Quick view SB Mini Engineering Weld on Jackshaft Plates - Fits Bonanza 3-5/8" wide x 3" tall. 1-3/8" bearing bores, 5/8 swing arm/scrub brake holes, 11/32 hole. These need to be welded on to your bike. Correct for most Bonanza BC series bikes. Made in U.S.A $24.95 $16.95 Add to Cart