{"id":12950,"date":"2017-03-10T09:38:54","date_gmt":"2017-03-10T00:38:54","guid":{"rendered":"http:\/\/www.bikebros.co.jp\/vb\/sports\/sfeat\/yoshimura-cam-en\/"},"modified":"2017-11-28T13:14:48","modified_gmt":"2017-11-28T04:14:48","slug":"yoshimura-cam-en","status":"publish","type":"post","link":"https:\/\/www.bikebros.co.jp\/vb\/sports\/sfeat\/yoshimura-cam-en\/","title":{"rendered":"YOSHIMURA CAMSHAFT: A NON-\u00adSTOP EVOLUTION"},"content":{"rendered":"<div id=\"mainimg950\"><img src=\"https:\/\/img.bikebros.co.jp\/vb_img\/tieup\/sports\/yoshimura\/08\/img\/en\/main-en.jpg\" alt=\"\" width=\"950\" \/><\/div> <div id=\"credit\"> <div class=\"left\"><strong>Thanks<\/strong> to <a href=\"http:\/\/www.bikebros.co.jp\/jump\/yoshimura\/en\/20161122-web.html\" target=\"_blank\" rel=\"nofollow\">Yoshimura Japan<\/a><img loading=\"lazy\" src=\"https:\/\/www.bikebros.co.jp\/vb_img\/tieup\/fifty\/example\/img\/ico_link.gif\" alt=\"\" width=\"16\" height=\"11\" \/> <strong>Text<\/strong> by Tomoya Ishibashi <strong>Photo<\/strong> by Naoyuki Shibata <strong>Edited<\/strong> by Bike Bros Magazines<br \/>\u3010 <a href=\"http:\/\/www.bikebros.co.jp\/vb\/sports\/sfeat\/yoshimura-cam\/\">Japanese Page&nbsp;&raquo; <\/a> \u3011<\/div> <div class=\"right\">Published on December 20, 2016<\/div> <\/div> <div class=\"bottom10\" style=\"float: right; text-align: right; padding-top: 5px;\"> <div style=\"width: 150px; float: right; margin-left: 5px;\"> <div class=\"fb-like\" data-href=\"http:\/\/www.bikebros.co.jp\/vb\/sports\/sfeat\/yoshimura-cam-en\/\" data-layout=\"button_count\" data-action=\"like\" data-show-faces=\"true\" data-share=\"true\"><\/div> <\/div> <div style=\"width: 90px; float: right;\"><a class=\"twitter-share-button\" href=\"http:\/\/twitter.com\/share\" data-count=\"none\" data-via=\"BikeBrosMagazin\" data-lang=\"ja\">Tweet<\/a><script src=\"https:\/\/platform.twitter.com\/widgets.js\"><\/script><\/div> <\/div> <div class=\"clear\"><\/div> <div class=\"contents_detail\"> <p class=\"leadbox\">Camshaft -\u00ad-\u00ad-\u00ad-\u00ad the heart of the four-\u00adstroke engine. Yoshimura, which has been leading the world since 1954 in camshaft tuning technology, has triggered an evolution by innovating new method and material. It was a historical accomplishment driven by their spirit and passion. Let\u2019s look closely at Yoshimura\u2019s latest cylinder head tuning.<\/p> <\/div> <div class=\"contents_detail\"> <h2 class=\"midashi\">DIGITIZING THE INTUITION &amp; CRAFTSMANSHIP<\/h2> <p>Yoshimura\u2019s camshaft tuning goes back to the days of Pop. Most of the 4-\u00adstroke gasoline engines rely on the cam which operates the intake and exhaust valves with egg-\u00adshaped lobes, and it has been well known that a good cam drastically improves engine performance.<\/p> <p>In the early days, stock cams were modified by skilled hands. With his hands-\u00adon experience, technical expertise, amazing intuition and craftsmanship, \u201cPop\u201d Yoshimura used to handcraft various high-\u00adlift cams, either by grinding down the base circle to gain valve lift and duration or by depositing stellite alloy directly onto the lobes.<\/p> <p><img class=\"lazy\" src=\"https:\/\/www.bikebros.co.jp\/vb_img\/js\/lazyload\/transparent.gif\" alt=\"\" data-original=\"http:\/\/img.bikebros.co.jp\/vb_img\/tieup\/sports\/yoshimura\/08\/img\/01.jpg\" \/><\/p> <p>After it became possible to obtain pre-\u00admachined blank camshaft billets, Yoshimura began producing high-\u00adlift, high-\u00adduration cams on a mechanical profiling grinder. Cams were then calibrated, examined and tested on a dyno, before hitting the tracks for further research and development.<\/p> <p>The son took a different approach. At some point between the late 1970s and early 1980s, Fujio Yoshimura began using a computer to design camshafts and eventually wrote a program for drawing new cam profiles from the valve lift data measured at every degree of camshaft rotation. The first fruit of this program was installed on the Yoshimura Suzuki GS1000S which took the 1st and 2nd place in the 1981 Daytona Superbike race.