Editing Semi-automatic transmission (section)

{{short description|Type of multi-speed motor vehicle transmission}}
{{Use dmy dates|date=September 2022}}
A '''semi-automatic transmission''' is a multiple-speed [[Transmission (mechanics)|transmission]] where part of its operation is [[Automation|automated]] (typically the actuation of the [[clutch]]), but the driver's input is still required to launch the vehicle from a standstill and to manually change gears. Semi-automatic transmissions were almost exclusively used in motorcycles and are based on conventional [[manual transmission]]s or [[sequential manual transmission]]s, but use an automatic clutch system. But some semi-automatic transmissions have also been based on standard hydraulic [[automatic transmissions]] with [[torque converter]]s and [[Epicyclic gearing|planetary gearsets]].<ref>{{cite web |last1=Wan |first1=Mark |title=AutoZine Technical School, Manual Transmission |url= https://www.autozine.org/technical_school/gearbox/Gearbox_Manual.html |website=autozine.org |date=2019 |access-date=17 November 2020}}</ref><ref>{{cite web |title=How to Shift Gears on a Motorcycle |url= https://www.wikihow.com/Shift-Gears-on-a-Motorcycle |website=wikiHow |access-date=17 November 2020 |date=21 September 2020}}</ref>

Names for specific types of semi-automatic transmissions include ''clutchless manual'',<ref name="autonews1">{{cite web |url= https://www.autonews.com/article/20010401/SUB/104010719/the-next-shift-the-clutchless-manual |title=The next shift: The clutchless manual |website=autonews.com |date=13 December 2005 |access-date=29 February 2020}}</ref> ''auto-manual'',<ref>{{cite web |title=1993 Ferrari Mondial T Cabriolet Valeo |url= https://bringatrailer.com/listing/1993-ferrari-mondial-t-cabriolet-2/ |website=Bring a Trailer |date=October 2018 |access-date=18 November 2020}}</ref><ref>{{cite web|url=https://bringatrailer.com/listing/1992-ferrari-mondial-t-cabriolet-3/|title=1992 Ferrari Mondial T Cabriolet Valeo Transmission|date=20 July 2023 }}</ref> ''auto-clutch manual'',<ref name="yamahamotorsports.com">{{cite web|url=https://www.yamahamotorsports.com/trail-motorcycle/models/tt-r110e|title=2022 Yamaha TT-R110E Trail Motorcycle – Photo Gallery, Video, Specs, Features, Offers, Inventory and more|website=www.yamahamotorsports.com|access-date=16 August 2020|archive-date=29 September 2020|archive-url=https://web.archive.org/web/20200929011521/https://www.yamahamotorsports.com/trail-motorcycle/models/tt-r110e|url-status=dead}}</ref><ref>Archived at [https://ghostarchive.org/varchive/youtube/20211205/XC29R9CSx-M Ghostarchive]{{cbignore}} and the [https://web.archive.org/web/20201209164403/https://www.youtube.com/watch?v=XC29R9CSx-M Wayback Machine]{{cbignore}}: {{cite web| url = https://www.youtube.com/watch?v=XC29R9CSx-M| title = How to make any bike an AUTOMATIC | website=YouTube}}{{cbignore}}</ref> and ''paddle-shift'' transmissions.<ref>{{cite web|url= http://www.geartronics.co.uk/paddleshift.htm|title = Geartronics – Sequential gearbox electronic systems – Professional paddle shift system}}</ref><ref>{{cite web|url= https://www.hewland.com/wpcproduct/semi-auto-systems/|title = Semi-Auto Systems}}</ref><ref>{{cite web|url= https://www.hewland.com/race-series-control-components/|title = Control components for race series reduce cost, improve competition}}</ref> These systems facilitate gear shifts for the driver by operating the clutch system automatically, usually via [[switch]]es that trigger an [[actuator]] or [[servomechanism|servo]], while still requiring the driver to manually shift gears. This contrasts with a [[preselector gearbox]], in which the driver selects the next gear ratio and operates the pedal, but the gear change within the transmission is performed automatically.

The first usage of semi-automatic transmissions was in automobiles, increasing in popularity in the mid-1930s when they were offered by several American car manufacturers. Less common than traditional hydraulic automatic transmissions, semi-automatic transmissions have nonetheless been made available on various car and motorcycle models and have remained in production throughout the 21st century. Semi-automatic transmissions with paddle shift operation have been used in various [[Auto racing|racing cars]], and were first introduced to control the electro-hydraulic gear shift mechanism of the [[Ferrari 640]] [[Formula One car]] in 1989. These systems are currently used on a variety of top-tier racing car classes; including [[Formula One]], [[IndyCar]], and [[touring car racing]]. Other applications include motorcycles, trucks, buses, and [[Rail transport|railway vehicles]].