Motorcycle Transmissions & Parts
- Twin Power®Transmission Nut Lock Plate Kit (410008)Transmission Nut Lock Plate Kit by Twin Power®. This kit has the transmission pulley nut with lock plate and two screws. This top-grade product is expertly made in compliance with stringent industry standards to offer a fusion of a...Made in USACrafted to deliver unbeatable levels of quality$24.35
- Baker Drivetrain®DD7 7-Speed Direct Drive Builders KitDD7 7-Speed Direct Drive Builders Kit by Baker Drivetrain®. Included BAKER Direct Drive 7 Speed Stock Side Cover emblem. The DD7 upgrades any existing 2006-later big twin 6 speed to a full 7 speed transmission. The BAKER DD7 is more...Shorter first gear ratio to help with the off the light get up and go, as well as slow speed maneuvering around the bar parking lotFully assembled gear set and shift system. No adjustments needed for installation$3,102.76 - $3,695.00
- Andrews Products®Transmission Close Ratio Gear SetTransmission Close Ratio Gear Set by Andrews Products®. All speed gears are made from high nickel alloy and heat treated and shot-peened to give maximum durability and strength. Also, where applicable, lead-in ramps have been machined...Precise engineering provides great longevityPeak accuracy and effectiveness$192.78 - $273.89
- Andrews Products®Transmission GearTransmission Gear by Andrews Products®. All speed gears are made from high nickel alloy and heat treated and shot-peened to give maximum durability and strength. Also, where applicable, lead-in ramps have been machined into most gears...Precise engineering provides great longevityPeak accuracy and effectiveness$79.57 - $711.66
- Baker Drivetrain®6-Into-4 Transmission6-Into-4 Transmission by Baker Drivetrain®. Made to satisfy the old school tendencies while providing the ability to run reasonable RPM's at highway speeds. Panhead and Shovelhead riders will love the ability to ride hard with their...OD6-based transmission insideSmooth out the rattle on the highway$3,795.00
- Accutronix®Knurled Transmission DipstickKnurled Transmission Dipstick by Accutronix®. Accutronix has added a Transmission Dipstick to Accutronix line of billet products. These Knurled dipsticks replace the OEM item and really clean up the look of the transmission. Accutronix...Designed to provide unrivaled value and maximum reliabilityExpertly crafted from the highest grade materials$63.95
- Baker Drivetrain®DD6 6-Speed Direct Drive Transmission Builders KitDD6 6-Speed Direct Drive Transmission Builders Kit by Baker Drivetrain®. Anti-overshift ratchet pawl and Longer primary chain included. From an engineering standpoint, it is difficult to design a machine or mechanism that achieves...Billet 6061-T6 bearing door1/8" thick bearing retainer plate$2,652.41 - $2,895.00
- Andrews Products®Transmission Countershaft GearTransmission Countershaft Gear by Andrews Products®. Transmission gears are made from high nickel alloy steel which is heat-treated and shot peened for maximum durability. Shot peening greatly improves the wear resistance of drive edges...Precise engineering provides great longevityPeak accuracy and effectiveness$45.86 - $129.12
- Baker Drivetrain®Function-Formed Hydraulic Side CoverFunction-Formed Hydraulic Side Cover by Baker Drivetrain®. The Hydraulic Side Covers was one of the first parts in the FF product line. Baker took away all the 'fat' of the standard aftermarket side cover and left the function. The...Forged 6061 Side Covers tuck tighter to the transmission than the stock cable style side coversCompact and versatile hydraulic line routing enabling the banjo fitting to be on the front or rear of the transmission$362.00
- Andrews Products®Transmission Mainshaft GearTransmission Mainshaft Gear by Andrews Products®. Transmission gears are made from high nickel alloy steel which is heat-treated and shot peened for maximum durability. Shot peening greatly improves the wear resistance of drive edges...Precise engineering provides great longevityPeak accuracy and effectiveness$84.01 - $124.53
- SMP®Neutral Safety SwitchNeutral Safety Switch by SMP®. Precision manufactured to stringent specifications to ensure proper function and long life in the toughest of conditions. All switches feature a high carbon steel plunger hardened to 48 Rockwell C for...Direct O.E.M. replacement type switchesGasket or seal included$13.11 - $20.93
- JIMS®4-Speed Transmission Rebuild Kit4-Speed Transmission Rebuild Kit by JIMS®. Use JIMS® proven transmission parts to start with, then top it off with a JIMS® Gasket set, together in one convenient package. This is a big time saver.Made in USABuilt to match your exact requirements$234.32 - $337.82
- Baker Drivetrain®Roller 5-Speed Shift KitRoller 5-Speed Shift Kit by Baker Drivetrain®. The design principles that made Baker Six-Speed Overdrive shift so smooth were applied to create a shift drum/pillow block kit that will bolt on to any 5-speed and give super smooth and...Made to offer outstanding performancePerfect for both professionals and enthusiasts$265.00
