Subjective, I know..

[PWM]

Ordinarily, I wouldn't ask a question about oils, but this bike warrants it.

Cold, all smooth changes. Summer temps hot engine, kind of metallic feeling.
I've always used semi oils, (of the 35-40£ 5L range ) road or track bikes, and halfords own in the diesel van.

So, I'm wondering - and I know this engine was designed on semi's - have others used a full mineral oil,
and noticed anything nicer about it? Is that metallic feeling lost, or just a characteristic of this box?

[Mister Fishfinger]

If it's any consolation, mine is a bit like this. Nice and slick when cold, I don't even get a 'clunk' going in to first.

When it's hot it seems to need a firm foot, and the change just doesn't feel so nice. And going into first from neutral it sounds like an accident in a saucepan factory.

I don't worry about it though. I just figure the bike has a lot of torque, so Suzuki went a bit Massey-Ferguson on the gearbox design. And on the plus side, with all that torque you don't need to change gear so much anyway.

[PWM]

If it's any consolation, mine is a bit like this. Nice and slick when cold, I don't even get a 'clunk' going in to first.

When it's hot it seems to need a firm foot, and the change just doesn't feel so nice. And going into first from neutral it sounds like an accident in a saucepan factory.

I don't worry about it though. I just figure the bike has a lot of torque, so Suzuki went a bit Massey-Ferguson on the gearbox design. And on the plus side, with all that torque you don't need to change gear so much anyway.

Thanks bud, it kinda feels like that's the way it is supposed to be, but you have to ask. I know when stuff gets fully hot the oil is thinner too.  I still might try some full mineral, dependant on any feedback from others..

Regards the torque, you're right....

But I'll see how a set of St-1's improve on that ;-).  ( and I said I wouldn't modify this bike )

[gsxbarmy]

Subjective - as you said in the heading.

I don't want to start (or get into) a "this oil is better than this one" or "I use this oil because its cheaper at..." type thread, but what I will say is that it might be a question of trying different oils to find out what suits you, as guaranteed - especially on this forum  - there will always be a host of opinions.

For instance - here's 5 pages of views 
http://gsx1400owners.org/forum/index.php?topic=17.0

My personal choice was always Silkolene, however I did also find other contributary factors as to the "clunk" in first gear such as how tight (or loose) your chain was, clutch adjustment, cleanliness of the clutch push rod, how good the clutch fluid was, how well your chain was oiled and did it have tight spots, how good the gearbox sprocket was etc etc.

Regards semi or fully synth - a very debatable question, again with many views, never tried it myself, however I'd be wary of using a fully synth on a clutch which is used to semi synth as  arguably it could (note only could) cause some clutch slip (no doubt I'll be shot at dawn for that comment..... )

Doesn't answer your question - but not sure you'll ever get a straight answer either.....

[PWM]

Subjective - as you said in the heading.

I don't want to start (or get into) a "this oil is better than this one" or "I use this oil because its cheaper at..." type thread, but what I will say is that it might be a question of trying different oils to find out what suits you, as guaranteed - especially on this forum  - there will always be a host of opinions.

For instance - here's 5 pages of views 
http://gsx1400owners.org/forum/index.php?topic=17.0

My personal choice was always Silkolene, however I did also find other contributary factors as to the "clunk" in first gear such as how tight (or loose) your chain was, clutch adjustment, cleanliness of the clutch push rod, how good the clutch fluid was, how well your chain was oiled and did it have tight spots, how good the gearbox sprocket was etc etc.

Regards semi or fully synth - a very debatable question, again with many views, never tried it myself, however I'd be wary of using a fully synth on a clutch which is used to semi synth as  arguably it could (note only could) cause some clutch slip (no doubt I'll be shot at dawn for that comment..... )

Doesn't answer your question - but not sure you'll ever get a straight answer either.....

You're right, I won't... i was kinda asking about full mineral vs the semi/full synths ;-)

And it wasn't the donk/clunk of first gear - my k6 supersport has more of a donk than this one - rather just the metallic feeling when hot..

but I might be lucky and someone come along and say "well I put in a full mineral and noticed......... ( maybe even fcuk all!)"

