A Bonneville T120 Custom Build That Does Not Look Modified
At Bonvent Motorbikes, the objective is not to make a motorcycle look heavily modified. The objective is to make every new component feel as though it naturally belongs on the original bike.
We prefer restrained custom motorcycles over builds that look improvised, overworked or assembled from unrelated universal parts. Brackets should disappear. Wiring should remain organised. Bodywork should follow the existing lines of the motorcycle. The finished result should feel coherent from every angle.
The 2024 Triumph Bonneville T120 is an ideal platform for this approach. It already combines a classic twin-cylinder silhouette, a strong frame structure and premium roadster proportions. The role of the custom parts is therefore not to replace its identity, but to reveal a lighter, more compact and more purposeful version of the same motorcycle.
This black T120 build uses a shorter rear section, a redesigned seat, compact side panels, smaller lighting, a cleaner cockpit and carefully machined details. A black Zard exhaust, a wider handlebar and bar-end mirrors complete the motorcycle without turning it into an exaggerated show build.
Riders planning a similar project can explore the current range of Triumph Bonneville T120 custom parts and accessories.
Starting With a 2024 Triumph Bonneville T120
The Bonneville T120 has the proportions of a traditional British roadster: a long fuel tank, horizontal seat, twin rear shocks, exposed parallel-twin engine and round headlight.
Those classic foundations make the motorcycle highly adaptable, but they also mean that an unsuitable custom part can disrupt the entire profile. A rear fender that is too short, an unfinished side-cover conversion or a universal headlight bracket can quickly make a premium motorcycle feel less resolved than the original.
For this project, each area was considered as part of the same visual system. The shorter seat works with the rear mudguard. The smaller side panels reveal more of the frame. The compact headlight works with the front indicator position. The new speedometer housing reduces the cockpit without sacrificing the original Triumph electronics.
The motorcycle remains recognisably a Bonneville. It is simply leaner, darker and more focused.
A Shorter Bonneville Rear End With Integrated Lighting
The original Bonneville rear mudguard and lighting assembly have a strong visual presence. They suit the factory roadster, but they can feel large once the rest of the motorcycle has been made more compact.
This build uses a new Bonvent short rear mudguard system developed for the Bonneville platform. It replaces the large original rear assembly with a smaller mudguard, an integrated LED tail light and a cleaner license plate arrangement.
The compact rear light is mounted directly within the mudguard assembly and provides both running-light and brake-light functions. Its smaller housing removes unnecessary visual weight while keeping the light clearly visible from behind.
The rear light and license plate light used on the build are E-marked components. They provide a road-use oriented lighting solution, although final positioning and compliance must always be checked against the regulations of the country where the motorcycle is registered.
A license plate holder designed for international formats
The plate holder uses multiple mounting positions rather than one fixed national pattern. This allows it to accommodate a broad range of European, UK, US and other international number plate dimensions.
Because plate sizes, hole positions, reflectors and lighting requirements vary between countries, the final installation should always be checked with the rider’s actual plate before the motorcycle is used on the road.
Rear indicator mounting points are positioned on each side of the license plate. This creates a symmetrical lighting layout and keeps the indicators away from the seat and tail-light housing.
Upper and lower anti-splash protection
A common weakness of extremely short motorcycle rear fenders is the open space around the license plate. Water and mud can travel between the mudguard and the upper edge of the plate, or pass beneath the plate assembly and reach the rider’s back.
The Bonvent design addresses both main spray paths. An upper return helps close the gap between the mudguard and license plate, while a lower section extends the protection around the bottom of the plate assembly.
This does not turn a compact custom mudguard into a full touring fender in every riding condition, but it substantially reduces the direct opening that causes many conventional tail tidy systems to throw road spray toward the rider.
A Shorter Custom Seat Built on a Dedicated Bonvent Base
The original Bonneville T120 seat is comfortable and practical, but it is also long, thick and visually dominant. On a more compact custom build, the seat can make the rear section appear heavier than necessary.
For this project, Bonvent developed a complete replacement seat with its own dedicated base. The original Triumph seat does not need to be cut, reshaped or sacrificed.
