The 1st downhill time-trial race took place in Fairfax, California on October 21, 1976 on a fireroad now referred to as Repack Road,[2][3][4] due to the need to repack the hub brake(s)[5] after a descent. The bikes used were based on cruiser bicycles that had Drum brake(s) or a single rear coaster brake that worked by pedalling backwards. A mechanism came into operation causing a conical metal (bronze?) brake shoe to be wound on a thread into a conical metal hub. To prevent a metal to metal brake from snatching it was always filled with grease. Heavy use of the brake during the descent would cause the brake to over heat, melting the grease till it drained from the hub and required repacking. Ten riders descended 1,300 feet (400 m) of Repack in about 5 minutes.[6]
The first bikes used for descending were known as "klunkers" or "paperboy bikes": cruisers using balloon tires and coaster brakes, a sturdy bicycle, designed by Ignatz Schwinn[7] in the depths of the Great Depression, that could endure abuse that could damage other bicycles, by changing features from the Henderson and Excelsior motorcycles his company had built during the 1920s, including a heavy "cantilevered" frame with two top tubes and 2.125-inch-wide (54.0 mm) "balloon" tires from Germany. Innovations like the fat-tire Schwinn with derailleur gears by Russ Mahon[5] of The Morrow Dirt Club in Cupertino at the 1974 Marin County cyclo-cross and Gary Fisher's[5] 1975 use of a tandem rear hub (from a flea market) with internal steel drum brake and threaded for a freewheel derailleur cluster developed the sport and by 1979, two organizers and competitors of the Repack downhill, Charlie Kelly[5] and Gary Fisher founded the company which named the sport, MountainBikes.[8] As mountain biking grew enormously during the 80s, downhill riders continued to use either rigid or limited suspension travel (under 2 inches (5 cm)) bicycles, and purpose made downhill bikes were not made until the 90s. Some of these innovations included dual crown suspension forks and disc brakes, as well as very elaborate frame suspension designs.
Later, riders from all disciplines of cycling began focusing on downhill. Particularly, many BMX racers made the crossover, including champions such as Daniel Solano (Team Tomac Bikes), and Brian Lopes. Their influence is seen in the increased difficulty of many courses, especially the big jumps and drops aspect of downhill. The coming of age for downhill biking was its inclusion at the first UCI Mountain Bike Championship, held in 1990 in Durango, Colorado.
เวลาทดลองแข่งขันดาวน์ฮิลล์ 1 เอาในแฟร์แฟ็กซ์ แคลิฟอร์เนียในวันที่ 21 ตุลาคม 1976 บน fireroad ที่ตอนนี้ เรียกว่าถนน Repack, [2] [3] [4] เนื่องจากต้อง repack brake(s) ฮับ [5] หลังจากเชื้อสาย จักรยานที่ใช้ถูกยึดจักรยานครุยเซอร์ที่มีกลอง brake(s) หรือ coaster หลังเดียวเบรคที่ทำงาน โดย pedalling ย้อนหลัง กลไกมาเป็นทรงกรวยโลหะ (สำริด) เบรครองเท้าบาดบนเธรดฮับเป็นทรงกรวยโลหะที่ทำให้เกิดการดำเนินงาน เพื่อป้องกันไม่ให้มันวิ่งราวทรัพย์เบรคโลหะกับโลหะก็จะเต็มไป ด้วยไขมัน ใช้เบรคระหว่างโคตรหนักจะทำให้เบรกการผ่านความร้อน ละลายไขมันจนระบายออกจากฮับ และต้องวิเคราะห์ ผู้ขับขี่ 10 1300 ฟุต (400 เมตร) ที่สืบเชื้อสายของ Repack มาทุก ๆ 5 นาที [6]The first bikes used for descending were known as "klunkers" or "paperboy bikes": cruisers using balloon tires and coaster brakes, a sturdy bicycle, designed by Ignatz Schwinn[7] in the depths of the Great Depression, that could endure abuse that could damage other bicycles, by changing features from the Henderson and Excelsior motorcycles his company had built during the 1920s, including a heavy "cantilevered" frame with two top tubes and 2.125-inch-wide (54.0 mm) "balloon" tires from Germany. Innovations like the fat-tire Schwinn with derailleur gears by Russ Mahon[5] of The Morrow Dirt Club in Cupertino at the 1974 Marin County cyclo-cross and Gary Fisher's[5] 1975 use of a tandem rear hub (from a flea market) with internal steel drum brake and threaded for a freewheel derailleur cluster developed the sport and by 1979, two organizers and competitors of the Repack downhill, Charlie Kelly[5] and Gary Fisher founded the company which named the sport, MountainBikes.[8] As mountain biking grew enormously during the 80s, downhill riders continued to use either rigid or limited suspension travel (under 2 inches (5 cm)) bicycles, and purpose made downhill bikes were not made until the 90s. Some of these innovations included dual crown suspension forks and disc brakes, as well as very elaborate frame suspension designs.ภายหลัง ผู้ขับขี่จากทุกสาขาของจักรยานเริ่มเน้นทางลง โดยเฉพาะ นักแข่ง BMX หลายทำไขว้ รวมถึงแชมป์เช่น Daniel โซลาโน่ (ทีม Tomac จักรยาน), ไบรอัน Lopes อิทธิพลจะเห็นในความยากลำบากเพิ่มขึ้นในหลักสูตร กระโดด และหยดด้านทางลงโดยเฉพาะอย่างยิ่งใหญ่ มาอายุสำหรับการขี่จักรยานลงเนินไม่รวมของที่ที่แรก UCI ภูเขาแชมป์จักรยาน จัดขึ้นในปี 1990 ใน Durango โคโลราโด
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