{"id":548,"date":"2026-04-01T17:11:05","date_gmt":"2026-04-01T21:11:05","guid":{"rendered":"https:\/\/commons.princeton.edu\/58-tiger-cub-2\/?p=548"},"modified":"2026-04-01T17:11:05","modified_gmt":"2026-04-01T21:11:05","slug":"week-9-class-notes-posted-by-eugene","status":"publish","type":"post","link":"https:\/\/commons.princeton.edu\/58-tiger-cub-2\/2026\/04\/01\/week-9-class-notes-posted-by-eugene\/","title":{"rendered":"Week 9 Class Notes (posted by Eugene)"},"content":{"rendered":"<p><span style=\"font-weight: 400\">Monday Notes<\/span><\/p>\n<p><span style=\"font-weight: 400\">No recap<\/span><\/p>\n<p><span style=\"font-weight: 400\">Presentation by Bill Becker &#8211; Discovering the Motorcycle Wheel<\/span><\/p>\n<p><span style=\"font-weight: 400\">About Bill &#8211; retired architect, worked with Littman on toy trains at Franklin Institute. Did a lot of educational work, nonprofit work. Decided he wanted to work on motorcycles after retiring, been a long interest. Lots of shop experience, loves to make things and now focuses on antique toys and building them from scratch<\/span><\/p>\n<p><span style=\"font-weight: 400\">Looking at wheel &#8211; through lens of materials, design, and physics<\/span><\/p>\n<p><span style=\"font-weight: 400\">Round &#8211; good geometry for moving things<\/span><\/p>\n<p><span style=\"font-weight: 400\">1790 &#8211; first bicycle, made out of wood and radial spokes<\/span><\/p>\n<p><span style=\"font-weight: 400\">1885 &#8211; motorized bicycle, still wooden and radial spokes but has a transmission<\/span><\/p>\n<p><span style=\"font-weight: 400\">1895 &#8211; no longer wood, metal spokes and metal hub, horizontal motor with jack shaft, back wheel has a filler and has a brake, block of wood that pushes down onto the wheel<\/span><\/p>\n<p><span style=\"font-weight: 400\">1960 &#8211; tiger cub &#8211; spokes no longer radial and cross and triangulate, drive mechanism that drives the rear wheel<\/span><\/p>\n<p><span style=\"font-weight: 400\">1960 &#8211; casting wheels that replace spokes<\/span><\/p>\n<p><span style=\"font-weight: 400\">Today &#8211; cast wheels made out of carbon fiber strong and light<\/span><\/p>\n<p>&nbsp;<\/p>\n<p><span style=\"font-weight: 400\">What are some major forces that played a role in the evolution of the motorcycle wheel?<\/span><\/p>\n<ul>\n<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">Need stronger wheels because motor power<\/span><\/li>\n<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">Materials improve and become better<\/span><\/li>\n<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">Depends on the surface the bike travels on, different wheels for paved areas vs mountain bikes<\/span><\/li>\n<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">Increased speeds<\/span><\/li>\n<\/ul>\n<p>&nbsp;<\/p>\n<p><span style=\"font-weight: 400\">One of most important factors<\/span><\/p>\n<p><span style=\"font-weight: 400\">Weight &#8211; make lighter<\/span><\/p>\n<p><span style=\"font-weight: 400\">Wheels have inertia, so if it is heavy it takes more work to make it move<\/span><\/p>\n<p>&nbsp;<\/p>\n<p><span style=\"font-weight: 400\">Response to forces &#8211; better design<\/span><\/p>\n<p><span style=\"font-weight: 400\">Turning more requires different forces esp when faster, impact forces<\/span><\/p>\n<p>&nbsp;<\/p>\n<p><span style=\"font-weight: 400\">Technology &#8211; better machinery<\/span><\/p>\n<p>&nbsp;<\/p>\n<p><span style=\"font-weight: 400\">Materials in wheel<\/span><\/p>\n<p><span style=\"font-weight: 400\">Each material has unique properties<\/span><\/p>\n<ul>\n<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">Strength<\/span><\/li>\n<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">Flexibility<\/span><\/li>\n<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">Hardness<\/span><\/li>\n<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">Workability (how easily it can be machined, malleable and ductible)<\/span><\/li>\n<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">Resistance