 17:00:23 · update #1
Amy has a lot of good points in her analysis. She is correct in her assessment of the weight on the axel pulling down (tension) on the upper spokes. As you go around the wheel in degrees the tension changes from the axel (hub) to the wheel rim. The weight exerts pressure on the wheel rim and the spokes on the horizontal keep the wheel true and not go out of round, or become oval.
As the bicycle wheel turns the spokes support the axel at the top of the spin. As the spokes rotate to the horizontal the tension pulls on the rim to keep the circle true and transfers the weight of the bike to the rim. The spokes on the bottom 'rest' and carry no load or tension because the horizontal spokes transferred the weight of the bike and rider to the rim, innertube and tire. The transfer of weight is gradual in degrees from spoke to rim. That is why bicycles have so many spokes. That little bit of information was just for the front wheel. The back wheel has the additional stresses of tortional force because it carries more of the weight and also propels the bike. (Same goes for autos. Whichever wheel(s) propel the vehicle) Here is a site sponsored by Purdue Engineering that can explain some of what I just wrote: https://engineering.purdue.edu/MSE/GOT-MATERIALS/Sports/Lindamood.whtml
There is flexing of the spokes during rotation. If you have ever put your hand on the spokes after a hard bike race the spokes feel warm. You would think because of the motion they would be cool, but the rapid flexing as the wheel rotates creates heat. This heat causes metal fatigue. As for the arched spokes they would flex more and have a greater chance of fracturing due to metal fatigue. Most spokes are chromed and chrome is not all that flexible, it could chip and flake off.
Henry Ford's cars had spokes. As new ways of developing and casting metal have been developed we have been able to go from many spokes to the four, six, seven, eight and more we have today on our automobiles.
Here is a unique site on the mathmatics of spokes: http://www.bikexprt.com/bicycle/pitcheqn.htm This site details wheel-building: http://www.sheldonbrown.com/wheelbuild.html I was amazed at the complexity involved in rebuilding bicycle wheels.
The last site has links to the mathmatics of wheel building. It's not a glitzy site, but it more than makes up for it in the amount of detailed information. Wish I had this site when I was teaching my son bits and pieces of bike repair.
Hope these sites help. Good luck with your project.
2007-01-18 05:11:20 · answer #1 · answered by Ding-Ding 7 · 2⤊ 1⤋
keep this in mind...the spokes are working in tension not compression.
Think about a bicycle. The weight of the bicycle and the rider are connected to the wheels at the axel (center of the wheel). The axel is "pulling" on the spokes that connect to the wheel above, not pushing down to the wheel below.
An arched spoke would create more "give". It would kind of act like suspenion...interesting way to accomplish suspenion.
2007-01-11 09:19:22 · answer #2 · answered by Amy B 2 · 0⤊ 0⤋
its right on the engine plate and cal horse power a h p =100
2007-01-11 08:28:34 · answer #3 · answered by Anonymous · 0⤊ 1⤋