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raising handlebars? 
PostPosted: Mon Jun 09, 2014 5:19 pm Reply with quote
txmnjim
Joined: 02 May 2014
Posts: 25
Location: Minnesota
i just spent a wad on fixing my 83 Gransport up so i certainly dont want to screw it up, but could someone help we with this newbie question. i unlossened the hex key at the top of the stem and it still wouldnt budge. i even cracked open the large nut and it still wouldnt budge. i read somewhere that i just need to whack it with a hammer but wanted to check here before i proceed Wink thanks ahead of time!
jim

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1983 Gran Sport
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Stuck Stem 
PostPosted: Tue Jun 10, 2014 1:04 am Reply with quote
verktyg
Joined: 14 Jan 2007
Posts: 2814
Location: SF Bay Area
From the original pictures, the stem appears to be at it's maximum "SAFE" height. See note below about stem height.

To remove it, loosen the expander bolt enough so that it protrudes above the stem.

Tap it with a hammer to see if the expander at the base of the stem will loosen.

Use a block of wood between the bolt and the hammer or else something like a brass or copper hammer so that it wont damage the bolt.


There are 2 common types of expanders. Some stems have a tapered cone inside the base of the stem quill. Others have an angled external wedge.




Now try twisting the bars to see if the stem will loosen up. You might need to apply a little oil.

If the expander or wedge comes loose and the stem still wont budge then you have a seized stem. This is usually caused electrolytic corrosion between the aluminum stem and the steel steering tube.

One thing to try , remove the front wheel and brake caliper. Remove the expander or wedge - if loosened from the bolt, it should fall out of the bottom of the steerer.

Take a drift pin - a piece of steel rod small enough to fit inside the stem from the bottom (1/2" or smaller) and long enough to stick out the bottom of the steerer - and try to try to tap the stem loose from the underside of the fork.

If that doesn't work you could try some penetrating oil applied from underneath. Let is soak in for a day or so.

Another thing that works for some people is with the bike upside down pour some ammonia down the steerer and let it soak in. It will dissolve some of the aluminum corrosion.

Note: use some rags to keep the ammonia from getting in contact with the paint on the frame (it will run out of the expander bolt hole if you use too much.

If you use ammonia after applying penetrating oil, you will need to clean all of the oil out of the steerer with a mild solvent like oil based paint thinner or kerosine (don't use gas or petrol or lacquer thinner).

One other thing to note:

Most stems from the 80s and later have a "Minimum Insertion Line". The stem needs to be inserted at least 75mm to 80mm into the steerer. About the same length will stick out the top with a standard stem.

If you need the bars higher then you will either have to get a stem with a longer quill (Nitto makes them) or you could try a shorter stem.

Before you reinsert the stem coat the inside of the steerer and the stem quill with a lot of grease. Same thing with the expander and bolt. It will keep corrosion from happening in the future.

Also: If you have the seat up too high then the frame might be too small for you and the bars will be too low.

BTW, the "large nut" is the headset lock nut. If not re-tightened properly, it will give you problems - too loose and it will keep coming loose eventually damaging the bearings; too tight and it will definitely damage the bearings.

The fork should rotate smoothly with no play or feeling of notches.

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Chas.
SF Bay Area, CA USA
==============
1984 Criterium
1969 TdF
1971 TdF
1974 TdF
1984 TdF x 2 Bikes
1970 SC
1971 SC
1972 SC
1984 SC
1984 Team Pro
1985 Professional
1990s Team Replica
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PostPosted: Tue Jun 10, 2014 2:51 am Reply with quote
txmnjim
Joined: 02 May 2014
Posts: 25
Location: Minnesota
thank you sir, that is a LOT of help! i will try it after work, but if it gives me too much trouble i may just leave as it is. i raised the seat a little more and just thought the handlebars may now be a little too low...
jim

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1983 Gran Sport
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PostPosted: Tue Jun 10, 2014 4:15 pm Reply with quote
txmnjim
Joined: 02 May 2014
Posts: 25
Location: Minnesota
oh well, i went and broke my front brake cable from tapping too hard! i just cant seem to catch a break some days Sad

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1983 Gran Sport
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PostPosted: Tue Jun 10, 2014 6:19 pm Reply with quote
vanhelmont
Joined: 11 Dec 2007
Posts: 242
Location: Florida
Is it a new cable? Shocked If so something's wrong. If the bike shop put it on, let them see it. Brake cables breaking at the wrong time could be really bad, and they are strong. Could the screw that holds it to the brake have slipped?

