I'm trying to find out what spring rate people are using for there TTX forks. I have 48's in there and I think they're to stiff. CAn someone tell me what they are using. I'm 185 without gear, the front end feels like it's on ice, and on the trail there is about 6" of travel not being used. If I smash something real hard there is about 3" left. I had 46's in the sach's fork before.
TTX spring question
- Thread starter mikemoto
- Start date
Wow that is stiff. A fork is a fork so spring rate shouldn't be setup different, just the valving.
twowheels
New member
My guess would be 0.44s, with 0.46s on the upper end if you carry a car jack in your tool kit or you're incredibly fast. I'm with Glenn though - spring rate should be defined by the combined weight of you and the bike.
Just to cover all bases though I've got a call in to Ohlins. Are these full TTX forks or inserts for the 48mm Sachs?
Simmo737
Gold Level Site Supporter
I'm 205Lb and they wanted to send me .50 I got .48 sent, started using the .46 I already had and bottomed, went up to .48 and added 20cc of oil and I'm soft bottoming occasionally on big jumps, I'm 20 out comp, 15 reb which is five steps each. Ohlins definately seems to need a one step stiffer spring and the clickers really work and seem more linear (dont have a bigger impact the closer the get to all the way in). The forks are really really good, but feel different. They follow the ground a lot more but don't transmit shock, once you are used to it they are great.
Simmo737
Gold Level Site Supporter
My stock oil was 280, I'm at 300, if I went to 320, I reckon I'd never bottom, that's including doubles, grass track drop offs and g outs, I can't bottom them on braking bumps at 300 ml. I reckon youd get away with 300 to 310 ml. I first used silkolene rfs5 and I've decided I don't like it, I went back to motul 5w expert and it feels better, might just be in my head, but it feels less busy.
I ran the TTX inserts in my 08 KTM 200XC (best forks ever...). I weigh 200 with gear and I never could get the fork sag correct with anything but .48s. My Ohlins tuner was real, real picky on the fork sag being (if memory serves me correctly) between 25-35mm. The bike was great in everything but the real slow and choppy stuff. I am the first to tell you that I am willing to trade off a bit of plushness for more control. You could point the bike at a field full of bowling ball sized rocks or at the gnarliest set of roots imaginable going WFO and the bike would not miss a beat. It only got better when I added the TTX shock....
Oh, I still have the fork inserts for sale....
Oh, I still have the fork inserts for sale....
I'm using the Ohlins 5 wt. oil My biggest complaint is turning. The bike feels like the front end wont hook up. I have no complaints about TTX this is the second bike I have put them in. I will be flying down a trail and all of a sudden there's a 6" log across the trail I didn't see, the fork smash's into it and you don't even feel it. I took them apart last night but have not put them back together yet. Maybe I'll try the 48's with less oil, and lower the triple clamps a little. I know these are race forks and they don't like slow going, but when the speeds pick up, it's a magic carpet ride.
GMP
Active member
To me it makes perfect sense it doesn't turn and feels crappy, probably rides like a chopper. Fork sag is a poor diagnostic due to the stiction, unlike the rear. I'm sure most tuners will tell you this. I've had Ohlins forks before, and read all the manuals, they place too much emphasis on this IMO. All TTX is afterall is a dampening system, and there is no way its perfect out of the box for everyone, just like any other fork. Some guys seem to think this is a magic bullet and revalves do not apply. I'd just set the spring rate to what you typically run, and adjust oil level and valving accordingly. I'd start off with a .44 - .46, a couple mm of preload, add oil so it doesn't bottom too much, and go from there.
Simmo737
Gold Level Site Supporter
I found the forks unusually sensitive to rebound change, it really helped with harshness and didn't affect control, it also seemed to aid grip, I have them flush with the clamp and no preload insert and 108mm sag 10 mm preload rear , turns inside an rmx 450 no problem and tracks way better. I would try the .46 and 280 to 300 if your not using the last 4 inches.
I reckon the vinduro sag settings over on cafe husky are the way to go, sag is geometry, but to a point determines where the fork rides in the stroke.
I reckon the vinduro sag settings over on cafe husky are the way to go, sag is geometry, but to a point determines where the fork rides in the stroke.
44 in both legs is magic. 300 cc oil tested on my 4 mi. practice track that has super tight rooty woods, some fast straights, and even some woops. Felt perfect to me. And just for fun a few of my buddies went out and put about 30 3-4" logs across the trail in about a 50 ft. Section and the bike blew through them like they weren't even there. Now I will play with the ttx shock clicker to dial that in. The heavy spring made the bike not turn. it was weird, now the bike turns and eat trail just for lunch
GMP
Active member
mikemoto,
Yes, thats a 5.4 spring (actually 54Nm as Ohlins rates them). Like the fork it does not matter what brand shock it is. For the same bike with the same rider weight, the correct spring rate will be the same, no matter what the damper units are, Ohlins TTX, OHlins 888, Sachs, etc.
Yes, thats a 5.4 spring (actually 54Nm as Ohlins rates them). Like the fork it does not matter what brand shock it is. For the same bike with the same rider weight, the correct spring rate will be the same, no matter what the damper units are, Ohlins TTX, OHlins 888, Sachs, etc.
