Competition Traction Bars

[Kissfan113]

ok guys, I am building a set of traction bars from 2 inch 1/2 inch wall DOM tubing, How long should these be, is there a magic lenght. I am thinking 8 foot long with heim ends on both sides, 1/2 plate mounts with grade 8 hardware. any help is appreciated

Kevin

 

[Diesel Freak]

This weekend I am drawing up a set to replace my Rancho Bars.

 

[Bloomy]

I think mine ended up being around 7. 5'. I wanted them in the boxed section of the frame. I used 1-3/4" DOM w/ 1/2" wall and 7/8" heims. I think they work pretty good. I don't even qualify as an amateur puller yet, but they save parts.



Thomas

 

[TReed]

I just made mine bigger yesterday, I used 2 5/8 DOM tubing 1/2'' wall, they are a couple inches shy of 8ft long, with big heim joints.

 

[AK RAM]

54" here. They are perfect.

 

[AMassaro]

AKram, can you explain why yours are so much shorter?

 

[dieseldude]

This weekend I am drawing up a set to replace my Rancho Bars.

what is wrong with your rancho bars? are they not strong enough?

 

[AK RAM]

AKram, can you explain why yours are so much shorter?

Oops. Mine are 55", not 54". They just need to be long enough to get you to a good mounting spot and provide a little flex. If you've got 8-feet, use it. If you've got 55", use it. The longer they are, the more flex you will have, and at some point they will flex enough to kind of defeat the purpose. 55" gets me from the axle to the straight portion of the frame, just past the last bend. Perfect. Mine are from http://www.anninengineering.com. Their 55" Heavy Duty Adjustable Truck Ladder Bars were on sale for $199, so I jumped on them. I used Jeff K's mounting system outlined in the .pdf here: http://www.cumminsforum.com/forum/showthread.php?t=2808

 

[jwilliams3]

Short or Long are both fine but bar diameters are important as well wall thickness. The longer the bar the larger and thicker the bar you will have to use to maintain integrity. I am not really on the page of them flexing at all.



I have 1. 5" od bars and I am probably going to change to 2" for next year.

 

[pwerwagn]

The other item to consider when building bars is spring movement. Ideally, you want the bars length/position to be placed so that the Arc at the axle end of the bar closley mimics the axle movement as it travels upward in its stroke.



On my 74, I found a point on the frame and measured the distance from the point to the axle at full compression and full droop. I kept measuring from different distances and mounting points until I found one that lent itself well to axle movement.



For the purposes of these trucks, where wheel travel isnt to much of an issue since there isnt a great deal of it, this is probably irrelevant but I thought I'd throw it out there anyway...



DF, what are you gonna do with your old ranchos?



-Jeff

 

[BigBadDodge]

Build them only once fellers, 2" DOM 1/2" wall



BBD

 

[Turbo Thom]

Pwerwagon... ... ... . that's true unless you have the front on the bar in a mount that allows the bar to rotate on an axis at the front. Welded to the axle at the rear. I build mine to swivel with a "shackel" for the front of the ladder bar. I can post a picture if you like.



. . Preston. .

 

[Diesel Freak]

sorry guys, I have not had a chance to get to it... . I have to re-install some software on the old computer... . had to reformat the hard drive!!



All I am going to do is design a set of bars that have a higher moment of inertia than the tubular rancho bars... . this will practically eliminate the bowing deflection I am experiencing. As BBD eluded to, wall thickness has a huge affect on the stability of the bar. The Rancho bars are very thin, and even on a 300 HP truck, they deflect severely.



I can not remember the length, but I currently have the "medium" length bars.

 

[Kissfan113]

Trav, if you don't mind my asking, what is the going rate for that 2 5/8 tubing, i think i have a good source for heim ends, Thanks to everyone who has posted, i think i am gonna go for 8' bars.

Kevin

 

[Diesel Freak]

A longer bar will work better with the suspension as it compresses under a load.



However, the longer bar will have to be more substantial to minimize deflection under load... . if the bar is under compression.



If the bar is under tension, deflection under load will be a non-issue.

 

[TReed]

mine being 8ft with 2 5/8 DOM 1/2'' wall they don't flex.

 

[Diesel Freak]

lol... I would hope not!!!!

 

[AK RAM]

Geeeez..... and must weigh 150 lbs each.

 

[lmills]

mine being 8ft with 2 5/8 DOM 1/2'' wall they don't flex.

They are rather impressive looking.

 

[TReed]

thanks lloyd