| Diagram | Fig. 30 — A70 MODEL — Except for the following, all other items are as A65 Lightning · ref 3 |
| Listed in parts books | 1972 |
BSA Shell bearing — connecting rod big-end (·030" undersize)
A ·030" undersize big-end shell bearing for the BSA A70 connecting rod.
This is a big-end shell bearing machined ·030" undersize, for the connecting rod on a BSA A70 engine. The catalog entry ties it to the A70 model, noting that apart from a handful of listed exceptions, the A70 shares its parts with the A65 Lightning.
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A big-end shell bearing sits between the connecting rod and the crankpin, letting the rod ride on the crank under load. The ·030" undersize designation means it's ground for a crankpin that's already been machined down from standard, which typically comes up after a regrind following wear or a rebuild.
We only have this part tied to a single catalog listing from 1972, so if you're sourcing this for a rebuild, check your crankpin's actual measured diameter against what this shell is ground for before you order, and call the shop if you want us to confirm fitment.
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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