The Ford Barn

LopezCarguy · 06-17-2015, 09:08 PM

Do shocks have same resistance up and down, in other words does shock dampen more on up stroke or down stroke??

RHD · 06-17-2015, 09:36 PM

Hi LopezCarguy.
The original type Houdaille shocks from new would have 10% in one direction (the downward stroke) and 90% the other.
I have tested NOS shocks and found them close to 5/95. Today if you can get a shock to perform at around 25/75 you are doing well. Many of the professionally restored shocks only obtain this resistance.
Best of luck.
Cheers,
Les.

updraught · 06-18-2015, 04:50 AM

Depends on whether you want a "performance" ride or a smooth ride. "Performance" shocks tend to be stiff in both directions for handling (at the expense of ride).

A "Koni Special D" shock, for example, has almost no resistance on compression (going over a bump), and the rebound is adjustable to "heaps" of resistance.

It is good for controlling a stiff spring as it allows it to compress quickly on a bump. The rebound resistance can then control the rebound (expansion) of the spring to create a smooth ride.

If you adjust the Koni up too much the wheels won't come down fast enough after a bump, and you will feel them leave the road. This is not good and it is then time to back them off a bit ...

Kurt in NJ · 06-18-2015, 08:24 AM

Moving the shock arm up should have much less resistance than moving it down----when I was rebuilding shocks for my car I found that with the adjusting valve closed the 2 foot handle would still move up, but could feel like it was stuck moving the lever down---then I opened the needle valve so it took about 60 seconds to move with about 50 lbs on the handle----there is an article in the model A service bulletins about rebuilding and setting shocks---the 50lbs and 2 foot lever was my interpetation of the tool in the service bulletins

fiddlybits · 06-18-2015, 09:17 AM

Now that everyone has explained how to build the clock in answer to the question "what time is it?"......

No, they do not have the same resistance up and down.

For more information.... see previous posts.

ericr · 06-18-2015, 10:57 AM

Sponsored Links (Register now to hide all advertisements)

perhaps I mis-read it but two posts are contradictory as to what stroke requires greater resistance....

updraught · 06-18-2015, 07:18 PM

Quote:

The original type Houdaille shocks from new would have 10% in one direction (the downward stroke) and 90% the other.

Hey Les,

All my A shocks are like house bricks!

Is this 10% of full resistance on the downward (rebound) stroke?

Kurt in NJ · 06-18-2015, 08:01 PM

When you hit the bump and compress the spring you want the shock to let it move easy --to absorb the bump---after the bump the shock has to slow the rebound of the spring so you don't bounce

Mike V. Florida · 06-18-2015, 11:07 PM

Quote:

Originally Posted by RHD

Hi LopezCarguy.
The original type Houdaille shocks from new would have 10% in one direction (the downward stroke) and 90% the other.
I have tested NOS shocks and found them close to 5/95. Today if you can get a shock to perform at around 25/75 you are doing well. Many of the professionally restored shocks only obtain this resistance.
Best of luck.
Cheers,
Les.

This is the guy that literally wrote the book on Houdallie shocks.

Tudortomnz · 06-18-2015, 11:13 PM

If you want to know about & work on original Houdaille shocks, Les Pearsons book is invaluable.

06-17-2015, 09:08 PM	#1
LopezCarguy Senior Member Join Date: Oct 2013 Location: Lopez Island, Wa. Posts: 276	Shocks Do shocks have same resistance up and down, in other words does shock dampen more on up stroke or down stroke?? __________________ The only thing worth learning is what you learn after you know it all !!

06-17-2015, 09:36 PM	#2
RHD Senior Member Join Date: Jan 2011 Location: New Zealand Posts: 665	Re: Shocks Hi LopezCarguy. The original type Houdaille shocks from new would have 10% in one direction (the downward stroke) and 90% the other. I have tested NOS shocks and found them close to 5/95. Today if you can get a shock to perform at around 25/75 you are doing well. Many of the professionally restored shocks only obtain this resistance. Best of luck. Cheers, Les. __________________ R.H.D. Author of Model 'A' Ford technical manuals. Supplier of good original RHD parts.

06-18-2015, 04:50 AM	#3
updraught Senior Member Join Date: Feb 2015 Location: Australia Posts: 1,969	Re: Shocks Depends on whether you want a "performance" ride or a smooth ride. "Performance" shocks tend to be stiff in both directions for handling (at the expense of ride). A "Koni Special D" shock, for example, has almost no resistance on compression (going over a bump), and the rebound is adjustable to "heaps" of resistance. It is good for controlling a stiff spring as it allows it to compress quickly on a bump. The rebound resistance can then control the rebound (expansion) of the spring to create a smooth ride. If you adjust the Koni up too much the wheels won't come down fast enough after a bump, and you will feel them leave the road. This is not good and it is then time to back them off a bit ...

06-18-2015, 08:24 AM	#4
Kurt in NJ Senior Member Join Date: May 2010 Location: on the Littlefield Posts: 6,156	Re: Shocks Moving the shock arm up should have much less resistance than moving it down----when I was rebuilding shocks for my car I found that with the adjusting valve closed the 2 foot handle would still move up, but could feel like it was stuck moving the lever down---then I opened the needle valve so it took about 60 seconds to move with about 50 lbs on the handle----there is an article in the model A service bulletins about rebuilding and setting shocks---the 50lbs and 2 foot lever was my interpetation of the tool in the service bulletins

06-18-2015, 09:17 AM	#5
fiddlybits Senior Member Join Date: Jan 2014 Location: N Illinois Posts: 447	Re: Shocks Now that everyone has explained how to build the clock in answer to the question "what time is it?"...... No, they do not have the same resistance up and down. For more information.... see previous posts.

06-18-2015, 10:57 AM	#6
ericr Senior Member Join Date: Apr 2012 Posts: 1,542	Re: Shocks Sponsored Links (Register now to hide all advertisements) perhaps I mis-read it but two posts are contradictory as to what stroke requires greater resistance....

06-18-2015, 08:01 PM	#8
Kurt in NJ Senior Member Join Date: May 2010 Location: on the Littlefield Posts: 6,156	Re: Shocks When you hit the bump and compress the spring you want the shock to let it move easy --to absorb the bump---after the bump the shock has to slow the rebound of the spring so you don't bounce

06-18-2015, 11:13 PM	#10
Tudortomnz Senior Member Join Date: May 2010 Location: Canterbury, New Zealand Posts: 1,242	Re: Shocks If you want to know about & work on original Houdaille shocks, Les Pearsons book is invaluable.