I bought a used Giant OCR3 with an adjustable stem on it. I want to adjust it a little bit, but I can't figure out how to go about this. I tried loosening the nut/bolt right next to the degrees labels, but that didn't budge. What's the proper procedure to go about this?

Side view:


Top view:

If it's like my Ritchey, you will need to take it off the bicycle - leaving the handlebars on. Start by removing the top-cap on your headset. Loosen the bolts on the stem and slide it up & off. Then loosen the silver bolt on the adj. stem. From there it should be able to be adjusted to the height/angle you wish. Re-tighten the silver bolt and slide it back on the steering-tube. Tighten the bolts TIGHT and replace the top-cap. Adjust that until the handlebars turn freely when you tilt the bike towards the ground - but not so that it's loose. Make sure by applying the front brake and, holding by the middle of the handlebars, push the bike (on the floor) back and forth. Make sure there is no play.

I have a Trek 7200 with a similar-looking adjustable stem. On the wheel side (bottom of the adjustable part) there's a hex set screw that holds in a wedge-shaped part with teeth that match those on the vertical part. Loosen the set screw and the wedge comes loose enough to adjust it (or falls out onto the ground like mine did).

I have a Nashbar house brand adjustable (Kalloy?) stem. You loosen the hex bolt whose head faces the drive side of the bike several turns and push in on it's head. That pops out the disk on the other side that has teeth that mate with teeth on the stem itself. Adjust the angle, push the nds disk back in to reengage the teeth and tighten the hex bolt TIGHT.

I followed Drivr8 and HillRider's advice in trying to loosen the hex bolt at the bottom of the adjustable part on the drivetrain side, but no matter how hard I tried, I couldn't loosen it. There's actually an identical hex screw on the opposite side, which I find odd. I tried loosening that also, but it did not budge. Do your stems have the same hex screw on both sides of the adjustable portion of the stem?

Well - why don't you try it my way then? It might be the magical one.

I'm going to leave that for Wednesday since it seems more complicated/likely to mess up because of my inexperience, and I need my bike til then. Will report back then!

The other screw you need to loosen is here:

+1 on that. The two adjustable ones I've encountered worked that way. The teeth engagement is quite deep, so you really need to loosen the bolt several turns to get the stem moving. It's not something you can undo a little and get it to slide.

I have a similar stem on my mtb. One of the hex bolts screws into the other one.

If none of the above procedures work (but I have a feeling flanso's diagram will do the trick) try lightly tapping the top of the hex bolt with a hammer after you have loosened it to see if it pushes the other hex bolt out the other side. It may just be a bit tight.

Like dabac says, loosen it a lot first - i.e. loosen it until it's falling out then reinsert it and tap it.

+1 It may well need to be totally removed, and the adjusting mechanism smacked with a rubber-mallet to get it to let go. While a PITA, this is good as it means that stem won't likely come loose while you're riding the bike.

I loosened this, even taking it out completely, but that did not help me in loosening the hex screw immediately to the right of the degrees labels in the first picture. I then took Panthers007's advice in removing the stem with the handlebars attached. This also did not help me loosen the same hex screw stated above. So...I'm bringing it to the LBS tomorrow to see if I'm just really sorely lacking in muscle because no matter how hard I twist, that hex screw does not loosen.

Just to make sure, since I can't loosen that screw, I can't do the whole push it in so the other part comes loose, right?

Try the hammer-trick. Drive the hex-bolt out. Then, if still no-go, take it to your LBS.

Good Luck!

The LBS said that yeah, all you need to do is to loosen the screw marked in green in that one picture, and the aluminum blocked with the teeth should just fall out. I showed them it didn't, and they attacked it with screwdrivers, pliers, hammers, and brute force. After much banging of my bike on the floor, the thing popped loose.

So you guys were all right, the bike was just damn stubborn. Thanks for your help!

I hope you put some grease in it before re-assembling.