<\/p> <p><img class=\"lazy\" src=\"https:\/\/www.bikebros.co.jp\/vb_img\/js\/lazyload\/transparent.gif\" alt=\"\" data-original=\"http:\/\/img.bikebros.co.jp\/vb_img\/tieup\/sports\/yoshimura\/08\/img\/02.jpg\" \/><\/p> <p><strong>FY: <\/strong>My father\u2019s intuition and craftsmanship were incredible, but we needed to analyze them and improve the precision. So, I went and bought a Hewlett-\u00adPackard HP-\u00ad41C handheld computer and wrote a program from scratch. Computers in those days were indeed not as user friendly as they are today.<\/p> <p><strong>Fujio Yoshimura<\/strong><br \/>  The 2nd and current President of Yoshimura was born on November 17th, 1948, a son of the tuning genius Hideo \u201cPop\u201d Yoshimura. As a man of theory, Fujio had succeeded in digitizing his father\u2019s intuition and craftsmanship by means of a computer. It was way ahead of its time in many ways.<\/p> <p>It was the dawn of a new era in camshaft design. The mechanical cam grinder -\u00ad-\u00ad-\u00ad-\u00ad which duplicates the profile of a master cam -\u00ad-\u00ad-\u00ad-\u00ad was then replaced with a CNC (Computer Numerical Control) machine. The master cam was no longer needed. The product precision and production efficiency were dramatically improved.<\/p> <p>The rocker-\u00adarm's motion was also studied. Thoroughly understanding the mechanical characteristics of rocker-\u00adarm system -\u00ad-\u00ad-\u00ad-\u00ad involving multiple complex variables such as leverage ratio and pad radius -\u00ad-\u00ad-\u00ad-\u00ad was another landmark achievement for Yoshimura. This experience eventually lead to the development of the Desmo type camshaft.<\/p> <div><img class=\"lazy\" src=\"https:\/\/www.bikebros.co.jp\/vb_img\/js\/lazyload\/transparent.gif\" alt=\"\" data-original=\"http:\/\/img.bikebros.co.jp\/vb_img\/tieup\/sports\/yoshimura\/08\/img\/en\/graph01.png?20161207\" \/><\/div> <p>A lift curve is a graph correlating the valve lift with crank angle. The horizontal axis represents crank angle, displaying valve opening\/closing phase and maximum lift (full-\u00adopen) position. As shown in the graph, the maximum lift of Stage 2 cam (red curve) is about 1 mm greater than that of Stage 1 cam (blue curve). Duration is defined as the angle between the valve opening\/closing points. There are separate valve lift curves for intake and exhaust, and the valve overlap period can be visualized by plotting the two curves together on the same chart. Yoshimura\u2019s cam specs for opening\/closing are all measured at 1-\u00admm of valve lift.<\/p> <p>However, the cam design was still based on the valve lift curve. Sure, the maximum lift and duration are fundamental factors, but are not the only factors that affect the performance of the valvetrain. What else -\u00ad-\u00ad-\u00ad-\u00ad besides 4-\u00adinto-\u00ad1 exhaust system -\u00ad-\u00ad-\u00ad-\u00ad will improve the intake and exhaust efficiency? One of the key factors is valve spring.<\/p> <p>Valve springs can function properly only within the range they are designed for. The valves will float (jump) and become unable to follow the lift curve if they move faster than the reaction of the springs. Nevertheless, installing heavy-\u00adduty valve springs that are too stiff (so-\u00adcalled \u201cbad\u201d performance valve springs) will increase friction losses. You need to find the perfect balance between camshaft which increases power and valve springs which could be either beneficial or harmful to the engine performance.