CUB CADET 490-501-C070 50" T L Deck Belt 05078 RZT LX SX ZT1 ZT2 Ultima 50 S L50

What It Is

This is the OEM 50-inch “T”-shaped deck drive belt for Cub Cadet zero-turn mowers. It connects the engine pulley to both spindle pulleys, driving the blades on select ZT1, ZT2, Ultima, RZT, SX, and L-series models with a 50-inch fabricated deck.

Fitment & Compatibility

Before buying, confirm three things:

• Deck size: This belt is for 50-inch decks only. It will not work on 46-inch, 54-inch, or other widths.
• Model range: Fits Cub Cadet ZT1 50, ZT2 50, Ultima 50, Ultima ZT1 50, Ultima ZT2 50, RZT 50, RZT S 50, RZT LX 50, SX 50, and L50 series. Check your model number (e.g., 17AWA or 17BWA) against your owner’s manual or parts diagram.
• OEM vs. aftermarket: This is genuine Cub Cadet part 490-501-C070 (also listed as 05078). Aftermarket belts may be cheaper but often differ in length, width, or Kevlar reinforcement. Measure your old belt’s length (end-to-end) and width (typically 1/2-inch or 5/8-inch) to verify.

Quick check: If your mower’s deck has a 50-inch cut and the original belt part number is 490-501-C070 or 05078, this is the direct replacement.

Key Things to Do

• Quality matters: This OEM belt uses Kevlar cord and aramid fiber for better heat and wear resistance than most aftermarket belts. It lasts longer under heavy use.
• Installation is moderate: You’ll need to remove the deck or at least the belt covers. Route the belt exactly as shown in your diagram—wrong routing causes blade timing issues or belt damage.
• Check pulleys and spindles first: A worn or seized spindle pulley will shred a new belt quickly. Spin each spindle by hand before installing. Replace any that feel rough or wobble.
• Tension adjustment: After installation, verify belt tension per your manual. Too loose causes slipping; too tight wears bearings and the belt prematurely.

Should You Buy It

If you own a Cub Cadet 50-inch zero-turn and want a belt that fits perfectly, lasts, and won’t cause headaches, this is the right choice. It’s priced higher than generic belts, but the OEM construction and reliability make it worth it for regular mowing. Skip it if you’re on a tight budget and willing to gamble on aftermarket fitment.