{"product_id":"spark-exhaust-bent-tube-30-degrees-45mm","title":"Spark Exhaust Bent Tube 30° Ø 45 × 1.0 mm Stainless Steel Universal G9104","description":"\u003cp\u003eForty-five millimetres at thirty degrees. Large enough to carry a big twin on its own, gentle enough to cost the gas almost nothing.\u003c\/p\u003e\u003ch2\u003eKey Features\u003c\/h2\u003e\u003cul\u003e\n\u003cli\u003eMandrel-formed 30° bend, AISI 304 stainless steel.\u003c\/li\u003e\n\u003cli\u003eØ 45 mm outside, 1.0 mm wall thickness.\u003c\/li\u003e\n\u003cli\u003eOne of two diameters Spark also bends through 180°.\u003c\/li\u003e\n\u003cli\u003eMatches Spark's 45 mm straight tube, article G9002.\u003c\/li\u003e\n\u003cli\u003eSpark part number G9104, made in Mantova, Italy.\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch2\u003eSizing the Run\u003c\/h2\u003e\u003cp\u003eForty-five suits a large parallel twin, a V-twin between eight hundred and a thousand, or the front section of a four before the collector. On anything smaller the gas slows and the bottom end goes with it.\u003c\/p\u003e\u003ch2\u003eThe Full Set at This Diameter\u003c\/h2\u003e\u003cp\u003eForty-five is one of only two sizes Spark bends through a complete 180 degrees, alongside fifty. That makes it the diameter with the widest choice of angles: thirty, forty-five, ninety and a full U.\u003c\/p\u003e\u003cp\u003eIf a design has an underseat loop in it, this is one of the two diameters that can be built without welding two ninety degree bends together.\u003c\/p\u003e\u003ch2\u003ePurging a Curved Joint\u003c\/h2\u003e\u003cp\u003eBack-purging a straight tube is easy: plug both ends, fill with argon, weld. A run with bends in it holds gas differently and needs longer to displace the air, particularly if the bend traps a pocket at the top.\u003c\/p\u003e\u003cp\u003eGive it more time than seems necessary. A sugared root inside a bend is invisible until the joint cracks.\u003c\/p\u003e\u003ch2\u003eWeld Preparation\u003c\/h2\u003e\u003cp\u003eA butt joint in one millimetre stainless does not want a chamfer — there is not enough wall for one. What it wants is a square cut, a tight gap and clean metal on both sides, wiped with acetone rather than brake cleaner.\u003c\/p\u003e\u003ch2\u003eMandrel, Not Crush\u003c\/h2\u003e\u003cp\u003eA mandrel bender supports the tube from inside as it forms, so the section stays round and the bore stays constant through the curve. A crush bender flattens the tube on the radius, exactly where the gas is already having to turn. Every bend Spark sells is mandrel-formed, and at forty-five millimetres in one millimetre wall that is not something a workshop press will match.\u003c\/p\u003e\u003ch2\u003eOrdering\u003c\/h2\u003e\u003cp\u003eOne bend per article. Spark makes 30°, 45°, 90° and 180° in this diameter.\u003c\/p\u003e","brand":"Spark Exhaust","offers":[{"title":"Default Title","offer_id":53618098405642,"sku":"G9104","price":205.02,"currency_code":"DKK","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0949\/7831\/0410\/files\/5c0e93a56b88f_1044453a-9a64-4dc7-aebe-f312f8cf5b32.png?v=1788354203","url":"https:\/\/inter-pace.com\/en-fo\/products\/spark-exhaust-bent-tube-30-degrees-45mm","provider":"Inter-Pace","version":"1.0","type":"link"}