<\/p> <div><img class=\"lazy\" src=\"https:\/\/www.bikebros.co.jp\/vb_img\/js\/lazyload\/transparent.gif\" alt=\"\" data-original=\"http:\/\/img.bikebros.co.jp\/vb_img\/tieup\/sports\/yoshimura\/08\/img\/en\/graph02.png?20161207\" \/><\/div> <p>Graph showing the correlation between the intake\/exhaust valve\u2019s sprung mass inertia and the valve spring\u2019s reaction force. The spring force plotted here are of the same valve. Note the similarity of the gaps between the curves of the same color (shown by arrow). The Stage 2 cam (red curve on the top) is also carefully designed not to produce inertia that exceeds the spring force (red curve at the bottom) in order to avoid valve float. This feature eliminates the need for heavy-\u00adduty valve springs, making it possible to get more power out of the stock low-\u00adpressure springs.<\/p> <p><img class=\"lazy\" src=\"https:\/\/www.bikebros.co.jp\/vb_img\/js\/lazyload\/transparent.gif\" alt=\"\" data-original=\"http:\/\/img.bikebros.co.jp\/vb_img\/tieup\/sports\/yoshimura\/08\/img\/04.jpg\" \/><\/p> <p><strong>FY: <\/strong>Valve acceleration was the key factor. We knew it since my father\u2019s time -\u00ad-\u00ad-\u00ad-\u00ad since the early 1970\u2019s -\u00ad-\u00ad-\u00ad-\u00ad but, we just didn't know how to analyze and integrate the data into design back then. Today, it\u2019s different. Hideto is now generating new cam profiles, not from the lift curve but from valve acceleration data. With our new design software, we can now perform high-\u00adprecision analysis.<\/p> <p><img class=\"lazy\" src=\"https:\/\/www.bikebros.co.jp\/vb_img\/js\/lazyload\/transparent.gif\" alt=\"\" data-original=\"http:\/\/img.bikebros.co.jp\/vb_img\/tieup\/sports\/yoshimura\/08\/img\/05.jpg\" \/><\/p> <p><strong>HY:<\/strong> When you compare old and new cams side by side, you\u2019ll notice some similarity in the lift curves. But, the acceleration data proves that they are completely different in character. Conventional cams tend to exhibit linear and peaky power characteristics, and therefore you had to choose the right spring with the right tension, maintain the appropriate safety margin and keep the friction as low as possible. Our new generation cams on the other hand, feature much smoother power development. The new cam profile is a continuous curve and not a series of arcs of various radii.<\/p> <p><strong>Hideto Yoshimura<\/strong><br \/>  The 2nd son of Fujio, who was born on August 2nd, 1986. The young engineer has been designing camshaft profiles from valve acceleration data and is regarded as a leader of the new era of 4-\u00adstroke engine tuning.<\/p> <p>Yoshimura\u2019s new generation camshaft is designed entirely using computer programs and through analyzing valve acceleration data. It\u2019s a reverse-\u00adthinking approach. The weak points of the lift curve become immediately obvious when the data (collected throughout the rev-\u00adrange) are plotted on a graph of valve acceleration versus cam angle. Following the final decision, the ideal lift curve will be converted into a profile data with CAD, which then will be exported into a CNC camshaft grinder for precision machining.<\/p> <p><strong>FY: <\/strong>Our CNC production process requires certain know-\u00adhow for optimal results.<\/p> <p><img class=\"lazy\" src=\"https:\/\/www.bikebros.co.jp\/vb_img\/js\/lazyload\/transparent.gif\" alt=\"\" data-original=\"http:\/\/img.bikebros.co.jp\/vb_img\/tieup\/sports\/yoshimura\/08\/img\/06.jpg\" \/><\/p> <p>It\u2019s one of their best kept secrets. Yoshimura\u2019s experiences, collected data and cutting-\u00adedge technology are fully integrated into the design and production process.<\/p> <p>Hideto showed us the analysis of the contact force between cam and rocker-\u00adarm (or tappet). When idling, the contact force is very large at the maximum lift point. As the rev goes up, the force at the maximum lift point decreases while the force at the valve opening\/closing points increases, because of the influences of the cam inertia.