What is the most important thing to decide before starting a custom motorcycle build?

Decide how the bike will be used first. Whether it’s for city riding, cross-country touring, camping, or track riding, each purpose points toward different part choices. Once the bike’s intended use is clear, selecting the right components becomes much easier. The How to Build a Bobber guide is a solid starting point for the full build process.

How do I make my motorcycle faster?

Start with a free-flowing air filter and an exhaust system that is properly tuned for your carburetor or fuel injection setup. For greater performance gains, consider increasing engine displacement with a big bore kit and improving airflow with custom camshafts or cylinder head work. Since each modification builds on the previous one, tuning after every upgrade is important.

What should I change first to make my motorcycle more comfortable?

Focus on three key areas: the seat, footpeg position, and handlebar setup. Handlebar rise and pullback typically have the greatest impact on comfort, handling, and riding posture. Investing in a quality seat can also significantly improve comfort on long rides.

Are custom Harley parts compatible with all Harley-Davidson models?

No. Fitment depends on the specific part and model year. Harley-Davidson aftermarket parts are often designed for particular platforms such as Big Twin, Sportster, or Softail models, and compatibility can vary by year range. Always review the fitment information on the product listing before ordering, and contact the supplier if compatibility is unclear.

Custom Motorcycle Parts

Sort by

Custom Motorcycle Parts CATEGORIES

Closeouts

Air Intake & Fuel Systems

Brakes

Drivetrain & Transmission

Electrical & Wiring

Engine

Exhaust

Fenders

Frame & Chassis

Gas tanks

Gauges & Instruments

Handlebars & Controls

License Plates

Lighting

Oil Tanks

Seats

Sissy Bars

Suspension

Tires & Tubes

Wheels & Wheel Components

BEST SELLING BRANDS

TOP Custom Motorcycle Parts

Colony #2874-1 Rear Axle Spacer 1967-1972 Harley-Davidson FL/FLH - Parkerized
1 review $16.94

Colony #2872-1 Rear Axle Spacer 1958-1966 Harley-Davidson FL/FLH - Parkerized
$19.36

Colony #2870-1 Rear Axle Spacer 1952-1978 Harley-Davidson K/KH/Sportster - CAD Plated
2 reviews $19.36

Colony #2865-2 Shifter Lever Stud Kit 1916-1936 Harley-Davidson All Models - Nickel Plated
$16.94

Colony #2862-2 Instrument Panel Dash Base 1938-1946 Harley-Davidson Big Twins/45s - CAD Plated
$19.36

Colony #2859-6 Grease Fitting Harley-Davidson OEM #9852 67-1/2 Degree - 6 Pack - Chrome Plated
$19.36

Colony #2856-6 Grease Fitting Harley-Davidson OEM #9853 90 degree - 6 Pack - Chrome Plated
$19.36

Colony #2850-24 Stock Style Panhead Valve Cover Screw Kit 1951-1954 Harley-Davidson Panhead
1 review $22.00

Colony #2815-2 Spring Retainer and Acorn Nut Set 1939-1948 Harley-Davidson Big Twin Springers 1936-1952 45s 1953-1954 Servi-car - Parkerized
$19.36

Colony #2777-9 Headlight Bracket Mount Kit 1936-1948 Harley-Davidson Big Twin 1940-1957 45s - CAD Plated
$19.97

Colony #2742-2 Left Bearing End Oil Slinger 1936-1954 Harley-Davidson Big Twin
$16.94

Colony #2739-2 Transmission Sprocket Nut Kit 1953-1970 Harley-Davidson K/KH/Sportster
$17.55

Colony #2736-1 Fork Tube Cap/Bolt 1984-2001 Harley-Davidson FLT - Chrome Plated
1 review $20.31

Colony #2671-2 Instrument Panel Light Shield Kit 1939-1946 Harley-Davidson Big Twins/45s - CAD Plated
$19.36

Colony #2641-3 Front Brake Drum Grease Fitting Extension 1936-1948 Harley-Davidson Big Twin 1941-1957 Servi-car
$16.94

Colony #2581-6 Shifter Lever Stud Kit 1936-1937 Harley-Davidson Big Twin with Handshift/45's
$19.51

Colony #2926-2 Front Axle Nut and Washer Kit 1952-1972 Harley-Davidson K/KH/XL/XLH/XLCH - CAD Plated
$15.73

Colony #2917-1 Motor Sprocket Nut 1970-1988 Harley-Davidson Sportster
$18.15

Colony #2896-7 Starter Crank and Kick Starter Pedal Mounting Kit 1941-1967 Harley-Davidson FL/FLH - Chrome Plated
$18.15

Colony #2895-7 Starter Crank and Kick Starter Pedal Mounting Kit 1941-1967 Harley-Davidson FL/FLH - CAD Plated
$18.15

Colony #2861-6 Grease Fitting Harley-Davidson OEM #9852 67-1/2 Degree - 6 Pack - Parkerized
$16.34