- JIMS®Countershaft Gear BushingCountershaft Gear Bushing by JIMS®. Designed with precision and functionality in mind, this accessory ensures outstanding performance and easy use which makes it the perfect deal for your ultimate satisfaction.Unique design to meet your tastes and preferencesManufactured to deliver incredible quality$28.04 - $28.35
- Andrews Products®Transmission Main Belt Drive GearTransmission Main Belt Drive Gear by Andrews Products®. Transmission gears are made from high nickel alloy steel which is heat-treated and shot peened for maximum durability. Shot peening greatly improves the wear resistance of drive...Precise engineering provides great longevityPeak accuracy and effectiveness$50.27 - $217.98
- Andrews Products®Transmission CountershaftTransmission Countershaft by Andrews Products®. Three types of countershafts fit transmissions through 1985. Countershafts are not interchangeable, take care in ordering. This top-grade product is expertly made in compliance with...Precise engineering provides great longevityPeak accuracy and effectiveness$35.67 - $132.08
- Colony®Transmission Mainshaft LocknutTransmission Mainshaft Locknut by Colony®. This top-grade product is expertly made in compliance with stringent industry standards to offer a fusion of a well-balanced design and high level of craftsmanship. Manufactured from...Precise manufacturing and high-grade materialsExpertly crafted from the highest grade materials$13.75 - $18.18
- Baker Drivetrain®Transmission Rebuild KitTransmission Rebuild Kit by Baker Drivetrain®. Includes bearings, snap rings, gaskets, seals and retaining nuts. An all inclusive kit designed to freshen up those high mileage bikes. This kit was put together to assist you with that...Made to offer outstanding performancePerfect for both professionals and enthusiasts$379.00
- Andrews Products®Transmission Shift ForkTransmission Shift Fork by Andrews Products®. A must for all transmission rebuilds. This top-grade product is expertly made in compliance with stringent industry standards to offer a fusion of a well-balanced design and high level of...Precise engineering provides great longevityPeak accuracy and effectiveness$18.97
- Baker Drivetrain®Speedo Hole PlugSpeedo Hole Plug by Baker Drivetrain®. If you need to cap off the speedo sensor hole for whatever reason, you need this plug. Some other companies do this with a steel plate and a gasket, just like old 4-speeds. Ever seen a 4-speed with...6061-T6 AluminumLow-profile top$27.00 - $31.00
- JIMS®Overdrive Transmission Rebuild KitOverdrive Transmission Rebuild Kit by JIMS®. JIMS® proven transmission parts to start with, then top it off with a JIMS® gasket set, together in one convenient package. This is a big time saver. If you're looking for a quality...Unique design to meet your tastes and preferencesManufactured to deliver incredible quality$293.90 - $360.50
- Andrews Products®Transmission MainshaftTransmission Mainshaft by Andrews Products®. Made of aircraft alloy steel. Heat-treated and finish ground to ensure maximum durability. Replacement mainshafts for all versions of Big Twin boxes. Made of aircraft alloy steel....Precise engineering provides great longevityPeak accuracy and effectiveness$226.38 - $266.48
- K&S Technologies®Neutral SwitchNeutral Switch by K&S Technologies®. This top-grade product is expertly made in compliance with stringent industry standards to offer a fusion of a well-balanced design and high level of craftsmanship. Manufactured from...Made to the highest quality standardsEngineered for your motorcycle racing needs$14.96 - $18.31
- Baker Drivetrain®Transmission DipstickTransmission Dipstick by Baker Drivetrain®. Have you ever heard of a 5-speed transmission dipstick breaking off and working its way into the gearbox with disastrous results? Ask any seasoned technician; he's seen one. The low frequency...Made of billet aluminum and show chrome-platedLargest radius possible between the stalk and the head$29.00 - $40.81
- Colony®Transmission PlugTransmission Plug by Colony®. This product is made of high-quality materials to serve you for years to come. Designed using state-of-the-art technology and with customers in mind. It will meet your needs and deliver great quality at an...Made in USADesigned specifically for Harley-Davidson motorcycles$12.12 - $19.45
- Compu-Fire®8620 Hardened Steel Gear Set8620 Hardened Steel Gear Set by Compu-Fire®. 10/84 Gear Set made with 8620 Hardened Steel. This top-grade product is expertly made in compliance with stringent industry standards to offer a fusion of a well-balanced design and high...Wicked style meets astounding performanceExcellent upgrade for die-hard performance fans$194.80
- JIMS®Shift Fork ShaftShift Fork Shaft by JIMS®. Designed with precision and functionality in mind, this accessory ensures outstanding performance and easy use which makes it the perfect deal for your ultimate satisfaction.Unique design to meet your tastes and preferencesManufactured to deliver incredible quality$22.91 - $35.06
