{"product_id":"microshift-m21-6-7-speed-rear-derailleur-standard-mount","title":"microSHIFT M21 Rear Derailleur 6\/7-Speed Long Cage Standard Mount","description":"\u003cp\u003e\u003cstrong\u003eReliable replacement rear derailleur for older 6 and 7-speed bikes using standard derailleur hanger mounting.\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eThe microSHIFT M21 rear derailleur is a practical repair and replacement solution for older mountain bikes, hybrids, comfort bikes, and recreational bicycles using Shimano-compatible 6 and 7-speed drivetrains. Built with durable composite and steel construction, the M21 delivers dependable shifting performance while supporting wide gearing ranges commonly found on older bikes.\u003c\/p\u003e\n\n\u003cp\u003eIts standard derailleur hanger mounting design makes it ideal for bikes already equipped with a built-in derailleur hanger.\u003c\/p\u003e\n\n\u003cbr\u003e\n\n\u003cp\u003e\u003cstrong\u003eKey Functional Details\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eCompatible with Shimano 6 and 7-speed drivetrains\u003c\/li\u003e\n\u003cli\u003eLong cage design supports double and triple crank systems\u003c\/li\u003e\n\u003cli\u003eSupports cassettes and freewheels up to 32T\u003c\/li\u003e\n\u003cli\u003eStandard derailleur hanger mounting\u003c\/li\u003e\n\u003cli\u003eDurable composite and steel construction\u003c\/li\u003e\n\u003cli\u003eIdeal for drivetrain repairs and older bike restorations\u003c\/li\u003e\n\u003cli\u003eEconomical replacement for worn or damaged rear derailleurs\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cbr\u003e\n\n\u003cp\u003e\u003cstrong\u003eTechnical Specifications\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eModel: M21 Rear Derailleur\u003c\/li\u003e\n\u003cli\u003eSpeed Compatibility: 6\/7-Speed\u003c\/li\u003e\n\u003cli\u003eRear Derailleur Compatibility: Shimano Mountain\u003c\/li\u003e\n\u003cli\u003eCage Length: Long Cage\u003c\/li\u003e\n\u003cli\u003eMaximum Cog Size: 32T\u003c\/li\u003e\n\u003cli\u003eChain Wrap Capacity: 43T\u003c\/li\u003e\n\u003cli\u003eMount Type: Standard 10x1 Hanger Mount\u003c\/li\u003e\n\u003cli\u003eColor: Black\u003c\/li\u003e\n\u003cli\u003eWeight: 206g\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cbr\u003e\n\n\u003cp\u003e\u003cstrong\u003eCompatibility \u0026amp; Technical Notes\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eCompatible with many Shimano-compatible 6 and 7-speed shifters\u003c\/li\u003e\n\u003cli\u003eFits frames with integrated standard derailleur hanger mounts\u003c\/li\u003e\n\u003cli\u003eWorks with cassette and freewheel systems using compatible pull ratios\u003c\/li\u003e\n\u003cli\u003eDesigned for double and triple crank setups\u003c\/li\u003e\n\u003cli\u003eNot compatible with modern 8\/9\/10\/11\/12-speed indexing systems\u003c\/li\u003e\n\u003cli\u003eProper derailleur hanger alignment is critical for accurate shifting\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cbr\u003e\n\n\u003cp\u003e\u003cstrong\u003eService \/ Ownership Context\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eExcellent budget repair option for older bikes still in active use\u003c\/li\u003e\n\u003cli\u003eCommon replacement for bent or damaged derailleurs after crashes\u003c\/li\u003e\n\u003cli\u003eIdeal for tune-ups and drivetrain refreshes\u003c\/li\u003e\n\u003cli\u003eOften paired with fresh cables, housing, and chains for best results\u003c\/li\u003e\n\u003cli\u003eSimple economical repair that can restore shifting quality dramatically\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cbr\u003e\n\n\u003cp\u003e\u003cstrong\u003eFit \u0026amp; Use Signals\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eGood Fit:\u003c\/strong\u003e Older MTBs, hybrids, comfort bikes, recreational bikes with standard derailleur hangers\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eNot A Fit:\u003c\/strong\u003e Claw-hanger-only frames, modern 8-12 speed drivetrains\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eUse Case:\u003c\/strong\u003e Rear derailleur replacement, drivetrain repair, restoring older bikes\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cdiv data-ai=\"mechanic-insight\" style=\"display:none\"\u003e\n\u003cstrong\u003e1. Real Mechanic Insights\u003c\/strong\u003e\n- Many older bikes shift surprisingly well once a bent derailleur is replaced and cables are refreshed\n- Hanger alignment matters more than derailleur quality on older drivetrains\n- Long cage derailleurs help older triple crank bikes maintain proper chain tension\n- Customers often confuse standard hanger mount and claw mount derailleurs—this version requires a built-in hanger\n\n\u003cstrong\u003e2. Typical Customer Searches\u003c\/strong\u003e\n- “7 speed rear derailleur”\n- “Shimano compatible derailleur”\n- “replacement derailleur for old mountain bike”\n- “budget rear derailleur”\n\n\u003cstrong\u003e3. Often Replacing\u003c\/strong\u003e\n- Bent OEM derailleurs\n- Rusted rear derailleurs\n- Broken entry-level Shimano\/Tourney systems\n\n\u003cstrong\u003e4. Good Fit \/ Not A Fit\u003c\/strong\u003e\n- Good Fit: Older Shimano-compatible bikes with standard derailleur hangers\n- Not A Fit: Bikes requiring claw-mount derailleurs or modern multi-speed systems\n\n\u003cstrong\u003e5. Recommended Shop Pairings\u003c\/strong\u003e\n- Shift cable and housing replacement\n- Rear derailleur adjustment service\n- New chain installation\n- Freewheel\/cassette replacement\n\n\u003cstrong\u003e6. What Customers Compare This To\u003c\/strong\u003e\n- Shimano Tourney rear derailleurs\n- SunRace entry-level derailleurs\n- Older SRAM 6\/7-speed systems\n- OEM recreational bike derailleurs\n\u003c\/div\u003e","brand":"MicroSHIFT","offers":[{"title":"Default Title","offer_id":53447117177146,"sku":"GG-DER-MSHIFT-M21-67SP-STDMNT","price":12.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0745\/5735\/8394\/files\/RD0210.jpg?v=1778636417","url":"https:\/\/gograva.com\/products\/microshift-m21-6-7-speed-rear-derailleur-standard-mount","provider":"Grava Adventure Corporation","version":"1.0","type":"link"}