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.

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BEST SELLING BRANDS

TOP Custom Motorcycle Parts

Colony #3227-4 Seat Post Roller Shaft Kit 1952-1970 Harley-Davidson K/KH/XL/XLH/XLCH
1 review $46.75

Colony #3222-1 Spark Plug Cable Bracket 1966-1984 Harley-Davidson Big Twins - Zinc Plated
1 review $18.15

Lowbrow Customs Rubber Mount Bracket Kit for Lowbrow Oil Tanks - for 500 / 650 c.c. unit Triumph Motorcycles - Brass Washers
25 reviews $64.25

Cycle Standard LED Bulb for Lucas Headlight Unit replaces Lucas OEM #446, 414, 370, and 312
9 reviews $61.04

Gasbox 4 Speed Transmission Mounting Plate for 1958 - 1964 Harley-Davidson Big Twins OEM #47698-58
$59.95

Gasbox 4 Speed Transmission Mounting Plate for 1958 - 1961 Harley-Davidson Big Twins OEM #47698-36A
1 review $59.95

Gasbox Front Motor Mount Plates for 1957 - 1981 Harley-Davidson Ironhead Sportster
6 reviews $29.95

Gasbox Oil Filter Front Motor Mount Plates for 1957 - 1981 Harley-Davidson Ironhead Sportster
4 reviews $49.95

Gasbox Bolt-On Oil Tank for Rigid Harley-Davidson Big Twin Frames 1936-1957
11 reviews $299.99

Gasbox Horseshoe Bolt-on Oil Tank for Harley-Davidson 1952-78 Harley Sportster XL
13 reviews $299.99

Colony #3238-2 Oil Pump Cover Nipple 1950 - 1964 Harley-Davidson Big Twins - Chrome — Colony #3238-2 Oil Pump Cover Nipple 1950-1964 Harley-Davidson Big Twins - Chrome Plated
1 review $9.68

Colony #3233-10 Shifter Assembly Cover Screw Kit 1965 - early 1979 Harley-Davidson FL FX — Colony #3233-10 Shifter Assembly Cover Screw Kit 1965-E1979 Harley-Davidson FL/FX
$14.22

Colony #3230-2 Seat Post Bushing Sleeve Kit 1952 - 1970 Harley-Davidson K KH XL XLH XLCH — Colony #3230-2 Seat Post Bushing Sleeve Kit 1952-1970 Harley-Davidson K/KH/XL/XLH/XLCH
$48.40

Colony #3225-2 Delco-Remy Horn Diaphram Screw and Nut Kit 1931 - 1957 Harley-Davidson — Colony #3225-2 Delco-Remy Horn Diaphram Screw & Nut Kit 1931-1957 Harley-Davidson - Parkerized
$10.89

Colony #3221-1 Horse Shoe Oil Tank Mounting Bracket 1953 - 1965 Harley-Davidson K KH XLCH — Colony #3221-1 Horse Shoe Oil Tank Mounting Bracket 1953-1965 Harley-Davidson K/KH/XLCH - Parkerized
1 review $27.50

Colony #3208-28 Rocker Box Screw Kit 1977 - 1985 Harley-Davidson Sportster - CAD Plated — Colony #3208-28 Rocker Box Screw Kit 1977-1985 Harley-Davidson Sportster - CAD Plated
$51.70

Colony #3207-28 Rocker Box Screw Kit 1957 - 1976 Harley-Davidson Sportster - CAD Plated — Colony #3207-28 Rocker Box Screw Kit 1957-1976 Harley-Davidson Sportster - CAD Plated
$49.50

Colony #3203-4 Cam Follower Retainer Kit 1970 - early 1978 Harley-Davidson FL, 1971-early 1978 FX XL — Colony #3203-4 Cam Follower Retainer Kit 1970-E1978 Harley-Davidson FL 1971-E1978 FX/XL
2 reviews $36.30

Colony Axle / Wheel Spacer 1-1/4 x 3/4 x 1.250 Harley-Davidson #AS-004 — Colony #AS-004 Axle/Wheel Spacer 1-1/4 x 3/4 x 1.250
$9.75