<\/p> <p><img class=\"lazy\" src=\"https:\/\/www.bikebros.co.jp\/vb_img\/js\/lazyload\/transparent.gif\" alt=\"\" data-original=\"http:\/\/img.bikebros.co.jp\/vb_img\/tieup\/sports\/yoshimura\/08\/img\/07.jpg\" \/><\/p> <p>It shows how harmful idling is to both camshaft and valvetrain. Remember to keep the rev\u2019s up a little -\u00ad-\u00ad-\u00ad-\u00ad to reduce the contact force -\u00ad-\u00ad-\u00ad-\u00ad when warming up.<\/p> <div><img class=\"lazy\" src=\"https:\/\/www.bikebros.co.jp\/vb_img\/js\/lazyload\/transparent.gif\" alt=\"\" data-original=\"http:\/\/img.bikebros.co.jp\/vb_img\/tieup\/sports\/yoshimura\/08\/img\/en\/graph03.png?20161207\" \/><\/div> <p>The horizontal axis displays cam angle with the top position at zero. When idling, the highest contact force is generated at the top position (the peak of the lobe). The relatively high speed of slippage (the speed of contact point) tends to cause an insufficiency of oil film, which consequently leads to cam scuffing.<\/p> <div><img class=\"lazy\" src=\"https:\/\/www.bikebros.co.jp\/vb_img\/js\/lazyload\/transparent.gif\" alt=\"\" data-original=\"http:\/\/img.bikebros.co.jp\/vb_img\/tieup\/sports\/yoshimura\/08\/img\/en\/graph04.png?20161207\" \/><\/div> <p>As the rev goes up, the contact force at the top position decreases. This is caused by the large inertial force of the camshaft rotating at a faster rate. By the time when the engine reaches the rev limit, the contact force at the valve opening\/closing points becomes higher than that at the top position. The relatively low speed of slippage at the beginning of the lift assures that the lubrication is adequate (the oil film will be maintained).<\/p> <p><strong>HY: <\/strong>Race cams have these radically sharp lobes. These are also designed with factors such as valve acceleration, contact force and desired rev range in mind.<\/p> <p><img class=\"lazy\" src=\"https:\/\/www.bikebros.co.jp\/vb_img\/js\/lazyload\/transparent.gif\" alt=\"\" data-original=\"http:\/\/img.bikebros.co.jp\/vb_img\/tieup\/sports\/yoshimura\/08\/img\/08.jpg\" \/><\/p> <p><strong>FY: <\/strong>We also developed new material for the project. It\u2019s a new type of ductile cast iron, containing high amount of graphite particles -\u00ad-\u00ad-\u00ad-\u00ad with high uniformity -\u00ad-\u00ad-\u00ad-\u00ad for improved self-\u00adlubricating properties. It is far superior than the conventional material from which stock cast cams are made. Cast iron has an excellent anti-\u00adscuffing property and that\u2019s why it has been the standard. We had made cams out of extremely rigid SCM (Chrome-\u00adMolybdenum Composite Steel), because blank cams can be hard to come by for some older bikes, but cam scuffing was always a concern. So, we made our own material for making camshafts. They come in rods, and are ready to be machined on CNC machines. Now we can produce camshafts for all sorts of bikes, including classic bikes and the rocker-\u00adarm bikes (such as ZRX and GPZ900R) with cams which tend to get scuffed easily. You name it.<\/p> <p><img class=\"lazy\" src=\"https:\/\/www.bikebros.co.jp\/vb_img\/js\/lazyload\/transparent.gif\" alt=\"\" data-original=\"http:\/\/img.bikebros.co.jp\/vb_img\/tieup\/sports\/yoshimura\/08\/img\/09.jpg\" \/><\/p> <p><strong>HY: <\/strong>The new generation cams with new profiles should also last longer, since they are redesigned with valve acceleration in mind.<\/p> <p><strong>FY: <\/strong>However, we will continue using SCM material for racing applications. Cam scuffing is not an issue here since race bikes stay on high rev. We also do DLC (Diamond-\u00adLike Carbon) coating on cams and rocker-\u00adarms. It\u2019s great that we can now choose various types of material according to the applications.<\/p> <p>Thus, Yoshimura now has a new method and a new material for producing camshafts. We are witnessing an evolution of the heart of the 4-\u00adstroke engine. What comes next? I do not know, but for sure it will be another breakthrough.