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Posted: Sat Mar 26, 2011 7:31 pm |
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Signals |
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Joined: 10 Apr 2010 |
Posts: 10 |
Location: New York, NY |
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Removed the existing bottom bracket this evening and thought I'd share what was in there: a very old school cup&cone style Stronglight touring bottom bracket, seemingly from the early to mid-80's (looks a bit older than the model year of the frame, though):
The parts look fairly similar to the bottom bracket in the 1984 Stronglight catalog - Have I id'd these correctly?:
http://www.velo-pages.com/main.php?g2_itemId=25881&g2_imageViewsIndex=1
Given how rudimentary these open bearing cups are, I'm half tempted to put a little elbow grease into it, clean these up and repack them to see how it runs with a little TLC (this thing hasn't been serviced in 15 years). What do you guys think? I realize that there is the issue of having to repack this bearing every so often, which can start to wear out the spindle...but, any other issues?
Some other questions related to this bottom bracket:
- There are two numbers on the side of the spindle: "6" and "18", which you may be able to see in the above photo. Any idea what these refer to?
- Chas: are you still fairly certain that this is British threaded having now seen the bearing cups?
Now, let's take a look at the headset. It is in pretty good shape considering the lack of service. No idea who makes it or the year it was made, but check out the tight bearing set on this one:
As I said in previous posts, I really do not want to have to restore and reinstall this headset, but as Chas pointed out, I may have a stacking issue if I try to use a more modern style headset with the existing Reynolds fork. That said, if you guys have any advice on how to remove these headset bearing caps, I'd greatly appreciate it!
BTW: speaking of the Reynolds fork, the steering tube has an imprint stating "REYNOLDS 531". The frame and fork blades are marked with stickers indicating that the material is 501SL; is it typical to see 531 used for the steering tube only? Or is the whole fork likely made of 531?
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| | | | | | | | | British or French Threads? | | | | | |
Posted: Sun Mar 27, 2011 2:56 am |
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verktyg |
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Joined: 14 Jan 2007 |
Posts: 2814 |
Location: SF Bay Area |
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Signals wrote: |
...(looks a bit older than the model year of the frame, though)
- Chas: are you still fairly certain that this is British threaded having now seen the bearing cups?
- There are two numbers on the side of the spindle: "6" and "18", which you may be able to see in the above photo. Any idea what these refer to?
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They look like the much older style Stronglight cups used up until the late 70s. The octagonal fixed cup is the giveaway. There is a good chance that the BB has been overhauled once or twice since the bike was new. The newer style replacement cups may not have been available so someone used the older ones.
British fixed cups had 8 flats around the outside plus 2 rings in the face. They were left hand thread - clockwise to remove and counter clockwise to tighten.
French cups with 8 flats had 1 ring. They have right hand threads on both cups - counter clockwise to loosen, clockwise to tighten.
The later style Stronglight Competition cups had 2 flats on the fixed cup and the thread size and standard was rolled into the faces of both cups.
In general, most French bikes used metric headset, BB and freewheel threads until the late 70s. After that they standardized on BSC or ISO (British) threads.
Which way did the fixed cup (right side) screw out. clockwise or counter clock wise? That will pretty much answer your question about metric or British BB threads.
The spindle is a later model. What the numbers mean, who knows? 18 could stand for 118mm length, 2 or 6 the year of manufacture, 1982 or 1986???
The older spindles looked like this with the length stamped in the middle.
If you are planing on reusing this BB inspect the bearing race surfaces closely. Replace the cup/s or spindle if they show any chipping or pitting.
Use 11 1/4" loose balls in each side. Get some 1/4" grade 25 chrome steel bearings.
While you have the bike apart it would be a good idea to have the bottom bracket and head tube refaced by someone with the correct tools who knows how to use them!
Check out the candidates closely before you entrust your 25 year old collectors item to some shade tree mechanic. When you say French, if their eyes glaze over or roll back, RUN AWAY! RUN AWAY!
