Fairing vs no fairing...

Guzzi's Spada fairing was indeed developed in the firm's wind tunnel,
but was designed for protection and comfort, not speed.

It worked - brilliantly. But a Spada was faster if you took it off....

BMW's ground-breaking R100RS fairing was also wind tunnel-developed.
Again, the aim was protection rather than speed. The BMW also used the
fairing as an aerodynamic "crutch", increasing high-speed stability.

Actually, I reckon that the old RS fairing was decades ahead of its
time. I think you have to look at the Hayabusa before you see
equivalent attention paid to aerodynamics - except that in the 'Busa's
case, the objective was indeed speed.

As for Hailwood's Duke - I dunno if it made it faster or not. I doubt
it. It was rather unsophisticated.

 

No. It won't. Not a ShiteOld1980s fairing, anyway.

For a start, it will accelerate *worse* because you've got the extra
weight of the fairing and all its mountings, so you have a worse
power/weight ratio, and secondly, fairings from that era simply didn't
add anything to top speed. At least, not on road bikes.

On bikes from the 1970s and 1980s, and right into the 1990s, low
frontal area mattered more. That was one reason why Ducatis and
especially Laverdas managed to go as fast as they did on not a lot of
power. A Jota managed 140+mph on a claimed, repeat *claimed*, 90bhp,
and that measured at the crankshaft.

If you ever look at a Jota head-on, you wonder where the engine is,
it's that narrow.

The guy who really knows, actually, is M J Carley, as he did some
interesting tests at Bristol for some thesis or other. He was testing
modern machines. He appealed for volunteers here, I think, and I
daresay a good Google will turn up the details.

 

Gotta say I would be surprised if the R100 doesn't get some speed
benefit from the RS fairing but not a lot I suspect

'Hog

 

On 11 May 2005 09:00:40 -0700, "TOG@toil

This is obviously true of any faired bike, right up to the point where
the improvement in reducing wind resistance provided by the fairing
(if any) starts to work.

It should perhaps be noted that Kawasaki were the only jap
manufacturer to have their own wind tunnel in the 80s and into the
90s, and this shows with bikes like the first ZX10 and, more
significantly, the ZZR1100, which was obviously wind tunnel designed
to go Very Fast Indeed.

 

Which proved the point, like the Hyabusa, the go fast can look fecking
horrible

'Hog

 

That's right. Those two were the first bikes I can think of where about
as much attention had been paid to the aerodynamics (in terms of making
the thing go Very fast Indeed) as to the engine.

And even then, it was a while before the opposition caught up. The
CBR1000 wasn't in the same league. I suppose we had to wait until the
Blackbird before we saw anything as well-designed, and then the 'Busa
moved things on further.

I didn't know that Kawasaki were the only Jap firm to have their own
wind tunnel, though. I suppose it comes from the aerospace division, or
is it specifically for the bike business?

 

I think frontal area is again the problem - that's a hell of a large
lump to punch through the air.

And the RS never as fast as the (bikini-faired) R90/S, anyway. As you
say, though, the difference, if any, would be minimal. RS true top
speed.... what? 120-plus? R90/S 125-plus?

 

TOG@toil says...

It's all irrelevant cos everyone knows BMWs won't get to top speed
before they break down.

 

Yeah about 125 restricted by gearing on the RS and really I think the
R90S is more urban folklore

'Hog

 

Every silver lining has a cloud.

--
| ___ Salad Dodger
|/ \
_/_____\_ GL1500SEV/CBR1100XXX/KH500A8/TS250C
|_\_____/_| ..75073../..18420.../..3184./.19406
(>|_|_|<) TPPFATUICG#7 DIAABTCOD#9 YTC#4 PM#5
|__|_|__| BOTAFOT #70 BOTAFOF #09 two#11 WG*
\ |^| / IbW#0 & KotIbW# BotTOS#6 GP#4
\|^|/ ANORAK#17 IbB#4
'^' RBR Landmarks: 12 Pts: 220 Miles: 914

 

Good enough for me. You couldn't get much more authoritative than JR,
God rest his soul.

He was a helluva rider, as well. I have happy memories of haring after
him on a BMW launch, never managing to get past him, but always on his
tail, and ditto on the GPX750 launch at castle Combe, where we diced
for lap after lap.

I'm convinced that the only thing that prevented him from losing me and
buggering off into the distance was the presence of a brake light. I
remember that I'd watch for his brake light to come on, on both road
and track, and reckon that while was good, he wasn't *that* good and
there had to be a margin of error. So I'd leave my own braking
fractionally later.

The possibility that he might cock the braking up entirely never
entered my mind. Of course, he didn't.

 

I liked my old VFR 750. I didn't much like the VFR800 that replaced it
after the 750 got nicked.

Which is why I traded the 800 in for a fireblade (without
authorisation from my financial controller which lead to some extended
frosty silences).

The Blade I did like - a lot. But my wrists and shoulders didn't like
it hence the current old farts bike (that I also like a lot).

Phil