Tmax any Good?

[Bluebottle]

How do we know that mk2 was Japan made and the mk3 .....

Have a look at the the VIN number (frame/chassis number) it has a nationality code within it.

If the vehicle was made in Japan the number will have a two letters beginning with J
If it was made in Spain I think the code will begin with a V

Fairly sure Spain is V but many things are falling off the back of my memory these days
Knew them all off by heart once upon a time

[MrGrumpy]

MrGrumpy wrote
For me the mk3's standard screen was utterly abysmal (I'm 5'9"), but that problem was entirely cured by the addition of a Laminar Lip.

How much above the screen did you fit the Laminar Lip?[/quote]

I fitted it more or less as high as it would go, which actually meant that the top of the lip wasn't that much above the top of the screen say 1" or so. You don't need it to be high to be effective actually - with hindsight, I'd have fitted it slightly lower. Having it high makes it very quiet, but turbulence begins to creep back in at high speeds (80+), whilst lower its a little noisier, but keeps turbulence down. Or so the literature implies!

[MrGrumpy]

How do we know that mk2 was Japan made and the mk3 .....

Have a look at the the VIN number (frame/chassis number) it has a nationality code within it.

If the vehicle was made in Japan the number will have a two letters beginning with J
If it was made in Spain I think the code will begin with a V

According to my Reg document, the VIN of my mk4 starts with JYAS (as did previous Tmaxs), so by your info, I guess that means Japan.

Japanese quality control obviously isn't as good as it used to be - the mk4 is 18 months old, and the Centrestand is already rusting, both the legs and the bit at the top where its bolted to the chassis. The mk3's did exactly the same thing, but took around 9 months longer to do it!

[Bluebottle]

....You don't need it to be high to be effective actually......

I don't know if its any use to anybody and I've never studied that particular setup, but:

I think the purpose of the laminar lip is to create "jet" of air that effectively extends the screen. That is why it doesn't have to be right at the tip.

With that in mind, it should be most effective if it is slightly angled from the screen so that the biggest gap is toward the front and the smallest at the back edge.

That gives the air on the screen the idea of being "laminar" ( layered parallel to the screen) and the squeeze gives it a kick up the arse to speed up and shoot out beyond the screen screen edge. The oncoming air then treats this a an extra bit of screen.

I often see people angle the lip so that it is angled the other way and trying to kick the air higher but I think that will be less effective - but I'm going on gut feeling and experience, I haven't fiddled with that particular doodab.

(Notice that on the Givi airflow screens the top panel angles away at its bottom/front edge, to isn't parallel or "spoiler" fashion)

In the old days we would tape bits of wool all over to see what was going on, so if you've got time on your hands.......

On the noise side, more noise doesn't always mean more turbulence. Smooth air hitting your helmet might cause more noise if it now being concentrated into striking a join, edge or tight radius.

[MrGrumpy]

You can't change the angle of the Laminar Lip - you can pick what height to mount it, but you are stuck with that choice for ever....(or until it falls off, which ever is the sooner). I have the Bike-hps screen with variable flip-up on the mk4, you do get a choice of positions, which don't make a huge amount of difference!

[Bluebottle]

Sorry, it must be a different product I was looking at

[Globs]

On the noise side, more noise doesn't always mean more turbulence. Smooth air hitting your helmet might cause more noise if it now being concentrated into striking a join, edge or tight radius.

Yes, if it's a smooth hiss you are out of turbulence, if it's a blustery sound the screen is making is worse.

[irev]

A complete misrepresentation of what laminar flow, and how it is achieved is the product infamously described as a Laminar Lip - You CANNOT achieve laminar flow by altering flow that has already detached from the surface.

The reason turbulence exists in motorcycle screens is because of eddies and vortices from the detached flow, not the actual smooth (laminar) element. This is caused not by early detached flow but rather by incompetent design of the flow of the deflected air - The effin Wright Brothers had a better understanding of aerodynamics than Yamaha, based on a paper published in the very early 1900's.

In motorcycles, the proportion of crosswind component materially affects the mean effective flow propagation rate - or in simple terms, you get smooth flow when the airflow takes the least deviation from the angle of the screen but it's physically impossible to achieve laminar flow with the current pathetic aerodynamics of every modern two wheeler and the inability of the screen to take a laminar angle to the `apparent` airflow, especially when rate-variation is considered.

But never let physics get in the way of a good story... Noah built an ark, all the animals trooped in, and Hollywood make a film about it = Must be true.

[MrGrumpy]

A complete misrepresentation of what laminar flow, and how it is achieved is the product infamously described as a Laminar Lip - You CANNOT achieve laminar flow by altering flow that has already detached from the surface.

Well, their science may be complete fantasy, but it worked brilliantly on my mk3 Tmax!

[Globs]

A complete misrepresentation of what laminar flow, and how it is achieved is the product infamously described as a Laminar Lip - You CANNOT achieve laminar flow by altering flow that has already detached from the surface.

The air flow up a windscreen has not detached until AFTER the lip.