SOHC Model 30M (and 40M) and DOHC Manx Big End Assembly (No Nuts)

Product no.: 0072 A11M/27

In stock

Recommended Retail Price, plus delivery

Manufactured by a well established British bearing supplier, these twin row caged roller bigends are made as per the original design (Like the International variety, I use them in my own bikes).

Fitted to Model 30M (Longstroke Manx type) SOHC and Pre 1962 (non-lipped) DOHC Shortstroke Manx's, i.e. those with magnesium crankcases - these Bigends are narrower than the 500cc Norton International Bigend assemblies we also sell (Item 0071), which can be seen in the second photograph for comparison.  The Manx crank was slightly narrower than the Inter crank, to allow for the fitting of a twin row bearing on the timing side crankcase.  If you are unsure which type of BigEnd you reqire - email us on

We have also found that many 350cc magnesium crankcase M40/Manx models use the same Bigend - but the nuts can vary, and some early models look to have used smaller 42mm nuts (which we normally also keep a couple of in stock) - again email us first to confirm if you have one of these models, before placing order.

Note: These Manx type Bigend units are supplied without nuts (that is how they come to us, hot grease dipped - as different nut types are used on different model years). Earlier Manx Bigends (all SOHC\DOHC magnesium cased pre-featerhbed engines and earlier Featherbed engines) used large 47mm AF Hex Nuts. Later shortstroke DOHC engines used castellated nuts.

We can supply both 500cc Nut types - Hex nuts being Item being Item 0072B and the castellated nuts being Item 0072C. If you are not sure if your flywheels should be using Hex nuts - look for the 'Mickey Mouse ear' cutaways, for grub screws (see 3rd photograph), which signify it was fitted with Hex nuts. Wherever possible, if the engine was fitted with these larger nuts, you should try and refit them, as they provide a larger surface area than castellated or International nuts.  Email us if you have a 350cc Manx crank, to confirm nut size before ordering.

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