{"product_id":"ohlins-shock-spring-68-n-mm-170-mm-51-mm-21042-18","title":"Öhlins Shock Spring 68 N\/mm \/ 170 mm \/ Ø 51 mm – 21042-18","description":"\u003cp\u003eÖhlins part number 21042-18 is a shock absorber spring rated at 68 N\/mm, 170 mm long with a 51 mm inner diameter. The damper can only control the spring it is given; the wrong rate makes every click a compromise.\u003c\/p\u003e\u003ch2\u003eKey Features\u003c\/h2\u003e\u003cul\u003e\n\u003cli\u003eStraight-wound, constant rate\u003c\/li\u003e\n\u003cli\u003e89 mm of usable stroke\u003c\/li\u003e\n\u003cli\u003eInner diameter 51 mm\u003c\/li\u003e\n\u003cli\u003eÖhlins part number 21042-18\u003c\/li\u003e\n\u003cli\u003ePowder-coated yellow\u003c\/li\u003e\n\u003cli\u003eFree length 170 mm\u003c\/li\u003e\n\u003cli\u003eMeasured spring rate 68 N\/mm\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch2\u003eManufacture and Tolerance\u003c\/h2\u003e\u003cp\u003eÖhlins sets a baseline for each part number on the machine it was developed on, so it works before anything is adjusted. Öhlins machines its own critical components instead of buying them in, and the tolerances are where the money goes. Seals are specified for temperature stability rather than for the lowest unit cost.\u003c\/p\u003e\u003ch2\u003eDimensions\u003c\/h2\u003e\u003cp\u003eAt 170 mm free length and 51 mm inner diameter, this spring is dimensionally interchangeable with anything of the same size — the rate is what makes it a different part.\u003c\/p\u003e\u003ch2\u003eChoosing 68 N\/mm\u003c\/h2\u003e\u003cp\u003eA firm rate keeps the fork high in its stroke under braking, which preserves the geometry when the front is loaded hard. Heavier riders, two-up use and track days all push the choice towards this end. Support under braking improves; small-bump comfort gives a little back. A road machine spends most of its life in the first third of the fork's travel — that is the part the rate governs.\u003c\/p\u003e\u003ch2\u003eWhat the Rear Spring Decides\u003c\/h2\u003e\u003cp\u003eTwo riders 20 kg apart on the same motorcycle genuinely need different rates, not different clicks. Öhlins supplies most of its shocks without a spring precisely so the rate can be matched to the rider rather than averaged. Öhlins sells rear springs separately precisely because rider weight varies more than machine weight does.\u003c\/p\u003e\u003ch2\u003eApplications\u003c\/h2\u003e\u003cp\u003eRate is the variable that depends on the rider, not on the machine. Two people on the same bike may well want two different numbers. Sag figures, not feel, decide whether a rate is right. Öhlins publishes the targets for its own units. Any workshop with the fork or shock in front of it can answer whether this spring fits — the three figures above are all it needs.\u003c\/p\u003e\u003ch2\u003eWhat Fitting Involves\u003c\/h2\u003e\u003cp\u003eWork on both legs in one session so the fork stays symmetrical. The job needs no special tools beyond a fork spring compressor and a measuring rod for the oil level. The fork legs come off, the springs are swapped and the oil level is reset — half a day in most workshops.\u003c\/p\u003e\u003ch2\u003eRoad Approval\u003c\/h2\u003e\u003cp\u003eRoad approval: a spring is a like-for-like replacement of a wear part and carries no separate type approval. Where Öhlins states an approval for a particular motorcycle, it is named under Applications.\u003c\/p\u003e\u003ch2\u003eFitting and Setup Service\u003c\/h2\u003e\u003cp\u003eÖhlins recommends that its suspension is fitted by an authorised service centre. We are one, and we do the work here: installation, servicing and a proper setup. Ask us and we will include it with the order.\u003c\/p\u003e\u003ch2\u003eSpecifications\u003c\/h2\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cem\u003eBrand:\u003c\/em\u003e Öhlins\u003c\/li\u003e\n\u003cli\u003e\n\u003cem\u003ePart Number:\u003c\/em\u003e 21042-18\u003c\/li\u003e\n\u003cli\u003e\n\u003cem\u003eSpring Rate:\u003c\/em\u003e 68 N\/mm\u003c\/li\u003e\n\u003cli\u003e\n\u003cem\u003eFree Length:\u003c\/em\u003e 170 mm\u003c\/li\u003e\n\u003cli\u003e\n\u003cem\u003eInner Diameter:\u003c\/em\u003e 51 mm\u003c\/li\u003e\n\u003cli\u003e\n\u003cem\u003eStroke:\u003c\/em\u003e 89 mm\u003c\/li\u003e\n\u003cli\u003e\n\u003cem\u003eConstruction:\u003c\/em\u003e Straight\u003c\/li\u003e\n\u003cli\u003e\n\u003cem\u003eFinish:\u003c\/em\u003e Powder-coated yellow\u003c\/li\u003e\n\u003cli\u003e\n\u003cem\u003eCountry of Origin:\u003c\/em\u003e Sweden\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"Öhlins","offers":[{"title":"Default Title","offer_id":53645406961930,"sku":"21042-18","price":134.17,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0949\/7831\/0410\/files\/RearOhlinsSpring_ee66b469-a0f9-4a7a-a928-7ffe4972cc65.png?v=1788866860","url":"https:\/\/inter-pace.com\/en-ca\/products\/ohlins-shock-spring-68-n-mm-170-mm-51-mm-21042-18","provider":"Inter-Pace","version":"1.0","type":"link"}