New site coming soon. Preview Now!

Formula OS Extension
Add to Compare
View Compare lineup Review
By Justin diFeliciantonio on April 28, 2013

The Pitch
The Formula OS Extension, in keeping with Donnay’s newest performance line, is injected with XeneCore, a proprietary tubing that yields racquets with solid-core constructions. Donnay claims that solid-core racquets—compared to most conventional frames, which are hollow—flex and reshape more quickly upon impact, returning more energy to the ball, better absorbing shock and vibration, and reducing the chances of arm injury. The upshot, Donnay says, is a rare combination of power and comfort.

How It Tested
If you’re an experienced beginner searchingfor a lightweight, head-heavy frame, the Formula OS Extension is worth a trial. Playtesters with slower-paced, punchy strokes enjoyed the Formula’s forgiveness—namely, a generous margin for error, abetted by a large head size and solid response, which they said increased the depth of their serves, volleys and groundstrokes. As one 3.0 player with a Continental forehand and one-handed backhand commented, “This racquet delivers plenty of power, it offers a large sweet spot, and the stability is ample.” For these reasons, several other club-level playtesters recommended the racquet for doubles specialists. Said a 3.0 player with a two-handed backhand,“The racquet was sturdy and stable.”

Bottom Line
A boon for club-level beginners and seniors with short, slow swings.


Released on April 28, 2013

  • Price:
  • Length:
    27.25 in
  • Head size:
    110.0 sq in
  • Strung weight:
    9.9 oz
  • Strung balance:
    4 pts. HH
  • Swing weight:
    324.0 oz
  • String pattern:
  • Flexibility:
  • Suitable NTRP:
    2.5 - 3.5
  • Beam width:

General information

    No manufacturer description available yet.

Short summary

    Extremely lightweight with a significant head-heavy balance.


Still haven't found the right gear? Try our Gear Finder...

Review Finder

Before commenting, please read our Posting Guidelines.

Top Ranked Players
More Rankings