Limit strap legnth and stretch during use

shrive81

shrive81

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Ok so in the process of finishing up class 1 prerunner build and running 37" tires. I am setting up my limit straps for the car and was told at Kartek that when measuring and setting up straps I need to account for the dynamic stretch of the strap during use. I was told that they stretch during the down stroke of the suspension and the 1" per 12" was what was told to me. I am running a 23" strap on the front and was told I should droop the suspension out then limit it by 2". this is due to the dynamic force and stretch during the down force of the suspension.

Is this correcr cause everything I have read so far is bssically just stretch over time?
Will the limit straps actually stretch under load during use or do they just slowly stretch over time...


Thanks in advance
 
Slippery P

Slippery P

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shrive81 said:
Will the limit straps actually stretch under load during use or do they just slowly stretch over time...
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Both, I use the 1" per 12" rule and have not had an issue.
 
Wendell #527

Wendell #527

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They do both. They stretch on load and they stretch permanently over time. On load obviously some cars strwetch more than others. A little 1600 might not stretch 1" per foot but add 37" tires, lots of spring rate, little rebound control and they will go that much easily. Also over time. I have compared limit straps with a few races on them with new straps bought at the same time, the same length just not used (they were spares). The old ones were longer. They grow over time. That needs to be taken into consideration if you run the same limit straps for a while. Check the stroke marks on the shocks when testing to make sure you aren't drooping further out than you want to.
 
G

GDRBORETIRED

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Sorry, they are 3 years old and I have forgotten the name of the material. I think it is some type of poly-something. Not your typical nylon straps.
 
dan200

dan200

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GDRBORETIRED said:
Sorry, they are 3 years old and I have forgotten the name of the material. I think it is some type of poly-something. Not your typical nylon straps.
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Thanks. If you remember I'd appreciate it if you let me know.

Question- shouldn't one want the ability so stretch a bit? It seems that the stretch would act as a dampener (in reverse kinda) and lessen stress on components. Imagine using a chain or cable. BANG!


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GDRBORETIRED

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You already have dampers. How much stretch do you want? It could be nylon is the answer you want. I was looking for less, I seem to recall something like 2%. I don't think our limit straps actually come into play as we rarely top out the shocks. No evidence of squashed zipties but they are at the very end of the shaft.
 
dan200

dan200

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Tho guy pulls up to our sales trailer every year at KOH. He had the gnarly home built crawler. His limit straps are actually chains. "I use what I have" he says. He says they work but they beat the shiz out of his rig because they don't flex. His upper mounting position shows the stress caused by a lack/absence of stretch.

In a Dezert racing application I could see this being even worse.

I dunno why someone would want zero stretch and am curios why they might.


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07FJRog

07FJRog

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GDRBORETIRED said:
You already have dampers. How much stretch do you want? It could be nylon is the answer you want. I was looking for less, I seem to recall something like 2%. I don't think our limit straps actually come into play as we rarely top out the shocks. No evidence of squashed zipties but they are at the very end of the shaft.
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Of course they come into play, but not for compressing your shocks, your ziptie is at the "end of the shaft" and not squashed, that has nothing to do with limit strap and extension of your shock.
 
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