OK, I went ahead and bought some new springs to test. Try and follow along as it gets a little confusing! This is by no means a scientific test, but it is a comparative test. I'm comparing the springs I have on hand to each other, that's it. If you're not interested or are bored and just looking to stir the pot, go elsewhere.
This is what I tested:
Used stock springs (don't know how long they have been in the bike, but it's a 2001 and I bought it used).
New in the package stock Honda spring, #22401-MBG-D00.
New in the package EBC supposed to be 10-15% "stronger" stock springs, #CSK29. 10-15% stronger is what the actual packaging says.
New in the package Barnett #501-99-06091. Supposed to 99lbs, but unknown compressed length to get to that spec. I found one spec that said 99lbs at one inch so used that.
Clutch - Spring - Barnett - Colors - Gold: 501-75-06005 (MT-05) = 75lb at 1-inch (default)Clutch - Spring - Barnett - Colors - Green: #501-82-06023 (MT23) = 82lb at 1-inchClutch - Spring - Barnett - Colors - Red: #501-99-06091 (MT91) = 99lb at 1-inch
Since I don't know the installed (compressed) length when in the bike, I had to find some way to compare them. The stock springs are at 18lbs before the Barnetts even start due to the difference in lengths. I could graph them but that's too much work for non-exact data.
Here's how they measured:
Used original: Length 45.9mm - Wire diameter: 2.4mm - Outside diameter: 18.7mm
Stock new: Length 47.2mm - Wire diameter: 2.4mm - Outside diameter: 18.7mm
EBC new: Length 46.7mm - Wire diameter: 2.5mm - Outside diameter: 19.5mm
Barnett new: Length 42.5mm - Wire diameter: 2.8mm - Outside diameter: 20.4mm
My SAE Metric washers: 2mm thick, outside dia: 19.6mm, inside dia: 13.2mm
What I can do is compress them to the same length, and measure the force at that same length. I measured them all at 2 different lengths just to see if they were linear in the compression rates.
The results were as follows:
30mm compressed length:
Original 58lbs
NOS 62lbs
EBC 62lbs!
Barnett 77lbs
Washers added about 9%
25mm compressed length:
Orig 72lbs
NOS 75lbs
EBC 75lbs!
Barnett 99lbs
Washers added about 10%
So, what's the conclusion? Only conclusion I can come to for sure is this: The Barnett springs are about 25% heavier than stock or EBC, and the EBC measured exactly the same as NOS. Also, the original springs were slightly weaker than new, as well as slightly shorter (I'm sure due to metal fatigue). Now, I know there can be variations in new springs due to manufacturing, but I averaged the ones I had multiples of and these were the numbers I came up with. As they say: Your results may vary.
Good riding!
Jim