Technical Rear shock placement - model A

I'm in the planning stages for rear shock placement on my 29 full fendered high-boy project. Please share photos of what you've done.

Thanks!

 

On a stock model a axle and original top mount points on the frame......

 

Get some tubing and weld some nuts or plates on each end so you can thread an Eye Bolt in each end. Then use it to moch up the location and the length you need. Don't buy shocks and try to make them fit after you get them, use the adjustable tubes and buy the actual shocks later .

 

Don't know if this will help or not but here is how I did mine. Just used plate and shock studs and welded them in place on the top of the rails. Sorry I don't have any better pictures.

 

Never would have thought to mount to the radius rods. Nice! Thanks

 

Smart! ...very smart.

 

I like the way you think..................but actually I got the idea from a magazine years ago. It worked well for me so I'm just passing it along. Depending on your setup, I usually put more than one mounting point so I can adjust the height by tilting the shock more or less when the car is done. Its not good to get an expensive (coil over) shock and find out later that its too long or too short.

 

How many miles do you have on this set up?

 

Fitted last year... about 1100 miles so far

 

Good question. I would be concerned about flex in the lower bracket over time. A gusset wouldn't go astray. Clean design though.

 

You can do your own design but its 5mm plate and is perfectly adequate for the application.

 

Yes, but it is what you are attaching it to....and not all Model A radius rods are created equal however it looks like you have the more robust casting/forging to attach to.
Nice design

 

Thanks... Early A's had a pressed steel end which is extreemly flimsy. I upgraded to the later version which is forged. A worthwhile upgrade for any A.

 

I do like the design. But also have some concerns like yours, though I'm not necessarily alarmed. I think he'd have seen problems by now, after 1100 miles. If he'd said 50 miles, I'd have a lot more reservations. Lol

The weld is the weak link in my opinion. Not the plate. Though it all looks plenty good to me in the pictures. I'm not necessarily concerned either is an issue or will be. I'd have more reservations if you'd said 50 miles on it and I feel like you'd see issues already at 1100 miles if you were gonna have them.

Just my thoughts. Neat design. Thanks for sharing

 

PotvinV8(above) has his shocks in the corners and I've seen an IronTrap video where his are mounted closer to the banjo. Is there any advantage one vs. the other?

 

Here is how we did it on the back of my A.

 

That's neat, what length of shock did you use?

 

Fendered highboy??

 

Typically speaking, the closer they are to the end of the axle, the more effective, as it's the shocks job to try to dampen the movement of all that unsprung weight (wheel, tire, brake, etc.). A slight inward angle also helps as each side of the axle travels in an arc.

 

Thanks for that!

 

From a best practice perspective, PotvinV8 has his in an ideal location. It may not always be possible, but this is what you should aim for, for reasons he has given.

 

You're welcome!

 

I don't recall. I took my measurements and went on Monroe's website and found a shock that fit my needs. The body of the shock has been the same forever so there are tons of options.

 

Yes - with the closer-to-the-banjo shock location, the tire/wheel/brake has greater lever arm on the shock, so that theoretically, one would need a stiffer shock there, than if the shock is located further outboard.

 

I like the brackets on the crossmember, very clean!

 

I used bolt on shock studs. Lower ones on 48 Ford style brackets mounted to axle ends.

 

Consider the movement of the rear end. Fore and aft movement is minimal. Most all movement is in an arc around the driveshaft and in that plane. I wouldn’t feel comfortable mounting the pivoting eyes in any other plane. Henry used the dog bone links to prevent issues with his original shocks that pivoted in the “wrong” plane.

 

Cool! Would love to see the lower shock mount better.