What OIL in older bikes

[sparky]

I have done a complete rebuild on my Tri T100T 1967 and Im running on castrol oil (mineral) BUT, can I change to a semi synthetic when the run in period is over, some say yes others no, but what differece will it make as long as its not in the clutch, Your input would help please..Cheers all.

[Revband]

I have a Tiger 90 which I have fitted an external oil filter and used semi synthetic for quite some time now and find it is good, it seems to stay cleaner and lower consumption.

Some people say that you should only use the makers recommended oil, I consider this short sighted, if semi synth was available 50 years ago the makers would probably have recommended it, it is better oil.

[twolitre]

I would urge anyone with doubts about suitable oil to log on to http://www.realclassic.co.uk/techfiles/oil30319.html .
The document runs to five pages (if printed off) and contains a wealth of informed information about oils, additives and suitability, by Gerry Bristow who spent most of his working life in the oil industry.

I think that will answer your questions.
JIM.

[step2534]

Sparky,
 Ive a 1971 bonny and Ive been told to stick to 20/50 mineral oil. Apparently its better for the bearings, mine was running on synthetic but Ive had it serviced by a bloke who does nothing but classics and has 35 yrs experience and thats what he advised and what its now running on. Oil changes are every 1500 or so miles anyway so is there any benifit re using synthetic.   KEITH

[sparky]

Kieth, Thanks for your help, I was a triumph mechanic back in the sixties but oil and times change so I will stick with what I remember cheers .

[Goldie]

I use a 50 monograde in my 1950s Goldies as per manual, but there again multigrades were not on the market at that time.

Would they have reccommended a 20/50 oil in the 50s if available? Most probably.

[Revband]

Hi Goldie

I started using 20/50 in my B32 about a year ago, the bike is easier to kick over when cold, no more noticeable noise, no extra oil consumption, in fact no downside that I can find, I have also fitted an external cartridge oil filter.

I now only change the oil at 3000 miles instead of 1500 miles good 20/50 is cheaper than monograde and easier to obtain, all in all well worth the cost of the filter which hides underneath partially between the engine and gearbox totally out of sight unless you lay down and look for it.

[Malcolm G]

Beware of changes to oil, the makers are removing without notice ZDDP (zink) as it messes up cat converters, check the zink content of any oil you plan to use as old engines need it, most synthetic do not have it and even recomended oils has lost it. Check out the USA web sites regarding ZDDP to see the problems there having with pre 80's push rod V8's. A good brand is Penrite availabale in the Uk who add ZDDP but even they have started to reduce it on some blends.

[TBS]

Silkolene or Morris monograde 40wt.

[LJ.]

no more noticeable noise

What ever oil your using I'd want to investigate that 'noise' Don't use an oil to mask noises or problems. 

All my pre 1960 bikes use Castrol xxL 50 apart from one A10 that uses Castrol R40.