Hawk GT rear suspension leverage ratio

Here's my first set of measurements of the leverage ratio of the rear suspension of my '88 Honda Hawk GT. I did it by installing a Fox shock into the bike with the spring removed. I put the bike on its centerstand and put various wedges under the swignarm to lift it in little increments. I used a digital caliper to measure the displacement of the shock, and a tape measure hooked into the axle hole and against a piece of tape with a pen line on it on the rear cowl. I started with the rear wheel hanging, and stopped with the rubber bumper in the shock just touching the shock body, which gives you just a smidge over 4 inches of rear wheel travel. Although there is a little more travel there (that bumper compresses pretty easily for the 10mm or so, giving another inch of wheel travel) I didn't feel that any of that range is interesting because the springing and damping goes all wonky when the bumper starts to compress.

Keep in mind that this is not a sophisticated approach. I had to move stuff around a lot to get the right wedges, and I'm fairly certain my measurements of the shock displacement was not as consistant as it should be. I'll do this again some day, using a jack (instead of wedges) and another person to make all measurements more reapeatable and accurate.

Here's the raw data and some calculated values:

sag (in) sag (mm) wheel raw shock raw Δ wheel Δ shock rate note
469.00 0 <-- there's 2mm slop in all the joints
0.000 0.0 467.00 0.00 - - -
0.335 8.5 458.50 0.32 8.50 0.32 26.56 These two look like bad measurements.
0.492 12.5 454.50 1.05 4.00 0.73 5.48
0.886 22.5 444.50 4.13 10.00 3.08 3.25
1.280 32.5 434.50 6.57 10.00 2.44 4.10
1.299 33.0 434.00 6.62 0.50 0.05 10.00 <-- ignore this, must be bad measurement
1.565 39.8 427.25 8.56 6.75 1.94 3.48
2.087 53.0 414.00 12.33 13.25 3.77 3.51
2.333 59.3 407.75 14.05 6.25 1.72 3.63
2.539 64.5 402.50 15.54 5.25 1.49 3.52
3.031 77.0 390.00 18.96 12.50 3.42 3.65
3.327 84.5 382.50 21.20 7.50 2.24 3.35
4.055 103.0 364.00 26.54 18.50 5.34 3.46
4.075 103.5 363.50 26.65 0.50 0.11 4.55

sag (in)	sag (mm)	wheel raw	shock raw	Δ wheel	Δ shock	rate	note
		469.00	0				<-- there's 2mm slop in all the joints
0.000	0.0	467.00	0.00	-	-	-
0.335	8.5	458.50	0.32	8.50	0.32	26.56	These two look like bad measurements.
0.492	12.5	454.50	1.05	4.00	0.73	5.48
0.886	22.5	444.50	4.13	10.00	3.08	3.25
1.280	32.5	434.50	6.57	10.00	2.44	4.10
1.299	33.0	434.00	6.62	0.50	0.05	10.00	<-- ignore this, must be bad measurement
1.565	39.8	427.25	8.56	6.75	1.94	3.48
2.087	53.0	414.00	12.33	13.25	3.77	3.51
2.333	59.3	407.75	14.05	6.25	1.72	3.63
2.539	64.5	402.50	15.54	5.25	1.49	3.52
3.031	77.0	390.00	18.96	12.50	3.42	3.65
3.327	84.5	382.50	21.20	7.50	2.24	3.35
4.055	103.0	364.00	26.54	18.50	5.34	3.46
4.075	103.5	363.50	26.65	0.50	0.11	4.55

Here's what it looks like if you plot it: