{"product_id":"aluminum-bottom-bracket-socket-t47","title":"Aluminum Bottom Bracket Socket T47","description":"\u003cp\u003eT47 is the bottom bracket standard Chris King helped develop, adopted by Trek (T47i, internal-bearing) among others. The shell is 47 mm threaded with a 1.0 mm thread pitch; wider than BSA (33.7 mm at 1.37\") which lets the cup house a 30 mm spindle without forcing the bearing inboard into the frame, where it traditionally lived in the BB30 era. The T47 cup is the answer to the ”want a 30 mm spindle without going press-fit“ question that came out of the BB30 \/ PF30 era.\u003c\/p\u003e\n\u003cp\u003eThe 1671 Aluminum BB Socket cut for T47 fits the cup's specific notch profile. T47's wide diameter means the cup OD is dimensionally different from any other BB family in the catalog; a standard 16-notch wrench won't fit at all, not just fit imprecisely. The dedicated socket is the only correct tool for T47 cup installation and removal.\u003c\/p\u003e\n\u003ch2\u003eT47 thread handedness\u003c\/h2\u003e\n\u003cp\u003eT47 mirrors BSA's per-side thread handedness: \u003cstrong\u003eright-hand thread on the non-drive side, left-hand thread on the drive side.\u003c\/strong\u003e The split-handedness exists to prevent the drive-side cup from backing out under pedaling load; the drive-side spindle rotates in the loosening direction relative to a right-hand thread, so the drive side is left-hand threaded to make pedaling load tighten the cup, not loosen it. Chris King helped develop the spec; Trek's T47i and the asymmetric T47a use the same handedness.\u003c\/p\u003e\n\u003ch2\u003eCarbon-shell T47 variants\u003c\/h2\u003e\n\u003cp\u003eModern carbon frames; notably the Trek Domane SLR 9 AXS (2021+) and Trek's broader Domane \/ Madone T47 lineup; ship with bonded metal threaded inserts sized to T47. The bonded insert lets the T47 standard apply to a carbon frame without full-frame threading, and the BB tool doesn't distinguish between a metal-shell T47 and a carbon-shell-with-insert T47 (the engagement face is metal in both cases).\u003c\/p\u003e\n\u003ch2\u003eCompatibility\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003eT47 threaded BB cups (Chris King ThreadFit T47; Trek T47i internal-bearing; T47a asymmetric)\u003c\/li\u003e\n\u003cli\u003eCarbon frames with bonded T47 metal threaded inserts\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eNot for\u003c\/strong\u003e press-fit shells; the T47 designation requires threading\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch2\u003eSpecs\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eDrive:\u003c\/strong\u003e 1\/2\" square drive (use with a torque wrench, ratchet, or fixed handle such as the Pro Socket Handle)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMaterial:\u003c\/strong\u003e CNC-machined aluminum, red-anodized\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eNotch fit:\u003c\/strong\u003e T47 outer profile\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eIncludes:\u003c\/strong\u003e the socket itself; pair with the \u003ca href=\"\/products\/bottom-bracket-socket-retaining-tool\"\u003eBottom Bracket Socket Retaining Tool\u003c\/a\u003e for low-profile cup engagement\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch2\u003eBuilt in Zreče\u003c\/h2\u003e\n\u003cp\u003eUnior has been forging hand tools in Zreče since 1919, and sponsors professional road and mountain-bike race teams. The T47 socket entered the workshop tool palette when the BB standard itself moved from boutique (Chris King's original spec) to mainstream (Trek Domane, BMC Roadmachine), and the aluminum body keeps the cup face mark-free on the carbon frames where T47 lives most often.\u003c\/p\u003e\n\u003ch2\u003ePro tip from our mechanics\u003c\/h2\u003e\n\u003cp\u003eThe T47 cup wants to be checked for cleanliness more thoroughly than a BSA cup, because the wider thread diameter means a small contamination; a fleck of frame paint, a dried grease deposit; translates to a worse thread engagement than the same contamination on a narrower thread. Wipe the frame's T47 thread with a clean rag before threading the cup, and inspect the cup's leading threads for shipping debris. The five seconds spent looking is what keeps the cup square in the shell on the first quarter-turn.\u003c\/p\u003e\n\u003cp\u003eFor the install \/ torque \/ thread-direction reference: \u003ca href=\"\/blogs\/tech-tips\/replace-or-clean-your-hollowtech-ii-bottom-bracket\"\u003eReplace or clean your bottom bracket →\u003c\/a\u003e.\u003c\/p\u003e","brand":"Unior","offers":[{"title":"T47","offer_id":44140854935596,"sku":"628495","price":54.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0012\/5786\/5260\/products\/1671.t47.jpg?v=1642715755","url":"https:\/\/uniorusa.com\/products\/aluminum-bottom-bracket-socket-t47","provider":"Unior USA","version":"1.0","type":"link"}