Colony Axle / Wheel Spacer 1-1/4 x 3/4 x .500 Harley-Davidson #AS-003 — Colony #AS-003 Axle/Wheel Spacer 1-1/4 x 3/4 x .500
$8.35

Colony Axle / Wheel Spacer 1-1/2 x 25mm x 1.015 Harley-Davidson #83888-09 — Colony #83888-09 Axle/Wheel Spacer 1-1/2 x 25mm x 1.015
$10.59

Colony Axle / Wheel SpacerAxle Harley-Davidson #47577-94 — Colony #47577-94 Axle/Wheel Spacer Axle
1 review $20.57

Colony Axle / Wheel Spacer 1-1/2 x 1 x .150 Harley-Davidson #43757-04 — Colony #43757-04 Axle/Wheel Spacer 1-1/2 x 1 x .150
$7.45

Colony Axle / Wheel Spacer 1-1/2 x 1 x .523 Harley-Davidson #43706-04 — Colony #43706-04 Axle/Wheel Spacer 1-1/2 x 1 x .523
$10.42

Colony Axle / Wheel Spacer 1-1/2 x 1 x .815 Harley-Davidson #43642-01 — Colony #43642-01 Axle/Wheel Spacer 1-1/2 x 1 x .815
1 review $11.17

Colony Axle / Wheel Spacer 2-1/4 x 3/4 x .930 Harley-Davidson #43624-97 — Colony #43624-97 Axle/Wheel Spacer 2-1/4 x 3/4 x .930
1 review $20.88

Colony Axle / Wheel Spacer 2-3/16x3/4x.468 tapered Harley-Davidson #43624-00 — Colony #43624-00 Axle/Wheel Spacer 2-3/16x3/4x.468 Tapered
1 review $20.31

Colony Axle / Wheel Spacer 1-1/8 x 3/4 x .930 Harley-Davidson #43617-95 — Colony #43617-95 Axle/Wheel Spacer 1-1/8 x 3/4 x .930
$10.42

Colony Axle / Wheel Spacer 1-1/2 x 1 x .317 Harley-Davidson #43571-01 — Colony #43571-01 Axle/Wheel Spacer 1-1/2 x 1 x .317
1 review $8.93

Colony Axle / Wheel Spacer 1.470 x 25mm x .648 Harley-Davidson #43522-08 — Colony #43522-08 Axle/Wheel Spacer 1.470 x 25mm x .648
2 reviews $11.17

Colony Axle / Wheel Spacer 1-3/8 x 3/4 x .970 Harley-Davidson #43520-00 — Colony #43520-00 Axle/Wheel Spacer 1-3/8 x 1 x .970
$10.42

Colony Axle / Wheel Spacer 1-5/8 x 3/4 x.819 SPECIAL Harley-Davidson #43360-97 — Colony #43360-97 Axle/Wheel Spacer 1-5/8 x 3/4 x.819
1 review $15.54

Colony Axle / Wheel Spacer 1.470 x 25mm x .317 Harley-Davidson #43358-08 — Colony #43358-08 Axle/Wheel Spacer 1.470 x 25mm x .317
1 review $9.68

Colony Axle / Wheel Spacer 1.350 x 25mm x 1.013 Harley-Davidson #41901-08 — Colony #41901-08 Axle/Wheel Spacer 1.350 x 25mm x 1.013
1 review $11.90

Colony Axle / Wheel Spacer 1.480 x 25mm x .375 Harley-Davidson #41694-08 — Colony #41694-08 Axle/Wheel Spacer 1.480 x 25mm x .375
$9.68

Colony Axle / Wheel Spacer 1-1/8 x 3/4 x 1.975 Harley-Davidson #41519-00 — Colony #41519-00 Axle/Wheel Spacer 1-1/8 x 3/4 x 1.975
1 review $12.67

Colony Axle / Wheel Spacer 1-1/2 x 1 x .895 Harley-Davidson #41504-07 — Colony #41504-07 Axle/Wheel Spacer 1-1/2 x 1 x .895
$10.44

