Single row ball bearing - Fitted to the outer of the two driveside mainshaft bearings in the crankcase on all SOHC engines, both International and early Manx.  This is the correct C3 (loose tolerence) type, from top quality manufacturer RHP.

Feb 2021:  Sorry to say, that just like all other SOHC RHP C3 (loose tolerance) bearings, these are now obsolete and we are down to our last handful of bearings we have been able to obtain.

Once this small stock has gone I fear we will either have to supply RHP non-C3 type or those from a lesser brand.

Single row roller bearing - fitted to the inner of the two driveside mainshaft bearings in the crankcase on all SOHC engines, both International and Manx models.  This listing is for the Non-C3 (standard tolerance) version of the high quality RHP brand, as the original C3 tolerance are now unobtainable. 

This roller bearing can be found in both lipped and un-lipped type, these are the un-lipped version.  It does not make any difference which type is fitted - but obviously you must ensure you fit the original inner mainshaft spacer in place - between roller bearing and ball bearing - and ensure the spacer results in the roller inner race sitting approximately central in the outer race (this can be done before assembling the crankshaft, by just placing the spacer in place on top of the ball bearing with the drive side crankcase lying flat, inner bearings sitting uppermost).  It is always good practice to have the roller inner race running as central as possible to the outer race, while ensuring their is some positive clearance between inner side of roller and flywheels, once the crank is locked to the timing bearing.

We also sell driveside mainshaft shims (Item 0262 and 0262b) for this purpose

Background on the difference between 'C3' fit and 'STD' fit bearings (these bearings are 'STD' fit):

If you have already looked at the detail description for Item 0019 (and if you have not already done so - we suggest you read the bearing background in that detail listing)- you will know that the original fitment in Norton SOHC engines was this same bearing - made by RHP or their predecessor - Hoffman, but in a looser 'C3' tolerance. 

These 'C3' fit bearings from RHP have been obsolete for many years and remaining supplies held by bearing stockits have been virtually used up in the last 15 years, with our last stock being sold in 2020.  Theye are now virtually unobtainable (although I may be able to obtain a small quantity by Special Order - but at an extremely expensive price) - but instead can still offer these RHP 'Non-C3' tolerance version.

These are still manufacutred to the same high quality by the original RHP manufacturer, but slightly more care should be taken when running in your engine after first fitting - to allow the bearings to bed in, as they will have a fractionally tighter tolerance than the C3 version.

However, I have also heard a counter argument from other well known Norton engine builders that says - as original Norton crankcases have nearly always had replacement bearings fitted over the years - so the crankcase journals start to loose their 'interference fit' tolerance, and therefore the need for fitting 'C3' type bearings also diminishes.  I can see the logic to this argument - particularly as many Norton original engines used to spin their bearings anyway, but I will leave the choice with you.  However, I know for my part - I will be fitting this bearing into any future engines I build for myself, and just ensure the crank spins freely and the journals are in good condition on engine assembly.

As a final point - many owners over the years did not know that Norton engines were originally fitted with C3 bearings (or sometimes called 3 spot bearings in older times - as sometimes the outer ring of a C3 bearing had 3 dots stamped on it) - so you may find that your engine has already been re-fitted with 'Std' tolerance bearings anyway, and the tolerance difference is minimal.  Normally if a bearing does not have 'C3' or 3 dots ground on the outer ring information, it is a standard bearing.

Sorry these are not cheap - but as at Feb 2021 these are now obsolete too and are getting just as difficult to source as the C3 type.  Therefore the price I am having to pay to source them reflects this.  Again - the supply is also very limited . . . and once they are gone they are gone! (the minimum batch quantity for RHP to make a new batch would be prohibitive for us).

We do occasionally get stocks of these bearings from cheaper (normally 'offshore') brands.  If you are prepared to use non-RHP brands, email us on sales@racingvincnent.co.uk and we can confirm availability - we normally have at least one of these cheaper bearings available in stock.

