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Discussion Starter · #1 ·
i have a 06' tora 318 fork. i was reading on how to set it. it says bottom it out and adjust the preload, etc. i cant seem to bottom it out. i weigh about 140lbs. do the preload really do much and does it really matter? i can probably push it down about 2" at the most. it says it has a 4" travel.
 

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Discussion Starter · #3 ·
fred3 said:
"do the preload really do much and does it really matter?" Yes it does do much and yes it does matter.
can u go into more detail plz. when i was deciding on the bike, i read i a lot ppl saying that they can bottom their forks easy. i cant even come close.
 

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Old man on a bike
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Can you go into detail, please? Do you have the air fork I see on the SRAM website for a Tora 318? It seems only to be an air fork, so how does preload come into the equation? What air pressure are you running? What do you weigh? What kind of terrain do you ride? I haven't seen the manual, but something tells me it doesn't ask you to bottom it out until you set the sag correctly, did you do this? If you do have a coil spring, which spring do you have?
 

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Haro Sonix LT VL120
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I am going to give you a general way to set your forks preload properly. Get a zip-tie and tie it around one of the fork's upper tubes (the silver ones) and push it to the bottom of the upper tube. Then sit on your bike like you were riding normally. When I say normally I mean like any normal person. When I say any normal per... you get the idea. Adjust your preload until the fork sags about twenty percent of it's travel. When you get off the bike the sip-tie should be at around 80mm of the forks travel.

Again this is a general setting. Use your own jugdement according to how you like the fork to feel when you're riding. Try this setting on the trail and fiddle with it until you get the feel you want.

Happy riding,
David
 

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Old man on a bike
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I came back here as I realized there could be preload on the 318 air, duh. Positive chamber/negative chamber, wasn't thinking. On the other hand, what both D-avid and iloveclimbinghills describe is setting sag, not preload. Still need what you are doing specifically to setup your fork...
 

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Discussion Starter · #8 ·
im not sure what u mean by setting up my fork. the LBS didnt tell me much when i pick up the bike. i will be going back in a cople of weeks to get it tuned. its on a speacialized rockhopper comp disc. i do normal riding. mainly trail and paved trails. may start looking into tougher trails thats why i want to know how to use the fork properly. i turn both preload knobs and it doesnt seem to do much. there is one on the bottom rt and one on the top left. i weigh about 140lbs. its not an air fork. i dont think so, there is no valve to pump it.


by the way, where can i go to get definitions of what sag, etc mean. im assuming sag is the travel on the fork from my weigh +gravity???

thanx for the info. it is much needed.
 

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Old man on a bike
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Yes, sag is basically the measurement of how much the fork/shock compresses under you while stationary on the bike in a normal riding position (helps a lot to have a second person doing the measurements on a fs bike, for just a fork the ziptie method mentioned earlier works well).

For most forks/shocks you set sag to be somewhere between 20-30% for cross country riding, more for fr/dh but it varies with your shock. Did you download a shock manual from SRAM for your fork? It likely has instructions on adjustments and guidelines for sag amount. I doubt very much you have two preload adjusters, one's probably a rebound adjuster.
 

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Discussion Starter · #10 ·
ur rt. upper lt is preload. upper rt is compression. lower rt is rebound. what do all those do anyways? sorry for the noob questions.

i figured the compression part out. im asuuning the other 2 are to fine tune the compression.
 

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Compression damping is the damping applied to the spring in the compression mode, rebound damping is the damping applied to the spring in the rebound mode. Preload is a way of adjusting a spring for a given rider's weight.
 

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Discussion Starter · #12 ·
ok, so compression is how fast or slow spring compresses when u hit a bump. rebound is how fast or slow the spring returns to original shape after a bump. preload is the "X" factor , the variable...my wt.

i must be too lite cuz when i adjust the preload i dont notice much difference at all. i set everything to low and i jump on the bike with all my wt and str. and i can probably drop it about,.... wait,does the entire silver part of the fork disappear when it bottoms out. i forget what the silver part is called. there's a name for it, the shiny smooth silver part the goes up and down. does steerer sound rt??? hmm ill have to measure it. 100mm is about 4inches i think.


thanx for the replies and help everyone. man, good thing i dont have a FS , just front fork is hard enough for now, lol.
 

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Did the manual have a chart of available springs and the weight range they're intended for? I know sometimes it isn't clear when you buy the complete bike just what spring the fork has installed, but the shop you bought it from should be able to tell you if the manual doesn't. If you take the spring out of the fork they're often color-coded or otherwise marked. You're weight might be a bit low for the "average" spring that comes in the fork.

Not all stanchions are silver; the stanchions will disappear into the lowers when fully compressed, or bottomed out. The steerer tube is the part that extends from the crown (the connecting piece at the top of the stanchions) up thru your head tube and to which your stem/handlebar attaches (why it's called the steerer).
 

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Discussion Starter · #14 ·
thanx for all the replies and help. your rt, the standard spring is for 14-170 lbs i believe. im gonna go talk to my LBS about maybe getting a lighter spring. sram has a 140 or less one. i think that spring may feel a little better on me. dont think ill be gaining 10-15 lbs anytime soon.

thanx again for all the help!!!!!!!!!:thumbsup:
 
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