How to change a stem?

canada16

Hey I am buying a Wet red ritchey stem.

Is as easy as just taking off bolts from the old one and taking the headset bolt off and just changing them over?

Anything I need to watch out for?

Cant seem much on google about changing just the stem.

Thanks

nicklouse

no need to remove all the bolts.

canada16

I assume I just loosen the front 4 to slide the bar off, then the ones attached to the forks?

And would then need to remove the top cap ?

d3matt

I've just replaced my stem with a shorter Ritchey WCS. It's very easy and quick.
Four bolts to remove bar and just remove the cap and undo the headset bolt. The longest bit is getting the handle bars at the same angle. All in, a 10 minute job - if that.

canada16

Nice one, thats what I thought

nathanst170

watch you dont over tighten the bolts make sure you follow the torque setting for the stem that way your less likely to round the bolts off also tighten corner to corner in a diagonal patternsor you apply an even amount of pressure and also slightly grease the bar to stop creaking

Simon G

Can16,

Yes, as the other poster's have stated, it's a very easy job to replace a stem. I notice that no one has mentioned the fact that you use the top-cap bolt on top of the stem to preload the headset bearings.

http://www.parktool.com/blog/repair-hel ... et-service
(scroll down to the headset adjustment part of the document or just read from the copieed extract below):

Headset Adjustment - Threadless Type

Threadless headsets work on the same principal as threaded headsets. The bearing races need to press against the bearings. The bolt in the top cap will put pressure on the stem, which presses on washers below the stem, which press on the bearing races, which press against the bearings.

NOTE: The cap and bolt at the top of the stem do not secure the stem onto the steering column. The bolt or bolts on the side of the stem keep the stem from moving once the adjustment is made. The cap is used for bearing adjustment only.

Begin by removing the adjusting bolt in the center of the steering column. Next, remove the top cap. There may be a star-shaped nut or other fittings inside the steering column. The bolt threads into this fitting and pulls on the fork against the headset bearing surfaces, which acts to tighten the adjustment. Note the height of the steering column relative to the stem. It should be about 3mm (1/8") below the level of the stem. The stem needs to press down on the spacers in order to adjust the bearings. If the steering column is level with the top of the stem, another spacer is needed below the stem.



1. Remove bolt and top cap to inspect steering column. Lubricate adjusting bolt and re-install cap and bolt by hand only. DO NOT TIGHTEN.
2. Loosen stem bolt(s) that secure stem to the steering column. Lubricate these bolts if they are dry. NOTE: DO NOT LUBRICATE INSIDE STEM OR ON STEERING COLUMN SURFACE.
3. Wiggle the stem side to side to see that it is loose. If the stem is jammed or rusted frozen to the steering column, no adjustment can be made.
4. Align stem straight to wheel and gently secure the top bolt. Stop when any resistance is felt.
5. Tighten stem bolt(s).
6. Check for play by pulling back and forth on fork. Turn the handlebars in different directions while checking for play. There may be play at this early setting. Use care when grabbing suspension forks, because the legs may have play. Grab upper portion of fork.
7. To adjust bearings, LOOSEN STEM BOLT(S).
8. Turn adjusting bolt in center cap only 1/8th turn clockwise.
9. Secure stem bolts, check for play again.
10. Repeat adjustments as above until play disappears. Remember to loosen stem bolts before turning adjusting bolt in cap.
11. Check alignment of stem and tighten stem binder bolts fully.

NOTE: Another test of play is to place the bike on ground and grab the front brake tightly. Press downward on the handlebars and rock the bike forward and back. A knocking sensation may indicate a loose headset. In effect this does the same thing as grabbing and pulling on the fork. However, play in the brake caliper arms may also cause a knocking. Front suspension forks may also have play in the legs, which can cause a knocking.If the adjustment seems very tight, there may be other problems in the headset. Bearing surfaces may be worn out, or the ball bearing retainers may be upside down, or a seal may be improperly aligned. If play always seems present no matter the adjustment, the steering column may be too long for the stem and top cap. Add spacers beneath stem in this case.
Bearing Adjustment and "Feel"

Bearing surfaces are made from hardened steel. The surfaces are cut typically by grinding. Round ball bearings roll on the curved surface of the cup and cone. Even the highest quality bearing surfaces will have slight grinding marks. In the left image below is a high quality cone magnifed two hundred times. Notice the parallel marks from the grinding stone. Also note a slight pit from wear. The right hand image is a bearing magnifed the same amount. It does show some surface marking, but is generally smoother than the cone or cup. Bearing surface smoothness will vary between manufacturers and between models. Some bearing system will simply "feel" smoother because they are smoother. This is why it is difficult to adjust by using a subjective feeling of smoothness. Generally, adjust bearings for the loosest setting that has no knocking or play, regardless of this relative smoothness.

canada16

I am a bit worried as I have carbon bars, but TBH I am sure I wont over tighten.

Thanks again for the detailed explenation, will ensure I take my time. and test ect..

d3matt

Then buy one of these. Well worth the £10.

02gf74

^^^ don't have the time/will to read all that but 2 points, if not already mentioned.

the stem cap bolt is done up enough to take the slack out of the heaset bearings and then the stem bolts done up - it is this that holds the stem to the steerer.

obviously you need to get the correct size stem for you steerer - you can buy shims is your steerer is smaller.

generally the stem heighs are the same but there are some that are different. you must have the steerer about 5 mm less than the top of the stem so that you can fit the cap and tighten that down. if the steerer is more than 5 mm belwo top of stem, you need to get spacers - again ensure you have correct size.

if the steerer protrudes above the stem and there are no spacers fitted, you need to cut the steerer down.

re: torque - I don;t have a torque wrench just use common ssnse and experieince.