{"product_id":"spark-exhaust-bent-tube-90-degrees-38mm","title":"Spark Exhaust Bent Tube 90° Ø 38 × 1.0 mm Stainless Steel Universal G9137","description":"\u003cp\u003eThirty-eight millimetres at ninety degrees. The corner that gets a middleweight exhaust past the swingarm pivot, which on most machines is the point where a custom system either works or does not.\u003c\/p\u003e\u003ch2\u003eKey Features\u003c\/h2\u003e\u003cul\u003e\n\u003cli\u003eMandrel-formed 90° bend, AISI 304 stainless steel.\u003c\/li\u003e\n\u003cli\u003eØ 38 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 38 mm straight tube, article G9007.\u003c\/li\u003e\n\u003cli\u003eSpark part number G9137, made in Mantova, Italy.\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch2\u003ePast the Pivot\u003c\/h2\u003e\u003cp\u003eThe swingarm pivot is a fixed point on every motorcycle, and the exhaust has to get past it while turning outward. There is rarely room for a gentle sweep there, so a right angle is what fits between the pivot and the frame.\u003c\/p\u003e\u003cp\u003eCheck the clearance with the swingarm at full compression rather than at rest. The gap that looks generous on a paddock stand is not the gap the pipe will have on a bumpy road with a passenger.\u003c\/p\u003e\u003ch2\u003eOrder of Assembly\u003c\/h2\u003e\u003cp\u003eA right angle tucked against a frame member leaves nowhere to put a torch once the surrounding pieces are in place. Decide the welding sequence before anything is tacked: the joints that will become inaccessible get welded first, and the open ones last.\u003c\/p\u003e\u003cp\u003eIt is the usual reason a fabricated system has one bad-looking bead in it.\u003c\/p\u003e\u003ch2\u003eHeat Wrap and What It Does\u003c\/h2\u003e\u003cp\u003eWrapping a bend keeps heat in the gas and off the surrounding components, and it also keeps moisture against the metal. On a road machine that combination corrodes stainless from the outside in, under the wrap where nobody looks.\u003c\/p\u003e\u003cp\u003eOn a track bike used dry it is fine. On anything that sees rain, a shield is the better answer.\u003c\/p\u003e\u003ch2\u003eMeasuring the True Angle\u003c\/h2\u003e\u003cp\u003eA digital angle gauge held on the two straight tangents gives the real figure. Eye judgement does not, and half a degree at the first corner becomes a centimetre of misalignment at the silencer.\u003c\/p\u003e\u003ch2\u003eHow Many a System Uses\u003c\/h2\u003e\u003cp\u003eMost one-off runs on a middleweight need one right angle and two or three shallower bends. Buying a spare of the ninety is worth more than a spare of anything else — it is the piece with the least margin for a mistake and the one that cannot be improvised from a shallower article.\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":53618247532810,"sku":"G9137","price":289.73,"currency_code":"DKK","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0949\/7831\/0410\/files\/6087d4eca98d3_49df3a17-02ef-46c1-8baf-2894dad9ae37.png?v=1788348517","url":"https:\/\/inter-pace.com\/en-dk\/products\/spark-exhaust-bent-tube-90-degrees-38mm","provider":"Inter-Pace","version":"1.0","type":"link"}