- Eastern Performance®Main Drive Gear SpacerMain Drive Gear Spacer by Eastern Performance®. Precision spacers used between main drive gear and sprocket for belt drive Sportsters and Big Twin transmissions. Manufactured from high quality alloy steel, hardened and ground....Crafted with precision using leading innovationsDesigned specifically for Harley-Davidson motorcycles$14.64 - $32.46
- JIMS®Transmission Main Bearing RaceTransmission Main Bearing Race by JIMS®. Standard O.D, is 2.314", I.D, is 1.8802", It will depend on the amount of press fit and will determinethe amount of line lapping required to fit new bearing and mainshaftUnique design to meet your tastes and preferencesManufactured to deliver incredible quality$86.99
- Colony®Transmission Mount KitTransmission Mount Kit by Colony®. Includes bolts and washers necessary for installation. This product is made of high-quality materials to serve you for years to come. Designed using state-of-the-art technology and with customers in...Made from the highest quality materialsMade in USA$35.69 - $43.70
The majority of modern motorcycles use manual sequential gearboxes with five or six gears. “Sequential” means that the rider cannot select any gear any time. He or she has to pull up a shifting lever to select one gear higher or press it down to change gear from higher to lower in strict order. As standard, the shifting lever is positioned on the lower left side of the bike to be operated by the rider’s left foot. A clutch lever is located over the left grip so that the rider can operate the bike without taking his or her hand off the handlebars.
In a traditional “1 down 4 up” or “1 down 5 up” scheme, the neutral gear is positioned between the first and second gear because it makes the most sense. That way, by pushing the lever down several times, you know that you have reached the first gear and to put your bike in neutral, you have to pull the lever half a click up. From the neutral position, you can select the second gear when starting downhill. The construction of sequential motorcycle transmissions allows experienced riders to use the clutch only when starting from a complete stop while performing clutchless upshifting between higher gears.
Since the conventional manual gearbox with an H-pattern of shifting used in cars is too large to be fitted into a compact motorcycle frame, and shifting using hand lever on bikes is proved to be impractical, modern motorcycles use a compact “dog clutch” scheme where all of the gear teeth are always engaged. Some of the gears are connected to input and output shafts through splines but can shift from side to side. Some of them rotate freely. When the rider pushes the shift lever, it rotates the shift drum or barrel through a ratchet mechanism. The drum has grooves around its surface used to actuate shift forks.
As the drum rotates, these forks literally shift gears on transmission shafts to engage the needed gear pairs, thus the term ""shifting gears."" The engagement between freely rotating gears and those splined to the same shaft is performed through dog clutches. Some gears have pegs on their sides called “dogs.” They are designed to nest in corresponding recesses on adjacent sprockets. To complete the shift to an adjacent gear, you need to provide only a brief interruption of engine torque. A shift fork makes neighboring gears lock together and rotate as one. By pushing the shift lever up without clicking it, you can synchronize the rotation of two gears, which allows you to shift them after rolling off the throttle without disengaging the clutch and without causing damage to transmission components.
A smoothly running gearbox is essential for your success on the track or comfort on the road. If something goes wrong with the gears, you can tell with certainty that the problem is in the transmission. When it is time for repairs or upgrade, visit our online store and browse the catalog of motorcycle transmissions and components where we’ve gathered only high-quality products made by some of the most reputable manufacturers in the industry. We offer high-performance gearboxes with additional overdrive gears. Some models feature rear gears, which is convenient if you own a heavy cruiser. Here you can find rebuild kits, replacement shafts, gear, shift forks, drums, transmission covers, and much more.
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Related Categories
- Drive Chains
- Sprockets
- Chain & Sprocket Kits
- Drive Belts & Pulleys
- Primary Chains & Belts
- Clutches
- Variators
- Driveshaft
- Axles & Accessories
- Wheel Hubs
- Chain Guide, Protection & Sliders
- Sprocket Guards
- Transmission Covers
- Chain & Belt Adjusters
- Primary Chain & Belt Tensioners
- Transmission Sensors & Switches
- Clutch Lines
- Transmission Gaskets, Seals & Bushings
- Drivetrain & Transmission Bearings
- Drivetrain & Transmission Mounts
- Engine & Transmission Custom Covers
- Drive Belt & Drive Shaft Covers
- Chain Lubes & Cleaners
- Transmission Fluids & Oils
- Gear Oils
- Greases
- Drivetrain & Transmission Tools