{"product_id":"ohlins-piston-8-25-21923-01","title":"Öhlins Piston 8\/25 – 21923-01","description":"\u003cp\u003ePiston 8\/25, Öhlins part number 21923-01. A worn piston band lets oil past the outside of the piston, which shows up as damping that has gone soft.\u003c\/p\u003e\u003ch2\u003eKey Features\u003c\/h2\u003e\u003cul\u003e\n\u003cli\u003eÖhlins part number 21923-01\u003c\/li\u003e\n\u003cli\u003eDimension B 25 mm\u003c\/li\u003e\n\u003cli\u003eDimension A 8 mm\u003c\/li\u003e\n\u003cli\u003eOriginal Öhlins service part\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch2\u003eFunction\u003c\/h2\u003e\u003cp\u003e21923-01 is the 8 mm, 25 mm version — Öhlins lists each size separately. The piston carries the shim stacks and meters the oil; its port layout is what makes an Öhlins damper behave the way it does. Öhlins machines its pistons rather than sintering them, which is why the port edges stay sharp. Piston bands are consumables — they wear against the bore and lose their seal gradually.\u003c\/p\u003e\u003ch2\u003eWhy the Original\u003c\/h2\u003e\u003cp\u003eÖhlins keeps service parts available for units long after they leave the current price list. Öhlins lists this part under its own number in the service catalogue so a workshop can order exactly what it needs. We can supply the whole position from the drawing rather than the single piece if that is easier. Where a number has been superseded, Öhlins states the replacement — we pass that on.\u003c\/p\u003e\u003ch2\u003eHow to Be Sure It Fits\u003c\/h2\u003e\u003cp\u003eIf the unit is already open, compare the dimensions below with the part in your hand before ordering 21923-01. The published dimensions are dimension a 8 mm, dimension b 25 mm — measure the old part against them if you are unsure. A scored piston face means oil bypasses the shims entirely. Port area and seat geometry decide the damping before any adjuster is touched.\u003c\/p\u003e\u003ch2\u003eFitting and Setup Service\u003c\/h2\u003e\u003cp\u003eA damper rebuild is workshop work: it needs the unit dismantled, the shim stack rebuilt in the correct order and the gas charge reset. We are an authorised Öhlins service centre and do exactly that in house — send us the unit or ask us to fit the part with your 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 21923-01\u003c\/li\u003e\n\u003cli\u003e\n\u003cem\u003eCategory:\u003c\/em\u003e Pistons\u003c\/li\u003e\n\u003cli\u003e\n\u003cem\u003eDimension A:\u003c\/em\u003e 8 mm\u003c\/li\u003e\n\u003cli\u003e\n\u003cem\u003eDimension B:\u003c\/em\u003e 25 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":53653028700426,"sku":"21923-01","price":305.53,"currency_code":"DKK","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0949\/7831\/0410\/files\/21923-01_26362327-454c-4a6e-b888-681dee7d5f15.png?v=1788880474","url":"https:\/\/inter-pace.com\/en-fo\/products\/ohlins-piston-8-25-21923-01","provider":"Inter-Pace","version":"1.0","type":"link"}