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markdoane · 11-14-2010, 08:48 AM

I've done similar studies with my Reese 600 lb bars and Draw-Tite 800 lb bars. In my study I used deadweight loads on the bars and calculated deflection in lbs/inch.

Here are the summarized results:

Bar dimensions (mean of two bars):

Reese 600 lb bars:
thickness at head end 1.136"
thickness at taper end 0.599"
taper 0.0302"/inch

Draw-tite 800 lb bars:
thickness at head end 1.132"
thickness at taper end 0.645"
taper 0.0271"/inch

The spring rates for single bars are:

Reese 600 lb bars: 179 lbs/inch
Draw-Tite 800 lb bars: 195 lbs/inch

It's pretty easy to calculate the centering force using these rates and the dimensions of the cam follower on the Reese Dual Cam set-up, along with the angle between the tow vehicle and the trailer.

There doesn't appear to be that much difference between the bars. I think this is probably due to manufacturing variations. It's possible that if I checked another set of bars the ratings would be 10% higher or lower.

toastie · 11-14-2010, 08:57 AM

Quote:

Originally Posted by markdoane

It's pretty easy to calculate the centering force using these rates and the dimensions of the cam follower on the Reese Dual Cam set-up, along with the angle between the tow vehicle and the trailer.

There doesn't appear to be that much difference between the bars. I think this is probably due to manufacturing variations. It's possible that if I checked another set of bars the ratings would be 10% higher or lower.

On your setup, what head angle did you use?...........toastie

markdoane · 11-14-2010, 09:05 AM

Quote:

Originally Posted by toastie

On your setup, what head angle did you use?...........toastie

In the study I did, the head angle is not a factor. I inverted the head so the bars were horizontal during the test. That eliminated any cosine errors. The bars were loaded with up to 420 lb of weight, and the deflection was measured directly. I did not use the setup shown in your post.

toastie · 11-14-2010, 09:14 AM

Quote:

Originally Posted by markdoane

In the study I did, the head angle is not a factor. I inverted the head so the bars were horizontal during the test. That eliminated any cosine errors. The bars were loaded with up to 420 lb of weight, and the deflection was measured directly. I did not use the setup shown in your post.

Markdoane, my question wasn't related to the study, I have the same setup as you have and trying to figure out what head angle I should start with..........toastie

toastie · 11-14-2010, 10:41 AM

tiger

This is the system that I went with: Strait-Line Weight Distribution w Sway Control - Trunnion Bar - 10,000 lbs GTW, 600 lbs TW

My TV is a 2008 Cheve Trailblazer, gross vehicle weight rating 5,550 lbs, curb weight 4,356 lbs. with max towing capacity is 5400 lbs. The trailer is a 1955 Safari approx weight is 2800 lbs tw approx 300 lbs. The bars are 600lb MAX load, so my 300lb TW is at a sweet spot.

I'm learning how to set it up now and here are a few sites that is helping me in that set up.

RV.Net Open Roads Forum: Towing: Travel Trailer Hitch Set-up Procedure

Google Image Result for http://i23.photobucket.com/albums/b378/JBarca/Hitch%20Setup/Reesetopview-shimed.jpg

YouTube - Dual Cam High Performance Sway Control Installation - etrailer.com

toastie

markdoane · 11-14-2010, 12:15 PM

Quote:

Originally Posted by toastie

Markdoane, my question wasn't related to the study, I have the same setup as you have and trying to figure out what head angle I should start with..........toastie

I would start in the middle of the range and adjust accordingly. We have different trailers, tow vehicle, ball height and tongue weight.

I think I am just a tooth or two tilted back.

toastie · 11-14-2010, 12:22 PM

Quote:

Originally Posted by markdoane

I would start in the middle of the range and adjust accordingly. We have different trailers, tow vehicle, ball height and tongue weight.

I think I am just a tooth or two tilted back.

thanks

SteveH · 11-14-2010, 01:27 PM

Quote:

Originally Posted by r carl

Take it easy Steve, Andy has forgotten more than you and I together know about airstreams.....

