{"product_id":"spark-exhaust-bent-tube-30-degrees-40mm","title":"Spark Exhaust Bent Tube 30° Ø 40 × 1.0 mm Stainless Steel Universal G9101","description":"\u003cp\u003eA thirty degree elbow in the diameter most aftermarket link pipes turn out to be. If a run needs a gentle lean rather than a corner, this is the part.\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 40 mm outside, 1.0 mm wall thickness.\u003c\/li\u003e\n\u003cli\u003eStraight tangents at both ends.\u003c\/li\u003e\n\u003cli\u003eMatches Spark's 40 mm straight tube, article G9001.\u003c\/li\u003e\n\u003cli\u003eSpark part number G9101, made in Mantova, Italy.\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch2\u003eThe Default Diameter\u003c\/h2\u003e\u003cp\u003eForty millimetres carries a large twin or a middleweight four without slowing the gas, and routes around a shock and a swingarm without fouling. It is also the internal bore of several Spark db killers — the wide Force and Moto GP inserts and the Force Evo and Konix Evo plug.\u003c\/p\u003e\u003cp\u003eThose parts and this bend are sized for the same class of machine, which is why a Spark-based build tends to settle on forty and stay there.\u003c\/p\u003e\u003ch2\u003eBend Radius and What It Costs\u003c\/h2\u003e\u003cp\u003eEvery bend has a centreline radius, and a tighter one costs more flow than a generous one at the same angle. A production bend is made at the tightest radius the tooling will hold without distorting the section — which is a good deal tighter than anything achievable by hand.\u003c\/p\u003e\u003cp\u003eAt thirty degrees the loss is small in any case. This is the cheapest change of direction there is.\u003c\/p\u003e\u003ch2\u003eStacking Bends\u003c\/h2\u003e\u003cp\u003eLosses add. Three 30° bends in a row cost noticeably more than one 90° at the same radius, because each transition disturbs the flow again before it has settled.\u003c\/p\u003e\u003cp\u003eWhere a single larger bend will do the job, use it. Where it will not, put a short straight between the bends and let the gas recover.\u003c\/p\u003e\u003ch2\u003eTest-Fitting\u003c\/h2\u003e\u003cp\u003eAluminium tape holds a bend to a straight well enough to hang the assembly on the motorcycle. It is worth doing every time: the difference between a run that looks deliberate and one that looks bodged is usually a few degrees of clocking, and you cannot see that on a bench.\u003c\/p\u003e\u003ch2\u003eDeburring the Cut\u003c\/h2\u003e\u003cp\u003eTrimming a bend leaves a burr on a curved edge, which is more awkward to reach than one on a straight. At forty millimetres that burr sits squarely in the gas path and stops a slip joint seating properly. A half-round file or a rotary burr clears it; a thumbnail run round the bore is the test.\u003c\/p\u003e\u003ch2\u003eOrdering\u003c\/h2\u003e\u003cp\u003eOne bend per article. Spark builds 30°, 45° and 90° at this diameter, plus a 500 mm straight.\u003c\/p\u003e","brand":"Spark Exhaust","offers":[{"title":"Default Title","offer_id":53618096341258,"sku":"G9101","price":1055.0,"currency_code":"THB","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0949\/7831\/0410\/files\/5c0e8f7698556_421eeda9-9bc1-47c4-bc63-32ba505151ef.png?v=1788354195","url":"https:\/\/inter-pace.com\/en-th\/products\/spark-exhaust-bent-tube-30-degrees-40mm","provider":"Inter-Pace","version":"1.0","type":"link"}