The shocks are brand new from a well known dealer.
The spring rate was discussed at purchase and suggested springs installed. It was also advised by seller to buy the better type of shock for a number of additional benefits.
The thing is that I have been running around on a set of 1972 Yamaha shocks on an AT1 for 4 years now and they are still almost perfect for that bike. The RT1 has now had 3 different set on it, the first set where stuffed Yamaha ones (possibily from a CT1), second set where $75 imports that was just for sorting the rest of the bike out. I crushed the top eye on both sides (they weren't steel) after 2 races and as a mental note they definitely seem to offer zero damping anyway. The third set were not cheap but not a $1000 either. I'm certainly not a complaining customer (was told of pitfalls at time of selection), just dissapointed that I have to actually fine tune something that I would ordinarily take for granted would work out of the box. Unreallistic I know! It does seem obvious now that the rebound is way off, so I'll pull them down shortly and have a play.
However, I am struggling with the static / dynamic sag settings for older twin shocks. I know sag validates the spring rate (soft or weak) but with only 4" of wheel travel, I really don't want 1" taken up when sitting my fat as* on the seat!
It is a black art and a huge time taker to get right. Any helpful points taken with great respect at stage.
If you only have 12mm of sag sitting on the bike your springs are way too stiff and if it takes 30 secs for the springs to unload then the shocks are over damped also. You've been sold a pair of shocks not suitable for a pre 75 bike and more likely to suit an Evo.
Like I said before there are well known dealers selling the wrong spec suspension to customers and you've just confirmed it! There are also certain suspension brands that have been around a long time and always get it right.
I'm rebuilding twin shocks for vmx customers pretty much every week so I see plenty of them and you're not the first with this complaint and you won't be the last!