Builder Series TT silencer on a black Triumph Street Cup, close up past the shock and footpeg

Builder Series TT outlet on a black Triumph Street Cup, low rear angle showing the tapered tip

Rear view of a black Triumph Street Cup showing both Builder Series TT outlets either side of the tyre

Black Triumph Street Cup with cafe fairing, front three quarter, Builder Series TT exhaust fitted

Single Builder Series TT silencer, three quarter view, brushed 304 stainless with mounting bracket

Close up of the Builder Series TT mounting bracket and exposed weld beads on brushed stainless

British Customs

BC902.2.112-BS-BR

Builder Series TT Slip-On Exhaust for Triumph Street Cup, Street Twin & Speed Twin 900

Name: Builder Series TT Slip-On Exhaust for Triumph Street Cup, Street Twin & Speed Twin 900
Brand: British Customs
SKU: BC902.2.112-BS-BR
Price: 599.95 USD
Availability: OutOfStock
Rating: 5 (183 reviews)

$599.95

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The Builder Series TT is a bolt on slip on exhaust for the Triumph Street Cup, Street Twin, and Speed Twin 900, built in 20 gauge 304 stainless with a Two Stage Core that holds mid range torque and a Dimpled Baffle that shapes a deep exhaust note. At 14 inches it also opens up chain access. Bolt on, no tune needed.

This is a loud exhaust by design and it does not accept a dB Killer. If you want a quieter setup, we recommend the Predator Pro, which takes an optional dB Killer.

Fits

Triumph Street Cup 2016-2019, Street Twin 2016-2022, Speed Twin 900

Material

20 gauge 304 stainless steel · brushed finish · exposed weld

Origin

Made in the USA

Install

Bolt on · about 30 minutes · socket set, Allen keys, torque wrench · no ECU tune with the factory catalytic converter

Check Fitment for Your Bike

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Need Help

Talk to a rider. Monday to Friday, 9am to 4pm PST.
Call: +1 (877) 999 BRIT
Email: support@british-customs.com

The Exhaust That Belongs on a Rider's First Build

Since 1907 the Isle of Man TT has run through stone villages, over a mountain pass, and along hedgerow lined roads on a small island in the Irish Sea. The same roads every year. What changes are the bikes. The ones that make it to the start line are not the most expensive. They are the ones where every component was chosen with the finish line in mind.

The Street Cup and Street Twin are where a lot of riders start building their first custom motorcycle. The platform is capable. The stock exhaust is not the limiting factor for riding, but it does not match the intention of a bike being built into something personal. It is heavy, restrained, and it looks like the exhaust on every other bike in the parking lot.

The Two Stage Core controls flow in two stages, holding mid range torque for the riding these bikes actually do: city traffic, stop and go commutes, back road weekends. The Dimpled Baffle shapes a deep note that matches the character they deserve. At 2.4 pounds per silencer against 8 to 10 pounds of stock muffler per side, the bike changes direction differently from the first ride.

The TT is loud. That is the design, not a side effect, and it does not accept a dB Killer. If quiet matters more to you than volume, look at the Predator Pro instead, which takes an optional dB Killer.

Key Features & Benefits

Dimpled Baffle: shapes a deep note that brings out the engine's natural voice. The TT is loud by design and is not compatible with dB Killers. For a quieter setup, we recommend the Predator Pro, which takes an optional dB Killer.
Two Stage Core: two stage flow control keeps the engine responsive through the low and mid range. The bike pulls clean from stops and rolls smoothly through traffic, which is where these riders spend most of their time. Exclusive to the Builder Series TT.
Real weight off the back: 2.4 pounds per silencer against 8 to 10 pounds per side for stock. Noticeably lighter and quicker to change direction through city streets and tight corners. Physics, not marketing.
Better chain access: at 14 inches the silencers are shorter than stock, which opens space around the swingarm and rear wheel and makes chain adjustment and cleaning easier.
20 gauge 304 stainless steel: corrosion resistant, handles heat cycling, and holds its appearance without polishing. Low maintenance for a daily rider.
Raw exposed weld construction: unfinished welds give a vintage custom look that fits a first build. Intentional, not catalog perfect.

Specs & Warranty

Material: 20 gauge 304 stainless steel, brushed, exposed weld
Design: Two Stage Core with Dimpled Baffle
Weight: 2.4 pounds per silencer, 4.8 pounds per pair. Stock is 8 to 10 pounds per side
Length: 14 inches
Diameter: 3.75 inches
Origin: made in the USA
Fitment: Triumph Street Cup 2016 to 2019, Street Twin 2016 to 2022, Speed Twin 900 2023 to 2024
Tuning: no ECU tune required with the factory catalytic converter in place
Warranty: 1 year limited warranty covering defects in materials and workmanship under normal use. Excludes damage from improper installation, modification, or misuse

What's Included

(1) Pair of Builder Series TT mufflers
(1) Stainless steel exhaust clamp
(1) Mounting spacer

Install

Difficulty: Beginner · Time: about 30 minutes · Tools: socket set, Allen key set, torque wrench

Let the exhaust cool, then loosen the stock exhaust clamps and remove the factory mufflers from the header pipes.
Position the Builder Series TT silencers onto the stock headers.
Attach each silencer with the included stainless steel exhaust clamp and bring it to a snug fit.
Install the mounting spacer and torque all fasteners to the manufacturer specification.
Start the bike and recheck the joints for leaks.

Before You Buy

Check your model and year: fits the Street Cup 2016 to 2019, Street Twin 2016 to 2022, and Speed Twin 900 2023 to 2024. All three share the same exhaust mounting interface.
Loud by design, and it does not accept a dB Killer. If you want it quieter, we recommend the Predator Pro with the optional dB Killer.
No tune needed with the factory catalytic converter in place. The install is fully reversible.
Shorter than stock at 14 inches, which is why chain access improves. Worth knowing if you were expecting stock length.

Frequently Asked Questions

Builder Series Shorty

Does this fit the Street Cup, the Street Twin, and the Speed Twin 900?

Yes. The Builder Series TT mounts directly to stock headers and factory mounting points. No cutting, welding, or permanent modification is required. Select your fitment above for model-specific installation details.

Will shorter mufflers affect chain access for maintenance?

It improves it. At 14 inches the silencers are shorter than stock, which opens up space around the swingarm and rear wheel and makes routine chain adjustment and cleaning easier.

Is this too loud for daily commuting?

It is loud by design and not compatible with dB Killers. The Dimpled Baffle gives a deep classic tone rather than a harsh one, but if you commute through quiet neighbourhoods at early hours, the Predator Pro with the optional dB Killer is the quieter option.

Can I install this myself with basic tools?

Yes. It is a bolt on exhaust using factory mounting points. About 30 minutes with a socket set, Allen keys, and a torque wrench. No cutting or welding.

Is it street legal where I ride?

Sound and emissions rules vary by state and by country, and this exhaust is loud by design with no dB Killer option. Check your local regulations before ordering.

Do I need a tune or an ECU remap?

No, not with the factory catalytic converter in place. The Two Stage Core controls flow in sequence rather than opening the system wide, so the bike keeps its mid range without a remap.