{"product_id":"shimano-altus-rd-m370-sgs-9-speed-rear-derailleur","title":"Shimano Altus RD-M370-SGS Rear Derailleur - 9-Speed, Long Cage, 34T Max, Black","description":"\u003cp\u003eThe Shimano Altus RD-M370-SGS is a reliable 9-speed rear derailleur built for mountain bikes, hybrids, comfort bikes, and utility builds that need dependable shifting without unnecessary complexity. This is a long cage derailleur designed for wider gear range setups and everyday durability.\u003c\/p\u003e\n\n\u003cp\u003eIt works especially well as a direct replacement for older Shimano 8\/9-speed mountain and hybrid drivetrains where riders want smooth shifting, easy serviceability, and affordable long-term parts support.\u003c\/p\u003e\n\n\u003cp\u003eThis is not a modern clutch derailleur for aggressive trail riding—it is a practical workhorse derailleur for real-world riding and service repairs.\u003c\/p\u003e\n\n\u003ch3\u003eKey Functional Details\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eShimano Altus RD-M370-SGS rear derailleur\u003c\/li\u003e\n\u003cli\u003e9-speed drivetrain compatibility\u003c\/li\u003e\n\u003cli\u003eLong cage (SGS) for wider gear range setups\u003c\/li\u003e\n\u003cli\u003eMaximum 34T largest rear cog compatibility\u003c\/li\u003e\n\u003cli\u003e45T total chain wrap capacity\u003c\/li\u003e\n\u003cli\u003eStandard 10x1 derailleur hanger mount\u003c\/li\u003e\n\u003cli\u003eCompatible with Shimano mountain-style pull ratio\u003c\/li\u003e\n\u003cli\u003e11-tooth upper and lower pulleys\u003c\/li\u003e\n\u003cli\u003eStrong replacement option for MTB, hybrid, and commuter bikes\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eTechnical Specifications\u003c\/h3\u003e\n\n\u003ctable\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eBrand\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eShimano\u003c\/td\u003e\n\u003c\/tr\u003e\n\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eModel\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eAltus RD-M370-SGS\u003c\/td\u003e\n\u003c\/tr\u003e\n\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eDrivetrain Speeds\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e9-Speed\u003c\/td\u003e\n\u003c\/tr\u003e\n\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eCage Length\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eLong Cage (SGS)\u003c\/td\u003e\n\u003c\/tr\u003e\n\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eLargest Rear Cog\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e34T Max\u003c\/td\u003e\n\u003c\/tr\u003e\n\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eChain Wrap Capacity\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e45T\u003c\/td\u003e\n\u003c\/tr\u003e\n\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eMount Type\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e10x1 Standard Derailleur Hanger\u003c\/td\u003e\n\u003c\/tr\u003e\n\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eCompatibility\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eShimano Mountain Pull Ratio\u003c\/td\u003e\n\u003c\/tr\u003e\n\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003ePulley Size\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e11T Upper \/ 11T Lower\u003c\/td\u003e\n\u003c\/tr\u003e\n\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eColor\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eBlack\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/table\u003e\n\n\u003ch3\u003eCompatibility \u0026amp; Technical Notes\u003c\/h3\u003e\n\n\u003cp\u003e\u003cstrong\u003eGood Fit:\u003c\/strong\u003e Shimano 9-speed mountain bikes, hybrids, fitness bikes, comfort bikes, and commuter builds using standard Shimano MTB shifter pull ratios.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eNot A Fit:\u003c\/strong\u003e Shimano 10\/11\/12-speed systems, SRAM exact actuation drivetrains, modern clutch derailleur applications, or oversized cassette conversions beyond 34T without special adaptation.\u003c\/p\u003e\n\n\u003cp\u003eThis derailleur must match the correct shifter pull ratio—not just the speed count. That is one of the most common ordering mistakes.\u003c\/p\u003e\n\n\u003ch3\u003eService \/ Ownership Context\u003c\/h3\u003e\n\n\u003cp\u003eFor many older bikes, replacing the derailleur is often smarter than trying to rebuild a bent or worn unit. This is a dependable service replacement that keeps older bikes shifting properly without forcing expensive drivetrain upgrades.\u003c\/p\u003e\n\n\u003cp\u003eIt is especially common on bikes where the derailleur hanger gets bent during transport, crashes, or tip-over damage.\u003c\/p\u003e\n\n\u003ch3\u003eFit \u0026amp; Use Signals\u003c\/h3\u003e\n\n\u003cp\u003eBest for:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eHybrid bike repairs\u003c\/li\u003e\n\u003cli\u003eOlder 9-speed MTB replacements\u003c\/li\u003e\n\u003cli\u003eCommuter bike drivetrain repairs\u003c\/li\u003e\n\u003cli\u003eComfort bike service work\u003c\/li\u003e\n\u003cli\u003eBudget-conscious reliable repairs\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eNot ideal for:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eModern wide-range MTB builds\u003c\/li\u003e\n\u003cli\u003e12-speed upgrades\u003c\/li\u003e\n\u003cli\u003eAggressive trail riding requiring clutch derailleurs\u003c\/li\u003e\n\u003cli\u003eLarge cassette performance conversions\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cdiv data-ai=\"mechanic-insight\" style=\"display:none\"\u003e\nThe most common mistake is customers ordering by \"9-speed\" only and ignoring pull ratio compatibility. Shimano road and Shimano mountain systems are not always interchangeable even if both are 9-speed.\n\nAlways check the shifter first. If the original bike used flat bar MTB-style Shimano shifting, this is often correct. If it used road brifters, compatibility needs closer inspection.\n\nAlso check the derailleur hanger before replacing the derailleur. A bent hanger often causes the shifting problem, not the derailleur itself.\n\nTypical customer searches:\nShimano 9 speed long cage rear derailleur\nreplacement derailleur for hybrid bike 9 speed\nAltus RD-M370 SGS rear derailleur\nShimano rear derailleur for 34 tooth cassette\n\nOften replacing:\nbent stock rear derailleurs\ndamaged commuter bike derailleurs\nolder Acera or Altus derailleur systems\nhanger damage after bike falls\n\nRecommended shop pairings:\nderailleur hanger alignment\nnew shift cable and housing\nchain wear check\ncassette inspection\nfull drivetrain tune-up\n\nCustomers comparing this often also look at:\nShimano Acera RD-M3000\nShimano Alivio RD-M3100\nShimano Tourney TX Rear Derailleur\nMicroSHIFT Advent 9-Speed Rear Derailleur\nSR Suntour XCM drivetrain replacements\n\u003c\/div\u003e","brand":"Shimano","offers":[{"title":"Default Title","offer_id":53377540849978,"sku":"GG-DER-SHIMANO-ALTUS-M370-SGS-9SP-BLK","price":34.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0745\/5735\/8394\/files\/RD3101.jpg?v=1777417628","url":"https:\/\/gograva.com\/products\/shimano-altus-rd-m370-sgs-9-speed-rear-derailleur","provider":"Grava Adventure Corporation","version":"1.0","type":"link"}