to corrosion<\/span><\/li>\n<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">Conductivity<\/span><\/li>\n<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">Friction<\/span><\/li>\n<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">Cost<\/span><\/li>\n<\/ul>\n<p>&nbsp;<\/p>\n<p><span style=\"font-weight: 400\">Materials in rim &#8211; mild steel sheet, rolled into correct profile, welded, plated with copper nickel and chromium<\/span><\/p>\n<p><span style=\"font-weight: 400\">Needs to be strong rigid, workable, resistant to corrosion, cost effective, available<\/span><\/p>\n<p>&nbsp;<\/p>\n<p><span style=\"font-weight: 400\">Cold vs Hot while machining &#8211; if hot then it is malleable and can change shape<\/span><\/p>\n<p><span style=\"font-weight: 400\">If you heat tempered things then immediately cool it then it makes it stronger<\/span><\/p>\n<p><span style=\"font-weight: 400\">Copper is opposite, depending on how it is cooled it can be hard or soft<\/span><\/p>\n<p>&nbsp;<\/p>\n<p><span style=\"font-weight: 400\">Spokes &#8211; mild steel wire<\/span><\/p>\n<p><span style=\"font-weight: 400\">Has to be strong efficient (small amount of material), workable, resistant to corrosion, cost, available<\/span><\/p>\n<p>&nbsp;<\/p>\n<p><span style=\"font-weight: 400\">Hub<\/span><\/p>\n<p><span style=\"font-weight: 400\">Attached motorcycle to wheel<\/span><\/p>\n<p><span style=\"font-weight: 400\">Needs to be light weight, conducts heat, workable, natural resistance to corrosion, cost effective, available<\/span><\/p>\n<p><span style=\"font-weight: 400\">Needs to conduct heat as tires get hot from braking<\/span><\/p>\n<p>&nbsp;<\/p>\n<p><span style=\"font-weight: 400\">Bearings<\/span><\/p>\n<p><span style=\"font-weight: 400\">Extremely hard, withstands wear, reduces friction, cost effective, available<\/span><\/p>\n<p>&nbsp;<\/p>\n<p><span style=\"font-weight: 400\">Tire<\/span><\/p>\n<p><span style=\"font-weight: 400\">Flexible, durable, moldable, resilient, high coefficient of fraction, cost effective, available\u00a0<\/span><\/p>\n<p>&nbsp;<\/p>\n<p><span style=\"font-weight: 400\">Designers select materials based on their suitability for the task<\/span><\/p>\n<p><span style=\"font-weight: 400\">Best performance at lowest cost = efficiency<\/span><\/p>\n<p>&nbsp;<\/p>\n<p><span style=\"font-weight: 400\">What are the forces on our wheel?<\/span><\/p>\n<p><span style=\"font-weight: 400\">Loads in engineering terms<\/span><\/p>\n<ul>\n<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">Dead loads = weight of the wheel itself and the motorcycle<\/span><\/li>\n<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">Live load = rider, passenger, gas and oil, luggage &#8211; the loads because of what we\u2019re asking the motorcycle to do, asking it to carry passengers<\/span><\/li>\n<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">Static loads &#8211; loads when object at rest, wheels at rest &#8211; effects of gravity<\/span><\/li>\n<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">Dynamics loads &#8211; loads when moving, wheels in motion &#8211; effects of applying motor power and acceleration, effects of braking and deceleration, effects of turning the motorcycle, effects of striking an object &#8211; impact forces<\/span><\/li>\n<\/ul>\n<p>&nbsp;<\/p>\n<p><span style=\"font-weight: 400\">Forces act in a directional manner, geometry of the wheel reacts to forces<\/span><\/p>\n<p><span style=\"font-weight: 400\">Spokes are arranged in crosscrossing teams<\/span><\/p>\n<p><span style=\"font-weight: 400\">Within ur teams you have 2 spokes that focus on acceleration and declaration and 2 spokes focus on side forces from turning<\/span><\/p>\n<p><span style=\"font-weight: 400\">Loads are distributed in teams, better than radial<\/span><\/p>\n<p>&nbsp;<\/p>\n<p><span style=\"font-weight: 400\">How do forces affect the elements within a structure?