{"product_id":"ohlins-shock-spring-90-n-mm-250-mm-57-mm-20580-29","title":"Öhlins Shock Spring 90 N\/mm \/ 250 mm \/ Ø 57 mm – 20580-29","description":"\u003cp\u003eÖhlins part number 20580-29 is a shock absorber spring rated at 90 N\/mm, 250 mm long with a 57 mm inner diameter. Adding a pillion or luggage changes the load enough that the standard rate stops working.\u003c\/p\u003e\u003ch2\u003eKey Features\u003c\/h2\u003e\u003cul\u003e\n\u003cli\u003eInner diameter 57 mm\u003c\/li\u003e\n\u003cli\u003eFree length 250 mm\u003c\/li\u003e\n\u003cli\u003eÖhlins part number 20580-29\u003c\/li\u003e\n\u003cli\u003eMeasured spring rate 90 N\/mm\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch2\u003eManufacture and Tolerance\u003c\/h2\u003e\u003cp\u003eEvery Öhlins dealer can re-valve the unit, because the shim stack is a documented, serviceable assembly. Production has stayed in Sweden since the company was founded in 1976. Öhlins machines its own critical components instead of buying them in, and the tolerances are where the money goes.\u003c\/p\u003e\u003ch2\u003eThe Numbers That Matter\u003c\/h2\u003e\u003cp\u003eThe 57 mm bore and 250 mm length are the two figures that decide whether it physically fits; 90 N\/mm decides whether it suits the rider.\u003c\/p\u003e\u003ch2\u003eChoosing 90 N\/mm\u003c\/h2\u003e\u003cp\u003eIf the suspension bottoms out or the geometry collapses under load, this is the direction to go. Firm rates trade some small-bump comfort for support — the right trade on a good surface at speed. Support under braking improves; small-bump comfort gives a little back. Road surfaces are the hardest test of a spring rate, because the fork has to cope with both a smooth stretch and a broken one.\u003c\/p\u003e\u003ch2\u003eHow a Rear Spring Works\u003c\/h2\u003e\u003cp\u003eOn a linkage-equipped machine the wheel moves several millimetres for every millimetre the damper moves, and the spring rate has to account for that ratio. The damper can only control the spring it is given; the wrong rate makes every setting a compromise. A spring that has settled in service sits shorter than new, which quietly lowers the bike and steepens the steering.\u003c\/p\u003e\u003ch2\u003eApplications\u003c\/h2\u003e\u003cp\u003eSelection is by measurement. If the diameter and free length match your fork, the remaining question is the rate. Where Öhlins lists this size against a particular unit, the listing is a starting point rather than a boundary. 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\u003eSet static sag after fitting; the rate is only right if the sag figure lands where Öhlins specifies. Öhlins supplies a setting sheet with the springs; the numbers on it assume the specified oil. If the fork has not been serviced recently, bushes and seals are worth replacing while it is apart.\u003c\/p\u003e\u003ch2\u003eRoad Approval\u003c\/h2\u003e\u003cp\u003eRoad approval: springs are not separately type-approved in Germany because they substitute a part that is already homologated with the fork. Model-specific documents, where they exist, are named above.\u003c\/p\u003e\u003ch2\u003eFitting and Setup Service\u003c\/h2\u003e\u003cp\u003eWe are an authorised Öhlins service centre, so the installation does not have to be your problem: we fit and set up Öhlins components in our own workshop. Ask us when you order and we will include the work.\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 20580-29\u003c\/li\u003e\n\u003cli\u003e\n\u003cem\u003eSpring Rate:\u003c\/em\u003e 90 N\/mm\u003c\/li\u003e\n\u003cli\u003e\n\u003cem\u003eFree Length:\u003c\/em\u003e 250 mm\u003c\/li\u003e\n\u003cli\u003e\n\u003cem\u003eInner Diameter:\u003c\/em\u003e 57 mm\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":53645400408330,"sku":"20580-29","price":164.05,"currency_code":"EUR","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0949\/7831\/0410\/files\/RearOhlinsSpring_e36b5ac7-cfcb-49f4-8be2-b226821cbbeb.png?v=1788866835","url":"https:\/\/inter-pace.com\/products\/ohlins-shock-spring-90-n-mm-250-mm-57-mm-20580-29","provider":"Inter-Pace","version":"1.0","type":"link"}