Universal Bearing Press

The Universal Bearing Press 1721 is a hand-driven, threaded-shaft press kit for the cartridge bearings on a modern bike: headset cartridges, external bottom bracket cup bearings, and most hub bearings. A drift matched to the bearing's outer race diameter draws it into its bore square and fully seated, with no hammering and no side load. It's a bench tool for shops and home mechanics who'd rather press a bearing once than buy it twice.

Square seating is the whole job. Push a press-fit bearing in cocked and it binds and wears out in a season; push it through the inner race and you crush the seal and contaminate the grease before the bike leaves the stand. A bearing whose grease is contaminated at install isn't a long-term bearing.

What the tool does

The 1721 is a threaded-shaft press with a handle on one end and a drift on the other. Slip the matching drift onto the press shaft and draw the bearing into its bore by turning the handle. Steady, controlled pressure throughout; no chance of glancing the drift off-axis. The force transmits through the drift to the bearing's outer race only, which keeps the seal between the two races intact.

The drift assortment covers the common bearing outside-diameter range across all three. The drifts live in a laser-cut SOS foam tray inside a plastic case, so they stay paired with the press and don't migrate into the bench drawer. The size match is what “universal” means here: the right drift for the bearing, not a generic mid-size that might or might not bear on the right surface.

Pressing is half of any bearing job. The old bearing comes out first (the Bearing Puller's side of the bench), and the bore gets cleaned and inspected before the new one goes in. The handoff between the two, hubs and headsets alike, is in our full service walkthrough.

Specs

• Operation: threaded-shaft press, hand-driven
• Drift set: sized for the common bearing OD range across headset, BB, and hub bearings
• Storage: laser-cut SOS foam tray in a plastic case
• SKU: 623301
• Made in Slovenia by Unior

Includes: Press body, threaded shaft, handle, full drift assortment in the foam tray.

Made in Slovenia, since 1919

Unior has been forging hand tools in Zreče since 1919, and is the official technical partner of multiple World Tour and downhill teams. The 1721's drift set is the load-bearing decision in the design; a press without the right drifts is a press that bottoms out on the wrong surface. Unior makes the drifts and the press together so the kit fits the bearings the catalog actually services.

Pro tip from our mechanics

When the press resistance suddenly stiffens, the bearing is bottomed in its bore. Stop. A few more turns past bottom doesn't make the bearing more seated; it just compresses the cup or shell against whatever face is on the other side, which (for a headset) is the face you carefully prepped with the head-tube reamer and facer earlier in the same build. Press to the bottom, stop, back the press off, move on.

The headset prep workflow the 1721 sits inside is in our walk-through: Frame prep: head tube, crown race, and star nut work →