The new base is slightly shorter than the factory version and follows the upper line of the motorcycle more closely. Its lower visual profile creates a cleaner transition between the fuel tank, exposed frame and short rear mudguard.
The seat shown on this motorcycle uses black diamond-stitched upholstery. Other planned finishes include black ribbed, brown, leather and additional material combinations for different Bonneville, café racer and refined scrambler projects.
The internal construction uses proper motorcycle foam rather than a thin decorative pad. The aim is to preserve real riding comfort while giving the T120 a more elegant and compact side profile.
The upholstery, stitching, foam and dedicated seat base are all treated as parts of one complete product. This is important on a premium motorcycle: changing the shape should not require accepting a lower standard of comfort or finishing.
Compact T120 Side Covers That Reveal the Original Frame
The build uses the Bonvent Triumph Bonneville T120 Side Panels.
The original Triumph side covers extend forward around the V-shaped frame area and meet the aluminium injector covers. They hide a large part of the structure and create a relatively enclosed centre section.
Bonvent developed a smaller side panel that sits more closely within the centre of the frame. Carefully positioned cut-outs allow the original cables and sheaths to pass without being compressed or awkwardly rerouted.
The reduced panel size leaves more of the T120 frame visible. This makes the motorcycle feel lighter from the side and gives the centre section a more mechanical, purposeful character.
It also changes the rear three-quarter view. Because the side covers no longer wrap around such a large area, the seat, shock absorbers and frame become more clearly defined.
Reinforced composite construction and mesh details
The side covers are made from lightweight glass-fiber reinforced composite, with a deep hand-finished gloss surface.
Three openings with mesh inserts add a restrained custom detail. The vents introduce a small amount of visual aggression, but their position and proportions remain consistent with the vintage lines of the Bonneville.
This is deliberately different from simply drilling openings into a panel that copies the original shape. The entire Bonvent side cover was redesigned around a smaller profile and the frame that it reveals.
These specific side panels are designed for the Bonneville T120. They should not be presented as T100-compatible unless a dedicated T100 version is confirmed.
A Low-Mounted Black Zard Exhaust
The motorcycle is fitted with a black Zard exhaust system for the Triumph Bonneville T120.
Its low-mounted routing leaves the rear wheel, side covers and frame more exposed. This works particularly well with the smaller Bonvent bodywork because the exhaust does not add another large visual element beside the seat.
The black finish continues the monochrome direction of the motorcycle and allows the machined aluminium, engine fins and small lighting details to provide the contrast.
Visually, the Zard system is extremely well suited to this build. Acoustically, it is not a discreet exhaust. On this particular motorcycle, the sound is strong and noticeably louder than the original system.
The exact sound level and road-use status depend on the specific Zard configuration, catalyst, removable inserts and local regulations. Riders reproducing the setup should identify the precise exhaust version rather than assuming that every Zard system has the same approval or sound level.
A Short Front Mudguard With a Vintage Profile
The front uses the Bonvent Triumph Vintage Café Racer Front Mudguard.
Many minimalist front mudguards are little more than thin, flat metal blades. They reduce the size of the original fender, but they often remove the shape and character at the same time.
The Bonvent mudguard is shorter than the original while retaining a rounded profile. Its outer edge rises slightly along the sides, creating a subtle border that gives the part more definition.
This small detail is particularly effective on a black motorcycle. Light catches the curved edge and makes the shape visible without introducing a contrasting colour or decorative trim.
The mudguard retains the original low-mounted position and uses the stock mounting structure. It therefore creates a cleaner front wheel area without requiring a universal support or permanent modification.
This front mudguard is suitable for compatible liquid-cooled Triumph models including the Bonneville T100, Bonneville T120, Street Twin, Street Cup and Street Scrambler, subject to the fitment information on the product page.
A Compact 5.75-Inch LED Headlight Conversion
The large original headlight assembly was replaced with a compact 5.75-inch LED headlight.
The smaller diameter opens the space between the fork legs and visually brings the front wheel, handlebar and fuel tank closer together. It creates a more compact cockpit without losing the classic round-headlight identity of the Bonneville.
