kevvyd
Active member
Hey all,
I had installed the kit referenced in this posts' title and thought it was terrible!
Honestly, I thought it was worse than stock. While the ability to pre-load the springs was desperately needed. The hydraulic damping was incredibly harsh at initial movement, but still blew though a lot of travel, AND still exhibited awful brake dive.
I went back into the forks a couple of times and changed the preload on the PD Valve (emulator, aka generic Race Tech Gold Valve....and yeah I know RT did not invent the emulator. But they are the most well known)
I also did 10, 15, &20wt oil swaps to little improvement. Tried a few different oil heights too....didn't matter much until you get toward "too low/little" oil, at which point you could tell the oil readily cavitated.
I had enough and decided experimenting was concluded. The YSS Kit simply sucked, and I rode it that way for 1000 or so miles all the while dreading it and hating the notion of going back to stock and admitting I had wasted my time and money.
Then I was building out (another) pitbike(TTR125) and I was considering installing some RT Gold Valves like I have in some of my other pitbikes (KLX140) and I remembered that Race Tech installation instructions include a process where you enlarge and ADD holes to the damper rods-----"thereby passing all of the VALVING duties to the Gold Valve (emulator/PD Valve/et al) allowing unrestricted free flow of the oil up the damper rod without the restriction of the tiny OEM compression damping orfices.
.....and a light bulb ignited in my head.
If the oil had to FIRST pass through the restricted OEM orfice before it slams into the PD Valve mechanical valve (emulator)---Then you've probably quadrupled the restriction of oil flow on the Compression side of the damping circuit. Also when the oil makes it up to the PD Valve (emulator) it'd be moving low volume/high pressure, which is often more harsh than high volume/lower pressure valving.
Nowhere in the YSS instructions do they tell you about enlarging, or adding, the OEM compression damping orfices in the rods.
But I thought (I knew) that this had to be done in order for the system to not have excessive restriction. AKA harshness.
Fortunately the fork damping rods for CT125 are cheap (like $6 ea.) and readily available, so I ordered a pair and modified them per Race Tech Gold Valve instructions. I installed the newly Modified damper rods, then reinstalled the rest of the YSS kit. This time setting the PV Valve to approximately "3ish Full turns" preload on the PD Valve spring, whereas I had been running it with nearly zero preload with the unmodified damper rods seeking more plushness. The "3ish turns" decision was also inspired by reviewing some Race Tech DVS setup sheets from other kits I'd done.
The fork was refilled with 20wt and set to the 140mm height specified by Honda rather than the 185mm spec suggested in the YSS instructions. Again, oil cavitation seemed more perceivable at the lower (185mm) oil height
(15wt might be better, jury out still)
I put about 3mm (3 turns) spring preload on the adjusters even though I carry very little cargo and weigh only 165 lbs.
I took it out for a test ride on a nearby high-speed run that I know has really shitty asphalt.....holes, surface changes, joints, sunken manholes. I know the road well and usually dodge as many of these "features" as possible on my commutes from home......but not on this ride.
OMG, it was incredible!
The difference was staggering!
The bike was very supple and balanced over some "big hits" at speed.
The dive when the front brake are applied was reduced by probably 75%. (aka GREAT, problem solved)
It felt very planted, smooth, and stable. Everything you want really!
Planted like the size of the tires on the bike had doubled and you just have more cushion.
Being greedy.....I took most of the fork mainspring preload that I had preemptively applied back out to nearly zero turns on the external top adjuster. And it did indeed ride softer....
The stability and consistency was noticeable as I banged a couple aggressive 90* turns.....no mid-turn adjustment required or "unsettled-ness". I was shocked at the benefit in this aspect.
The "goodness" of the front suspension highlighted how terrible the rear is!
I might go back down to 15wt, or take 1-turn off the preload off the PD Valve (internal) as I thought it might be a little slow on rebound, and could probably be fine with slightly less Compression damping.
Otherwise it is fantastic. I definitely could leave it "as is" and be totally pleased. If there is a 100%-------I got 85% right out the gate.
Very happy right now.
