| Diagram | Fig. 5 — GEAR CLUSTER · ref 89 |
| Listed in parts books | 1969–1970 |
BSA Bearing, mainshaft (Hoffman 130)
A Hoffman 130 mainshaft bearing used in the gearbox gear cluster.
29-3857 is a mainshaft bearing, listed in the catalog as a Hoffman 130 type. It shows up in the gear cluster figures, which puts it right in the gearbox internals where the mainshaft needs a solid, low-friction seat to spin against.
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The catalog record ties this to appearances between 1969 and 1970, so it's a bearing that shows up in gearbox parts books from that window. We don't have a specific model listed for it, so if you're matching this against a particular bike's gearbox, check the physical bearing and its housing before you order.
The manufacturer field on this one says BSA, but the figure title and description point to a mainshaft bearing in a gear cluster assembly with no BSA model named anywhere in our records. If you're sourcing this for a BSA gearbox, confirm the fitment against your own parts book first — we can't vouch for cross-brand fitment without that model name in the file.
We've never carried this one. Tell us what you're after and we'll go looking — you'll get a price and photos before you commit to anything.
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