We are still asking: What did you get done on your Bolt today ????
The question, initially posted May 23, 2005, was:
"Whatcha do on your Bolt this weekend?"
After 51,906,997 views, 7378 replies over 185 pages, this thread in General Truck Talk is a happening! And it's not just weekends anymore.
I am wondering what appropriate angle should my rear shocks be at. I am using the rear axle conversion kit to install 1956 different on my 1950 truck . I am putting the leafs below the axle to keep stock height, I have not secured top shock mount yet but looks like if I put close to stock it would be 62 degrees. I read on previous forums 45 would be probably the best?
Rick, do a search for shock mount angle. I asked the a similar question early last year and it led to several responses. The stock mounting angle should work well, shocks are only there to dampen the spring rebound.
Come, Bleed or Blister something has got to give!!! 59' Apache 31, 327 V8 (0.030 over), Muncie M20 4 Speed, GM 10 Bolt Rear... long term project (30 years and counting)
Some people don't understand geometry. Somewhere between 45 and 60 degrees gives the longest shock travel, which equates to more dampening, not less. Be aware that the angle is constantly changing as the rear end moves through its range of motion. Jerry
"Freedom's just another word for nothing left to lose" Kris Kristofferson
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
After owning/driving AD trucks for 50+ years I'll add the rear axle when coupled with the stock leaf spring scheme (what it appears you have) in normal driving does not move up/down nearly as much or as freely as you might think. Very stiff, actually.
Now a 1965 pickup I owned for a summer was a completely different thing. In ways it rode more like a car. The rear moved up/down much more easily within the first 2 inches of spring travel. Driving through curves, you could actually feel and see it wallow in the rear. If two guys stood in the back and jumped up and down, the rear would bounce easily. When you hit the brakes, the front would stay pretty well level, but the back would elevate on you, giving an odd feeling of loss of control at any speed over 50. But if you loaded the bed (say with firewood), once it compressed past about 2 inches, you got into the "meat" of those rear coils and then it actually rode like a truck.
Housekeeping (Moderator) Making a Stovebolt Bed & Paint and Body Shop Forums
That figure isn't correct. For the same amount of suspension travel (vertically), a vertically mounted shock travels exactly the same amount. If that same shock is mounted at 45 degrees, the shock compresses ~1.4 times farther than the vertically mounted one. And 1.4 times faster. Since shocks work on a compression velocity principle the shock mounted at 45 degrees will have more resistance. 45 degrees is the sweet spot, and the compression distance decreases if mounted closer to horizontal. In the extreme, if a shock is mounted horizontally, it will have zero compression as the suspension compresses.
Kevin Newest Project - 51 Chevy 3100 work truck. Photos [flickr.com] #2 - '29 Ford pickup restored from the ground up. First car '29 Ford Special Coupe Busting rust since the mid-60's
I think the key is the word efficiency in the graph - and I'd posit another alternate, effectiveness. A shock cannot be designed and engineered at an angle other than vertical (it could but, since all shock mounting situations are different what angle would they pick) Most OEMs and shock manufacturers thus assuming the shock was designed to be most effective at vertical and so everyone works around those assumptions. However this rational only exists in my mind to justify the above graph and understanding - shocks are best installed as close to vertical as possible.
Plus there are other factors to the shocks performance besides it cycling velocity. As it moves farther from vertical it takes less force to compress it.
The angle, velocity, travel amount, force and spring rate are all variables a particular shock has to contend with in addition to similar size shocks (length and diameter) with different valving characteristics. You could mount a shock at 45 degrees and have it perform acceptably as long as it is sized and valved accordingly.
Note the suspension travel vs. shock travel in the chart. If the suspension compresses x amount but the shock only compress a portion of that, then only a portion of the potential amount of fluid is flowing through the valving to dampen the motion (regardless of the velocity with which it does it).
In this specific instance, the amount of travel is already determined by the springs and bump stops. You would want to mount the shock at a "reasonable" angle so that the shock is essentially nearly fully extended when at full droop and nearly completely compressed when on the bump stops. I would recommend somewhere close to factory, unless you want to do a bunch of trial and error with different mounting angles, shock sizes and valve characteristics.
Last edited by asilverblazer; Wed Jan 05 2022 11:07 PM.
Use the KISS principle. When I bought my Camaro rear axle, I grabbed the shock mounts along with other parts. The shock mounts have the angle set. I just followed that angle when I set up the shocks. IOW, the angle is the same as the factory Camaro. You have to trust the GM engineers. This does mean that I have 1 shock leaning forward and 1 shock leaning backward.