# Stock forks, whats the knob adjust?



## trail_boss2 (Jan 18, 2010)

Stock 2009 Specialized Hardrock. On the forks what does the the knob on the right side adjust? I'm assuming stiffness but not sure. Played with it just a bit today but couldn't tell a noticeable difference when just riding down the street.


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## hardtailkid (Jan 25, 2010)

On the right side it usually adjusts compression. i.e. the tighter you turn it (righty-tighty, lefty-loosy) the more pressure you will have to put on to the fork for it to get travel. Opposite for turning the knob to the left.


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## trail_boss2 (Jan 18, 2010)

Reading on the specialized website it says its external preload adjustment, same thing?


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## Bikinfoolferlife (Feb 3, 2004)

There were 3 different forks spec'd on the various models of Hardrock from what I see on Specialized's site. Sometimes changes are made in spec that aren't reflected on a website, too....best to specify what fork you've got (did you try going to the fork manufacturer's website for a manual?). Likely it's a rebound damping adjustment or a preload adjustment but hard to tell from your description, and could be that it has little effect in any case.


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## trail_boss2 (Jan 18, 2010)

SR Suntour SF8-XCT-V2, 80mm, 1pc. alloy lower, 28mm Hi-Ten stanchions, 13-15": standard spring, all others: "stiff" spring, coil/mcu spring w/ preload adj., spring assisted seals, disc only


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## Bikinfoolferlife (Feb 3, 2004)

So it's a preload adjustment, and depending on your weight and the spring rating, may or may not have much effect in helping you set sag (which is what it's basically for). What sag did you get setup for?


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## trail_boss2 (Jan 18, 2010)

Bikinfoolferlife said:


> So it's a preload adjustment, and depending on your weight and the spring rating, may or may not have much effect in helping you set sag (which is what it's basically for). What sag did you get setup for?


I didn't get set up. I rode 4 or 5 different bikes and this is the one that felt the best to me. I got the bike used and its my first mtb so I don't know much about that stuff to be honest. Not sure on the spring rating and I weigh about 180lbs.


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## Bikinfoolferlife (Feb 3, 2004)

To measure your sag you basically want to measure how much travel is used just by having your weight on the bike (no bouncing up and down, just a static riding position). Often helps to use either a zip tie on the stanchion if you're on your own, or have a friend measure for you. You probably want about 20-25% of the travel used as a starting point, and whether you get that or not will depend on what weight their "stiff" spring is designed for (at a guess it's probably the right spring for your weight). You get a small amount of adjustability with the preload, more preload tension makes the suspension sag less and less preload makes the suspension sag more (probably turning the knob to the right adds tension).


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## trail_boss2 (Jan 18, 2010)

So do I need it turned all the way to the left as the default and then measure my sag from there? When I have it adjusted to the default position I place a zip tie on the stanchion at the bottom and then sit on the bike and where the zip tie rests is my sag... then adjust the knob until I get the zip tie to rest at about 20-25% of the length of the stanchion? Sorry if that doesn't make sense and thanks for all of the answers! As a new guy I love learning stuff like this.


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## Bikinfoolferlife (Feb 3, 2004)

Sounds like you've got it down, although it really depends on the spring that came in your fork, rereading the description you provided I'm not sure what spring you've got (not sure what the 13-15 inches might mean, and it seems to say there's two springs, standard and stiffer but not sure...was the Suntour site any help?).

PS Don't expect a lot of performance or tuneability from a fork like this, either....


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## trail_boss2 (Jan 18, 2010)

Bikinfoolferlife said:


> Sounds like you've got it down, although it really depends on the spring that came in your fork, rereading the description you provided I'm not sure what spring you've got (not sure what the 13-15 inches might mean, and it seems to say there's two springs, standard and stiffer but not sure...was the Suntour site any help?).
> 
> PS Don't expect a lot of performance or tuneability from a fork like this, either....


Here is the link to the fork on the Suntour website. I am actually planning on upgrading the fork to something a bit better anyways, something affordable but not sure what yet. Just wanted to learn a bit about what I have and about the suspension in general.


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## Bikinfoolferlife (Feb 3, 2004)

Just took a look around at their manual and diagram (http://srsuntour-files.dbap.de/_pub.../Owners_Manual_RaidonCoil_XCR_XCM_XCTV2_M.pdf and http://srsuntour-files.dbap.de/_public/tuningbase/downloadarea/explosions/SF7-XCM.pdf) neither of which help with any possible spring info that I was curious about. The diagram is more useful than that manual, too.

PS Oops, wrong diagram, this is the right one http://srsuntour-files.dbap.de/_public/tuningbase/downloadarea/explosions/SF8-XCT-V2.pdf


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## trail_boss2 (Jan 18, 2010)

So while we are on the topic of forks, what are some of the other terms I need to know and what do they do for future reference when I am buying new forks? Lockout for instance?