<\/p> <p><img class=\"lazy\" src=\"https:\/\/www.bikebros.co.jp\/vb_img\/js\/lazyload\/transparent.gif\" alt=\"\" data-original=\"http:\/\/img.bikebros.co.jp\/vb_img\/tieup\/sports\/yoshimura\/08\/img\/10.jpg\" \/><\/p> <p>With passion towards the future, three generations of Yoshimuras continue to run the family business of tuning 4-stroke engines. <\/p><\/div> <p><!-- \/\/contents_detail --> <\/p> <div class=\"contents_detail\"> <h2 class=\"midashi\">NEW GENERATION CAM:DESIGNED WITH ACCELERATION IN MIND<\/h2> <div class=\"flexbox flexwrap flexbetween w100p\"> <div class=\"detailbox\"> <div class=\"capphoto\"><a class=\"highslide\" href=\"http:\/\/img.bikebros.co.jp\/vb_img\/tieup\/sports\/yoshimura\/08\/img\/detail01_b.jpg\"><img class=\"lazy\" src=\"https:\/\/www.bikebros.co.jp\/vb_img\/js\/lazyload\/transparent.gif\" alt=\"\" data-original=\"http:\/\/img.bikebros.co.jp\/vb_img\/tieup\/sports\/yoshimura\/08\/img\/detail01.jpg\" \/><\/a><\/div> <p>Camshafts for DOHC engines;\u037e rocker-\u00adarm type (on the Left) and direct-\u00adacting type (on the right). The rocker-\u00adarm type has an asymmetric lobe profile, since the angle and contact point of the rocker-\u00adarm changes in relation to valve movement. This geometric effect is generally known as \u201clever ratio\u201d and it varies as the camshaft rotates. If you have 8mm cam-\u00adlobe lift and 10mm valve lift, then your lever ratio is 1.25.<\/p> <\/div> <div class=\"detailbox\"> <div class=\"capphoto\"><a class=\"highslide\" href=\"http:\/\/img.bikebros.co.jp\/vb_img\/tieup\/sports\/yoshimura\/08\/img\/detail02_b.jpg\"><img class=\"lazy\" src=\"https:\/\/www.bikebros.co.jp\/vb_img\/js\/lazyload\/transparent.gif\" alt=\"\" data-original=\"http:\/\/img.bikebros.co.jp\/vb_img\/tieup\/sports\/yoshimura\/08\/img\/detail02.jpg\" \/><\/a><\/div> <p>Analyzing the motion of a rocker-\u00adarm mechanism. Even the smallest detail of tappet adjuster screw on the end of the rocker-\u00adarm cannot be ignored. The latest billet cam kit for classic CB750\u2019s contains optional tappet adjuster screws that are designed for optimal leverage ratio.<\/p> <\/div> <div class=\"detailbox\"> <div class=\"capphoto\"><a class=\"highslide\" href=\"http:\/\/img.bikebros.co.jp\/vb_img\/tieup\/sports\/yoshimura\/08\/img\/detail03_b.jpg\"><img class=\"lazy\" src=\"https:\/\/www.bikebros.co.jp\/vb_img\/js\/lazyload\/transparent.gif\" alt=\"\" data-original=\"http:\/\/img.bikebros.co.jp\/vb_img\/tieup\/sports\/yoshimura\/08\/img\/detail03.jpg\" \/><\/a><\/div> <p>Displaying the 3 stages of the billet-\u00adcam production process. From back to front: a ductile cast iron rod, a product halfway done and a final product (both are for ZRX1100). The billet-\u00adcam made from the new material undergoes laser heat treatment (laser surface hardening treatment) which is also a new technology. SCM cam follows the same process, but through different treatments and It takes more time.<\/p> <\/div> <div class=\"detailbox\"> <div class=\"capphoto\"><a class=\"highslide\" href=\"http:\/\/img.bikebros.co.jp\/vb_img\/tieup\/sports\/yoshimura\/08\/img\/detail04_b.jpg\"><img class=\"lazy\" src=\"https:\/\/www.bikebros.co.jp\/vb_img\/js\/lazyload\/transparent.gif\" alt=\"\" data-original=\"http:\/\/img.bikebros.co.jp\/vb_img\/tieup\/sports\/yoshimura\/08\/img\/detail04.jpg\" \/><\/a><\/div> <p>A workpiece on a high-\u00adspeed CNC camshaft grinder, waiting for data input. This one is for Honda Ape.<\/p> <\/div> <div class=\"detailbox\"> <div class=\"capphoto\"><a class=\"highslide\" href=\"http:\/\/img.bikebros.co.jp\/vb_img\/tieup\/sports\/yoshimura\/08\/img\/detail05_b.jpg\"><img class=\"lazy\" src=\"https:\/\/www.bikebros.co.jp\/vb_img\/js\/lazyload\/transparent.gif\" alt=\"\" data-original=\"http:\/\/img.bikebros.co.jp\/vb_img\/tieup\/sports\/yoshimura\/08\/img\/detail05.jpg\" \/><\/a><\/div> <p>Completed cam lobes exposing super clean surface. The grinding process took about 10 minutes.