BDL Primary Belt
BDL Primary Belts: The Industry Standard for Belt-Driven Harleys
When it comes to aftermarket primary drives, Belt Drives Ltd. (BDL) is the name trusted by custom builders and performance enthusiasts worldwide. A BDL Primary Belt is not just a replacement part; it is a high-strength component designed to survive the high-heat, high-torque environment of a V-Twin primary. Whether you are running a classic Shovelhead open-belt or a modern Milwaukee-Eight closed primary, BDL belts provide the reliability needed to keep your bike on the road.
Advanced Construction for Zero Stretch
The core of every BDL belt features high-tensile Kevlar or Fiberglass cords. These materials are chosen for their dimensional stability, ensuring the belt maintains its exact length even under hard acceleration. This stability prevents the belt from “walking” on the pulleys and eliminates the need for constant tension adjustments.
Versatile Pitch and Width Options
BDL manufactures belts in several configurations to match their specific drive kits:
- 8mm Pitch: The most common for street performance, offering a balance of strength and smooth operation. Available in widths from 1-1/2″ to 3″.
- 11mm Pitch: Often found on older 4-speed Big Twins and specific high-torque custom applications.
- 14mm Pitch: Used in Top Fuel and extreme-duty open drives where maximum tooth engagement is required.
Precision-Molded Tooth Profile
The teeth of a BDL belt are precision-molded to interface perfectly with BDL’s hard-anodized aluminum pulleys. This exact fitment reduces friction and noise, while a durable fabric facing on the teeth helps dissipate heat. This is especially critical for open belt drives, where the belt is exposed to the elements and must resist debris while maintaining a clean, show-quality appearance.
Fitment and Selection
Because BDL kits are used on everything from 1936 Knuckleheads to 2026 Touring models, selecting the correct tooth count is vital. Common lengths include:
- 132 Tooth (8mm): Standard for many 1-1/2″ and 2″ drives on 4-speed and early 5-speed models.
- 142/144 Tooth (8mm): Common for 3″ open drives on Softail and Dyna models.
- 99 Tooth (11mm): Specifically for older 11mm primary kits.
- Note: 1979-1984 4-speed models often require a +.030″ oversize belt due to factory variations in the inner primary casting.
BDL Primary Belt
Features:
Kevlar belts are thermal, chemical and wear-resistant for longer life
Kevlar is used for added performance in various racing competitions around the world
Over the years many other uses have become common such as reinforcement in rubber goods for mechanical applications
Kevlar enhances the compound’s mechanical performance particularly at high temperatures
| Product Style | AmericanV-twin Item # | Catalog Number | Store Sku | MFR. Product # | Availability |
|---|---|---|---|---|---|
| 85 Tooth 14mm Pitch 3-3/8″ Wide | 218327 | 603-924 | 3242 | BDL-14-85 | In Stock: Ships within 24 hours |
| 78 Tooth 13.8mm Pitch 1-1/2″ Wide | 218325 | 600-0509 | PCC-78-112/PC-78-112 | Out of Stock | |
| 78 Tooth 14mm Pitch 1-1/2″ Wide | 218323 | 600-0441 | BDL-38078 | In Stock: Ships within 24 hours | |
| 92 Tooth 11mm Pitch 1-1/2″ Wide | 218321 | 600-0508 | BDL-5S11 | In Stock: Ships in 1-2 business days | |
| 96 Tooth 11mm Pitch 1-1/2″ Wide | 218322 | 600-0437 | 7337 | BDL-30884 | In Stock: Ships within 24 hours |
Fitment Notes & Exceptions
This part has no direct OEM replacement.
