It's been posted on the Facebook groups here or there, but I haven't seen anything here, so for posterity sake I want to include my own review of it.
Not my discovery, just borrowing somebody else's hard work and then giving it my seal of approval. I also included it in the Upgrades part of the resource guide. I need to take the time to clean that up and add some stuff... someday.
Anyway, the clutch springs in question are these. EBC CSK41
https://www.amazon.com/dp/B001IUMGEY...Gbp4Rm-fWOvV3c
They are a tad shorter than the stock Hawk springs, but they are quite a bit stronger. They still preload properly when installed, and the clutch feel is greatly improved.
More importantly, and the main reason I did it... Clutch fade is greatly reduced. The clutch feel when the engine gets really hot is massively improved. I wish I would have done these from day one. Especially considering they are only $14. and can be installed in maybe 30 minutes or so.
Just make sure when you remove and install the pressure plate with the bolts to back them off evenly so you don't break the pressure plate. A couple turns at a time in a criss-cross pattern until they seat. I used the final torque spec for a CRF230F Clutch which is 12Nm/9ft-lb/108in/lb