50 weight oil?

**nsrpaul** · 23rd January 2011, 08:17

hi guys

last time I had the matchy on the road castrol gp50 was cheep and plentiful, that was about 4 years ago, cant find it now for love nor money

the alternatives at the bike shop (spectro) are real pricey, any recomendations?

**Voltaire** · 23rd January 2011, 08:53

Oh no....an oil thread....
My understanding was ball/roller cranks used to 'require' mono grade oil as it " stuck to the balls/rollers better" ( sounds a bit wives taily....
That was the view on bevel ducatis.....

Now it seems to be " any good oil , just change it regularly"
Then you get " don't use car oils as it makes the slutch slip and is not suitable for air cooled motors"
Lately its been pointed out that Mobil make one " for air cooled V twins"...that is good....why being in V should make any difference who knows

Last time I got 50 it was from Super Cheap a few years back.....um Penrite or summit.
I have a litre of Castrol r on the shelf...smells nice.
Any filtration of just a sludge trap?

I'm picking up a Norton Commando from Blenheim on Friday....I need to look at oils and stuff.

**nsrpaul** · 23rd January 2011, 09:16

the harsh reality for me is my older bikes do buger all ks between changes so I'm not suer fussed
in the norton I run castrol gtx(20/50) its whats recomended in the norton manual (!), its cheap and sure its car oil but theres no gearbox or clutch to worry about so it will be fine

in the matchy (g3l) i used to run 50 weight because i always had and its what it was meant to take, again no gearbox and clutch combined with frequent changes so as long as its not red stamp from the wharehouse I would be quite happy (someone once told me it was watered down, couldnt convince them otherwise)
given the likely 500ks between changes reasonbly cheap is good
as they dont do many ks it tends to get fresh oil if its been sitting for 6 months or more

**Motu** · 23rd January 2011, 09:26

I'm using Castrol Edge Sport 25-50 in my airhead,it's aimed at the performance V8 market - 2 valve pushrod engines,so I reckon it should be ideal for 2 valve pushrod engines.I had a used oil analysis done on it,and it looks pretty good for the job.Cheap...at Supercheap.

**Flip** · 23rd January 2011, 09:50

Penrite do a straight 50 motor oil, but its expensive.

I use a valvolene 20W40 mixed fleet truck oil in almost everything these days. Being a truck oil it has a good strong detergent package and should keep all the crap in suspension until it is flushed out. Its also cheap and available to me at a significant discount.

Even the modern vintage oils are sooo much better oils that they were 50 years ago. Its been a long time since I have seen a scuffed piston or even a motor that was full of black crap when it was taken apart. Oil technology has kept up well with the motor development over the years.

Oh don't put synthetic oils in vintage motors as they are not compatible with the old seal materials like natural rubber cork and felt. it has also been suggested, but I don't know if I believe it keep also away from the low ash oils, SH and later again as the low metal detergents may not compatible with old seals.

It's been a while since there has been a good discussion about oils. There is a lot of misunderstanding about oils and what they do, a lot of it is perpetrated by the oil companies marketing departments.

**Owl** · 23rd January 2011, 11:55

Forbes & Davies distribute "Maxima Maxum 4 Classic", which is a straight 50wt oil. I don't know what the price is, but you should be able to get it through any bike shop.

**Blackflagged** · 23rd January 2011, 12:51

You can get Motul straight 50 .

**ntst8** · 23rd January 2011, 13:08

I've been using Penrite in my Nortons, coz Repco is just around the corner and will get the stuff in if they don't have it.
The most important bit is some oil is better than none, new is better than old.

**ntst8** · 23rd January 2011, 13:12

Originally Posted by Voltaire

I'm picking up a Norton Commando from Blenheim on Friday....

You should point it south and quietly ride down to the Norton Owners Club rally at Monowai the following weekend

**Voltaire** · 23rd January 2011, 13:23

Originally Posted by ntst8

You should point it south and quietly ride down to the Norton Owners Club rally at Monowai the following weekend

As its a bit of an unknown I just want to get it on to this side of the strait.
Looking forward to riding it up the country, hope the weathers better than this weekend.

**Motu** · 23rd January 2011, 14:00

Originally Posted by ntst8

I've been using Penrite in my Nortons, coz Repco is just around the corner

Repco's oil is now made by Penrite - so you can buy Penrite oil at Repco cheaper than you can buy Penrite oil at Repco.

**ntst8** · 23rd January 2011, 16:54

Originally Posted by Voltaire

As its a bit of an unknown I just want to get it on to this side of the strait.
Looking forward to riding it up the country, hope the weathers better than this weekend.

Yes the rally would be a brave move on an unknown machine, hope it goes well.

**ntst8** · 23rd January 2011, 16:56

Originally Posted by Motu

Repco's oil is now made by Penrite - so you can buy Penrite oil at Repco cheaper than you can buy Penrite oil at Repco.

Thanks, i had better read up the Repco spec sheets.

**pete376403** · 23rd January 2011, 19:57

Does the matchless have a roller bearing crank ? Iused to ride speedway bikes which are roller cranks, initially used castrol R40 because everyone else did, after discussing the engine and use with a Shell technical rep, switched to Shell Rimula X50 monograde which was far cheaper and the crank lasted just fine. (refer this thread http://www.kiwibiker.co.nz/forums/ar...hp/t-2656.html )

I assume Shell still market this product. Also, bevel Ducatis are supposed to use 50wt monograde, so a Duc dealer should be able to supply something