<\/span><span style=\"font-weight: 400\"><br \/>\n<\/span><span style=\"font-weight: 400\">5 basic forces acting on elements<\/span><\/p>\n<ul>\n<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">Compression, squeezing<\/span><\/li>\n<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">Tension, stretching\/pulling<\/span><\/li>\n<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">Shear, trying to break molecular bond by cutting<\/span><\/li>\n<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">Bending, hybrid of compression and tension, middle of beam is neutral axis not affected<\/span><\/li>\n<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">Torsion<\/span><\/li>\n<\/ul>\n<p>&nbsp;<\/p>\n<p><span style=\"font-weight: 400\">The tire is for cushioning the other elements from impact<\/span><\/p>\n<p><span style=\"font-weight: 400\">The rim is purely compression ring that supports the tires<\/span><\/p>\n<p><span style=\"font-weight: 400\">Spokes member the support fo the rim and the hub<\/span><\/p>\n<p><span style=\"font-weight: 400\">Hub tension member that supports the spokes<\/span><\/p>\n<p>&nbsp;<\/p>\n<p><span style=\"font-weight: 400\">The 20 top spokes provide tensile reaction when static<\/span><\/p>\n<p><span style=\"font-weight: 400\">Spokes unable to hold compression by design, if compression it just pops out<\/span><\/p>\n<p>&nbsp;<\/p>\n<p><span style=\"font-weight: 400\">The 20 backward leaning spokes provide tensile reaction when accelerating<\/span><\/p>\n<p>&nbsp;<\/p>\n<p><span style=\"font-weight: 400\">20 right or left spokes provide tensile reaction when turning<\/span><\/p>\n<p>&nbsp;<\/p>\n<p><span style=\"font-weight: 400\">in team<\/span><\/p>\n<ul>\n<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">2 contribute to acceleration\u00a0<\/span><\/li>\n<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">2 contribute to declaration<\/span><\/li>\n<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">2 contribute to side to side<\/span><\/li>\n<\/ul>\n<p>&nbsp;<\/p>\n<p><span style=\"font-weight: 400\">Applying forces to an element creates stress<\/span><\/p>\n<p><span style=\"font-weight: 400\">And the reaction to the stress is strain<\/span><\/p>\n<p>&nbsp;<\/p>\n<p><span style=\"font-weight: 400\">Young\u2019s Modulus &#8211; stress strain diagram<\/span><\/p>\n<p>&nbsp;<\/p>\n<p><span style=\"font-weight: 400\">Elastic region &#8211; strain goes back, not permanent<\/span><\/p>\n<p><span style=\"font-weight: 400\">Plastic zone &#8211; deforms<\/span><\/p>\n<p>&nbsp;<\/p>\n<p><span style=\"font-weight: 400\">The transition from elastic to plastic is at the yield point, amount of stress it can take drops before it starts to harden itself and reaches ultimate strength before breaking<\/span><\/p>\n<p>&nbsp;<\/p>\n<p><span style=\"font-weight: 400\">Spokes must be tuned well as tightening one spoke affects a bunch of other spokes and you need everything in balance<\/span><\/p>\n<p>&nbsp;<\/p>\n<p><span style=\"font-weight: 400\">Wednesday Notes<\/span><\/p>\n<p><span style=\"font-weight: 400\">Rolled threads &#8211; stronger and higher quality than cut threads<\/span><\/p>\n<p><span style=\"font-weight: 400\">Two rollers press into a bolt and molds the threads<\/span><\/p>\n<p>&nbsp;<\/p>\n<p><span style=\"font-weight: 400\">If overtighten a screw, it stretched instead and if tightened too much it goes past yield point<\/span><\/p>\n<p>&nbsp;<\/p>\n<p><span style=\"font-weight: 400\">The finer your thread, the more mechanical advantage, and the more likely you are to damage it<\/span><\/p>\n<p>&nbsp;<\/p>\n<p><span style=\"font-weight: 400\">Steel is a hard material that can be magnetizied<\/span><\/p>\n<p><span style=\"font-weight: 400\">Soft iron &#8211; pure iron which can be an electromagnet but can\u2019t be a permanent magnet<\/span><\/p>\n<p>&nbsp;<\/p>\n<p><span style=\"font-weight: 400\">Recap<\/span><\/p>\n<p><span style=\"font-weight: 400\">Wheels &#8211; prepped bearings and worked on spokes with Bill, pressed in using arbor press<\/span><\/p>\n<p><span style=\"font-weight: 400\">Electrical &#8211; sandblasting<\/span><\/p>\n<p><span style=\"font-weight: 