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## Ktse (Jul 12, 2008)

trail_boss2 said:


> So while we are on the topic of forks, what are some of the other terms I need to know and what do they do for future reference when I am buying new forks? Lockout for instance?


Preload is what you have on your stock forks... if it's anything like my buddy's hardrock both those knobs will adjust preload because there are two coil springs in each leg. Each manufacture has different settings on their forks so it's hard to make a generalization on how the way things are.

http://en.wikipedia.org/wiki/Bicycle_suspension#Terminology

The wikipedia article should answer all your questions about what features higher end forks can have. All you can adjust right now is preload; there is no damper circuit in the low in suntour forks. What you look for in the future is damping; this will transform a fork from a uncontrolled spring into a real fork as it will slow down the spring when you hit bumps and keep everything in control. Lockout is not crucial unless you plan on riding on the road alot, lots of compression damping can substitute for that though.


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## biggoofy1 (Aug 24, 2009)

i found those knobs useless i never felt a difference but the stock suntour was such a piece of sh*t i replaced it as soon as i could


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## grivooga (Mar 14, 2009)

My Hardrock came with an RST Gila T5 but it sounds similiar. I'm a heavy rider but I felt most comfortable with mine set to the lowest preload. Because there's no damping circuit if you compress the fork hard it would spring back with a vengeance. I felt that reducing the horrible rebound was worth not having the sag set correctly. Lost a little bit of travel which probably steepened the angles some but it had no problem with bottoming out. Anything was better than having the bike bounce back uncontrollably. Until I upgraded to a much nicer full-suspension bike I thought the crazy rebound was something you had to learn to adapt to. Now I know better, it's just a cheap fork. 

For some real fun forget the suspension all together. My cyclocross bike with 38mm tires makes a fun trail runner for beginner/intermediate level trails.


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## AndrwSwitch (Nov 8, 2007)

Some of those low-end forks don't really need rebound damping because of how much friction there is in the system. Obviously it's not ideal, but at least they don't act like pogo sticks as much as they could.

Fancier forks tend to use an oil bath. I'm not sure if your fork would or not, but I'd put my money on your finding some grease slathered onto the spring and maybe the stanchions if you opened it up.

I thought you pulled the trigger on something on Jenson the other day?

Anyway, I think that compression/pre-load on a coil fork or air pressure on an air fork and rebound on either type are the two most important things to be able to adjust.

Lockout is kind of a funny adjustment and means different things on different forks. It has a blowoff function on almost all forks to prevent damage if you go off a drop or something with it on. On some forks, it's basically an on/off switch with the blowoff feature present only to prevent damage, but on others the blowoff force is adjustable. If it's adjustable, you can set the blowoff force low and leave the lockout on all the time in order to have a fork that doesn't bob when you pedal but opens up for bumps on the trail. Or so says the marketing text. Some forks have a platform damper, which is kind of like a lockout that's always on with a very finely tunable blowoff.

My own fork is an older Manitou R7 I got on EBay. It's an air fork, so sag is set by setting pressure in the air spring leg. It has a rebound damper, which I typically set to be pretty mellow and a platform damper. I believe that my race times are better because of having the damper, but I think that if I was just riding casually, I would only miss the damper during climbs out of the saddle. I like the platform damper because I think I would find it annoying to turn a lockout on and off, but I think I'd like a well-executed lockout with a tunable blowoff just as much - I'd just leave it on.

So ultimately it comes back, again, to how much you want to spend. I'd say that in order to have a fork you don't get annoyed by and replace in a season, you should buy something with at least a pre-load or pressure adjustment and a rebound damper. Everything else is for improving efficiency but shouldn't effect your ability to keep the bike in control as much.

Grivooga has a point as well - one of the biggest upgrades for me in switching to my current fork was having stiffer stanchions. I believe my Hardrock would have been more fun to ride with a decent-quality rigid fork than the RST that came on it. That's also a pretty inexpensive option. I'd try to match the axle-crown length of the rigid with the axle-crown length of a 100mm fork at sag (450-460mm, give or take.) I raced a rigid bike once last season while my fork was messed up. I didn't notice much of a difference pre-riding the (flat) course, but when I was racing, it was brutal - I felt like I was riding a jackhammer. I think descending on a rigid bike would be similarly difficult.


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## trail_boss2 (Jan 18, 2010)

Yeah I did pull the trigger on Jenson, got a Tora 318 Coil U turn. The stock forks felt so flexy and weak. I don't plan on doing anything crazy but I also don't want the constant worry of something happening to them. I messed with the adjustment of the stock forks and tried all kinds of different settings and to be honest it didn't make any sort of difference at all.


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## AndrwSwitch (Nov 8, 2007)

trail_boss2 said:


> Yeah I did pull the trigger on Jenson, got a Tora 318 Coil U turn.


I bet you'll be a lot happier with that once you get it. I'm going to be really curious to hear what you think of the motion control feature - it sounds like the "make me climb faster" feature on Rock Shox forks.


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