About Airsteams, no doubt.

About WD hitches, well not so much....Andy has proven to me he knows a little about one manufacturer's one model of hitch.

toastie · 11-14-2010, 02:51 PM

I bought my system about 2 weeks ago based on Andy's recommendation, very happy with the purchase, thanks Andy............

toastie

Inland RV Center, In · 11-14-2010, 02:52 PM

Quote:

Originally Posted by toastie

I bought my system about 2 weeks ago based on Andy's recommendation, very happy with the purchase, thanks Andy............

toastie

Your more than welcome.

Andy

AirHog · 01-15-2011, 12:35 PM

Hello,

I just bought a Curt # 15524 Class V hitch to replace my OEM hitch for my 2004 Yukon Denali. The 7 Pin connection bracket is actually welded to my old hitch. Of course the new hitch has no such item pre attached. I do not have any welding tools- I would appreciate any comments on how do I find a way to have a permanent attachment for the electrical connection.

Many Thanks.

Titu

markdoane · 01-15-2011, 01:29 PM

You're kinda stuck cutting the old 7way mounting bezel off with a hacksaw and drill and tap into the new hitch with some 1/4 or 5/16 screws. You might need to fabricate a bracket with some angle iron.
Won't be beautiful but it will work.

Dwight · 01-15-2011, 03:41 PM

Quote:

Originally Posted by AirHog

Hello,

I just bought a Curt # 15524 Class V hitch to replace my OEM hitch for my 2004 Yukon Denali. The 7 Pin connection bracket is actually welded to my old hitch. Of course the new hitch has no such item pre attached. I do not have any welding tools- I would appreciate any comments on how do I find a way to have a permanent attachment for the electrical connection.

Many Thanks.

Titu

I had the same problem when I bought my Curt. I cut the one off the GM hitch and mounted it upside down to the Curt hitch....works just fine.

If it wasn't raining, I would post a photo....

AirHog · 01-15-2011, 04:03 PM

A picture would be very much appreciated, if you get a chance. I am in no rush. 10 degree outside and as cold in the garage.

Dwight · 01-15-2011, 05:03 PM

I posted the photos at "My Photos"....

AirHog · 01-15-2011, 06:04 PM

Looks great. Thank you very much. I will do the same. Best to you my friend.

Titu

Dwight · 01-15-2011, 06:05 PM

I tried posting the photos to the thread, but wasn't able to....

Dwight · 01-15-2011, 06:14 PM

[IMG]file:///Users/dwightpurvis/Desktop/Curt1.JPG[/IMG][IMG]file:///Users/dwightpurvis/Library/Caches/TemporaryItems/moz-screenshot-2.png[/IMG][IMG]file:///Users/dwightpurvis/Library/Caches/TemporaryItems/moz-screenshot-3.png[/IMG]

Inland RV Center, In · 01-15-2011, 08:21 PM

Quote:

Originally Posted by Dwight

[IMG]file:///Users/dwightpurvis/Desktop/Curt1.JPG[/IMG][IMG]file:///Users/dwightpurvis/Library/Caches/TemporaryItems/moz-screenshot-2.png[/IMG][IMG]file:///Users/dwightpurvis/Library/Caches/TemporaryItems/moz-screenshot-3.png[/IMG]

If you can, turn the connector 180 degrees, so that the bootom of it will be at the top.

You will get far less dirt in it that way.

Andy

overlander63 · 01-15-2011, 08:42 PM

Quote:

Originally Posted by AirHog

Hello,

I just bought a Curt # 15524 Class V hitch to replace my OEM hitch for my 2004 Yukon Denali. The 7 Pin connection bracket is actually welded to my old hitch. Of course the new hitch has no such item pre attached. I do not have any welding tools- I would appreciate any comments on how do I find a way to have a permanent attachment for the electrical connection.

Many Thanks.

Titu

That bracket is available separately. I'd just run to the parts store and buy a new one and screw it on for the little amount it costs (less than $5).