{"id":829,"date":"2026-10-11T01:47:23","date_gmt":"2026-10-11T01:47:23","guid":{"rendered":"https:\/\/aft-forge.jk-ideaweb.com\/?post_type=product&#038;p=829"},"modified":"2026-10-19T11:40:52","modified_gmt":"2026-10-19T11:40:52","slug":"crank-2","status":"publish","type":"product","link":"https:\/\/aft-forge.com\/en\/product\/crank-2\/","title":{"rendered":"Crank"},"content":{"rendered":"<div id=\"prodNav\">\n<div class=\"tab-content responsive\" style=\"text-align: left;\">\n<div id=\"contentprod0\" class=\"tab-pane active txtNormal\">\n<h2>Forged Aluminum Bicycle Left Crank: Lightweight 6061-F Crank Arm<\/h2>\n<p>The forged aluminum bicycle left crank is the left-side crank arm of a crankset. One end connects to the bottom bracket axle and the other carries the pedal, with a lightening groove on the front face and round bosses at both ends. It is made of 6061-F aluminum with a published weight of 0.2 kg. Without a spider, the left crank has a simpler shape than the right crank.<\/p>\n<p>Cranks carry repeated bending and torsion under pedaling and are safety parts of the drivetrain, so grain flow must stay intact where the arm meets each boss. Al Forge Tech (AFT) closed-die hot forges the arm and lightening groove, then CNC-machines the axle interface (square taper or spline) and pedal thread, verifying center distance and parallelism of the two holes on CMM.<\/p>\n<h3>Key Features<\/h3>\n<ul>\n<li>6061-F aluminum, 0.2 kg (published specification)<\/li>\n<li>Lightening groove forged into the arm<\/li>\n<li>Axle interface and pedal thread CNC-machined<\/li>\n<li>Center distance and parallelism measured on CMM<\/li>\n<\/ul>\n<h2>Forged Aluminum Bicycle Left Crank Specifications and Manufacturing Capability<\/h2>\n<div class=\"table-container\">\n<table class=\"table table-bordered table-striped\">\n<thead>\n<tr>\n<th>Item<\/th>\n<th>Details<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>Product category<\/td>\n<td>Aluminum Forging Bicycle Parts<\/td>\n<\/tr>\n<tr>\n<td>Application<\/td>\n<td>Bicycle and e-bike cranksets (left side)<\/td>\n<\/tr>\n<tr>\n<td>Primary process<\/td>\n<td>Closed-die hot forging (hot forging presses 600T\u20138,000T)<\/td>\n<\/tr>\n<tr>\n<td>Material<\/td>\n<td>6061-F aluminum alloy<\/td>\n<\/tr>\n<tr>\n<td>Heat treatment<\/td>\n<td>Per customer specification (published specification: 6061-F)<\/td>\n<\/tr>\n<tr>\n<td>Secondary machining<\/td>\n<td>CNC machining (52 machining centers, 30 lathes), deburring, vibratory finishing<\/td>\n<\/tr>\n<tr>\n<td>Surface finish<\/td>\n<td>Anodizing (including hard anodizing), shot blasting, e-coating or painting, as required<\/td>\n<\/tr>\n<tr>\n<td>Inspection<\/td>\n<td>Zeiss CMM (4 units), hardness testers, spectrometer, fluorescent penetrant inspection line<\/td>\n<\/tr>\n<tr>\n<td>Weight<\/td>\n<td>0.2 kg<\/td>\n<\/tr>\n<tr>\n<td>Dimensions and tolerances<\/td>\n<td>Per customer 2D\/3D drawings<\/td>\n<\/tr>\n<tr>\n<td>Quality system<\/td>\n<td>IATF 16949:2016, ISO 14001:2015<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<h2>Forged Aluminum Bicycle Left Crank Manufacturing Process<\/h2>\n<ol>\n<li><strong>Drawing review and DFM<\/strong>: we confirm alloy, load direction and critical dimensions, then run QForm simulation to predict metal flow and defect risk.<\/li>\n<li><strong>Die design and manufacturing<\/strong>: the number of die sets (for example, blocker and finisher dies) is planned around part complexity, and die contours are checked with a portable 3D scanner.<\/li>\n<li><strong><a href=\"https:\/\/aft-forge.com\/forging-service\/hot-forging-service\/\">Hot forging<\/a><\/strong>: closed-die forming on 600T\u20138,000T hot forging presses creates a continuous grain flow that follows the part contour.<\/li>\n<li><strong>Heat treatment<\/strong>: T4 solution treatment and T6 artificial aging are performed in-house, with parameters set by alloy and strength requirement.<\/li>\n<li><strong><a href=\"https:\/\/aft-forge.com\/forging-service\/aluminum-cnc-machining-services\/\">CNC machining<\/a> and finishing<\/strong>: holes, threads and mating surfaces are machined, followed by deburring, vibratory finishing, shot blasting or anodizing as required.<\/li>\n<li><strong>Inspection and shipment<\/strong>: dimensions, hardness and chemical composition are verified with CMM, hardness testers and a spectrometer, with lot traceability kept under IATF 16949.<\/li>\n<\/ol>\n<h2>FAQ<\/h2>\n<h3>What does 6061-F mean on the crank specification?<\/h3>\n<p>6061 is the alloy designation and F stands for &#8220;as fabricated&#8221;, meaning no specific heat-treatment temper is specified after forming. The published specification for this left crank is 6061-F; if the design needs more strength, it can be changed to T6 or another temper to customer specification, and AFT has in-house T4 solution and T6 aging equipment for this.