ROTIX GX20072 Kevlar Mower Deck Belt for John Deere 42 Inch L110 L100 E100 D100 D105 D110 D120 D130 S100 LA105 LA115 Lawn Tractors, Replaces GY20570, 1/2" x 103-7/8"

What It Is

The ROTIX GX20072 is a Kevlar-reinforced mower deck belt designed to drive the blades on 42-inch John Deere lawn tractors, including the L100, L110, E100, D100 series, S100, and LA100/LA105 models. It replaces OEM part GY20570 and is suited for residential mowing on medium-sized lawns.

Fitment & Compatibility

Before buying, confirm your mower has a 42-inch stamped deck (not 38-inch or 48-inch). Check your owner’s manual or old belt for the OEM number GY20570—this belt is a direct replacement. The belt measures 1/2 inch wide by 103-7/8 inches long. Measure your old belt’s length and width to verify. This belt fits John Deere models: L100, L110, E100, D100, D105, D110, D120, D130, S100, LA105, LA115. It does not fit older or commercial-series tractors. If your mower uses a different belt length (e.g., 104.5 inches), this will not work.

Key Things to Know

• Kevlar construction provides better heat and wear resistance than standard rubber belts, especially under heavy grass or frequent use.
• Installation is moderate—you’ll need to remove the mower deck, release the tensioner pulley, and route the belt around all pulleys. A belt diagram is helpful; take a photo before removing the old one.
• Common gotcha: Ensure the belt is seated fully in all pulley grooves, especially the tensioner. A misrouted belt can slip or throw off blade timing.
• Price point ($15) is competitive with OEM belts (typically $25–35) but offers Kevlar reinforcement for added durability.

Should You Buy It

If you own a 42-inch John Deere lawn tractor from the listed models and want a reliable, budget-friendly upgrade over standard belts, the ROTIX GX20072 is a solid choice. It’s ideal for homeowners with medium-duty mowing who value longer belt life without paying OEM prices. Not for commercial use or non-John Deere decks.