How do I know if a custom primary cover will fit my bike?

Fitment is very specific to the year, model, and engine of your motorcycle (e.g., Sportster, Evo Big Twin, Twin Cam). Always use the bike filter on our website and carefully read the product description, which lists the exact models and year ranges the cover is designed for.

Is installing an open primary kit a job I can do myself?

This is an advanced, expert-level installation. It requires precise alignment of the engine and transmission pulleys, proper belt tensioning, and clutch setup. We recommend this job for experienced mechanics only.

Do I have to change my clutch to run an open primary?

Yes, absolutely. Stock Harley-Davidson primaries use a "wet" clutch that runs in oil. An open belt drive must run "dry." Therefore, all open primary kits require you to convert to a dry clutch assembly, which has different friction plates designed to operate without oil.

Motorcycle Primary

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Primary Cover - Chrome - 1994-2003 Harley-Davidson Sportster XL Drag Specialties
$376.93

Primary Chain Adjuster Kit - 1965-2000 Harley-Davidson Big Twin Cycle Standard
$56.24 $70.30

Primary Chain Adjuster Kit - 1991-2003 Harley-Davidson Sportster XL Cycle Standard
$27.74 $34.67

Triumph Unit 650 Primary Cover Bonneville Tiger Trophy OEM 57-1727 British Standard
$190.35

Derby Cover - Wrinkle Black - 1999-2018 Harley-Davidson Big Twin/Twin Cam Drag Specialties
$63.81

Primary Cover Gasket & Seal Kit 1977-1990 Harley-Davidson XL James Gaskets
$30.70

Primary Chain 1957-2022 Harley-Davidson Sportster XL Diamond
$152.96 $169.95

Primary Cover Gasket & Seal Kit 2004-2022 Harley-Davidson XL James Gaskets
$35.61

Primary Chain 1957-2003 Harley-Davidson Sportster XL 2004-2022 XL 883 Drag Specialties
$129.73

Primary Chain Tensioner - 2001-2005 Harley-Davidson Dyna 01-06 Softail/Touring Cycle Standard
$56.09 $70.11

Primary Cover Gasket 1965-1988 Harley-Davidson Big Twin James Gaskets
$24.91

Renolds Duplex Primary Chain Triumph OEM #60-0477 Made in UK British Standard
$121.54

Primary Gasket for 1963-82 650/750 unit Triumph Motorcycles - Extra Thick OEM #71-7009 British Standard
$16.94

#8919-19-P Primary Cover Smooth Allen Kit 1989-2006 Harley-Davidson Softail 1991-2005 Dyna - Chrome Plated Colony
$48.73

Primary Chain Tensioner for Triumph Motorcycles OEM #70-6283 British Standard
$42.19

#7811-14 Inner Primary Mounting Kit - 1936-1954 Harley-Davidson Knucklehead/Panhead Colony
$26.08

#3194-1 Harley Primary Drain Plug - Zinc Plated - Big Twin & Softail - 1987-2003 & 1993-2003 Colony
$9.68

#2220-24 Primary Cover Allen Screw Kit 2004-Up Harley-Davidson Sportster - Chrome Plated Colony
$36.54

Primary Inspection Cover - Black - 2004-2021 Harley-Davidson Sportster XL Cycle Standard
$27.15 $33.94

3 Hole Chrome Derby Cover for 1970-98 Harley-Davidson Big Twins Replaces OEMs 60668-84A 253952-84T Cycle Standard
$17.94 $22.42

Colony #9769-17-P Primary Cover Smooth Chrome Allen Screw Kit Harley Sportster 1994-03 — #9769-17-P Primary Cover Smooth Allen Screw Kit 1994-2003 Harley-Davidson XL - Chrome Plated Colony
$31.13

Derby Cover - Chrome - 1970-1998 Harley-Davidson Big Twins Cycle Standard
$24.94 $31.18

#2342-18 Primary Cover Allen Screw Kit 2006-Up Harley-Davidson Dyna - Chrome Plated Colony
$29.78

#9869-24 Inner Primary Mounting Kit 1980-1985 Harley-Davidson FL/FX Colony
$29.54

Primary Cover Gasket 1967-1976 Harley-Davidson XL James Gaskets
$6.73

#8917-19 Primary Cover Chrome Acorn Head Screw Kit 1989-2006 Harley-Davidson Softail 1991-2005 Dyna - Chrome Plated Colony
$56.11

Slotted Inspection Cap / Plug for Triumph BSA OEM # 57-2166 70-8231 40-0715 Lowbrow Customs
$9.30 $11.62

Primary Inspection Cover - Polished - 1991-2003 Harley-Davidson Sportster XL Drag Specialties
$29.82

Derby Cover - Chrome - 1999-2018 Harley-Davidson Big Twin/Twin Cam Drag Specialties
$63.81

Replacement Primary Inspection Cover Gasket - 2004-2021 Harley-Davidson Sportster XL Cycle Standard
$5.01 $6.26