Photos are: Product, Race Tech Suggestions, Unmodified Damper rod, Modified Damper rod
I had installed the kit referenced in this posts' title and thought it was terrible!
Honestly, I thought it was worse than stock. While the ability to pre-load the springs was desperately needed. The hydraulic damping was incredibly harsh at initial movement, but still blew though a lot of travel, AND still exhibited awful brake dive.
I went back into the forks a couple of times and changed the preload on the PD Valve (emulator, aka generic Race Tech Gold Valve....and yeah I know RT did not invent the emulator. But they are the most well known)
I also did 10, 15, &20wt oil swaps to little improvement. Tried a few different oil heights too....didn't matter much until you get toward "too low/little" oil, at which point you could tell the oil readily cavitated.
I had enough and decided experimenting was concluded. The YSS Kit simply sucked, and I rode it that way for 1000 or so miles all the while dreading it and hating the notion of going back to stock and admitting I had wasted my time and money.
Then I was building out (another) pitbike(TTR125) and I was considering installing some RT Gold Valves like I have in some of my other pitbikes (KLX140) and I remembered that Race Tech installation instructions include a process where you enlarge and ADD holes to the damper rods-----"thereby passing all of the VALVING duties to the Gold Valve (emulator/PD Valve/et al) allowing unrestricted free flow of the oil up the damper rod without the restriction of the tiny OEM compression damping orfices.
.....and a light bulb ignited in my head.
If the oil had to FIRST pass through the restricted OEM orfice before it slams into the PD Valve mechanical valve (emulator)---Then you've probably quadrupled the restriction of oil flow on the Compression side of the damping circuit. Also when the oil makes it up to the PD Valve (emulator) it'd be moving low volume/high pressure, which is often more harsh than high volume/lower pressure valving.
Nowhere in the YSS instructions do they tell you about enlarging, or adding, the OEM compression damping orfices in the rods.
But I thought (I knew) that this had to be done in order for the system to not have excessive restriction. AKA harshness.
Fortunately the fork damping rods for CT125 are cheap (like $6 ea.) and readily available, so I ordered a pair and modified them per Race Tech Gold Valve instructions. I installed the newly Modified damper rods, then reinstalled the rest of the YSS kit. This time setting the PV Valve to approximately "3ish Full turns" preload on the PD Valve spring, whereas I had been running it with nearly zero preload with the unmodified damper rods seeking more plushness. The "3ish turns" decision was also inspired by reviewing some Race Tech DVS setup sheets from other kits I'd done.
The fork was refilled with 20wt and set to the 140mm height specified by Honda rather than the 185mm spec suggested in the YSS instructions. Again, oil cavitation seemed more perceivable at the lower (185mm) oil height
(15wt might be better, jury out still)
I put about 3mm (3 turns) spring preload on the adjusters even though I carry very little cargo and weigh only 165 lbs.
I took it out for a test ride on a nearby high-speed run that I know has really shitty asphalt.....holes, surface changes, joints, sunken manholes. I know the road well and usually dodge as many of these "features" as possible on my commutes from home......but not on this ride.
OMG, it was incredible!
The difference was staggering!
The bike was very supple and balanced over some "big hits" at speed.
The dive when the front brake are applied was reduced by probably 75%. (aka GREAT, problem solved)
It felt very planted, smooth, and stable. Everything you want really!
Planted like the size of the tires on the bike had doubled and you just have more cushion.
Being greedy.....I took most of the fork mainspring preload that I had preemptively applied back out to nearly zero turns on the external top adjuster. And it did indeed ride softer....
The stability and consistency was noticeable as I banged a couple aggressive 90* turns.....no mid-turn adjustment required or "unsettled-ness". I was shocked at the benefit in this aspect.
The "goodness" of the front suspension highlighted how terrible the rear is!
I might go back down to 15wt, or take 1-turn off the preload off the PD Valve (internal) as I thought it might be a little slow on rebound, and could probably be fine with slightly less Compression damping.
Otherwise it is fantastic. I definitely could leave it "as is" and be totally pleased. If there is a 100%-------I got 85% right out the gate.
Very happy right now.
Photos are: Product, Race Tech Suggestions, Unmodified Damper rod, Modified Damper rod
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