<\/p> <\/div> <div class=\"detailbox\"> <div class=\"capphoto\"><a class=\"highslide\" href=\"http:\/\/img.bikebros.co.jp\/vb_img\/tieup\/sports\/yoshimura\/08\/img\/detail06_b.jpg\"><img class=\"lazy\" src=\"https:\/\/www.bikebros.co.jp\/vb_img\/js\/lazyload\/transparent.gif\" alt=\"\" data-original=\"http:\/\/img.bikebros.co.jp\/vb_img\/tieup\/sports\/yoshimura\/08\/img\/detail06.jpg\" \/><\/a><\/div> <p>Grinding disk being applied to the journals of a Kawasaki Z1 &amp; Z2 cam.<\/p> <\/div> <div class=\"detailbox\"> <div class=\"capphoto\"><a class=\"highslide\" href=\"http:\/\/img.bikebros.co.jp\/vb_img\/tieup\/sports\/yoshimura\/08\/img\/detail07_b.jpg\"><img class=\"lazy\" src=\"https:\/\/www.bikebros.co.jp\/vb_img\/js\/lazyload\/transparent.gif\" alt=\"\" data-original=\"http:\/\/img.bikebros.co.jp\/vb_img\/tieup\/sports\/yoshimura\/08\/img\/detail07.jpg\" \/><\/a><\/div> <p>Making a precise measurement before press-\u00adfitting a sprocket (cam gear).<\/p> <\/div> <div class=\"detailbox\"> <div class=\"capphoto\"><a class=\"highslide\" href=\"http:\/\/img.bikebros.co.jp\/vb_img\/tieup\/sports\/yoshimura\/08\/img\/detail08_b.jpg\"><img class=\"lazy\" src=\"https:\/\/www.bikebros.co.jp\/vb_img\/js\/lazyload\/transparent.gif\" alt=\"\" data-original=\"http:\/\/img.bikebros.co.jp\/vb_img\/tieup\/sports\/yoshimura\/08\/img\/detail08.jpg\" \/><\/a><\/div> <p>A CNC machined cam (front) being compared to an old handmade high-\u00adlift cam for Honda S800 (back) which produced 128hp. They may look different but are based on the same tuning method and philosophy.<\/p> <\/div> <\/div> <p><!-- \/\/flexbox end --> <\/div> <p><!-- \/\/contents_detail --> <\/p> <div class=\"contents_detail\"> <div class=\"obi\">LINE-UP<\/div> <div class=\"lineup\"> <div> <p class=\"lineupimg\"><a href=\"http:\/\/www.bikebros.co.jp\/jump\/yoshimura\/en\/20161122-item01.html\" target=\"_blank\"><img src=\"https:\/\/img.bikebros.co.jp\/vb_img\/tieup\/sports\/yoshimura\/08\/img\/item01s.jpg\" alt=\"\" \/><\/a><\/p> <h4 class=\"lineupname capmidashi\"><a href=\"http:\/\/www.bikebros.co.jp\/jump\/yoshimura\/en\/20161122-item01.html\" target=\"_blank\">ZRX1100 ST-\u00ad1M Camshaft<\/a><\/h4> <p class=\"lineuplink\"><a href=\"http:\/\/www.bikebros.co.jp\/jump\/yoshimura\/en\/20161122-item01.html\" target=\"_blank\" rel=\"nofollow\">Product Detail<\/a><\/p> <\/div> <div> <p class=\"lineupimg\"><a href=\"http:\/\/www.bikebros.co.jp\/jump\/yoshimura\/en\/20161122-item02.html\" target=\"_blank\"><img src=\"https:\/\/img.bikebros.co.jp\/vb_img\/tieup\/sports\/yoshimura\/08\/img\/item02s.jpg\" alt=\"\" \/><\/a><\/p> <h4 class=\"lineupname capmidashi\"><a href=\"http:\/\/www.bikebros.co.jp\/jump\/yoshimura\/en\/20161122-item02.html\" target=\"_blank\">Z1\/Z2 ST-\u00adL1 Camshaft<\/a><\/h4> <p class=\"lineuplink\"><a href=\"http:\/\/www.bikebros.co.jp\/jump\/yoshimura\/en\/20161122-item02.html\" target=\"_blank\" rel=\"nofollow\">Product Detail<\/a><\/p> <\/div> <div> <p class=\"lineupimg\"><a href=\"http:\/\/www.bikebros.co.jp\/jump\/yoshimura\/en\/20161122-item03.html\" target=\"_blank\"><img src=\"https:\/\/img.bikebros.co.jp\/vb_img\/tieup\/sports\/yoshimura\/08\/img\/item03s.jpg\" alt=\"\" \/><\/a><\/p> <h4 class=\"lineupname capmidashi\"><a href=\"http:\/\/www.bikebros.co.jp\/jump\/yoshimura\/en\/20161122-item03.html\" target=\"_blank\">Z1\/Z2 Adjustable Lightweight Cam Sprocket Set<\/a><\/h4> <p class=\"lineuplink\"><a href=\"http:\/\/www.bikebros.co.jp\/jump\/yoshimura\/en\/20161122-item03.html\" target=\"_blank\" rel=\"nofollow\">Product Detail<\/a><\/p> <\/div> <div> <p class=\"lineupimg\"><a href=\"http:\/\/www.bikebros.co.jp\/jump\/yoshimura\/en\/20161122-item04.html\" target=\"_blank\"><img src=\"https:\/\/img.bikebros.co.jp\/vb_img\/tieup\/sports\/yoshimura\/08\/img\/item04s.jpg\" alt=\"\" \/><\/a><\/p> <h4 class=\"lineupname capmidashi\"><a href=\"http:\/\/www.bikebros.co.jp\/jump\/yoshimura\/en\/20161122-item04.html\" target=\"_blank\">Z1\/2 Valve Retainer &amp; Cotter