Bicycle Mechanics - Made a problem when flipping my stem.

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fastfly
03-07-08, 05:51 PM
So, I am mechanically inclined but I cannot understand what I cannot see and well, I do not know bicycles as well as I would like to.


So, I flipped my stem, took the two bolts out the front to remove the handlebars and undid the bolt that is vertical on top of the stem. I then loosened the bolt parallel to the ground and flipped the stem. I tighted everything back up and now the fork is allowed to move slightly forward and back.

How do I fix this issue? Do I just have to make sure the fork is tight when I tighten the stem?


Wordbiker
03-07-08, 05:53 PM
You need to tighten the top bolt first before tightening the pinch bolts. The top bolt is what adjusts the headset bearings.

Also, make sure that you didn't leave a spacer off that could prevent you from preloading the headset stack.

fastfly
03-07-08, 05:58 PM
Makes sense!

That is exactly what I did wrong. I tightened the other bolt before the one that goes into the headset.

Another quick question, my rear brake caliper is slightly off center. I mean that one of the pads hits the wheel way before the other one.

What tools do I need to adjust the position of the brake body? Do I just need to loosen and then retighten the bolt that goes through the seat stay? It just looks like a funny looking nut on the side of the brake.


(Is this a good kit to ride with or is there something important that is missing? http://www.nashbar.com/profile.cfm?category=600099&subcategory=60001232&brand=&sku=14017&storetype=&estoreid=&pagename=Shop%20by%20Subcat%3A%20Kits)


christama
03-07-08, 06:06 PM
What kind of brake is it on the rear? If its a road caliper, try loosening the fixing bolt on the back, squeeze the lever, and re-tighten it. If that doesn't work, there should be a small allen head or phillips head that you can loosen or tighten the spring tension with.

fastfly
03-07-08, 06:16 PM
It is a Shimano Ultegra brake.

orangepaint
03-07-08, 09:35 PM
You could just move the caliper with your hand...

fastfly
03-07-08, 10:25 PM
You could just move the caliper with your hand...

If I could I would. It is on there pretty good.

urbanknight
03-07-08, 10:37 PM
Loosen it 1/8 turn. I purposely leave mine like that so I can move the caliper by hand when changing wheels. Very important since I won't have tools on a race course.

Camilo
03-07-08, 10:48 PM
So, I am mechanically inclined but I cannot understand what I cannot see and well, I do not know bicycles as well as I would like to.


So, I flipped my stem, took the two bolts out the front to remove the handlebars and undid the bolt that is vertical on top of the stem. I then loosened the bolt parallel to the ground and flipped the stem. I tighted everything back up and now the fork is allowed to move slightly forward and back.

How do I fix this issue? Do I just have to make sure the fork is tight when I tighten the stem?

For future readers, the park tool website has an excellent "how to" for installing the stem and adjusting the headset bearings (called "preloading"). It's simple, but not necessarily obvious.

SweetLou
03-07-08, 10:57 PM
Or, if the brake has a centering adjustment, you could just try that.
Here is a link to Park Tools (http://www.parktool.com/repair/readhowto.asp?id=20) page about adjusting and centering dual pivot brakes. I am assuming you are using a dual pivot brake. Did Ultegra come in a single pivot model? If you have a single pivot model, there are directions on Park Tools site for that type also. Good site for some basic information.

Joshua A.C. New
03-07-08, 10:59 PM
Hey, make sure you don't overtighten the cap there. Tighten it just until it stops wiggling, then stop.

*Then* tighten the stem bolts.

Siu Blue Wind
03-07-08, 11:09 PM
Hey, make sure you don't overtighten the cap there. Tighten it just until it stops wiggling, then stop.

*Then* tighten the stem bolts.

Yeah really. Or else you won't be able to turn! *raises hand* I learned the hard way! :p

fastfly
03-07-08, 11:12 PM
Thanks for all the information!



Yeah really. Or else you won't be able to turn! *raises hand* I learned the hard way! :p

Haha, I will make sure I don't repeat your mistake :D

Joshua A.C. New
03-08-08, 12:26 AM
Yeah, well, we all have our "D'OH" moments. Like when I was out riding and couldn't figure out why the steering was so squishy, then realized that only the cap was tight — the stem bolts weren't. That was a potentially fatal error, right there. So, uh, don't do that, either.

fastfly
03-08-08, 03:11 PM
About centering the brakes. I noticed the centering screw on the rear and should be able to center the brake using that, but the front brake on my bike is missing the centering screw. It must have fallen out somehow. Is this an issue?

What should happen to a brake without any centering screw?

Al1943
03-08-08, 04:21 PM
Be sure your rim is centered on the wheel (properly dished) before you move your brakes.

Al