Colony Axle / Wheel Spacer 1-1/2 x 1 x 1.115 Harley-Davidson #41502-07 — Colony #41502-07 Axle/Wheel Spacer 1-1/2 x 1 x 1.115
2 reviews $11.13

Colony Axle / Wheel Spacer 1.480 x 25mm x 2.312 Harley-Davidson #41359-08 — Colony #41359-08 Axle/Wheel Spacer 1.480 x 25mm x 2.312
$14.89

Colony Axle / Wheel Spacer 1.470 x 25mm x 1.240 Harley-Davidson #41350-08 — Colony #41350-08 Axle/Wheel Spacer 1.470 x 25mm x 1.240
$11.90

Colony Axle / Wheel Spacer 1-3/8 x 1 x .471 Harley-Davidson #41084-02A — Colony #41084-02 Axle/Wheel Spacer 1-3/8 x 1 x .471
$8.35

Colony Axle / Wheel Spacer 1.470 x 25mm x 2.090 Harley-Davidson #40947-08 — Colony #40947-08 Axle/Wheel Spacer 1.470 x 25mm x 2.090
2 reviews $14.89

Colony Axle / Wheel Spacer 1-1/2 x 1 x .718 Harley-Davidson #40940-06 — Colony #40940-06 Axle/Wheel Spacer 1-1/2 x 1 x .718
$11.17

Colony Axle / Wheel Spacer 1-1/2 x 1 x .815 Harley-Davidson #40936-06 — Colony #40936-06 Axle/Wheel Spacer 1-1/2 x 1 x .815
1 review $11.17

Colony Axle / Wheel Spacer 1-1/2 x 1 x 1.480 Harley-Davidson #40930-05 — Colony #40930-05 Axle/Wheel Spacer 1-1/2 x 1 x 1.480
1 review $12.67

Colony Axle / Wheel Spacer 1-1/4 x 3/4 x 1.478 Harley-Davidson #40930-04 — Colony #40930-04 Axle/Wheel Spacer 1-1/4 x 3/4 x 1.478
$20.31

Colony Axle / Wheel Spacer 1.470 x 25mm x .883 Harley-Davidson #40927-08 — Colony #40927-08 Axle/Wheel Spacer 1.470 x 25mm x .883
$10.44

Colony Axle / Wheel Spacer 1-1/2 x 1 x .803 Harley-Davidson #40927-06 — Colony #40927-06 Axle/Wheel Spacer 1-1/2 x 1 x .803
$11.17

Colony Axle / Wheel Spacer 1.470 OD x 25mm ID x 1.150 Harley-Davidson #40926-08 — Colony #40926-08 Axle/Wheel Spacer 1.470 OD x 25mm ID x 1.150
$11.17

Colony Axle / Wheel Spacer 1-1/2 x 1 x 1.025 Harley-Davidson #40926-06 — Colony #40926-06 Axle/Wheel Spacer 1-1/2 x 1 x 1.025
2 reviews $11.90

Colony Axle / Wheel Spacer 1.840/1.498 x 25mm x 1.396 Harley-Davidson #11843 — Colony #11843 Axle/Wheel Spacer 1.840/1.498 x 25mm x 1.396
$14.89

Colony Axle / Wheel Spacer 1-1/2 x 1 x .985 Harley-Davidson #11804 — Colony #11804 Axle/Wheel Spacer 1-1/2 x 1 x .985
1 review $11.90

Cycle Standard Prime 1 inch Handlebar Switch Kit - Dual Mini Switch - Chrome
6 reviews $109.98

Kustom Tech Grimeca 1 inch Clutch Lever - Polished Aluminum
$233.26

Kustom Tech Grimeca Master Cylinder - Polished Aluminum - 1 inch Handlebars - 14mm piston
2 reviews $388.65

Gasbox Exhaust Port Clamps 1948-1965 Harley-Davidson Big Twin Models - Stainless Steel OEM #65519-48
$26.00

