Noted several posts referencing mods to shocks/springs. Have found cost for those mods. Benefits for my 2015 RT not clear.
1. What conditions are improved by the use of spring adjusters and how do adjusters improve those conditions?
2. What conditions are improved by the use of shock replacements (Elka, M2, Fox, etc) and how do these more expensive replacements improve those conditions?
Seems unusual either of these mods would be required under typical driving conditions.
Thanks
What you want to achieve is the million dollar question. Most will accept the Spyder suspension setup as it comes from the factory and adjust their riding styles and requirements to suit. Others will do the least expensive mods such as a beefier sway bar and such. Others will do this and replace the suspension shocks - front/rear.
There is a forum thread where the owner changed the rear OEM shock spring to a 600 lb/in shock spring with a preload adjuster installed. It is mentioned that this is a suitable setup and uses minimum air bag assistance. This would infer that the shock spring is sized for the riders profile and the shock spring does most of the work solo or two up. I have M2 shocks installed all round and have settled on a 660 lb/in rear shock spring and use minimal air bag assist for solo, two up riding and when towing a trailer.
Many will mention that the rear suspension is the easiest to adjust. In essence this is correct, however, like a Gold Wing it has issues. Keeping the OEM shock and shock spring, then loading the bike and compensating for this added weight with the air system, can cause the rear suspension to be very stiff, using two shocks instead of one. The solution to this is to have the rear shock spring sized correctly, and use minimal air bag assist for all riding profiles. Add to this a shock that has rebound damping and you can tailor the ride to suit.
To add to Baja Ron's post, preload adjusters set ride height and should only be used for this. When you load the front of the Spyder, ride height will be lost, and you can adjust the preload adjusters to compensate. The only issue with this is that accurately going between the two adjustments could be less than optimal.
As mentioned the shock spring supports the weight of the rider, and platform. Too light a shock spring and ride height will be difficult to maintain when Spyder is loaded whichever way. Too stiff a shock spring and ride quality can be compromised.
The shock spring along with the sway bar and tires, control the roll/lean of the Spyder when under way. Sway bars only come into play with the roll/lean aspect of the Spyder. Can improve road roll/lean characteristics, but only on the minor roll/lean aspects. When taking a sharp corner, or navigating a cloverleaf where the roll/lean characteristics are amplified, the shock springs are the determining factor assisted by the sway bar and tires. If you find yourself hanging out the side in these cases and slowing down significantly, the shock springs are probably too light.
The M2 shocks on the front of my Spyder came with 250 lb/in shock springs that I have changed out for 300 lb/in shock springs, using the factory rebound damping setting. Ride is very good and plush. Roll/lean characteristics that I have mentioned have been further reduced. I am still considering a shock spring upgrade to 350/400 lb/in shock spring. There are older forum posts regarding a front shock spring change to a 400 lb/in shock spring, how it came to be and what was accomplished with this change.
There is not a lot of information on shock spring upgrades; however, the Spyder does have similarities to the snowmobile industry that is well versed in suspension upgrades - BRP does make Skidoo.
There's a lot of opinion regarding this subject, and because a suspension shock upgrade is expensive, the less expensive mods are done and that is it. PMK has mentioned that these are not performance platforms, but it is possible to get a better ride and performance from your Spyder with a suspension upgrade. My thoughts are that the machine should do more work than you do.
As I mentioned at the start, no suspension upgrades are required, but you will tailor your riding style to suit the machine. If this does the trick, go for it and ride safe. If not it's a cost/benefit scenario. What do you want and what is your budget.
Thought I'd add some thought to your question. Good luck.