Set (Round Groove)<\/a><\/h4> <p class=\"lineuplink\"><a href=\"http:\/\/www.bikebros.co.jp\/jump\/yoshimura\/en\/20161122-item04.html\" target=\"_blank\" rel=\"nofollow\">Product Detail<\/a><\/p> <\/div> <div> <p class=\"lineupimg\"><a href=\"http:\/\/www.bikebros.co.jp\/jump\/yoshimura\/en\/20161122-item05.html\" target=\"_blank\"><img src=\"https:\/\/img.bikebros.co.jp\/vb_img\/tieup\/sports\/yoshimura\/08\/img\/item05s.jpg\" alt=\"\" \/><\/a><\/p> <h4 class=\"lineupname capmidashi\"><a href=\"http:\/\/www.bikebros.co.jp\/jump\/yoshimura\/en\/20161122-item05.html\" target=\"_blank\">GSX1100S ST-\u00adL1 Camshaft<\/a><\/h4> <p class=\"lineuplink\"><a href=\"http:\/\/www.bikebros.co.jp\/jump\/yoshimura\/en\/20161122-item05.html\" target=\"_blank\" rel=\"nofollow\">Product Detail<\/a><\/p> <\/div> <div> <p class=\"lineupimg\"><a href=\"http:\/\/www.bikebros.co.jp\/jump\/yoshimura\/en\/20161122-item06.html\" target=\"_blank\"><img src=\"https:\/\/img.bikebros.co.jp\/vb_img\/tieup\/sports\/yoshimura\/08\/img\/item06s.jpg\" alt=\"\" \/><\/a><\/p> <h4 class=\"lineupname capmidashi\"><a href=\"http:\/\/www.bikebros.co.jp\/jump\/yoshimura\/en\/20161122-item06.html\" target=\"_blank\">CB750Four Billet Camshaft [DAYTONA CAM2]<\/a><\/h4> <p class=\"lineuplink\"><a href=\"http:\/\/www.bikebros.co.jp\/jump\/yoshimura\/en\/20161122-item06.html\" target=\"_blank\" rel=\"nofollow\">Product Detail<\/a><\/p> <\/div> <div> <p class=\"lineupimg\"><a href=\"http:\/\/www.bikebros.co.jp\/jump\/yoshimura\/en\/20161122-item07.html\" target=\"_blank\"><img src=\"https:\/\/img.bikebros.co.jp\/vb_img\/tieup\/sports\/yoshimura\/08\/img\/item07s.jpg\" alt=\"\" \/><\/a><\/p> <h4 class=\"lineupname capmidashi\"><a href=\"http:\/\/www.bikebros.co.jp\/jump\/yoshimura\/en\/20161122-item07.html\" target=\"_blank\">CB400Four ST-\u00ad1M Camshaft<\/a><\/h4> <p class=\"lineuplink\"><a href=\"http:\/\/www.bikebros.co.jp\/jump\/yoshimura\/en\/20161122-item07.html\" target=\"_blank\" rel=\"nofollow\">Product Detail<\/a><\/p> <\/div> <div> <p class=\"lineupimg\"><a href=\"http:\/\/www.bikebros.co.jp\/jump\/yoshimura\/en\/20161122-item08.html\" target=\"_blank\"><img src=\"https:\/\/img.bikebros.co.jp\/vb_img\/tieup\/sports\/yoshimura\/08\/img\/item08s.jpg\" alt=\"\" \/><\/a><\/p> <h4 class=\"lineupname capmidashi\"><a href=\"http:\/\/www.bikebros.co.jp\/jump\/yoshimura\/en\/20161122-item08.html\" target=\"_blank\">SR400\/500 ST-\u00ad1M Camshaft<\/a><\/h4> <p class=\"lineuplink\"><a href=\"http:\/\/www.bikebros.co.jp\/jump\/yoshimura\/en\/20161122-item08.html\" target=\"_blank\" rel=\"nofollow\">Product Detail<\/a><\/p> <\/div> <\/div> <p><!-- \/\/lineup --> <\/div> <p><!-- \/\/contents_detail --> <\/p> <div class=\"contents_detail\"> <div class=\"clearfix mt20\"> <a href=\"\/jump\/yoshimura\/en\/20161122-store.html\" target=\"_blank\"><img loading=\"lazy\" class=\"lazy\" src=\"https:\/\/www.bikebros.co.jp\/vb_img\/js\/lazyload\/transparent.gif\" alt=\"\" width=\"950\" height=\"120\" data-original=\"http:\/\/img.bikebros.co.jp\/vb_img\/tieup\/sports\/yoshimura\/08\/img\/en\/banner.jpg\" \/><\/a> <\/div> <p><!--clearfix mt20--> <\/div> <p><!-- \/\/contents_detail --> <\/p> <div class=\"contents_detail\"> <h3 class=\"boxmidashi\">BRAND INFORMATION<\/h3> <div id=\"shopdata\"> <a href=\"http:\/\/www.bikebros.co.jp\/jump\/yoshimura\/en\/20161122-web.html\" target=\"_blank\"><img loading=\"lazy\" class=\"lazy\" src=\"https:\/\/www.bikebros.co.jp\/vb_img\/js\/lazyload\/transparent.gif\" alt=\"\" width=\"334\" height=\"219\" data-original=\"http:\/\/img.bikebros.co.jp\/vb_img\/tieup\/sports\/yoshimura\/08\/img\/logo.jpg\" \/><\/a><\/p> <p class=\"midashi\"><a href=\"http:\/\/www.bikebros.co.jp\/jump\/yoshimura\/en\/20161122-web.html\" target=\"_blank\">Yoshimura Japan<\/a><\/p> <p>The well-\u00adrespected Japanese racing constructor \/ aftermarket parts manufacturer &amp; supplier, started its business in 1954. The company has been racing and tuning Suzuki motorcycles since the late 1970\u2032s following the years of dedication to Honda and Kawasaki.Their product development, however, is targeting diverse applications ranging from 4-\u00adstroke minis to supersports of various brands.