This listing is for the original fitment - Single row roller bearing in C3 size from RHP.  RHP are the top quality UK bearing supplier that originally made this bearing, and before becoming RHP were called Hoffman (which may appear on some original bearings when you strip your old engine down).

This roller was fitted to all SOHC engines, both International and early Manx, on the drive side and was innermost to the crankshaft.  This original 'C3' Version is a slightly looser fit than the standard tolerance bearing - as original crankcases were made to take these crankcases on an 'Interference' fit, and once they had been 'shrunk in', the bearing would still be easily spinning - important for a racing engine with minimum Run-In time available.

Unfortunately the original RHP type have been obsolete for many years and now unobtainable.  We have been sourcing the dwindling supplies for many years - but these have now dried up.

Therefore, these are now the options we can offer:

1. This bearing by Special Order : My bearing supplier does have access to a handful of the original RHP C3 still - and the price here is the Retail price they will be as at Febrruary 2021 (but this may change when order is placed). If you still wish to purchase one of these - place the order here as normal - we will confirm if the bearing is still available and if the guide price shown here is still correct.  We may require a deposit to commit on this item.  Sorry the price is horrendous - but that is the position with those original bearings

2. Still Fit a high quality RHP brand Roller bearing, but in Normal Tolerance (i.e. Non-C3) Size:  This is now the most logical solution for many owners, and the one I will be taking myself for future SOHC engines. This 'non C3' version is also obsolete, and the price of those left is also very high, but we do have a small quantity of these still available in stock (see Item 0019B).  These are still made by top manufacturer RHP - and just the same high quality, but you need to give a little more thought to 'running in an engine' when fitting this type, and maybe consider using 'bearing fit' compound when fitting them if your crankcase journal is getting worn - as so many original crankcases now are.  However, a counter argument I have heard said by knowledgable Norton engineers is - as the original 'Interference Fit' on the crankase journal gets reduced by successive bearing change - so the requirement for C3 bearing tolerances also dimishes!  I will let you decide.

3. Fit the Original Lipped Roller C3 Fit from a Cheaper Modern Bearing Manufacturer:  There are also some limited quantities of cheaper (normally 'Offshore' manufactured) versions of the original C3 type bearing.  Update Feb 2021: We are talking to our specialist bearing supplier about a small batch of these.  Email for details: sales@racingvincent.co.uk 

Single row ball bearing. Fitted to timing side Model 30/40 (International) SOHC engines, in correct RHP C3 (loose tolerence) type, from top quality manufacturer. Now obsolete and extremely difficult to source 

Feb 21 Update:  Like all original RHP main bearings, these are now obsolete and are not likely to be available again once current stocks have gone (I know, as we have consulted with RHP and cost for their minimum batch run for making the correct C3 type is prohibitive).

We have managed to source one last small batch of original new RHP C3 tolerance bearings - listed here, but once this batch has sold there may be no further stocks available.

However, we may be able to obtain 'Standard' tolerance (i.e. Non-C3) type in the future.

Timing Side SOHC Bearing - Background Information:  The aluminium crankcase SOHC version (i.e. CS1/CJ or Model 30/40 International) all used this single row ball bearing on the timing side.  However, magnesium crankcase M30/M40 and later Manx (both SOHC and DOHC) adopted a twin row ball bearing on the timing side - giving additional strength and rigidity and a fractionally narrower crankshaft.  Therefore before ordering these bearings - confirm that your SOHC engine is aluminium crankcase version.  If you have a magnesium crankcase version (i.e. M30/M40 Racing International or Manx) then you will require the twin row bearing which we also supply - Item 0021. 

Obviously, the twin row bearing is not interchangeable with the single row type (and actually is still occasionally being made - so is actually cheaper on our catalog than the single row shown here, even though it is bigger - sorry!).  

