Honestly, I'm probably confused about what it is exactly that a more expensive suspension offers. Unlike you, I'm a very new rider
Correct me if I'm wrong, but as I understand it it's not about travel, which most always requires higher fork tubes and probably modifications to a swingarm.
I realize I may be putting my foot in my mouth.
So, is it solely about better compression and damping, which should help with heavier loads? I'm pretty sure what it does is improving overall stability of the bike but honestly this bike feels pretty stable to me, low or high speeds.
Anyway, is a more expensive suspension a right answer in my situation, i.e. too heavy load that pushes the limits of OEM suspension?
First of all, no worries about putting your foot in your mouth. How else can we learn?
Suspension is a mix of science and black magic! It takes days and much riding on off road and high performance bikes to dial it correctly step by step.
Right off, yes, too heavy of a load is going to totally push the limit and the remedy will only be of a front and rear stiffer spring effect but then if riding solo only it will be too stiff and again will need adjustment. Hence for the new "electronic on the fly" shock adjusters. Pricey!
You need to know that front and rear have to work together. I remember on a Ducati having ordered custom Penske shocks which takes about eight weeks. The front arrived ahead of the rear and even though I was told not to, I did install it while the rear was still stock. Bad experience as the handling was horrible and ended up not riding waiting for the second one.
They have done a nice job with the Van Van balancing both and again, with too much weight the handling will be counter productive.
There are a few factors to understand.
The first one is the tire pressure and I think you have that under control. Try different ones.
Next is the proper spring rate and most importantly the sag. The spring rate is what it is. The sag with the rider on [or 2 riders] works best with 95-115 mm travel [both]. The static sag with rider [s] off should be about 25-45mm. If off those numbers it is when one determines a stiffer or softer spring. Of course there is also the quality and physical construction of the shocks. Custom Penskes [$1000+...] being the best, Ohlins would be next even though now mass produced, followed by Progressive and some other brand I forget the names.
Fork oil height in the tubes also have much to do with the absorption. Adding oil will stiffen, removing oil will soften. Makes sense... right?
Greasing the linkage and headset is also very important for free movement of the rear. A properly adjusted headset and well greased will give a much more accurate rider feedback as all adjustments are of course based on such personal feedback.
Another important factor is to always have the proper chain tension and length. Keep in mind that the Van Van acts opposite to most bikes meaning the chain "loosens" with weight on and should have about 30-0-mm play only without any weight on.
Suzuki has done a good job off the factory with the Van Van suspension. I personally [I always ride solo] would not change a thing only play with tire pressure which is something I myself do. Now,if we were talking Ducati or other performance bike it would be a totally different story while handing that credit card towards new shocks!!! It does make a huge difference on those bikes and after many miles becomes one with the rider like a good pair of shoes.
Enjoy your ride... Ara