Custom Triumph Bobber Guide: Generations, Parts and Documented Builds
The references listed below support the regulatory, safety, and manufacturer statements in this guide. Any dollar figure is an editorial planning estimate based on typical scope, not a quote and not taken from those references, unless a current official price is explicitly cited at that point in the text. Confirm fitment, safety, legality, availability, and current pricing for your exact vehicle before you buy or commission work.
A custom Triumph Bobber usually starts from Triumph's factory Bonneville Bobber, a 1200cc twin sold as a solo-seat bobber since the 2017 model year. Because the factory bike already has the stripped-back look, most custom work changes the stance, controls, lighting, seat and exhaust rather than cutting the frame. The generation matters: parts listed for one Bobber do not automatically fit another.
Prices and model details below were checked October 19, 2026. For the style itself, see what a bobber is and the best bobber motorcycles; to compare it with other custom styles, see cafe racer vs bobber vs scrambler.
Identify The Bobber Generation First
A 2025 Triumph Bonneville Bobber, identified by the photographer, showing the factory solo seat, exposed frame area beneath it and 16-inch wheels. It is a stock reference, not one of the custom builds below.
2025 Triumph Bonneville Bobber by PackMecEng · CC0 1.0. Resized by Wikimedia; no crop or other editorial edits.
| Generation | What changed | Why it matters for parts |
|---|---|---|
| 2017–2020 | Launched as a single-seat Bonneville with a 2.4-gallon tank, a 19-inch front and 16-inch rear wheel and an adjustable solo seat (Cycle News first ride). | The small tank limited range to little more than 100 miles in Cycle News's test. |
| 2021–2025 | A 3.2-gallon tank, 47mm forks, a 16-inch front wheel and twin front brakes (Triumph's 2021 model page). Euro 5 exhaust changes arrived from 2021. | Some exhaust parts do not fit Euro 5 bikes where the mid-pipe is welded to the catalytic converter. |
| 2026 | A 3.7-gallon (14-liter) tank, a wider floating seat, new aluminum rims, cornering ABS and traction control (Triumph media kit). | No aftermarket part we checked lists 2026 fitment yet; confirm before ordering. |
Triumph's current US Bonneville Bobber page lists the 2026 model from $14,795 with the 1200cc engine (77 hp, 78 lb-ft). Triumph also sold a limited Bobber TFC, announced in December 2024 at $18,495 for 750 numbered bikes; some parts, such as the seat below, exclude it.
Record the year, VIN and any previous modifications before buying parts. Two-up riding is not an option on the stock Bobber; Triumph's Speedmaster uses the same engine with an optional passenger seat.
Two Documented US Builds
British Customs: Postwar Bonneville Bobber
British Customs in Gardena, California built a deliberately light custom from a 2019 Bobber, posted June 2021. It fitted a low 7-inch headlight, a pan tail light with retro LED turn signals, a fat handlebar kit, new levers and a gel seat, with paint by Anaheim Rod & Custom. It shows how far bolt-on parts and paint can move the look without frame work.
Glory Motorworks: Girder Fork And Hardtail Strut
Glory Motorworks in Ventura, California modified a 2023 Bobber for a film production company. It fitted a hydraulically damped girder fork from Voodoo Vintage, replaced the rear suspension with a solid strut, and changed to 19-inch front and 18-inch rear wheels. That is a major chassis change: it alters ride, handling and parts compatibility, and should be engineered and checked by a qualified builder.
Parts With Stated Fitment
These British Customs prices were checked October 19, 2026. Fitment is as the seller states it.
| Part | Price | Stated fitment |
|---|---|---|
| Solo Gel Seat | $425.44 | Bobber 2016–2025 and Bobber Black 2016–2020; not the TFC |
| Sleeper Pro slip-on exhaust | $827.94 (sold out when checked) | Bobber 2016–2025 |
| Turn Out performance tips | $402.44 | Not for Euro 5 bikes with a welded mid-pipe (some 2021 and later) |
| Retro handlebar kit | $287.44 | 1-inch bar for the Bonneville Bobber; model years set by the seller's selector |
| Pan tail light | $241.44 | Listed in the Bobber collection; no years given |
Triumph's own Bobber accessories include ape-hanger bars with a cable kit, a comfort seat, forward controls and footboards; the US page shows no prices, so ask a dealer.
A parts subtotal is not a build price. Add installation, any cable or wiring changes, lighting compliance for your state, paint and a final safety check. The bobber build cost guide and the project brief help turn the list into a quote.
Riding And Comfort Checks
Find A Triumph Builder
Compare shops with documented Triumph work in the Triumph Bonneville builder directory, or the motorcycle builder directory for wider searches. The Triumph cafe racer guide covers the same engine family in a different style.