| Also known as | T4186 |
| Diagram | Fig. 5 — CLUTCH AND PRIMARY CHAINCASE · ref 27 |
| Subsystem | primary |
| Listed in parts books | 1971 |
CENTRE-CLUTCH B25 B44 B50
Centre-clutch component for the BSA B25/B44/B50 singles, also listed in Triumph parts books for the 1971 Triumph 250 TR25W.
This is the centre clutch component listed for the BSA B25, B44, and B50 singles, and it also shows up in our Triumph parts books tied to the Triumph 250 TR25W for 1971. It sits in the clutch and primary chaincase assembly, part of the shock-absorbing clutch centre that takes up drivetrain snatch between the primary drive and the gearbox.
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The older book reference for this one is T4186, so if you're working from an earlier parts list and see that number, it's the same physical part as 57-4186. Our own catalog doesn't give a BSA-side year range for it, only that it's called out for those three BSA models, so if you're sourcing for a specific BSA machine, check your own parts book or give us a call to confirm the year lines up.
Because this part crosses between two marques that shared some drivetrain components in this era, it's worth double-checking the number stamped or listed on your own machine's parts diagram before ordering, particularly if you're not sure whether your bike uses this centre or a different one from the same clutch assembly.
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