[seth]

As already said oil is such a subjective subject.
My 5p worth is this I use semi synthetic oil as that what the manual says it would be .
I get mine from Halfords because it up to spec and comes in 5 liter containers (you need 4.8ltrs for a full oil and filter change).
Feel free to use what ever oil you like but final thought is a friend used mineral oil top spec stuff from his work in his Kawasaki zrx1100 he had to replace the cams at 35000.

If you going to fit the yoshi cams I wouldn't use mineral oil .
My 14 with the cams in has done 50000 with them fitted and they still look like new .

[PWM]

If you going to fit the yoshi cams I wouldn't use mineral oil .
My 14 with the cams in has done 50000 with them fitted and they still look like new .

Well, with that respect then, I'll stick with the semi's and the metallic feeling gearbox is just what it is..

question answered.

[Andre]

My take on this is that if you want an oil that makes gear changes more smooth you chose the one with the most viscosity improvers (VI additives) in it. These additives are large molecules that gives the gearbox something to chew on. Think of clacking your teeth. Sounds different with a full mouth of porridge

The most VI additives you get with low grade base oils (mineral oil). Full synthetics don't need much of these, semi are between. Unfortunately the gears grind these additives to bits in short time. So the benefit decreases. And then you have a 10w-30 instead of a 10w-40 after a couple k.

As to semi-synthetic. A few drops of synthetic oil in mineral oil allows the manufacturer to call it semi-synthetic. I suspect there is a broad range of quality in semis.

Wet clutches are not a primary concern with engine oil. For the wet clutch they put less friction modifiers in according to the MA classifications. Synthetic oil (with MA specs) does not cause clutch slip. What does cause the slip when switching to full synth (according to Suzuki dealer) is the cleaning power of synthetic oil. It loosens the sediments typically seen in various non-critical corners when using mineral oil. These then get between the clutch plates. When switching to full from semi I did not experience slip at all.

After putting new ball joints (originials were silly worn) and a metal bearing (instead of the worn plastic one) I noticed much improvement. Still a bit scratchy though. This disappeared completely after I replaced the gearshift shaft, cam plate (both worn) and return spring.

[PWM]

My take on this is that if you want an oil that makes gear changes more smooth you chose the one with the most viscosity improvers (VI additives) in it. These additives are large molecules that gives the gearbox something to chew on. Think of clacking your teeth. Sounds different with a full mouth of porridge

The most VI additives you get with low grade base oils (mineral oil). Full synthetics don't need much of these, semi are between. Unfortunately the gears grind these additives to bits in short time. So the benefit decreases. And then you have a 10w-30 instead of a 10w-40 after a couple k.

As to semi-synthetic. A few drops of synthetic oil in mineral oil allows the manufacturer to call it semi-synthetic. I suspect there is a broad range of quality in semis.

Wet clutches are not a primary concern with engine oil. For the wet clutch they put less friction modifiers in according to the MA classifications. Synthetic oil (with MA specs) does not cause clutch slip. What does cause the slip when switching to full synth (according to Suzuki dealer) is the cleaning power of synthetic oil. It loosens the sediments typically seen in various non-critical corners when using mineral oil. These then get between the clutch plates. When switching to full from semi I did not experience slip at all.

After putting new ball joints (originials were silly worn) and a metal bearing (instead of the worn plastic one) I noticed much improvement. Still a bit scratchy though. This disappeared completely after I replaced the gearshift shaft, cam plate (both worn) and return spring.

Now that's what I was looking for. You can always rely on a German? to be thorough and to the point.

Scratchy, yeah that's the best term to describe it.  I want to get rid of some of that scratchyness. I shall investigate your points.
( and I generally don't go beyond 2k for oil changes on road bikes )
Thankyou.

[Sweaty]

No issue here either, when changing from semi to full synthetic.

[Andre]

You can always rely on a German?

Good you put that ? at the end of the sentence!

[PWM]

You can always rely on a German?

Good you put that ? at the end of the sentence!

well, it was even odds ;-)