Mountain Biking - Chain tension?

Just wondering how I can get my chain tension a lot tighter so it doesn't hit the lower part of the back of my frame (hardtail). Would upgrading to a downhill type front crank assembly help at all? I'm planning on doing a lot of downhill riding with my new hardrock, but I don't want the chain to smack the the rear part every time I hit a jump, or something. Would it become tighter by putting a stiffer spring in the rear derailer? Any advice would be greatly appreciated...Thanks

Just get a chain tensioner. This way you can put some money aside for a DH bike. The Specialized hardrock is not a DH rig, the life span of it will greatly decrease using it that way.

You might also look into getting a chainstay protector from lizard skins. http://www.lizardskins.com/chainstay.html

Definately go with a chain tensioner, and chainstay protector wouldn't hurt either. Like Hunter said, the HardRock really isn't a downhill rig- although I guess it depends on what you consider "downhill" because it could be different than me. It will probably hold up to a beginner's level downhill, with small drops/jumps but I wouldn't go riding off your roof or anything.

Do you have the 2002 HardRock? Which model? The frames have really been beefed up this year into more of a freeride setup, but the components have been downgraded until you get into the Pro models. I've got the 2001 which is more of an XC bike and my definition of downhill is exactly that, riding down a hill. :)

Try putting the chain into the big ring up front. This will tension the chain to a degree, producing less noise. If you are doing some really tough downhill though, a chain tensioner is the only way to go. Also, A Lizard Skins chainstay protector is a great way not only to protect the chainstay, but it also cuts the noise down considerably.

Tighten the B set screw on the derailleur, its the one that touches the derailleur hanger, that will put more tension on the chain. You dont need a frickin tensioner unless you can get one for cheap.

Thanks for all the responses... I'd say th edownhill I'm going to be doing or at least trying will be more towards the intermediate side. Yes, I know I should probably get a better bike, but my 03' frame is pretty damn beefy, and I think it's up to what I'll do to it. I already know all the other components are gonna go downhill when I start (no pun intended) so I've already started a list of what I'm doing to it. I'm planning on trying the single speed thing with a chain tensioner, bash guard, etc on the front and was wondering if I can still use my stock one piece crank with that? If not, then whats the cheapest way to convert? Next would be beefier rims, handlebars, and a front disc. Most of my riding is urban assault, and I believe it's just as rough on my bike as the downhill I'll be doing, so you can see why I'll be upgradign a few things. :D Thanks...

Also, I have another question about chain tensioners. I'd like to get one of these, http://www.cambriabike.com/chain&guide/ac_sport_chainguide.htm , but wondering if it will fit my crank? This crank stuff sure makes my head hurt. I think it's time to indulge and just buy a whole new set-up. All I'm trying to do is get a chain tensioner, bash ring, and get rid of 1st, and 3rd gears up front without buying a whole new crank, but I dont think it will work. By the way my bike is an 03' Specialized Hardrock as pictured here... http://www.specialized.com/SBCBkModel.jsp?san=03Hardrock&bl=mountain

Hmm, I'm wondering how it's going to be doing downhill with a hardtail... :-\

Semi-downhill :p . The rough ride doesn't bother me, but I'm not planning on dropping 5ft+ drops. I prefer the hardtail for riding around the streets as well. I'm just trying to make the most of this bike until I muster up the money for a full suspension downhill bike.

Originally posted by transient
Hmm, I'm wondering how it's going to be doing downhill with a hardtail... :-\

Its rough. I ride a kona roast. There are a few of us out here who do the downhill tracks on a hardtail. It is possible but you have to EXTREMELY skilled at picking a clean line. I also can't go as fast, yet.

Ride what you got CR. When I was hard-tailed I used to just make sure and go to the middle or big ring on the front before I blasted over the lip. It makes the chain tight enough to keep it more still. A dually is better but I think I would be out there even if I was on a Huffy. The bike can take it if you can, trust me. Keep rolling...

Ya i have the same problem and i usually juss avoid the lower gears during a bumpy ride. I still want 2 tighten it so i heard that u tighten the B screw? Where's that? i have a giant rainier so it mite be different.

He is talking about the screw up near the threads that connect your derailure to your frame. I wouldn't mess with it if your shifts are crisp. It adjusts how far the top wheel on your derailure is below your cassette. On most systems, you want it very close to your cassete when in granny. It will tighten or loosen your chain but at the expense of correct shifts. Just get in the big ring if you have time, turn it downhill, hang on and smile... You will have bigger challenges to face than a sloppy chain on your bike. Enjoy.

Cr125Racer, I know you think that a chain guide or "tensioner" might be a cool thing to get, and if you have the money then get one. You should get a double bash ring setup and longer chainring bolts. One bash ring goes in place of the big ring and one goes on the other side of the middle chainring (right?). That way you can throw on the other chainrings AND be able to use them if you want to, because if you had a chainguide, you would have to hassel with the bb to take it off. But if you probably wont ever take a chainguide off, then get one....I think you can get some for like $30. Most chainguides attach to the bb, and you will have to get the right size depending on what size chainring your going to use.