I'm copying this from "WAKTMRider" who started the thread on a forum.
Suspension - rear shock fix for those of you that have kids on CRF/XR 80s might find the following valuable.
If you have a kid on a stock CRF80, you probably noticed that the rear shock is miserably stiff. Also, if you are like me, the jump from CRF50/70 to the 80 is pretty large in seat height for some kids. If you have looked for solutions online, you've probably been frustrated to find almost no options. The options that do exist are mostly to increase the spring rates for adults using 80s as pit bikes. But for those of you with kids riding the CRF80 as a trail bike (as intended by design), the rear suspension is very stiff.
I have a cheap solution that lowers the bike 1.5 inches, increases travel 50% (4.3 to 6.6 inches), and softens the spring rate more appropriate for rider weights 60-110 pounds.
Find a used Suzuki DS80 shock (ebay or other). The DS80 shock is shorter by 1/2 inch - which on linkage will lower the seat height 1.5". The spring is adjustable (Honda is not) and much better rated for weight of small riders. The shock stroke is 50% longer, resulting in longer travel. Importantly, there is still tons of room between fender and tire at top of stroke as most of this space if for looks - not travel clearance on stock bike.
Fitting the DS 80 shock is easy. The DS80 shock fits perfectly in top mount, same size bolt. The bottom of the DS80 shock has a larger bolt that Honda. To correct this, I went to Honda and ordered a new lower linkage bushing for the larger bolts that attached linkage to swingarm. The two lower linkage bushing use 10mm bolt, where as the stock lower shock mount bushing is 8mm. Simply replace the lower shock mount bushing with 10mm bushing from Honda and buy a new 10mm bolt/nut to fit.
Once the rear is set up, I recommend lowering the fork tubes as much as possible (up to handlebar contact) to balance the handling dynamics.
Softer ride, more travel, lower seat to touch ground better....happier youth riders!
I read about this after buying our CRF80, but never acted on it. Recently a couple others have posted that they have done it with good results. I bought one off a 93 Suzuki DS80 for $27 shipped. Got it last evening and installed it - it was an easy job. I had my son take it for a quick spin this evening. I doubt he will notice much difference in the softer setup, but he is so happy he can finally touch the ground now.
CRF80 suspension help
CRF80 suspension help
Ahhh, pre-mix!!