Colony #2860-6 Grease Fitting Harley-Davidson OEM #9852 67-1/2 Degree - 6 Pack - CAD Plated
$16.34

Colony #2857-6 Grease Fitting Harley-Davidson OEM #9853 90 - 6 Pack - CAD Plated
$16.34

Colony #2706-5 Clutch Booster Bracket Mounting Kit 1952-1967 Harley-Davidson FL/FLH - Chrome Plated
1 review $18.15

Colony #2705-5 Clutch Booster Bracket Mounting Kit 1952-1967 Harley-Davidson FL/FLH - Parkerized
$15.73

Colony #2676-2 Gear Box Grease Tube and Fitting Kit 1930-1936 Harley-Davidson VL - CAD Plated
$15.73

Colony #2590-13 Skid Plate Mounting Kit 1940-1942 Harley-Davidson WLA - Parkerized
1 review $19.06

Colony #2575-1 Clutch Cable Adjusting Sleeve 1957-1971 Harley-Davidson XL 1953-1956 K Model - Chrome Plated
$15.73

Colony #2570-2 Crank Pin Nut Set 1981-1998 Harley-Davidson Sportster - Parkerized
$20.90

Colony #2569-2 Crank Pin Nut Set 1954-1981 Harley-Davidson Sportster/KH - Parkerized
1 review $20.90

Colony #2924-6 Air Cleaner Mounting Screw Kit 1/8" Longer Screws 1956-1965 Harley-Davidson Twins - CAD Plated
$16.94

Colony #2757-6 Spotlight Fork Bracket Bolt Nut Kit 1938-1961 Harley-Davidson - Chrome Plated
$16.50

Colony #2746-2 Clutch Hub Nut Kit 1967-1984 Harley-Davidson Sportster
$14.52

Colony #2715-12 Valve Cover Seal Kit 1929-1973 Harley-Davidson 45s
$21.78

Colony #2608-3 Floorboard Mounting Stud 1924-1928 Harley-Davidson All Models - Parkerized
$17.60

Colony #2666-5 Rivet Replacement Kit Harley-Davidson Air Cleaner Backing Plates
$14.52

Colony #2791-4 Carburetor Air Cleaner Connection Mounting Screw Kit 1941-1952 Harley-Davidson WLA/WLC - Parkerized
$17.60

Colony #2790-4 Carburetor Air Cleaner Connection Mounting Screw Kit 1941-1952 Harley-Davidson WLA/WLC - CAD Plated
$17.60

Colony #2753-5 Tube Hose and Cable Straps 1965-1971 Harley-Davidson FL/FX 1958-1971 Sidecar - CAD Plated
$13.31

Colony #2664-5 Oversized Carburetor Throttle Lever Wire Block Kit Linkert & Bendix Carburetors - CAD Plated
$13.62

Colony #2640-1 Chain Housing Cover Cap 1965-Early 1966 Harley-Davidson FL/FLH
1 review $13.31

Colony #2576-1 Clutch Cable Adjusting Sleeve 1957-1971 Harley-Davidson XL 1953-1956 K Model - CAD Plated
$13.31

Colony #2853-6 Upper Engine Mounting Kit 1984-1999 Harley-Davidson Softail - Zinc Plated
1 review $12.71

Colony #2794-6 Grease Zerk Fitting 1936-1984 Harley-Davidson - 6 Pack - Parkerized
5 reviews $12.74

Colony #2679-2 Transmission Mainshaft Sprocket Nut and Lock Kit 1971-1984 Harley-Davidson Sportster
4 reviews $14.85

Colony #2661-7 Step Mounting Kit 1947-1965 Harley-Davidson Sidecars - Parkerized
$12.71

Colony #2628-4 Front Brake Cable Handlebar Clip 1928-1948 Harley-Davidson Big Twins 1932-1957 Servi-cars - Parkerized
$21.00

Colony #2627-4 Spark Control Coil Frame Clamp 1937-1946 Harley-Davidson Big Twins - Parkerized
$21.00

Colony #2566-2 Transmission Drain Plug 1981-1992 Harley-Davidson FLT/FXR - Chrome Plated
1 review $12.53

Colony #2951-1 Wire Clip 1951-1969 Harley-Davidson Big Twins 1963-E1967 Servi-car - Parkerized
1 review $12.10

Colony #2919-2 Speedometer Drive Block Off Plug 1952-1956 Harley-Davidson K/KH - CAD Plated
$12.10

Colony #2758-6 Spotlight Fork Bracket Bolt Nut Kit 1938-1961 Harley-Davidson - CAD Plated
$14.30

Colony #2704-3 Crankcase Oil Strainer Kit 1957-1976 Harley-Davidson Sportster 1937-1973 Flatheads
2 reviews $12.10

Colony #2632-3 Circuit Breaker Adjusting Screw Kit 1947-1964 Harley-Davidson Big Twins/45's - CAD Plated
$12.10

