Here's my experience with them...07 SM with extra accessories, with +10mm length shocks.
In early September I placed a call to Fast Eddy because I wanted to discuss spring rates on these things, in part due to the research that I did here & other places. Left a VM, however no return call. I would have preferred to buy from Eddy, however if I make the effort to call someone, I generally don't call twice.
After a few days I called Mike at Bella Corse, & he answered. Got right on it & ordered them same day, too. After describing my specific situation IN DETAIL, Mike suggested 23kg springs. Based on my prior research on Hagons, I thought that would be too light; however, Mike said if they didn't work out, he would cover the shipping back to Hagon, so what the he11, I agreed to do the deal, although I suspected they would be going back for a spring change.
Sure enough, the springs were too light...back to Hagon CA USA they went...Mike assured me that 26kg springs were what was needed. I waited...
Got them back, with the 26kg springs and...wait for it...they were better, however far from optimal, as it was still undersprung...too little on middle preload, slightly too much on max preload, with no margin for a passenger or extra load.
Next, I went direct to Hagon USA (Cali) and spoke with Billy...he said to try 30kg springs...so back to Hagon USA they went, this time on my dime.
Got them back...on they went...and lo and behold...much, much better. Approx. 2 months into this process the shocks are now good to go with the 30kg springs...the rider sag is where I want it - on middle preload - there is good small-bump compliance, & it does not bottom on big hits.
The funny thing is that Mike still thinks he was correct with his initial 23kg spec. I know my way around suspension and how to tune them. Mike may know Bonnies very well, however based on my experience he does not seem to know BA/SM setup & will most likely "underspring" your BA/SM. Ask me how I know.
The Good: The 2810's are narrow (think old-school Girling narrow), which is great for Tsukayu hard bag clearance. The damping adjusters are nice. And the SS springs look good. Hagon USA is SUPER responsive to deal with. I have only good things to say about their customer service. The springs were swapped twice and they didn't charge me a cent for doing so. Gotta love them for that.
The Bad: there is a small length disparity (approx. 1 - 2 mm) on the eye to eye measure between the two 2810 shocks that they sent me - I have swapped many a pair of shocks and never experienced that before. Fortunately, by dumb luck I had installed the longer one first, which made it possible to install the shorter one by then wedging the rear wheel...otherwise, what an effing pain. According to Mike, that length disparity is within Hagon's production tolerance. To me that is just sloppy. And the finish is lackluster - but hey, it's a price-point shock, & I knew that going in. The funny thing is that the longer of the 2810's is exactly 13", same as the Progressive 444 that preceded the 2810's. The biggest negative however is that the 2810's only have 3-level preload adjustment - what a bummer.
It's a good thing that Hagon USA is willing to work with their customers, as those who know what they are doing are going to need to get the spring rates correct since the preload adjustment is so limited. It sure would be nice to have threaded collar preload adjusters on these things.
Overall I think they are a good deal, however be prepared to send them back in order to optimize them, as there is no substitute for proper spring rates given the limited preload adjustment options. In a way, I now consider that as a feature, as it forces an experienced user to focus on getting the right spring rate.
Based on my experience I would not start below 26kg when it comes to a BA/SM with the +10mm extra length, & given the limited preload adjustment range would suggest starting at 30kg for two-up or extra weight.
I hope this helps someone else down the road...
