Help w/ soft top drumming

[Seanh]

I have a Badger/ RN top that drums like Micky Hart on speed. The worst configuration is when the top is on and the side and rear windows are out. The question I have is what about disturbing the flow of air over the top (Bernoulli)with lamps or a rack? Any first hand experience out there?

[Mike Hippert]

Lamps make a bit of noise themselves. Oddly enough Yousef and I found a way to quiet down the top. When we loaded our stuff on top of his 90 it pushed down on the top and stretched the top a bit, after doing that there was no flapping.

On another note, do you have rollbar pads? The Velcro ones? They help a little.

[paulb]

I gave up driving at speeds over 60 with the side and rear windows out. It got so bad that the drumming pulled out a rivet on the rail system at the rear left corner. The side window seem to be the problem so I put them in when traveling at speeed. The rear window I unzip and clip to the alpine bar to keep it out of the way. In my humble opinion, and not wanting to second guess or insult LR, the top attachment systems, either rail or snap can not handle the wind flow at speed.

The velcro rollbar pads DO help. And on Bernoulli, I believe the principle is that a when airflow is introduced to a disruptive shape (as in a wing) air is divided unequally into two flows. One is above and one below the object. If the flow below is smaller that that above, a pressure displacement occures allowing for lift (or in the reverse down pressure). Looking at the wind screen angle, ridge wher the top meets the front edge, the 3 humps in the top of my soft top to the rear, I venture to state (at my own peril) the aerodynamics of a D-90, at best, suck - literally - , and at worst, were just not engineered into the design.

Final comment. You are pretty close to CA or those warmer states. Ever concidered wintering there?

[Seanh]

Mike,
The velcro pads you refer to go where on the truck. I did make some fleece covers for the diagonal roll cage supports to quiet the window flapping. The top you streched, was it a bestop or a canvas top (RN or Badger)? Mine goes right back into a firm shape.

Paul,
If I winter in CA then I cant ski! With regard to bernoulli I was thinking that since the faster the air moved across the top the lower the air pressure relative to the air inside the truck. If I could slow the air down over the top then the top would not be pushed up as much. :confused

[ronward]

With the soft top windows in and zipped, open the drivers side door window about 2 inches by sliding the forward glass reward. Works like a charm on my 90.

[Mike Hippert]

The pads go on the vertical supports of the cage. The top that we stretched was a Bestop.

[Mark M]

Sean, We have great skiing here in California. Mammoth Mountain and Lake Tahoe come to mind. Here in So. Cal there are a couple of slopes within a few hours of Los Angeles. Kind of neat... surf in the morning and ski in the afternoon. :cool:

[Seanh]

Trade Western 3% powder for Sierra cement? :cool: Kidding, the back country skiing in CA is great and so is the cycling. At this point I'm only an hour away from great resort skiing and just a few minutes away from great bc runs. It's been snowing the last two days and I've had all the windown in which makes a huge difference.

[jstrong98]

I second the "open the window" method.

works like a charm for me.

[Seanh]

I live at 9000ft above sea level and the air gets quite chilly up here durring our 9 month winter. :)