Single row ball bearing. Fitted to timing side Model 30/40 (International) SOHC engines.  These are from top quality manufacturer - RHP, but are in a standard (non-C3 tolerance), slighty cheaper than Item 0020.  Now obsolete and extremely difficult to source.

These are of the same RHP high quality as our Item 0020 (which is the looser tolerance 'C3' fit), and are the same bearing - but are in the normal 'Std' tolerance.  Norton SOHC engines were originally fitted with loose tolerance C3 bearings - but as most people know, the C3 are now extremely difficult and expensive to source, and these are slightly cheaper.  For many owners - a 'Standard fit'  bearing is fullly acceptable (and actually - some find their engines had been previously renewed with stanard fit bearings!), you just need to be aware and alllow a little more time for running in (remembering these were originally fitted to race engines - where running in could have been just a couple of laps!).

May 21 Update: 

Like all original RHP main bearings, these are now obsolete and are not likely to be available again once current stocks have gone (I know, as we have consulted with RHP and cost for their minimum batch run for making the correct C3 type is prohibitive). For these particular bearings - i.e SOHC International Timing side, as at this point, we have been able to obtain another small batch of 0020 (C3) fit bearings, but knowing they would quickly run out, we were also able to obtain a batch of these non-C3 fit at the same time . ... as both are now obsolete, we decided to get both types now, while we still can! 

Timing Side SOHC Bearing - Background Information:  The aluminium crankcase SOHC version (i.e. CS1/CJ or Model 30/40 International) all used this single row ball bearing on the timing side.  However, magnesium crankcase M30/M40 and later Manx (both SOHC and DOHC) adopted a twin row ball bearing on the timing side - giving additional strength and rigidity and a fractionally narrower crankshaft.  Therefore before ordering these bearings - confirm that your SOHC engine is aluminium crankcase version.  If you have a magnesium crankcase version (i.e. M30/M40 Racing International or Manx) then you will require the twin row bearing which we also supply - Item 0021. 

Obviously, the twin row bearing is not interchangeable with the single row type (and actually is still occasionally being made - so is actually cheaper on our catalog than the single row shown here, even though it is bigger - sorry!).  

- This is the Bearing Spacerthat fits between the two driveside main bearings on SOHC International 30/40 (and CS1/CJ))  crankcases

 These are to fit aluminium crankcase engines as fitted to all road bikes - if you have a magnesium racing engine - we sell the different spacers for those too - item 0656, which have  a different width.

These spacers are machined from EN8 and CNC machined with oilway holes all the way around their circumeference - they look beautifully machined.  They should be used in unison with the inner mainshaft spacer, item 0664

Note: in the photograph the item in the bag looks wet - this is duck oil to protect them in storage

- This is the inner bearing spacer that fits between the two driveside main bearings on International 30/40 and CS1/CSJ aluminium-crankcases engines - they are the 'normal' correct width to ensure the inner roller race of the innermost roller bearing should just be held central to the outer roller bearing race (but this should be checked as part of assembly) and should be used in conjunction with the corresponding outer spacer - Item 0663

These spacers are machined from high tensile EN24 steel and CNC machined 

SOHC engines can be found fitted with both lipped and non-lipped roller bearings on the innermost drive side bearing.  As the SOHC engine had its crankshaft 'locked' to the Timing side bearing (because of the bevel gears on that side), a small amount of 'float' on the roller bearing on the drive side is acceptable.

This inner bearing spacer fits between the roller and ball type drive side bearings - and when fitted in conjunction with item 0663 should give approximately 15 thou of clearance on the lip if a 'Lipped Roller Bearing' is fitted.  Likewise if a non - lipped roller bearing is fitted, the rollers should run relaively central to the outer track.  However, it is essential when assembling an engine for the first time with these spacers for the first time to confirm this is the case - as the engine was manufacutred for many years and there can be slight variations (or modifications made by subsequent owners. 

