All BSA crankshafts are welded, ground, nitrided and balanced to your requirements. Customer must supply donor crank (flywheel not required) and weight of one piston, rings, wrist pin, circlips, connecting rod. Bearing shells are supplied. BSA offsets only available in 90 degree configuration but other offsets available upon request including standard 360 degree crankshafts with lightweight welded flywheel. Drive side journal is offset behind the timing side journal in the direction of crank rotation to assist users in finding custom camshafts. Pre-unit BSA cams can be modified to match specified crankshaft but we recommend using a special cam from www.srm-engineering.com for unit BSAs and large displacement engines. Large displacement engines should also be modified for roller bearing timing side conversion (SRM Engineering or British Cycle Supply at www.britcycle.com) or a high-pressure oil pump can be used with standard timing-side bearings. Cam modification diagrams are available at no additional charge. An oil filter must be used with all crankshafts. All cranks are lighter then stock as well as having less inertial weight for faster acceleration. Unit and pre-unit cranks balanced to 50% unless other balance factor specified by customer. Cranks can be supplied with timing side at 30mm for roller bearing or for standard BSA timing side bushing.