Seeking enlightenment on tender or helper springs

Or in the vernacular: 'Learn me tender springs.' First guy to start singing like Elvis gets a HARD kick in the goolies.

Anyway, it looks like in order to get the combination of ride height, suspension travel and spring rates I need, I am going to have to go with tender or helper springs on the rear of the Jensenator. Anybody have any experience with these, know any pitfalls, etc?

my coilovers have them on the Bimmer..

they do NOTHING for rideheight. They are totally compressed for normal use. What they do is expand at droop or full droop of your suspension to keep the (shorter)main spring from falling out of it's perches.

and it is SO tempted to sing "spring me tender"

No advice, but I am all ears(actually I guess eyes). Im thinking tender springs on the Subie as well.

I had been seeking info on a set for my Tacoma. I think that I am going with Timbrens, though.

To expand on my question: the various manufacturers (Eibach, Hyperco, etc) all show the springs and the 'dividers' but they don't get into the installation. I am thinking the helper spring should go on the top, but Hyperco's spacer/sleeve design seems to indicate it should go UNDER the main spring. So where are y'alls installed? Top, bottom, ?

mad_machine wrote: they do NOTHING for rideheight. They are totally compressed for normal use.

Not Quite True. While they are totally compressed in normal use, they do add their compressed height to the spring stack which will raise the ride height.

IMO, Tender springs and helper springs are two different items. As stated by mad_machine, I have used tender springs which totally compress under the weight of a vehicle at rest to compensate for short springs that would fall out of the perches when the suspension droops.

Helper springs do not compress totally when the vehicle is at rest and usually have a different rate than the main springs. I have used helper springs on my dual-purpose motorcycles to give me a comfortable ride on the road while still having a stiff spring for off-road. The helper spring was at the top of the spring stack and usually had a rate about 1/2 of the main spring.

The only problems I have had with either was when I didn't put a collar between the two springs to keep them aligned when the suspension was at full droop.

Jensenman wrote: To expand on my question: the various manufacturers (Eibach, Hyperco, etc) all show the springs and the 'dividers' but they don't get into the installation. I am thinking the helper spring should go on the top, but Hyperco's spacer/sleeve design seems to indicate it should go UNDER the main spring. So where are y'alls installed? Top, bottom, ?

I've always put them on the top.

They should change the spring rate somewhat as well. Even if they are 25lb/inch springs, a 2" spring will take 50lbs of force that would normally be compressing your main spring. What that means to your effective spring rate at ride height I haven't thought through.

I know what I mean, but I may not be able to explain it clearly.

You can have tender springs with no value that simply serve to keep everything tight under full droop and then there are tender springs with a value.

Using a tender spring with a value gives you dual rate springs.

You have one, usually softer, value for the first X amount of the suspension stroke and then it bottoms out and gives you the rate of the main spring. The tender springs, mine were Eibach, were of a special flat material that compressed predictably and gave a very firm foundation for when the main springs engaged.

I had them on my 280Z. The soft portion made it very nice when I was driving on rough roads. When I had the just the main springs the car bounced all over the road but when I added the tender springs the car followed the road. It wasn't just a softer ride, it held the road so much better. Big bumps would engage the main spring and when I was entering corners at any kind of speed I used the main spring. It was a best of both worlds experience.

Thank you for not saying "learn me about..."

Add on to my previous post. I wanted to run much stiffer springs than would be comfortable on the street. Running the softer tenders made that possible. I had enough suspension travel with the tender springs to make the car feel like an R1 RX7 (which always felt comfortable to me) and yet in hard turns or on a track I got to use the firmer springs. At autocross speeds they really helped my corner exit. I could get on the power much earlier.

Okay, so from what I have been able to find and what I see here 'tender' spring means 'soft spring for initial travel' and 'helper' spring means a zero rate spring to keep the main spring from falling off the perch. That's a big help right there.

Ground Control can help you a lot in determining which spring fits your situation. That's where I got mine and they got it right the first time.

But even if you have to experiment a little the springs are cheap.

Jensenman wrote: Okay, so from what I have been able to find and what I see here 'tender' spring means 'soft spring for initial travel' and 'helper' spring means a zero rate spring to keep the main spring from falling off the perch. That's a big help right there.

Thats backward from what I was taught but I see that Eibach uses that terminology so I will go with it.

If you are going to use "tender" springs the length and rate in comparison to the main spring will an important factor. You don't want the spring rate changing in the middle of a corner.

With the number of companies that will make springs to whatever length and rate you want I'm puzzled as to why you are considering "tender" springs

I need to run (as far as my math tells me) 225 inch pound springs on the rear. This means each spring will compress 1" for each 225 pounds put on them, or 450 pounds per axle. The car weighs ~1800 pounds (final number TBD) but this probably will not 'load' the springs far enough to reach the 5" ride height I need since this figure includes ~350 pounds of unsprung weight (rear axle, wheels and tires, etc).

I can do this with 12" springs, but now something else comes into play: I have a decent amount of articulation (droop) built into my suspension design, so that the inside rear tire will stay in contact with the asphalt in a hard turn. I could fix part of what I'm concerned about with shorter shocks but I lose that articulation. Same thing happens if I move the shock mountings.

In the event of a hillclimb rise, it's not unusual to get airborne and this will let the suspension drop fully. When the shock reaches full extension, the spring will be shorter than the available travel meaning it's flopping around loose. With 12" springs rather than the 14" I have on there now, the spring will no longer be holding the 'hat' in place on the shock eye. The hat can drop low enough that it won't stay in alignment with the upper shock eye. This means the hat can slide out of position or even fall out, meaning an immediate change in ride height and preload of the rear springs once the car gets back on the ground. At ~100 MPH, that's not a good thing. The 'tender' springs will hold the hat in position in this scenario. I can keep the spring rate and articulation I need and the spring hat won't fall out of place. Win all around.

The 'helper' spring is such a low rate it won't come into play.

canoe.

Jensenman wrote: With 12" springs rather than the 14" I have on there now, the spring will no longer be holding the 'hat' in place on the shock eye.

So you need a spring with an extended length of 2+ inches and as low a spring rate as possible that will compress completely under load and extend on droop to keep the top hat in place. Once you find one you will have to figure the compressed height of the spring into your ride height calculation.

Yeah, that's true. But then I will have a spring rate softer than the math says I should have. As you preload a spring, you change how much weight it's carrying but not the actual spring rate.