| Diagram | Fig. 17 — TWINSEAT — CHAINGUARD — SILENCER · ref 1 |
| Subsystem | primary |
| Listed in parts books | 1971–1972 |
BSA Twinseat
A BSA twinseat, PN 83-3633, cataloged for 1971–1972 machines.
This is the twinseat listed under BSA part number 83-3633, showing up in the catalog under the TWINSEAT — CHAINGUARD — SILENCER figure group for the 1971–1972 model years. It's a BSA part, not a Triumph one, despite living in a Triumph-heavy parts room — the catalog record ties it specifically to that era of BSA production.
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A twinseat is the two-up saddle that sits over the rear frame section, covering the seat pan, foam, and cover as one assembly. On these machines it's a bolt-on unit that comes off with a couple of fasteners to get at the electrics or battery tucked underneath.
Our record on this one is brief, just the description and the figure title, so if you're trying to match it to a specific BSA model or seat pattern, call the shop and we'll confirm fitment before you order.
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