My P3-SL came with 4 spacers installed, several of which I need to remove. Zinn calls this an “intermediate-level” wrench job, and before I undertake it (or go to my LBS), I thought I’d seek your input. I know I need to support the fork before removing the stem. Are there other possible pitfalls? I’ve searched for other threads, looked on the Park Tool website and elsewhere for other shop manuals.
It seems straightforward, but I certainly don’t want to screw up the steering column. Any advice would be appreciated.
Easiest to do if the bike is upright on the ground, that way you don’t need to support the fork. First loosen the stem bolts, then the top cap. Then slide the stem off the steerer tube, remove the spacers you want removed, replace the stem, and slide the spacers onto the steerer tube above the stem. Now you can put the top cap back on, making sure not to tighten it too much and then tighten the stem bolts. Once you are sure you like that position, you could cut the steerer tube shorter so that you don’t have any spacers on top of the stem…
Do you have a trainer? yes, great. No, no big deal.
Put bike in trainer, or support it so that it stands up on its own.
Remove fork cap, remove stem form fork tube (losen bolts slide it up and off). Remove spacers (they just slide off).
Reinstall stem, spacers on top, and cap.
The only thing that might make this hard is if you donot have enough play in your cables to slide the stem op and off the fork. In that case you will have to remove the stem from the bars. No big deal, just an extra step.
Its a snap. I usually leave the bike on the ground or in a trainer to keep the fork from falling out.
Remove the top cap (the round thing that probably says ‘cervelo’ on it)
Loosen the two allen bolts that hold the stem on the steerer tube.
Remove the stemm and whatever spacers you want to take out.
Replace the stem and the spacers that you just removed… but now they are on top of the stem.
Replace the top cap and tighten so that there is not ‘play’ in the headset… not too tight though… that will cause the headset to bind and not steer smoothly.
Line up the stem to the front wheel and tighten… tight enough fso it doesn’t slip but not too tight or the threads will strip.
Check to make sure the front steers smoothly and use the front brake to make sure there is noo play or rattling in the headset.
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 (1/8in) 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 the bolt and top cap to inspect the steering column. Lubricate adjusting bolt and reinstall the cap and bolt by hand only. Do not tighten. 2. Loosen the stem bolt(s) that secure the 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 the stem straight to the wheel and gently secure the top bolt. Stop when any resistance is felt. **5. **Tighten the stem bolt(s). 6. Check for play by pulling back and forth on the 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 the upper portion of the fork. 7. To adjust bearings, loosen the 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 steps 7, 8 and 9 until play disappears. Remember to loosen the 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 the 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.
The trickiest part of this is tightening the top cap enough to reduce play in the headset, but not so much that you bind the headset (essentially, the bearings grind against each other). There are several tricks for determining headset tightness, and it gets easier with practise (you get a feel for it). Basically, when you grasp the headset and pull on the front brake and rock the bike forward, you should feel no movement (play) in the headset.
To make sure it’s not too tight, lift the bike in the air with the front wheel lower than the back. Lean the bike slightly to the side, the front wheel/fork should turn smoothly towards that side. If it doesn’t, it’s too tight.
Great responses. It seems like a pretty straigtforward job (or at least you are making it sound as such) even for a novice bike mechanic like me. A coralary question … How much does removing the spacers change the fit? In other words, if I had FIST-certified fitter originally fit me with multiple spacers and now I think I could stand to go with fewer spacers, how much am I going to wreck the original fit by removing spacers? Is that going to mess with my seat angle, etc.? If I’m missing something, please answer the question I was too ignorant to ask.
Thanks Ken, and others, for these great responses. It was this Park Tool webpage (http://www.cyclingnews.com/tech/fix/?id=howfix_threadless) that made me fear I was biting off more than I could/should chew! Your help has given me confidence.
Great responses. It seems like a pretty straigtforward job (or at least you are making it sound as such) even for a novice bike mechanic like me. A coralary question … How much does removing the spacers change the fit? In other words, if I had FIST-certified fitter originally fit me with multiple spacers and now I think I could stand to go with fewer spacers, how much am I going to wreck the original fit by removing spacers? Is that going to mess with my seat angle, etc.? If I’m missing something, please answer the question I was too ignorant to ask.
Lowering your front end without any other changes will necessitate a change in body position to get your shoulders lower. How your body does this can be by rolling your hips forward, by making the leg/hip angle more acute, or by keeping the hip angle the same but arching the back (see Armstrong, L.). In addition, you will need to change your head position, assuming you want to be able to look forward. These changes require adaptation time; duration dependent on your physical condition, severity of the change, and your ability to suffer.
Usually, a drop in the front end is accompanied by moving the saddle forward (and up a bit) to maintain the presumptively fit hip angle.