i put them on because some of the trails we go thru are really tight with pine trees and my trail stripes are plentiful, but i rather now have the branches continually hit the windscreen or come in my window. eventually i plan on putting lighting on the rack so i will have to think about protecting them from being bashed in. if i put a spring in there im thinking it will never be taunt and if it is then a big branch would just max the spring out and any pressure that would be on the rack in the current setup would still apply. at some point with a spring or not i think the pressure from a big enough branch wouldnt actually take the roof rack off but shear the eye bolt in the rack.

 

A properly sized drawbar spring will keep tension.


They act like a shock absorber. Saying they won't do any good because once they stretch the force will be the same is like saying air bags don't do any good in an accident. It's the same principle, aside from one being compression forces and the other tension forces.

 

Tom how do you do that calculation? wouldn't i need to test the tension of the cable when taunt to figure out the load amount for the proper fit spring?

 

Most places that sell them, well, the good places, let you choose a spring based on various values.
Drawbar Springs

If you want to get exact, you could always hook a spring scale inline in the riser to get the load range.

 

just like i said in the beginning of this page. we went thru some very heavy brush. they held up great, but idiot me was going to fast and i hit a huge branch and it sheared the eye bolt on the rack.... just as i thought it would. im going to replace it and then see if i can get some springs to put in there.

 

You had fun though, right?!?! That's all the matters!

 

just an update... sheared another eye bolt on our last trip.... im buying springs now, hopefully it will prevent putting that much pressure on the eye bolts. I have been using thin eye bolts because that is all that will fit thru my roof rack tubing. The tubing is quite small.

 

im thinkin 2 of these

http://www.mcmaster.com/#catalog/117/1202/=ecxnu8

9630K4

or

9630K1