#9769-17 Primary Cover Allen Screw Kit 1994-2003 Harley-Davidson XL - Chrome Plated Colony
$24.37

#3193-2 Primary Drain Plug 2004-2006 Harley-Davidson Softail - Zinc Plated Colony
$11.50

Primary Inspection Cover - Chrome - 2004-2021 Harley-Davidson Sportster XL Cycle Standard
$37.54 $46.93

Primary Cover Gasket 1977-1990 Harley-Davidson XL James Gaskets
$8.84

#9770-17 Primary Cover Acorn Screw Kit 1994-Up Harley-Davidson XL - Chrome Plated Colony
$43.45

Derby Cover - Satin Black - 1994-2003 Harley-Davidson Sportster XL Drag Specialties
$47.33

Derby Cover - Gloss Black - 2006-2021 Harley-Davidson Sportster XL Cycle Standard
$33.07 $41.34

#8763-20-P Primary Cover Smooth Allen Screw Kit 1980-1984 Shovelhead & Evo 5 speed - Chrome Plated Colony
$37.22

#3537-17 Primary Cover Allen Screw Kit 1971-Up Harley-Davidson Shovelhead & Evolution 4 Speed Colony
$16.34

#8916-17 Primary Cover Allen Head Screw Kit 1985-Up Harley-Davidson FXR 1985-1999 FLT - Chrome Plated Colony
$28.42

#8155-30 Primary Cover Screw Kit 1936-1964 Harley-Davidson Big Twins - Chrome Plated Colony
$30.00

Primary Gasket for 1963-82 650/750 unit Triumph Motorcycles OEM #71-7009 British Standard
$13.97

Primary Cover Gasket 1952-1969 Harley-Davidson XL James Gaskets
$8.87

#3045-14 Inner Primary Chain Guard Kit 1936-1954 Harley-Davidson Big Twins - Parkerized Colony
$26.08

#3004-9 Inner Outer Primary Mounting Kit 1930-1936 Harley-Davidson VL Colony
$25.84

#8798-12 Inner Primary Mounting Kit - 1965-1969 Harley-Davidson Shovelhead Colony
$24.26

#2559-1 Primary Cover Filler Cap 1971-1976 Harley-Davidson Sportster Colony
$23.10

#8892-12 Primary Cover Screw Kit 1967-1970 Harley-Davidson XLH 1970 XLCH - Chrome Plated Colony
$23.01

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The Heart of the Drivetrain: Motorcycle Primary Drives The primary drive is where your engine's power meets the transmission. Housed behind a cover, the stock system is designed for quiet reliability. But for custom builders, this area is a massiv...

The Heart of the Drivetrain: Motorcycle Primary Drives

The primary drive is where your engine's power meets the transmission. Housed behind a cover, the stock system is designed for quiet reliability. But for custom builders, this area is a massive canvas for style. Upgrading your primary is a high-impact modification, whether you choose a new look with a custom primary cover or go for the radical mechanical beauty of an open belt drive.

The Heart of Your Drivetrain: Why the Primary Matters

The primary drive is far more than just a side cover; it’s the critical link responsible for harnessing your engine’s raw power and delivering it to the transmission. Every component in this system—from the clutch to the chain or belt—is under immense stress. This is why investing in quality here is non-negotiable.

Reliable Power Delivery: This system handles every bit of torque your motor puts out. A worn-out chain, a slipping clutch, or a flexing cover plate can all lead to power loss and poor performance. A solid primary setup ensures that power gets to where it needs to go.
The Visual Anchor of Your Bike: The primary cover is one of the largest visual pieces on your motorcycle. Changing it with a custom primary cover offers the biggest style impact for the least amount of work. Going for an open primary completely redefines the bike, showcasing its mechanical guts.
Defines the Rider's Experience: The primary system dictates how your clutch feels at the lever and the sounds your bike makes at idle. A stock wet primary is smooth and quiet. An open primary with a dry clutch is aggressive and loud, offering a direct, mechanical connection to the ride.
Crucial Fitment for a Long Life: Because this system connects the engine and transmission, proper alignment is everything. Whether you're installing a new Harley Evo primary cover or a full Sportster open primary kit, a perfect fit prevents catastrophic wear on bearings, seals, and belts.

Why Get Your Primary Components from Lowbrow?

We offer high-impact parts for every level of customization, all engineered for performance and durability.

A Path for Every Builder: We stock a huge range of custom primary covers for a quick style upgrade, as well as complete, engineered open primary kits for ground-up builds.
Built to Last: Whether it’s a beautifully finished custom cover or a complete Sportster belt drive primary, all our components are made from high-quality materials designed to handle the abuse of the road.

When you choose Lowbrow Customs, you're not just buying parts; you're joining a community of builders. We're committed to backing you up with:

Free Shipping on all US orders over $99.
90-Day Hassle-Free Returns because we stand by what we sell.
Real-Deal Tech Support from our experienced team, ready to offer expert advice for your projects.

Explore our collection of primary drive components and make a bold statement with your build.

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Motorcycle Primary FAQ

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