Colony #2599-6 Front Wheel Stabilizer Collar Mounting Stud Kit 1930-1952 Harley-Davidson 45 Solo 1930-1940 Servi-car
$14.85

Colony #2805-5 Fender Hinge Mounting Kit 1930-1942 Harley-Davidson All Models
$10.89

Colony #2796-2 Rear Brake Cross Over Shaft Grease Fitting 1938-1957 Harley-Davidson Big Twin - CAD Plated
2 reviews $10.29

Colony #2877-2 Spring Guide Collar Set 1929-1980 Harley-Davidson All Models
2 reviews $9.68

Colony #2849-14 Batwing Fairing Mount Button Head Allen Kit 1996-Up Harley-Davidson - Chrome Plated
6 reviews $9.08

Colony #2749-4 Handlebar Bolt Kit 1936-1939 Harley-Davidson Big Twin - Parkerized
$10.29

Colony #2618-12 Ignition Switch Mounting Spacer Kit 1940-1945 Harley-Davidson WLA - CAD Plated
$9.68

Colony #2611-8 Air Cleaner Cover Retaining Screw Kit 1936-1939 Harley-Davidson Big Twin 1936 45's - Parkerized
$9.68

Colony #2892-3 Starter Crank Clamp Bolt 1941-1967 Harley-Davidson FL/FLH - CAD Plated
$11.00

Colony #2863-7 Negative Brush Holder Assembly 1932-1951 Harley-Davidson Big Twins/45s - CAD Plated
$7.87

Colony #2806-5 Fender Hinge Mounting Kit 1943-1979 Harley-Davidson All Models
$8.47

Colony #2734-3 Transmission 2nd Gear Retaining Bracket Kit 1935-1973 Harley-Davidson 45s - Parkerized
$7.87

Colony #2623-1 Oil Pressure Switch Nipple 1939-1969 Harley-Davidson Big Twins - CAD Plated
$8.47

Colony #2949-1 Lower Brake Cable Clamp 1940-1952 Harley-Davidson 45s/Servi-car - Parkerized
1 review $8.80

Colony #2824-1 Crankcase and Chain Housing Drain Plug 1965-1984 Harley-Davidson FL 1971-1984 FX 1967-1992 Sportster - CAD Plated
$7.26

Colony #2685-1 Rear Wheel Brake Rod and Cable Adjusting Nut 1952-1978 Harley-Davidson K/KH/Sportster - CAD Plated
1 review $6.66

Colony #2652-3 Wheel Bearing Seal Kit 1935-1966 Harley-Davidson W/WL/UL/EL/FL/FLH
3 reviews $8.47

Colony #2616-4 Step To Fender Mounting Kit 1941-1964 Harley-Davidson Sidecars - Parkerized
1 review $6.66

CUSTOM MOTORCYCLE PARTS FOR HARLEY, TRIUMPH, AND BSA BUILDS The parts you choose define the bike. OEM keeps it stock. Aftermarket opens up fitment, finish, and function options the factory never offered. Whether you are sourcing a direct replaceme...

CUSTOM MOTORCYCLE PARTS FOR HARLEY, TRIUMPH, AND BSA BUILDS

The parts you choose define the bike. OEM keeps it stock. Aftermarket opens up fitment, finish, and function options the factory never offered. Whether you are sourcing a direct replacement for a worn component or tracking down a specific piece to finish a chopper or bobber build, the catalog here covers custom Harley parts, BSA, and vintage Triumph across hundreds of categories.

WHY BUILDERS GO AFTERMARKET

Stock parts do the job they were designed for. Aftermarket custom motorcycle parts do what the builder needs:

Fitment Where OEM Falls Short: Finding correct OEM components for older Harley Big Twin, BSA, or vintage Triumph motorcycle parts gets harder every year. Aftermarket and reproduction parts fill those gaps with components built to the same spec or better.
Material and Finish Options: Many aftermarket parts come in finishes the factory never offered, including billet aluminum, stainless, black oxide, and chrome. The part matches the direction of the build rather than fighting it.
Universal Parts for Custom Work: Raw, unfinished, and universal parts give you a starting point to cut, shape, and mount to your specific frame and geometry. That is something a stock replacement never offers, and it is where bobber motorcycle parts and chopper builds get interesting.
Cost and Availability on Older Platforms: For british motorcycle parts and vintage Triumph or older Harley platforms, reproduction aftermarket parts are often the more practical choice on both availability and price.

BRANDS AND WHAT WE STOCK

The catalog covers hardware, fabrication parts, engine components, controls, lighting, and everything in between. Key brands include Colony for hardware and fasteners and Mid-USA for drivetrain and engine components. Fitment data is listed on each product page. If you are not sure what fits your year and model, the team is reachable by chat, phone, or email.

Read less

Custom Motorcycle Parts FAQ

STAY CONNECTED
WITH LOWBROW

NO SPAM, EVER. JUST GREAT STUFF. YOUR INFO IS NEVER SHARED.