<\/p> <p>6748 Nakatsu, Aikawa-\u00adMachi, Aiko-\u00adGun, Kanagawa-\u00adPref. 243-\u00ad0303 Japan<\/p> <p> Official Website: <a href=\"http:\/\/www.bikebros.co.jp\/jump\/yoshimura\/en\/20161122-web.html\" target=\"_blank\">www.yoshimura-\u00adjp.com\/en\/<\/a> <\/div> <p><!--#shopdata--> <\/div> <p><!--\/.contents_detail--> <\/p> <div class=\"bottom10\" style=\"float: right; text-align: right; padding-top: 5px;\"> <div style=\"width: 150px; float: right; margin-left: 5px;\"> <div class=\"fb-like\" data-href=\"http:\/\/www.bikebros.co.jp\/vb\/sports\/sfeat\/yoshimura-cam-en\/\" data-layout=\"button_count\" data-action=\"like\" data-show-faces=\"true\" data-share=\"true\"><\/div> <\/div> <div style=\"width: 90px; float: right;\"><a class=\"twitter-share-button\" href=\"http:\/\/twitter.com\/share\" data-count=\"none\" data-via=\"BikeBrosMagazin\" data-lang=\"ja\">Tweet<\/a><script src=\"https:\/\/platform.twitter.com\/widgets.js\"><\/script><\/div> <\/div> <div class=\"clear\"><\/div> <div class=\"contents_detail\"> <div class=\"fblikebox\"> <div class=\"fb-page\" data-href=\"https:\/\/www.facebook.com\/YoshimuraJapan\/\" data-tabs=\"timeline\" data-width=\"500\" data-height=\"500\" data-small-header=\"false\" data-adapt-container-width=\"true\" data-hide-cover=\"false\" data-show-facepile=\"false\"> <blockquote class=\"fb-xfbml-parse-ignore\" cite=\"https:\/\/www.facebook.com\/protecproducts\"><p><a href=\"https:\/\/www.facebook.com\/YoshimuraJapan\/\">YoshimuraJapan<\/a><\/p><\/blockquote> <\/div> <\/div> <\/div> <p><!-- \/\/contents_detail --><\/p> <div class=\"pagetop\" style=\"display: block;\"><a href=\"#top\">\u25b2<\/a><\/div> <p><script src=\"https:\/\/code.jquery.com\/jquery-1.10.1.min.js\"><\/script><script src=\"https:\/\/www.bikebros.co.jp\/vb_img\/js\/jquery.lazyload.min.js\"><\/script><br \/> <script>\/\/ <![CDATA[\n$(\"img.lazy\").lazyload({ effect: \"fadeIn\" });\n\/\/ ]]><\/script><\/p>","protected":false},"excerpt":{"rendered":"<p>Camshaft -\u00ad-\u00ad-\u00ad-\u00ad the heart of the four-\u00adstroke engine. Yoshimura, which has been leading the world since 1954 in camshaft tuning technology, has triggered an evolution by innovating new method and material. It was a historical accomplishment driven by their spirit and passion. Let\u2019s look closely at Yoshimura\u2019s latest cylinder head tuning.<\/p>\n","protected":false},"author":4,"featured_media":12167,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"spay_email":""},"categories":[51],"tags":[],"jetpack_featured_media_url":"https:\/\/www.bikebros.co.jp\/vb\/wp-content\/uploads\/2016\/11\/yoshimura-cam.jpg","jetpack_shortlink":"https:\/\/wp.me\/p8ZsSB-3mS","_links":{"self":[{"href":"https:\/\/www.bikebros.co.jp\/vb\/wp-json\/wp\/v2\/posts\/12950"}],"collection":[{"href":"https:\/\/www.bikebros.co.jp\/vb\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.bikebros.co.jp\/vb\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.bikebros.co.jp\/vb\/wp-json\/wp\/v2\/users\/4"}],"replies":[{"embeddable":true,"href":"https:\/\/www.bikebros.co.jp\/vb\/wp-json\/wp\/v2\/comments?post=12950"}],"version-history":[{"count":0,"href":"https:\/\/www.bikebros.co.jp\/vb\/wp-json\/wp\/v2\/posts\/12950\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.bikebros.co.jp\/vb\/wp-json\/wp\/v2\/media\/12167"}],"wp:attachment":[{"href":"https:\/\/www.bikebros.co.jp\/vb\/wp-json\/wp\/v2\/media?parent=12950"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.bikebros.co.jp\/vb\/wp-json\/wp\/v2\/categories?post=12950"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.bikebros.co.jp\/vb\/wp-json\/wp\/v2\/tags?post=12950"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}