That spring is designed to be fully compressed. It is as has been pointed out to keep the main and tender spring taught at full droop.The OP mentioned their helper spring is almost fully compressed. Do they need to go to heavier springs? Not an expert by any means, but I would think if they're fully compressed your at the maximum pre-load.
So the helper spring really doesn't play much a role in the suspension other than what you stated above. I ask because I'm setting up pre-load on a set of after market shocks on my Mav S that have that type of spring setup.That spring is designed to be fully compressed. It is as has been pointed out to keep the main and tender spring taught at full droop.
Need specifics on your aftermarket shocks to answer this question. These comments are IRT stock shocks and springs. Pic of your shocks would helpSo the helper spring really doesn't play much a role in the suspension other than what you stated above. I ask because I'm setting up pre-load on a set of after market shocks on my Mav S that have that type of spring setup.
They are the Bandit shock kit for the Mav Sport. Front springs are 225 lb, the Rear are 300 lb. Photos of the Rear.Need specifics on your aftermarket shocks to answer this question. These comments are IRT stock shocks and springs. Pic of your shocks would help
Sent from my HD1925 using Tapatalk
So this is considered a tender spring, not a helper spring then.I only see a main and tender spring here. No top helper spring
Sent from my HD1925 using Tapatalk
You mentioned the rear are 300lb? This is a dual spring, not a dual rate spring set up which is what the OP was referring to. Is 300 the combined spring rate? (Top rate X bottom rate / top rate + bottom rate) from the photo it appears you will soon bind the top spring and will be riding on the bottom rate until the suspension is extended (jump/whoop etc) and you will have some of the combined rate as it compresses again. Speaking of extension: as you load them up with the upper spring seat, you are creating energy that wants to unload. This can make the rear want to buck over jumps/whoops etc.So this is considered a tender spring, not a helper spring then.
I'm still getting the springs to settle on the rear, front are fine. As you can see I have 1/8 inch space between the coils on the top (Tender) spring. If I have to add more Pre-load and compress it even more, where is the cut off point (space between the coils) where i need to look into heavier springs?
If the rear has (2) 300 pound springs stacked it takes 125 pounds of force to collectively compress them (the stack) every 1 inch or travel. (.5" coming from each spring) At some point of travel, the force required to compress them together will exceed the force required to compress the bottom spring as the shorter top spring has bound and then the lower will be compressing. Not knowing the relaxed spring lengths of each, makes it difficult to calculate where you are in terms of the compression. At 2.4" compression (combined) from free length you are at 300 pounds of force required. Years ago I installed a dual spring set-up on a rzr before I went long travel and triple rates. The dual springs were an improvement over the OEM single linear spring, it gave it more of a progressive feel. The only draw back was I sat very low because the kit was produced with springs which were not long enough to hold the vehicle at target height and I was not about to put them in bind to achieve ground clearance. That takes away from ride quality and gets scary bucky at high speed thru the rough.Both springs on the rear shocks have 300 lb printed on them, front 225 LB. I assume thats the rate of each spring(?)
If I have to add any more pre-load to keep the sag under 30%, like you say, It looks like i'm close to binding, I will then look into heavier springs from Bandit.
That answers my question. Thank you!