boom thickness RDM?

[galeforce79]

what are some good things and bad things about smaller diameter booms? my forarms burn after sailing a little, will a smaller boom help that?

[coachg]

I have two booms with smaller diameters and two booms with the larger diameters. I let my friends use the booms with larger diameters because the smaller one are much more comfortable. One of my small diameter booms is five or six years old - I bought it so my wife could used it - and I use it all the time. After trying one of the small diamete booms I doubt you will want to go back to the normal size.

[gutterroll]

the only concern with smaller radius booms is strenth . I cannot use one for my bigger sails 7.0+ because at 245lbs i do not trust them ( I had a boom faliure 4 miles off shore in 12 knot winds on my 8.5
but I attribute that to my size because i still use an rdb on my 5.5 and smaller . as for forarm burn try to shorten you harness lines and trust your harness by playing the piano with your fingers as you sail on your reaches. only using your arm strenth in your transitions .lose the death grip and relax youll sail longer and better

[gemoore]

I dont know the rated failure load limit on these booms, but from what I know about composites and the engineering mechanics, you might be mistaken in thinking that smaller = weaker.

There is, in fact, LESS tension and compression when loading a smaller diameter cylinder in comparison to a larger diameter cylinder. Moreover, compression is not the problem, but tension. The wall tension increases with the square of the radius of the cylinder. So in fact, there is much higher strain on a normal diameter boom (and mast). And tension exceeding the limits of the part is what makes composite parts fail.

Youll note that manufacturers of reduced diameter masts often claim they are unbreakable in any real-world windsurfing application.

But RD Booms present a different problem, which is that you dont want them to bend, because the sail changes shape when the boom bends. Bigger diameter cylinders are more rigid, pound for pound, than smaller diameter booms. Because a wide diameter makes the tube really rigid.

Maybe some of the members in the windsurfing business could comment on failure rates, but Id be really surprised if the smaller diameter booms break more often. I would more expect them to be strong but not rigid enough.

GEM

[Caribsurf]

I definately prefer the smaller booms...you control the rig much more than the rig contolling you alot easier to throw around.
If your forearms hurt so much maybe the problem is with your harness lines set up...you are using your hands/arms too much