400\">Clutch\/Oil &#8211; started old motorcycle, ran ok, at first no spark because no lead in, more adjustments need to be made for the engine, carburetor, and the timing. Also tighten all bolts<\/span><\/p>\n<p><span style=\"font-weight: 400\">Engine &#8211; laser cut gaskets, took out studs and wrist pin from old engine, will try to hone the barrel instead of boring it<\/span><\/p>\n<p>&nbsp;<\/p>\n<p><span style=\"font-weight: 400\">Chapter 3<\/span><\/p>\n<p><span style=\"font-weight: 400\">The idea of dependency<\/span><\/p>\n<p><span style=\"font-weight: 400\">Idea of learning by doing<\/span><\/p>\n<p><span style=\"font-weight: 400\">Autonomy vs agency<\/span><\/p>\n<p><span style=\"font-weight: 400\">Autonomy stereo , agency is playing musical instrument<\/span><\/p>\n<p><span style=\"font-weight: 400\">you\u2019re at the mercy of listening to what was already made, can&#8217;t play the things you want<\/span><\/p>\n<p>&nbsp;<\/p>\n<p><span style=\"font-weight: 400\">Ikea &#8211; following someone else\u2019s instructions, makes it feel like you did it yourself but you are given a solution<\/span><\/p>\n<p><span style=\"font-weight: 400\">Makes it feel like you accomplished something<\/span><\/p>\n<p><span style=\"font-weight: 400\">Also if you can\u2019t do it, it puts the blame on you.<\/span><\/p>\n<p><span style=\"font-weight: 400\">Ikea, Lego, Buildabear, are selling the idea that you did it yourself<\/span><\/p>\n<p><span style=\"font-weight: 400\">Marketing makes you want to buy more,\u00a0<\/span><\/p>\n<p>&nbsp;<\/p>\n<p><span style=\"font-weight: 400\">Not at complete liberty, even if you have 20 options you still have to pick a premade option<\/span><\/p>\n<p><span style=\"font-weight: 400\">Hard to make your own custom things<\/span><\/p>\n<p><span style=\"font-weight: 400\">To do things yourself takes more time than to use premade things<\/span><\/p>\n<p><span style=\"font-weight: 400\">Power comes with agency<\/span><\/p>\n<p>&nbsp;<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Monday Notes No recap Presentation by Bill Becker &#8211; Discovering the Motorcycle Wheel About Bill &#8211; retired architect, worked with Littman on toy trains at Franklin Institute. Did a lot of educational work, nonprofit work. Decided he wanted to work on motorcycles after retiring, been a long interest. Lots of shop experience, loves to make &hellip; <a href=\"https:\/\/commons.princeton.edu\/58-tiger-cub-2\/2026\/04\/01\/week-9-class-notes-posted-by-eugene\/\" class=\"more-link\">Continue reading<span class=\"screen-reader-text\"> &#8220;Week 9 Class Notes (posted by Eugene)&#8221;<\/span><\/a><\/p>\n","protected":false},"author":7328,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"class_list":["post-548","post","type-post","status-publish","format-standard","hentry","category-uncategorized"],"_links":{"self":[{"href":"https:\/\/commons.princeton.edu\/58-tiger-cub-2\/wp-json\/wp\/v2\/posts\/548","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/commons.princeton.edu\/58-tiger-cub-2\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/commons.princeton.edu\/58-tiger-cub-2\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/commons.princeton.edu\/58-tiger-cub-2\/wp-json\/wp\/v2\/users\/7328"}],"replies":[{"embeddable":true,"href":"https:\/\/commons.princeton.edu\/58-tiger-cub-2\/wp-json\/wp\/v2\/comments?post=548"}],"version-history":[{"count":1,"href":"https:\/\/commons.princeton.edu\/58-tiger-cub-2\/wp-json\/wp\/v2\/posts\/548\/revisions"}],"predecessor-version":[{"id":550,"href":"https:\/\/commons.princeton.edu\/58-tiger-cub-2\/wp-json\/wp\/v2\/posts\/548\/revisions\/550"}],"wp:attachment":[{"href":"https:\/\/commons.princeton.edu\/58-tiger-cub-2\/wp-json\/wp\/v2\/media?parent=548"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/commons.princeton.edu\/58-tiger-cub-2\/wp-json\/wp\/v2\/categories?post=548"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/commons.princeton.edu\/58-tiger-cub-2\/wp-json\/wp\/v2\/tags?post=548"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}