| Diagram | Fig. 10 — CLUTCH AND PRIMARY COVER · ref 11 |
| Subsystem | primary |
| Listed in parts books | 1970–1971 |
BSA CLUTCH DERBY,TR25W/B25
A BSA clutch pressure plate (Derby type) for the TR25W and B25, part number 57-4019.
This is a clutch pressure plate listed for the BSA TR25W and B25 machines, appearing in the parts book under the CLUTCH AND PRIMARY COVER figure. The plate is part of the clutch stack that clamps the friction plates together, so it lives inside the primary case where the clutch assembly is housed.
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The canonical description ties this part specifically to the TR25W and B25 designations, and the catalog record only shows it appearing once, in 1970. We don't have more detail on this one beyond that, so if you're working on something outside those two model designations, give us a call and we'll confirm before you order.
Since this is a BSA part and not a Triumph part despite showing up in a Triumph-numbered catalog, don't assume Triumph clutch components are interchangeable with it.
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