So, long shot I know but got the SID XX and Monarch XX on my bike, these are great sometimes but also truly shocking at other times, but anyone done a major overhaul to improve the damping of these?

The monarch seems to be fussy to weather can go from wallowy using all the travel over small bumps/pedalling to near solid barely using 1/3 travel of jumps and back all in a single ride. I’ve had it since late 2015 and it’s fairly high mileage, but by no means worn out. A full (damper too) service last year showed little to no wear but the service improved performance for ~20 hours of riding but it soon went back to it’s old ways. What doesn’t help is I’m not 100% sure if it’s the damper or the hydraulic lockout that causes this as last time after re-bleeding they felt a lot better for the first 2 hours of the ride, but I don’t see how the lockout can make them too soft?

The SID fork is less sensitive but I have found it to need tweaking between rides and that I blow through 90% of the travel sometimes but others can struggle to use 50%. I’ve played with damping and added a few air volume spacers which have helped the always “rides too firm but blows through travel issue” but still find them rather harsh at the best of times. Tempted to try a Charger damper but this is £200 on a potentially dead set of forks!

I know I might be searching for something that’s not possible but anyone had any luck modding or tuning their Monarch/SID XX? I’m 75kg in kit and it’s on a 29er Scott spark (2013) if that helps. Happy to go (really) drastic as otherwise they’re being flogged, even willing to ditch the remotes if they ride better! Tempting to chuck the Fox RP3 I have sat in the cupboard at the rear (maybe after modifications?). The only thing I will say in favour of the XX kit is that when new it was a massive improvement over the DT rear shock and FOX forks that came with the bike!

Being an engineer I’ve even started scheming a linkage fork to be made from a set of rigid forks I have sat in the garage! I’ve even taken to riding my rigid SS more as at least that’s predictable!

I had an XX on my Scalpel and didnt like it at all. Struggled to get full travel. I think they have quite a ‘race’ tune. ie not very plush. There is a great long thread on mtbr about tuning them and messing with the ISP pressure. I gave mine a strip down and altered the oil depth and dropped the ISP pressure from 550psi to about 250. Shock was better but in the end I bought a Manitou Macleod as loads of folks really rated them. Bike is totally different. Mid stroke is so much better and I can get full travel regularly. Just for reference mine was a 165×38. Still got the XX kicking around in the shed somewhere.

Read the reviews on the Macloed here. You can get a 4 stage remote for it too

https://www.chainreactioncycles.com/manitou-mcleod-rear-shock/rp-prod129744

Yeah, the Macloed had caught my eye, can be got for £160 and very tempting.
Mines 165×38 too, tried dropping to 400psi ISP but had read that they can cavitate at 250psi so avoided going that far, might give it a go if you felt it helped.