The LED unit used on the build is E-marked and mounted on a dedicated Bonvent support designed around the Triumph front end.
A fork cover that hides the unfinished area
Removing the original headlight brackets leaves wiring and open space around the fork area. Installing a smaller lamp without finishing this zone can make the conversion look incomplete.
Bonvent therefore developed a dedicated cover that follows the fork tubes and closes the space behind the new headlight. The cover conceals much of the exposed wiring and gives the lamp a clean visual background.
The result is intended to look like one complete front-end assembly rather than a universal headlight attached to an otherwise unfinished fork.
Bonvent Bullet Indicators With Discreet Front Brackets
The front and rear indicators are Bonvent Bullet LED Indicators.
Bullet indicators are widely available, but products that appear similar in photographs can differ significantly in brightness, sealing, wiring quality, connectors and mounting hardware.
The Bonvent version was developed with a specialist manufacturing partner as a complete premium indicator rather than selected from a generic catalogue. The compact metal body, sleeved wiring, waterproof mounting protection and 3.5 mm bullet connectors are designed for repeated real-world motorcycle use.
The indicators are E-mark certified and provide a powerful light output from a housing that remains visually appropriate for a Bonneville, café racer, roadster or restrained scrambler build.
Indicators positioned beneath the fork
At the front, the indicators are mounted using the Bonvent Triumph Front Indicator Bracket.
Instead of positioning the turn signals on a clearly visible plate in front of the fork, the bracket sits discreetly beneath the front fork area. The mounting hardware is visually secondary, leaving the indicator body and motorcycle structure as the main elements.
The bracket is CNC machined and finished in matte black. It is compatible with selected liquid-cooled Bonneville T100, T120, Street Twin and Street Cup models.
Plug-and-play connections for the original Triumph loom
The Triumph Plug & Play Indicator Adapters connect the aftermarket indicators to the original Triumph connectors.
At the rear, the Triumph Rear Light and Indicator Wiring Adapter provides dedicated outputs for the tail light, brake light, license plate light, left and right indicators and an auxiliary 12V connection.
This avoids cutting, splicing or soldering the original Triumph wiring loom. The rear adapter also includes an inline diode arrangement designed to help prevent warning errors when the factory rear light is removed.
The Mini Speedometer Housing: Keeping the Triumph Electronics, Losing the Bulk
One of the most important components on this build is the Bonvent Mini Speedometer Housing.
The original Triumph twin-clock layout is part of the Bonneville identity. The speedometer and tachometer suit the motorcycle, and the factory electronics retain the warning lights and information expected from a modern liquid-cooled Triumph.
The weakness is the original outer housing. It is large, predominantly plastic and positioned relatively far forward from the handlebar. Once the headlight and indicators are made smaller, the standard instrument case becomes one of the most visually dominant parts of the cockpit.
Replacing the complete instrument with universal aftermarket gauges is possible, but it normally requires an electronic interface or conversion box. The installation becomes more complex, and depending on the selected gauges, some original information or warning functions may require compromises.
A complete replacement housing, not a decorative cover
The Bonvent solution keeps the original Triumph speedometer and tachometer electronics but replaces the complete factory plastic outer case.
The original electronics are transferred into a compact CNC-machined aluminium housing. A dedicated powder-coated mounting bracket then positions the twin clocks closer to the handlebar and fork area.
This preserves the familiar Bonneville twin-clock appearance while reducing the overall size, thickness and distance from the cockpit.
The original Triumph rubber anti-vibration mounts are reused. The instrument therefore retains the same basic vibration-isolation principle as the factory assembly rather than being rigidly attached to a universal bracket.
Designed for normal road exposure
A silicone gasket seals the two main aluminium sections. Breathable vent membranes on the underside follow the same general pressure and humidity management principle used by the original Triumph instrument housing.
The aim is to create a proper road-use enclosure for the original electronics, not an open decorative shell.
Optional Bonvent installation service
The housing was designed so that an experienced owner can transfer the original instrument electronics with normal workshop tools and the installation guide.
