Hitchcocks Forum

For road riding and to not detract too much from the original design of the bike, the speedflow screen would still be much better than no screen - basically, pretty much any screen is better than none.

I think it was the "airflow" enfields. There was an article in the REOC magazine a bit back. When they came out they were advertised as being tested in a wind tunnel, which they were, but they caused a net increase in the aerodynamic drag of the bikes.

stinkwheel wrote: ↑

Tue Dec 01, 2020 6:45 pm

I think it was the "airflow" enfields. There was an article in the REOC magazine a bit back. When they came out they were advertised as being tested in a wind tunnel, which they were, but they caused a net increase in the aerodynamic drag of the bikes.

Who was sitting on it? Giant Haystacks?

https://www.royalenfields.com/2016/03/r ... -test.html

stinkwheel wrote: ↑

Tue Dec 01, 2020 7:34 pm

https://www.royalenfields.com/2016/03/r ... -test.html

Yeah, that's spectacularly bad - it looks like a 'how-not-to'

I understand that this thread isn't about the Airflow fairing - but as someone who rode a Crusader fitted with one in the 1960's I can say that they looked far better than you'd think when fitted to a brand new Crusader (I realise that this is a time-related assessment - I mean we'd not seen the sleek things that came later).

Also its weather protection was legendary. In use it made litter difference to the speed of the bike - one up or two up. Far better from that point of view than the Avon touring fairing. Weather protection as good if not better than the Ariel Leader!

I know looking back from here these bikes seem quirky and hopelessly unglamorous - but in their time they were fine machines - Ariel 250's and the Crusader in all its forms were by far the best of the British 250's of their times.

Then came Yamaha and Suzuki and Honda - but none offered bikes to fill that 250 tourer gap. And no one ever has - maybe except the T10 Suzuki. Oh dear - nostalgia creeping in - time for a cup of tea!

As far as fairings go, the faster a bike could go, the more beneficial a fairing might be. An example might be a pair of totally standard 350 and 500 Bullets. Let's say the 350 might have a top speed of 70 mph and the 500 80 mph. Put identical fairings on both machines and the 500 will probably show the more marked improvement for top speed, due to the greater wind resistance at 80 mph [which the 350 would not reach] being reduced by the fairing and allowing the top speed to rise even further, while any gains made on the 350 would probably be smaller in mph and / or percent, due to the top speed being lower to begin with. In classic and vintage racing, we found that a machine with, say, 100 mph capability [Crusader 250] 'naked' showed quite a marked improvement with a fairing, the gains obviously being more marked as the top speed was approached. So, 'on the road' at 50 or 60 mph, a fairing would perhaps make little noticeable difference, its biggest contribution being at or around the 'top speed', whatever that might be.

My most relevant experience with this would be from riding an Aprilia AF125 that had it's fairing removed for repair. The top speed was reduced by nearly 10mph. OK, it had a little more bhp than a 350 Enfield but the plastic certainly made the difference.

Nitrowing wrote: ↑

Wed Dec 02, 2020 10:23 am

My most relevant experience with this would be from riding an Aprilia AF125 that had it's fairing removed for repair. The top speed was reduced by nearly 10mph. OK, it had a little more bhp than a 350 Enfield but the plastic certainly made the difference.

Quite likely - they couldn't get 100 mph from the Suzuki X7 until the handlebar mirrors were removed ...

Bullet Whisperer wrote: ↑

Wed Dec 02, 2020 9:28 am

Let's say the 350 might have a top speed of 70 mph

If mine did 70, I wouldn't be looking for an extra 4mph! I think I'm around 60. Meteor piston, here I come.... next year.... of course, new piston and rings will help anyway....

On the subject of fairings, I've done many miles on an R80RT. There's lots of talk about the fairing weight reducing the MPG etc. But, whether it slowed the top speed or not, cruising at 70 to 80 was very pleasurable and there... was the benefit.

John