MTFCA Forum

Some time ago, I performed a search to see if someone has characterized single Hassler springs to correlate physical properties (wire diameter, coil diameter top and bottom, free length, and number of active coils) to the part numbers and delineated car body applications identified in the Hassler Parts Catalog No. 103. This would be under the assumption that the heavier spring rates would correlate to the part numbers for the heavier cars and notes about heavier applications in the Hassler catalog. I did not find anything. Does anyone know of such data?

As an aside, I haven't performed any testing, but it appears the single Hassler springs would have a non-linear spring rate, given their conical design and constant spring pitch (space between coils).

I suspect that, depending on Hassler's control of other factors affecting spring rate like heat treatment and materials, capturing the above data wouldn't be all telling, but it would be a huge step toward being able to determine the intended application for any given rusty, ol' spring that has lost its factory color-coded paint mark. I think identifying singles vs. doubles is easier, but identifying a single #39 from a single #40 from a single #41 seems more tricky without a pile of springs in front of you.

Also, I expect that so long as you put a matched pair (rate and free length) on each end of the car, you wouldn't see any troubles. However, it would be nice to know you're putting the "correct" Hassler springs on a given body style - yes, even though Hasslers aren't "correct" in the first place.

Being I've never found any original paint on the spring ends, I take my digital caliper & match up diameter & height.

Well, I guess not.

I do that too Steve and then stand on them and have the wife measure the distance.

Hank

I too just match by height, number of coils. Unless you are building a speedster should be just fine. If it's a speedster, there are better shocks to use, like friction.