Shimano's service manuals call for a specific grease during hub overhauls, bottom bracket installations, and headset service, and Premium Grease is what they're referencing. It's the same formulation applied at the factory to Dura-Ace and XTR hubs during assembly, so regreasing with it returns the bearing to its original lubrication state rather than mixing it with a different chemistry that may or may not play nicely with what's already there. If you're following Shimano's technical documentation to the letter—or servicing a wheelset under warranty—this is the product they expect in the bearing.

The formula is water-repellent and durable, which matters most in hubs and threaded bottom brackets where the bearing lives directly in the path of road spray. It holds up in headsets and works on Hollowtech II crank bolt threads as well, so a single container covers most of the bearing and threaded-interface grease work on the bike. It's also safe around the rubber lip seals and dust covers that protect cartridge bearings.

Three sizes are offered to match how often you're wrenching. The 50g tub suits home mechanics who service their own bikes a couple of times a season. The 100g tube gives you controlled application in tight spaces—useful for packing loose ball bearings or dabbing threads without over-applying. The 500g tub is the workshop size for anyone servicing multiple bikes or running through grease at a shop pace.... Read More