When assembling - I normally aim for approx 10-15 thou of side clearance between the driveside of the flywheel and main bearings, and for the roller bearing to be running close to central (and of course the inner part of the roller bearing will have a small amount of 'float'.

If you assemble the engine crank and bearings into the crankcases and it 'locks up' as the engine bolts are tightened - you may have 'negative' clearance', and not sufficient clearance on the drive side mainshaft.  If so - this inner spacer may need to be slimmed 

- 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. 

These are the inner bearing spacer(s) that fits between the two driveside main bearings on M30/M40 magnesium crankcase pre-Featherbed crankcases - they are used to provide the correct width between driveside ball and roller inner races - but this should always be checked on assembly, as their were minor variations over the years - as well as many orginal engines over the years having had small modifications or repairs carried out, requiring different width spacers to be fitted.

These spacers are machined from high tensile EN24 steel and CNC machined 

Rather than a single piece spacer, I had two slimmer spacers made for this model - 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. Therefore they are sold to be fitted as a pair, with a view to them being used with magnesium SOHC (racing type) crankcases and the corresponding (slimmer) M30/M40/pre-Featherbed Manx crank (which has less width than a Mod30/40/CS1/CSJ crank). 

SOHC engines can be found fitted with both lipped and non-lipped roller bearings on the innermost drive side bearing.  As the SOHC engine had its crankshaft 'locked' to the Timing side bearing (because of the bevel gears on that side), a small amount of 'float' on the roller bearing on the drive side is acceptable.

This inner bearing spacer fits between the roller and ball type drive side bearings - and when fitted in conjunction with item 0656 (outer spacer) should give approximately 15 thou of clearance on the lip if a 'Lipped Roller Bearing' is fitted.  Likewise if a non - lipped roller bearing is fitted, the rollers should run relaively central to the outer track.  However, it is essential when assembling an engine with these spacers for the first time to confirm this is the case - as the engine was manufacutred for many years and there can be slight variations (or modifications made by subsequent owners. Added to this - with any racing engine, years of use and rebuilds can mean they have had modifications made - so it is important to check for yourself these will give correct spacing and running clearance for your engine.

When assembling - I normally aim for approx 10-15 thou of side clearance between the driveside of the flywheel and main bearings, and for the roller bearing to be running close to central (and of course the inner part of the roller bearing will have a small amount of 'float'.

If you assemble the engine crank and bearings into the crankcases and it 'locks up' as the engine bolts are tightened - you may have 'negative' clearance', and not sufficient clearance on the drive side mainshaft.  If so - one of the inner spacers may need to be slimmed 

Twin row caged ball bearing. Fitted to Model 30M/40M (Manx) SOHC engines in original C3 looser fit, from good quality SNR manufacturer. 

This is the twin row bearing fitted to the timing side of SOHC magnesium crankcase M30/M40 (i.e. pre-Featherbed) Manx models.  It is different to the aluminium crankcase International models timing side bearing (which is only a single row bearing) - making the M30/Manx models stronger in this important area (which may explain why pre-featherbed M30/Manx magnesium crankcases are often found with the drive side crankcase damaged but timing side ok).

Original bearings had steel/bronze cages, but have not been available in that form for many years.  Modern versions of this bearing are now supplied with a nylon cage.  This is the correct looser fit 'C3' bearing as fitted to original models - but bear in mind the cage is nylon when soldering the whitworth screws over the bearing retaining plate - particularly if using a blowtorch, do not get the heat too close to the cage!

Update October 2019: These are a slightly cheaper brand of this twin row bearing than the SKF brand (Item 0022).  We have a small quantity of these SNR brand bearings, with the same C3 fit.  I spoke to my bearing supplier (a very experienced long term commercial supplier of bearings) who confirmed that these are also a good quality supplier - despite not having the same brand reputation as RHP/NSK/SKF etc.  I only have a limited quantity of these bearings left - but as sometimes the SKF version go out of stock, these are an alternative if you are less concerned about brand - construction and finish look virtually identical to the SKF version