Hmm, do you think I could get away with running one .90 spring? Since I still have the set that came on my bike...
Thanks for all your help!
IMO, it would certainly be better than running two .90's, or two OEM.
I hesitate to recommend it, not knowing how you're getting fork work accomplished.
If you're paying a tech to do it, then I think that a 0.9/OEM is not the best place to start, as it might take yet more internal fiddling to get it 'right'.
If you're DIY and game to spend the time, then go for it.
<rant>
Take specific and detailed notes of what springs and oil you're running, damper screw settings, how it feels when you ride it with those settings, etc. etc. etc.
Make your best effort on this, it is unlikely that you can take too many notes.
If you do not, it is nearly impossible to avoid getting lost and thus making wrong adjustments and wasting resources.
I've been doing R&D testing as part of my job for over 3 decades, my FHE is that crappy/no notes = you're make the beast with two backsed.
I see amateur racers that run season after season with no log book at all, so they've no accurate records of when what was done, nor what settings used, or results.
No checklist of what equipment to bring, no checklist of what pre-race tasks need to be done.
They have no idea why the bike doesn't behave the way it used to or why it breaks down all the time.
Honestly, it's an absolute disaster.
And zipties as structural fasteners....it makes me weep.
</rant>
There's a couple of annoying traps you can fall into with running different springs in each side:
Your forks have top-out springs in them; small springs in the damping cartridge that keep the fork from topping out with a clank.
With the front wheel not supporting any weight, as you add/remove preload, the forks will extend/retract a little bit, as you've got springs pushing against each other.
Different rate springs make the forks extend/retract different distances for the same # of turns on the preload.
So even moderate changes in preload can make it really hard to get the axle in or out.
Countermeasure:
Install the forks at the same outer tube height, with zero preload.
The stiffer spring's preload adjuster is the 'master', and the softer one is the 'slave'.
Fit the axle *only*, adjust the 'slave' preload such that it slides in and out easiest.
*Write that setting down* IE master 0, slave 1/2 turn.
Run the master preload in a couple turns, adjust the slave again.
"master 3, slave 4 3/4" (or whatever)
Step up a couple more times.
Finally, run the slave all the way in, and adjust the master.
"Master 13 1/2, slave 17"
That's your max.
You've now got a table to refer to for settings.
With that, you can avoid a lot of aggro and fuxxored parts.
Set the total length of the springs + spacers the same each side, as OEM and aftermarket springs are almost never the same length.
Racetech springs are often a bit smaller diameter on the inside, and they hang up on the plastic cup gizmo that's on the damper rod.
Remove said cup if that's the case.