<\/p>\n<h3>How is the center distance between crank holes ensured?<\/h3>\n<p>The center distance between the axle hole and pedal hole sets the crank length and thus the pedaling radius. AFT machines both holes in one CNC setup so they share a datum and measures center distance, parallelism and diameter on Zeiss CMM to keep left and right crank lengths consistent.<\/p>\n<h3>Can you assess forging feasibility while the Forged Aluminum Bicycle Left Crank is still in design?<\/h3>\n<p>Yes. Al Forge Tech works mainly as an OEM supplier, and our engineers can give design-for-manufacturability (DFM) feedback at the concept or drawing stage, such as adjusting thin ribs, abrupt section changes or draft angles to avoid laps and underfill. QForm simulation predicts metal flow early, and the results are cross-checked against our die design experience.<\/p>\n<h3>How do you keep the Forged Aluminum Bicycle Left Crank consistent from lot to lot?<\/h3>\n<p>Al Forge Tech runs incoming (IQC), in-process (IPQC) and final (FQC) inspection under IATF 16949:2016, supported by 4 Zeiss CMMs, hardness testers, a spectrometer and a fluorescent penetrant inspection line. First, middle and last pieces of every lot are checked against the die; when wear causes dimensional drift, the die is reworked to keep the Forged Aluminum Bicycle Left Crank stable across lots.<\/p>\n<h3>What information do you need to quote the Forged Aluminum Bicycle Left Crank?<\/h3>\n<p>Please send a 3D model and 2D drawing, alloy grade and temper, critical tolerances, surface finish requirements, estimated annual volume and target delivery date. Complete data lets our engineers judge forging feasibility, the number of die sets and the machining scope for the Forged Aluminum Bicycle Left Crank at the quotation stage. If the design is still conceptual, a sketch is enough to start a DFM discussion.<\/p>\n<h2>Request a Quote for the Forged Aluminum Bicycle Left Crank<\/h2>\n<p>Developing a new Forged Aluminum Bicycle Left Crank or converting an existing part to aluminum forging? Send us your 3D\/2D drawings, alloy and temper, annual volume and finishing requirements. Our engineering team will reply with a feasibility review, die plan and quotation.<\/p>\n<ul>\n<li>Online inquiry: <a href=\"https:\/\/aft-forge.com\/contact-us\/\">Contact Us<\/a><\/li>\n<li>Email: <a href=\"mailto:aft@aft-forge.com.tw\">aft@aft-forge.com.tw<\/a><\/li>\n<\/ul>\n<p>To compare similar parts, browse <a href=\"https:\/\/aft-forge.com\/bicycle-parts-bike-parts\/\">Aluminum Forging Bicycle Parts<\/a>\u00a0and our <a href=\"https:\/\/aft-forge.com\/category\/applications\/\">automotive aluminum forging applications<\/a>, or visit <a href=\"https:\/\/aft-forge.com\/about-us\/\">About Us<\/a> for our equipment and certifications.<\/p>\n<\/div>\n<\/div>\n<\/div>\n","protected":false},"excerpt":{"rendered":"<p>Forged Aluminum Bicycle Left Crank: Lightweight 6061-F Crank Arm The forged aluminum bicycle left crank is the left-side crank arm of a crankset. One end connects to the bottom bracket axle and the other carries the pedal, with a lightening groove on the front face and round bosses at both ends. It is made of [&hellip;]<\/p>\n","protected":false},"featured_media":830,"comment_status":"open","ping_status":"closed","template":"","meta":{"_acf_changed":false},"product_brand":[],"product_cat":[24],"product_tag":[],"class_list":["post-829","product","type-product","status-publish","has-post-thumbnail","product_cat-bicycle-parts-bike-parts","first","instock","taxable","shipping-taxable","product-type-simple"],"acf":[],"_links":{"self":[{"href":"https:\/\/aft-forge.com\/en\/wp-json\/wp\/v2\/product\/829","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/aft-forge.com\/en\/wp-json\/wp\/v2\/product"}],"about":[{"href":"https:\/\/aft-forge.com\/en\/wp-json\/wp\/v2\/types\/product"}],"replies":[{"embeddable":true,"href":"https:\/\/aft-forge.com\/en\/wp-json\/wp\/v2\/comments?post=829"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/aft-forge.com\/en\/wp-json\/wp\/v2\/media\/830"}],"wp:attachment":[{"href":"https:\/\/aft-forge.com\/en\/wp-json\/wp\/v2\/media?parent=829"}],"wp:term":[{"taxonomy":"product_brand","embeddable":true,"href":"https:\/\/aft-forge.com\/en\/wp-json\/wp\/v2\/product_brand?post=829"},{"taxonomy":"product_cat","embeddable":true,"href":"https:\/\/aft-forge.com\/en\/wp-json\/wp\/v2\/product_cat?post=829"},{"taxonomy":"product_tag","embeddable":true,"href":"https:\/\/aft-forge.com\/en\/wp-json\/wp\/v2\/product_tag?post=829"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}