If it's an old cable, be glad nothing serious happened and replace it, and I'd do the other cable too while I was at it.

Dave
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PostPosted: Wed Jun 11, 2014 2:54 am Reply with quote
txmnjim
Joined: 02 May 2014
Posts: 25
Location: Minnesota
yes, it was the new cable. i will take it by the shop today. problem is its called "Honest Bike Shop" and i cant be dishonest about how it happened...dummy me Wink

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1983 Gran Sport
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PostPosted: Wed Jun 11, 2014 4:35 pm Reply with quote
txmnjim
Joined: 02 May 2014
Posts: 25
Location: Minnesota
bike shop fixed the brake cable and raised the handlebar for free. picked up a nifty italian-made plastic water-bottle holder that doesnt require drilling holes in the frame. now i'm ready to hit the road again!
jim

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1983 Gran Sport
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Stem height 
PostPosted: Wed Jun 11, 2014 11:47 pm Reply with quote
verktyg
Joined: 14 Jan 2007
Posts: 2814
Location: SF Bay Area
Make sure that the stem isn't raised higher than the minimum insertion line on the quill.




If the stem expander is tightened in the threaded area of the steering tube it could cause an unexpected , catastrophic failure like riding down the road with unattached bars in your hands! Shocked

Been there - done that... Confused

This steerer is cracked and ready to fail....


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Chas.
SF Bay Area, CA USA
==============
1984 Criterium
1969 TdF
1971 TdF
1974 TdF
1984 TdF x 2 Bikes
1970 SC
1971 SC
1972 SC
1984 SC
1984 Team Pro
1985 Professional
1990s Team Replica
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PostPosted: Thu Jun 12, 2014 5:38 am Reply with quote
sandranian
Site Admin
Joined: 27 Feb 2006
Posts: 2701
Location: Southern California
In all of my years of riding, which is admittedly less than some people on this site, I have NEVER broken a brake or derailleur cable. Knock on wood.

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Stephan Andranian
Costa Mesa, CA
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Component Failures 
PostPosted: Thu Jun 12, 2014 7:24 am Reply with quote
verktyg
Joined: 14 Jan 2007
Posts: 2814
Location: SF Bay Area
sandranian wrote:
In all of my years of riding, which is admittedly less than some people on this site, I have NEVER broken a brake or derailleur cable. Knock on wood.


Me neither.... but I've had 2 stems and 1 steering tube break off while riding.

That was back in the early 70s. Fortunately I was able to safely bring those bikes to a stop! Shocked

I saved this stem as a reminder. This was a cheap cast aluminum stem from 1974. It was only inserted about 1 1/2" (40mm) and the bottom of the stem in the expander area broke off! Rolling Eyes





Here's what can happen when the stem isn't inserted far enough into the steerer and the stem is expanded in the threaded area.



The threaded area of the steerer is usually about 2 1/2" (60mm) long. The tubing wall thickness in that area is only about 1/2 of rest of the steering tube, thus 1/2 the strength!

That's why I always suggest inserting the stem at least 75mm to 80mm deep (3" minimum) to get the expander below the threads.

_________________
Chas.
SF Bay Area, CA USA
==============
1984 Criterium
1969 TdF
1971 TdF
1974 TdF
1984 TdF x 2 Bikes
1970 SC
1971 SC
1972 SC
1984 SC
1984 Team Pro
1985 Professional
1990s Team Replica
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PostPosted: Thu Jun 12, 2014 9:42 am Reply with quote
txmnjim
Joined: 02 May 2014
Posts: 25
Location: Minnesota
sandranian wrote:
In all of my years of riding, which is admittedly less than some people on this site, I have NEVER broken a brake or derailleur cable. Knock on wood.


it was actually a "cap looking thingie" that holds the cable tight. i cant help it--i always overtighten things and pound things too hard! i call it the "hammering ape" syndrome Wink

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PostPosted: Wed Jun 25, 2014 7:18 pm Reply with quote
txmnjim
Joined: 02 May 2014
Posts: 25
Location: Minnesota
thanks Verktyg! here is that nifty Italian bottle holder. no drilling holes or anything...i plan on sanding the bike down and repainting where the previous bottle holder caused all that rust Sad


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raising handlebars? 
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