Author Topic: Adnoh's DCP Rear Arm Fix  (Read 2696 times)

Adnoh

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Adnoh's DCP Rear Arm Fix
« on: October 29, 2010, 09:07:19 AM »
From ride at St Joe:  "I had another issue which was whoop related, as I curt across to a side trail I hit a hole a big hole and almost threw me over. Upon returning to camp I noticed the rear arms ball joint was in a weird angle. I unloaded the suspension and seen the ball joint stud was loose and had woollard the arm pivot point. I drove back the truck which was in day use and in the 100 degree heat disassembled the rear upright and replaced the ball joint and was good to go. The taper I put on the pivot ( which I do not remember doing)must not have been correct or the stripped stud and nut allowed it to wooler to which I did not catch until I check over the suspension after the hit. All that held the nut in place was the cotter pin. Thank goodness for the cotter pin. The damage could have been severe. "

Well I finally got around to Fabing up a new style of arm to fix the angle of the pivot point on the upper rear arm. Since I use the stock shock mounting locations the ATVR style of arm will not work due the arm support hits the shock and few other reasons. What I did with Hacker 1 arm was to find a angle that allowed the rear assembly to move bind free with my set up. The one thing I did I did not like and found to be a problem was the the angle the pivot support was orientated with the upright. Since the arm need to be fixed due to the loose ball joint and the wollor on the arm I opted to make all new arms that corrected the problem and allow for more travel in the assembly before bind.

The new arm allows for 13.75 inches of assembly travel with my present I rod and radius rod positions before arm and ball joint bind. I fell If I tweak the adjustments I can get 15. Since these arms are replacement rods for the current set up It goes beyond my shock travel so I do not see the point to move at this time. While I was at it  took some shaft angles at full droop and extended, at droop the drive axle would be at 25 degrees and at compressed at 16 degrees For the 13.75 of travel. At full compression the the new arms touches the frame as the stock one would as well. The other thing on compression is there is no advantage to increase unless you use taller tires or wheels. At full bump ( compression ) the tire pretty much go flat and the frame is on the ground or real close. If this was increased without taking that into account sever injury could accrue. I will look into a 12" wheel and see if that number can be increased and increase sag to retain ride height if I look into a 14 to 15 " travel set up. The thing  have to consider is a shock relocate the the massive size and weight of the shock.

The new arms weight 1 pound less per side than the ATVR arm which translates into 2 pound total and 1 pound unsprung weight.  The new arm is Molly and uses stock frame mount points and ball joint pivot that I salvages from the Hacker 1 arms and the stock ones used to make the Hacker 1 arms.  I cut up the Hacker 1 arms to fab these in order to make a jig to make a set of full Molly with heims and bungs for adjust ability and still fit with the stock shock locations.This means I will be able to make a set for about any set up and mounting locations. The jig will have adjustability of the ball joint mounting point so I can make it work with stock/Atvr/Hacker ect. Basically move the upright were I want it. The Idea behind the heims and adjustability is to get rid of the rubber bushings in the ATVR. I wish I had the skill to make the stock type ends for durability however there no adjust ability with them.

Ok here is some pics. As always any idea are appreciated

Adnoh

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Adnoh's DCP Rear Arm Fix
« Reply #1 on: October 29, 2010, 09:12:41 AM »
more pics.

Adnoh

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Adnoh's DCP Rear Arm Fix
« Reply #2 on: October 29, 2010, 09:43:19 AM »
more pics. ATVR,Hacker 1 and New Hacker 2 Comparisons

Adnoh

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Adnoh's DCP Rear Arm Fix
« Reply #3 on: October 30, 2010, 07:22:55 AM »
Last night I went out and fabed up a jig for the arm. This jig will be used for stock arm parts. A new jig will be made for the new hiem end arms. This arm could also be used for new parts if if bushing type pivot are used like the atvr arm. I will make a set using sleve bushing and new ball joint end. I also purched two new reamers to get the taper correct. When the old arm failed I was not sure #1 if I even tapered tehm to start with, which I did just  not correctly #2 if the impact or impacts striped out the stud or nut or both. #3 the arm pivot arm angle had an bearing on it other than squeezing the boot to tight. One other thing I did notice upon post ride tare down was the the nut position on the end of the ball joint and the amount of taper that allowed the ball joint to be sucked in futher into the arm creating less clearence on the ball joint boot. As the it failed it tore the boot. I will reuce the thickness of the arm pivot material to prevent this in the future.

I went out this morning a snaped a pic of the jig and marked up the proposed tubeing.

Adnoh

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Adnoh's DCP Rear Arm Fix
« Reply #4 on: November 13, 2010, 06:39:56 AM »
Update:

I now have a set of rewoked arm and called them hacker 2 arms.  I also have built a full set of molly with hiems as well. Now it was time to play with the increased in travle idea. I took the hacker two fabed arms are moved them around a little and and now can can get 14.5" of travle with out ball joint bind and cv bind. The camber change is 5 degrees full droop to full compression. It will take a 14" travle shock with relocate kit. I will try to mock shock relocate useing a fox 2.0 remote coil over.

980-02-012-A 14.0 C/O REMOTE RESERVOIR ZINC 35.10 21.15 2.0 X 11.00 $380.00

The other option is to do a little more work and go to a full 16". This will take it a 8" wider than stock and new axles. I mocked up a arm set up to get 15.75 and with a new rear upper arm pivot change can get it to 16. The change in pivot will keep the ball joint from binding sooner. than I can go with a 16" travle shock.  

980-02-059-A 16.0 C/O REMOTE RESERVOIR ZINC 40.10 24.15 2.0 X 11.00 $380.00

My question is would it be worth it to go to 14 or go big to 16. If a person had stock and was going long travle go 12,14 or 16. I look at if I was a open area duner the 16 would be good and if I was a dunner/trail rider 14 would be good.

edit: add pics of 16"