For customers who prefer not to open their original instrument cluster, Bonvent also offers an installation service for eligible European Union customers. The original speedometer can be sent to Bonvent, transferred into the aluminium case and returned ready to mount.
For riders in the UK, United States and other non-EU markets, remote technical support remains available, but the physical installation service is currently restricted to the EU to avoid customs complications when sending an original instrument cluster across borders.
A Higher Handlebar and CNC Bar-End Mirrors
A slightly higher and wider handlebar completes the riding position.
The change creates a more relaxed upper-body posture and gives the rider additional leverage compared with a narrower standard setup. It also visually broadens the front of the motorcycle, balancing the compact headlight and shortened rear section.
Any handlebar change should be checked at full steering lock. Throttle cables, clutch cable, brake hose, electrical wiring and the fuel tank must remain free from tension or contact in both directions.
The build also introduces new Bonvent bar-end mirrors machined from aluminium.
Fine lines in the mirror body reference the cooling fins of a classic motorcycle engine, while the Bonvent logo is integrated discreetly into the machined component.
The mirrors reduce the visual height of the cockpit and leave the space above the handlebar clear. Their material and finish also connect naturally with the CNC aluminium speedometer housing.
PARTS USED
Shop the parts used
Explore the model-specific Bonvent parts used to create this motorcycle.
Which Parts Also Fit the Bonneville T100 and Other Triumph Modern Classics?
Several components shown on this T120 build are also relevant to Bonneville T100, Street Twin and other liquid-cooled Triumph modern classic projects.
The Bullet Indicators are universal custom motorcycle components. The front indicator bracket, indicator wiring adapters and short front mudguard are compatible with several listed Triumph LC models. The Mini Speedometer Housing fits selected Bonneville T100, T120, Street Cup, Thruxton and Speed Twin 1200 models.
The compact side covers shown here are different: this specific design is made for the Bonneville T120.
The compatibility of the new seat, short rear mudguard, mini headlight kit and bar-end mirrors should be stated individually when their product pages are published. Similar-looking motorcycles do not always share the same frame, seat lock, wiring connector or mounting dimensions.
Bonvent products are custom motorcycle parts and accessories, not generic OEM replacement or spare parts. Each product page should therefore be used as the compatibility reference before ordering.
French-Designed Triumph Custom Parts for Worldwide Builds
Bonvent Motorbikes approaches custom motorcycles as a design and manufacturing project rather than a collection of one-off workshop improvisations.
The team develops parts around real motorcycles, original fixing points, wiring constraints and the visual relationship between each component. Bodywork, machined aluminium parts, brackets, upholstery and electrical adapters are designed to work as complete systems.
This approach is especially important on a Triumph Bonneville. The motorcycle already has a premium identity, so every modification must justify its presence through both function and finish.
Bonvent is based in France and ships custom parts internationally. Riders in France, the UK, the United States, Europe, Australia and other markets can use the same core components, while checking local requirements for lighting, exhaust noise, number plates and road inspections.
The objective is not to create a motorcycle that looks more modified. It is to create a Bonneville that looks more resolved.
Final Result: A Black T120 That Could Have Been Designed This Way
This 2024 Triumph Bonneville T120 custom build demonstrates the Bonvent philosophy clearly.
The short rear mudguard removes the visual weight of the original tail while preserving practical splash control. The shorter custom seat follows the motorcycle more closely. The compact side covers expose the frame instead of hiding it. The smaller headlight, discreet indicators and CNC speedometer housing transform the cockpit without removing the original Triumph identity.
The Zard exhaust, higher handlebar and bar-end mirrors add a more assertive character, but the motorcycle never becomes visually excessive.
From a distance, the build still reads as a classic black Bonneville. Up close, the redesigned proportions, machined details, concealed wiring and model-specific components reveal how much work has gone into it.
That is the result Bonvent looks for: a custom motorcycle that does not feel assembled, improvised or overstyled, but considered as one complete design.
Explore the current range of Triumph Bonneville T120 custom parts or browse all French-designed Triumph custom parts and accessories.
