- These are the Bearing Spacer(s) that fits between the two driveside main bearings on M30/M40 magnesium crankcase pre-Featherbed crankcases. These are to fit M30/M40 (i.e. pre Featherbed Manx) magnesium crankcase engines, as the bearing housing had a bigger width than aluminium crankcase spacers, therefore the distance between the two bearings is greater than that of International crankcases.
These spacers are machined from EN8 and CNC machined with oilway holes all the way around their circumeference - they look beautifully machined.
Rather than a single piece spacer, I had two slimmer spacers made - if fitted to standard magnesium M30 crankcases they both need to be fitted alongside each other. I made them as a pair, with a view that it may be possible to remove and possibly fit the wider International crank, although I have not tried this yet and cannot confirm conrod will line up in that configuration. They are sold to be fitted as a pair.