Potential impact of topping up Straight SAE with multigrade oil

[56G80S]

Just an idle thought.

My leakage/seepage reduced to very little and I'll take a small "top up" bottle of SAE50 with me to the IJR Diekirch. I just wonder what the effect would be of topping up with multigrade?

I'd think almost any oil is better than no oil, just drain and replace when home. From memory the G80S capacity is 4.5 pints and so even if a pint of multigrade is added it'll be heavily diluted. Although I won't be adding vegetable based oil, ha ha. That would mess things up.

I did a search but must've used the wrong terms.

Johnny B

[alanjennings]

John- not 50 grade-too thick!! I run all my old bikes on 20-50 for 40 years with no ill effects-but we can argue about oils till the cows come home! See you in Luxemburg soon! Alan j.

[jackstringer]

I follow the same logic, I see it as any lube is better than no lube.

I suspect there will be a wise one along to say they don't mix etc but if they mix ok, if they don't meh it will be ok. The issue I would have is if they make a new solution that is no good for the engine.

bwahahahaha,
https://addinol.de/en/products/lubrican ... grade-oil/

Can monograde oils and multigrade oils be mixed?
Due to the different properties of monograde and multigrade oil, we recommend that you do not mix the oils. Although mixing is possible, it makes no sense, as the oils drastically change their initial properties and viscosity, which can cause problems in the engine or transmission. If the mixed oil no longer lubricates as expected, engine damage may occur.

So they work ok its just that if it needs 10w40 and you mix some 5w50 then don't expect the engine to be happy about it. Then again I have an R100GS PD that makes use of a range of oils and if I swap oils I can't guarantee that I get 100% of the old oil out before putting in new.

[G15 Roy]

Hi John on some of my IJR trips I used so much oil I lost count of the different grades still got there and back.

[SPRIDDLER]

I did exactly that with my '54 G3LS on a 2 month 3,200 mile solo camping tour through France, Pyrenees, Spain, Andorra. I had been told beforehand that straight 50 was obtainable at agricultural merchants and tried a couple of times but without luck. I had completely rebuilt the engine (including new big end, mains etc) before leaving and changed back to 50 when home.
Incidentally, apart from adding oil the only thing I did was to adjust the rear chain.

Resting in Pyrenees.JPG

Marigold at St Emilion.JPG

[56G80S]

Well, it's always a hornets nest with oils, isn't it?

As for which oil usually, just not going there. I used Duckhams 20/50 in the early days but after a complete engine rebuild a couple of decades or more ago swapped to SAE30 winter/SAE50 summer as per the manual. I'd use multigade if I had a filter.

The quote from the oil company is fine but I don't reckon too important when topping up and taking a litre of SAE50 with me.

Sprid, attach a photo of my test load up. Had to move the top box back as I couldn't open the pannier lids, should've checked that first. further back than I'd wish but only putting bulky although light stuff in there like motorcycle cover, stoma kit, hi-vis vest, spare bulbs. weigh nowt. Just covered the old Townsed Thorsen sticker with a UK one. Reduced the pixels a bit too much for that pic.

Old style.jpg

Skinny lad fits.jpg

STOP PRESS - found the blow up bed! Was going to sleep on the self inflating mat.

Johnny B

[alanjennings]

With all that luggage onboard customs will think you are emigrating!

[39speedtwin]

20/50 is for engines with shell big end bearings and 30/40/50 monograde is for engines with rollers. In the 1950’s Duckhams 20/50 was specifically developed for motorcycles with shell bearings.

[griffin]

20/50 is for engines with shell big end bearings and 30/40/50 monograde is for engines with rollers. In the 1950’s Duckhams 20/50 was specifically developed for motorcycles with shell bearings.

Yes but with the twins we have shell big end bearings and roller main bearings so do we mix the mono with the multi ?......

[56G80S]

Oh dear, hornets nest as I first thought.

Alan, it's the tent etc in the rucksack. Clothes and spare, dry, riding kit, trainers, towel etc in the panniers, Soma kit and bike cover in the topbox. In the tank top I do have too many tools though (could do about everything except replace the crankpin) as well as spare cables, gaskets, inner tube, tyre levers, oil etc. Weighs a ton and tyre pressures increased accordingly. Can just get it on the Rob Swift centre stand. I don't have much avoirdupois at 75kg.

PS - thanks to Clive for his Slovenia post of trial load up, I would've been stuck if I hadn't followed his lead. I didn't fancy too much weight at the back and did fancy being able to get on more easily (leg over). Don't know how Clive managed with his rear "tower" though.

Johnny B