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

Triumph Bonneville T100 front three quarter from the right with the Builder Series TT slip on exhaust along the left side

Triumph Bonneville T100 in green and black, front three quarter view with the Builder Series TT exhaust fitted

Triumph Bonneville T100 rear three quarter with the Builder Series TT silencer and factory mounting point visible

British Customs

BC902.2.111-BS-BR

Builder Series TT Slip-On Exhaust for Triumph Bonneville T100 & T120

Name: Builder Series TT Slip-On Exhaust for Triumph Bonneville T100 & T120
Brand: British Customs
SKU: BC902.2.111-BS-BR
Price: 599.95 USD
Availability: OutOfStock
Rating: 5.0 (1 reviews)

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The Builder Series TT is a bolt on slip on exhaust for the Triumph Bonneville T100 and T120, built in 20 gauge 304 stainless with a Two Stage Core that holds mid range torque and a Dimpled Baffle that shapes the classic parallel twin note. Bolt on to OEM headers, 2.4 pounds per silencer, 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 Bonneville T100 & T120

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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Call: +1 (877) 999 BRIT
Email: support@british-customs.com

The Bonneville Exhaust That Gives the Twin Its Voice Back

Triumph's history at the Isle of Man TT runs deeper than most marques. Before the Bonneville carried that name, Triumph engines were already winning on 37 miles of closed public road in the Irish Sea. The bikes that ran there became the foundation for everything the Bonneville stands for.

The T100 and T120 carry that lineage. The stock exhaust does not. Factory mufflers on the modern Bonneville are quiet by design and heavy for what they are, and the exhaust note that defined the original Bonneville is muted before the bike leaves the factory.

The Two Stage Core runs two baffles at two different diameters to control flow in sequence, preserving the low and mid range torque the Bonneville is built around. The Dimpled Baffle brings out the natural voice of the twin. At 2.4 pounds per silencer against 8 to 10 pounds of stock muffler per side, the bike feels like what it was always supposed to be. The name is not borrowed. The Bonneville earned it decades ago.

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: delivers a deep classic note that brings out the twin cylinder voice of the Bonneville platform. 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: holds low and mid range torque by controlling flow in two stages. The Bonneville's relaxed character depends on smooth responsive power delivery, and this keeps it. 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. The bike feels more connected through turns and at low speed. Physics, not marketing.
20 gauge 304 stainless steel: corrosion resistant and rated for sustained heat cycling. The brushed finish needs no polishing and gains character over time.
Exposed weld aesthetic: visible unfinished welds give a raw vintage look that complements the Bonneville's classic lines. It looks like the rider built it, not like it came out of a box.
Factory replacement fitment: mounts to OEM headers and stock mounting points. No cutting, no welding, no permanent modification.

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 Bonneville T100 2017 and newer, Bonneville T120 2016 and newer
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 exhaust clamps and mounting hardware and remove the stock mufflers from the OEM headers.
Position the Builder Series TT silencers onto the stock header outlets.
Secure each silencer with the included stainless steel exhaust clamp.
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: fitment is identical for the T100 and the T120. T100 from 2017, T120 from 2016.
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.
Brushed finish is meant to age. No polishing, and it gains character with heat cycles.

Frequently Asked Questions

Builder Series Shorty

Does the same exhaust fit both the T100 and the T120?

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.

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.

How loud is it, and can I fit a dB Killer?

It is loud by design. The Dimpled Baffle brings out the classic parallel twin note, and the TT is not compatible with dB Killers. For a quieter setup, we recommend the Predator Pro, which takes an optional dB Killer.

How much weight does it save?

2.4 pounds per silencer, 4.8 pounds per pair. Stock mufflers run 8 to 10 pounds per side, so real weight comes off the back of the bike where you feel it through turns.

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.

Is the install reversible if I sell the bike?

Yes. It mounts to OEM headers and stock mounting points with no cutting, welding, or permanent modification. The stock mufflers go straight back on.

Other Slip-On Exhaust

Shorty Predator Pro 2.0 Slip-On Exhaust for Triumph Bonneville T100 & T120 (2016+)

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Shorty Predator Pro 2.0

$749.95

British Customs

Predator Pro 2.0 Slip On Exhaust

$749.95

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Reviewed by Rodd B.

Verified Buyer

I recommend this product

Rated 5 out of 5

Review posted

Great Slip-Ons

These are great slip-ons, in build quality, style, and sound.

I didn't know what to expect as my first purchase from British Customs as a new Triumph owner.

Had Harleys all my life (38 years)

I highly recommend these. They look amazing on a T120 Black, I don't care that their not black to match the bike, and I think it sets the look off in a different way.

Great sound and not too loud but loud enough to give the riding experience a little more feedback.

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