they are pretty good imo and they put tension on the spring because of their longer length even on lowest setting which mine and looks alot better iwould get plane with no anodizing scratch proof titanium is not bad either but yea stiffens for sure how much dont know
w w w.aliexpress.com/cheap/cheap-yamaha-r25-fork-cap.html
idk if its bad for the spring if you put at the max setting like rubbing against the fork tubes so do it at your own risk alot of people on you tube have done it too and do it with patience if u get em so you dont **** up the treads
Getting the springs right (correct rate for your weight) is very important; 1st thing to dial in when modifying your suspension.
A heavy weight oil can increase damping (compression and rebound) but is a false way of helping the front oem springs to support a heavier rider as it compromises the ride a lot for minimal gain.
Increasing the the preload can be a way to go if your weight is close to matching up with the eom spring. You can do this a few ways; buying a new cap with preload adjustability (~ $20) or simply cutting a short piece of pvc pipe (~$2) to put under the stock spacer in both forks or cutting a longer piece to replace the oem spacers altogether. The increased preload length (say 0.75" longer) is only going to add a small additional capacity. If you are a 190 lb rider, this might close the deal for you. If you are heavier, you are realistically going to have to change out the springs. If you do, go with straight rate springs.