Spark Exhaust Bent Tube 90° Ø 52 × 1.0 mm Stainless Steel Universal G9152

Fifty-two millimetres at ninety degrees. A right angle sized so that fifty millimetre pipe goes into either end of it — the piece that lets a large system come apart at its most awkward point.

Key Features

• Mandrel-formed 90° bend, AISI 304 stainless steel.
• Ø 52 mm outside, 1.0 mm wall thickness.
• Fifty millimetre bore.
• Matches Spark's 52 mm straight tube, article G9013.
• Spark part number G9152, made in Mantova, Italy.

The Day the System Comes Off

A rear tyre, a chain, a shock, a wheel bearing — sooner or later the exhaust has to come off a motorcycle that is not new. A welded run has to be manoeuvred out in one piece, usually past a swingarm and around a footrest hanger. A run with a joint at the corner lifts out in two halves.

Over the life of a machine that is what this article actually buys, and it is worth more than the difference in price.

Fifty Inside, Fifty-Two Outside

One millimetre of wall on each side means the bore is exactly the outside diameter of the standard size. Nothing is expanded, swaged or machined: the pipe goes in, the springs go on, and the corner is made.

Springs and Hooks

Spark sells the springs in two lengths, with or without a rubber sleeve, and hooks to fit them in stainless or titanium. Two per joint at opposing sides is the arrangement Spark uses on its own systems; three is not better, and one lets the joint rock.

The rubber sleeve is not decorative — it stops the spring ringing against the pipe at idle.

Carbon in the Gap

A slip joint that has run for a season will not simply pull apart: carbon builds in the overlap and locks it. Warming the outer part gently and twisting rather than pulling is the way; levering against a thin-wall bend distorts the socket and ruins the fit permanently.

Where This Diameter Comes From

Fifty-two exists in Spark's range because Spark's own exhausts use sprung slip joints throughout, and a slip joint needs a female half. A supplier building only to round numbers has no reason to own the tooling — which is why almost nobody else lists the size.

Ordering

One bend per article. Spark builds 30°, 45° and 90° at this diameter.