This set of (4) standard big-end shell bearings is suitable for fitment to the large-diameter BSA A10 models from 1958, as well as the A50 and A65 unit-construction models through 1972.
Manufactured in the US by Mahle/Clevite, these top-quality shell bearings are intended for fitment to the BSA twin models with standard condition 1.6865″-1.687″ crankpin journals. The original Glacier designation is B2046M.
The correctly sized connecting rod bearings are critical in maintaining sufficient oil pressure throughout the lubrication system. Connecting rod journals must be machined to undersized dimensions and corresponding undersized shell bearings fitted when wear on the journals becomes excessive.
The crankcases must be parted to access the crankshaft and connecting rods for rod bearing replacement. This procedure is outlined in the factory workshop manual and must be followed carefully. Plastigauge is useful for measuring clearance between the assembled connecting rods and the crankpin journals.