Gasbox Rear Muffler Exhaust Clamp 1957-1976 Harley-Davidson FX and Sportster XL Models - Stainless Steel OEM #65279-57
1 review $19.95

Gasbox UL Front Pipe to Frame Clamp 2 piece Set 1936-48 UL Harley- Davidson - Parkerized OEM #65511-36
1 review $20.00

Gasbox Rocket Tip Muffler 1941-1949 Harley-Davidson Knuckleheads and 74 and 80 ci Flathead Models - Bare Steel OEM #65251-41
1 review $150.00

Gasbox Panhead Exhaust Pipe Set 1958-1964 Harley-Davidson Swingarm FL FLH 74 ci - Bare Steel
1 review $239.95

Colony #3224-3 Brake Switch Clip Kit 1966 - 1947 Harley-Davidson Sportster XLH XLCH — Colony #3224-3 Brake Switch Clip Kit 1966-1974 Harley-Davidson Sportster XLH/XLCH - Parkerized
3 reviews $20.89

Colony #3215-4 Throttle Cable Bracket 1949 - 1953 Harley-Davidson Big Twins — Colony #3215-4 Throttle Cable Bracket 1949-1953 Harley-Davidson Big Twins - Parkerized
$20.57

Colony #3206-2 Fender Brace Bolt Kit 1941 - 1957 Harley-Davidson Big Twins and 45's — Colony #3206-2 Fender Brace Bolt Kit 1941-1957 Harley-Davidson Big Twins/45's - Chrome Plated
1 review $6.66

Colony #3202-4 Switch Box Fastening Bolt Kit 1929 - 1936 Harley-Davidsons — Colony #3202-4 Switch Box Fastening Bolt Kit 1929-1936 Harley-Davidsons - Parkerized
$11.99

Colony #3201-4 Seat Post Spring Set 1952 - 1970 Harley-Davidson Sportster K KH XL — Colony #3201-4 Seat Post Spring Set 1952-1970 Harley-Davidson Sportster K/KH/XL - Chrome Plated
2 reviews $54.99

Colony #3189-4 Chrome Rocker Arm Shaft Nut Set 1936 - 1947 Harley-Davidson Knuckleheads — Colony #3189-4 Rocker Arm Shaft Nut Set 1936-1947 Harley-Davidson Knuckleheads - Chrome Plated
$65.99

Colony #3211-4 Chain Guard To Gear Box Screw Kit 1930 - 1935 Harley-Davidson VLs — Colony #3211-4 Chain Guard To Gear Box Screw Kit 1930-1935 Harley-Davidson VLs - Parkerized
1 review $5.81

Colony #3214-4 Generator Pole Screw Kit 1951 - 1957 Harley-Davidson Twins — Colony #3214-4 Generator Pole Screw Kit 1951-1957 Harley-Davidson All Twins - Parkerized
$6.96

Colony #3218-1 Steering Damper Knob 1952 - 1966 Harley-Davidson K KH FL FLH Sportster — Colony #3218-1 Steering Damper Knob 1952-1966 Harley-Davidson K/KH/XL 1960-1984 FL/FLH 1960-Up Servi-car
$49.50

Colony #3219-5 Carburetor Support Bracket 1941 - 1947 Harley-Davidson OHV Big Twin — Colony #3219-5 Steering Damper Anchor Plate Kit 1952-1963 Harley-Davidson K/KH/XL - CAD Plated
$28.60

Colony #3179-8 Rocker Arm Cover Fitting Nuts and Seals 1957 - 1984 Harley-Davidson FL FX XL XLH XLCH — Colony #3179-8 Rocker Arm Cover Fitting Nuts & Seals 1957-1984 Harley-Davidson FL/FX/XL/XLH/XLCH - CAD Plated
3 reviews $20.90

Colony #3115-3 Headlamp Mounting Kit 1935 - 1948 Harley-Davidson Big Twins and 45's — Colony #3115-3 Headlamp Mounting Kit 1935-1948 Harley-Davidson Big Twins/45's - CAD Plated
$6.05

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.

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Custom Motorcycle Parts FAQ

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