Signals wrote: |
Now, let's take a look at the headset. It is in pretty good shape considering the lack of service. No idea who makes it or the year it was made, but check out the tight bearing set on this one:
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This looks like a standard Gitane headset which most likely would be metric.
The easiest way to tell is to measure the diameter of the outside of the steerer with calipers or a micrometer. French would be 25mm or 0.984". A British steerer is a little larger at 1" or 25.4mm.
If the headset isn't pitted you can reuse the parts after thorough cleaning. It's usually only the bottom races that get damaged.
If the crown race or bottom cup are pitted (indentations) then you could use a Tange headset like I suggested above. You need to remove the fork crown race and measure the mounting surface. It can be ~26.4mm or 27mm. You can get the Tange headset in both sizes.
If the headset is French, you can get by with only replacing the non-threaded bottom 2 pieces - the fork crown race and the bottom cup with Tange headset parts.
Get some grade 25 chrome steel bearing for the headset too. There are 2 or 3 common size balls used in headsets.
Again, use loose balls not caged bearings, They usually take about 23-25 balls per top and bottom.
There are special tools for hammering out the headset cups and crown race plus for pressing them back in. Inspect the old parts first and get back.
There is very little mechanical difference between Reynolds 531 and and 501. I suspect that 501 was cheaper to produce because they used commercially available 4130 chrome moly steel whereas 531 was made from a special alloy steel. Tubes may have frequently been interchanged
at the factory... If they ran out of one they'd use the other! Who knows? |
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Last edited by verktyg on Sun Mar 27, 2011 6:57 pm; edited 1 time in total _________________ Chas.
SF Bay Area, CA USA
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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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Posted: Sun Mar 27, 2011 3:41 am |
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Signals |
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Joined: 10 Apr 2010 |
Posts: 10 |
Location: New York, NY |
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If I do overhaul this bottom bracket, you are suggesting that I take the cage out of the equation and just pack it with the steel balls themselves? Why not use the cages? Just curious... |
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| | | | | | | | | Caged Ball Bearings | | | | | |
Posted: Sun Mar 27, 2011 2:14 pm |
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verktyg |
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Joined: 14 Jan 2007 |
Posts: 2814 |
Location: SF Bay Area |
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Signals wrote: |
If I do overhaul this bottom bracket, you are suggesting that I take the cage out of the equation and just pack it with the steel balls themselves? Why not use the cages? Just curious... |
Caged ball bearings were used to save time during assembly at the factory!
In fact the cages with 9 balls were used on many bikes because they were cheaper! Campagnolo and other manufacturers used caged BB bearings with 11 balls.
How many centimes could bike makers save by using 2 less ball bearings in those cages???
Only a very small area of a ball bearing is ever in contact at any one time with the bearing race in a cup, cone or spindle.
The balls have to withstand extremely high pressures as the contact areas roll around the races.
Increasing the number of balls in these loose ball type bearings distributes the load over a wider area. This can result in smoother operation and longer bearing life
Loose ball bearings are available in carbon steel or chrome alloy bearing steel. The chrome alloy steel balls are 2-3 times stronger and cost only pennies more.
Grade 25 ball are rounder and the difference in the size of the balls is much smaller.
So, buy Grade 25 chrome alloy steel balls. You can find them online or on eBay.
As an aside, I find it humorous that sellers on eBay charge exorbitant prices for caged bearings!
One other thing, the best quality cups, cones and bearings are made of chrome alloy bearing steel that has been hardened all the way through the metal. They have precision ground and sometimes polished bearing races.
Cheap bearings are made with carbon or lower alloy steel that has been heat treated to harden the surface of the part between 0.005" and 0.050" deep (0.13mm to 1.27mm deep).
The hardened surface surface area on cheap bearings is usually only 0.005" to 0.010" deep and these cups, cones and spindles wear out fast and look like this in a short amount of time.
One way to tell if the bearing components are made of cheap case hardened steel, the bearing races have not been ground or polished after heat treatment.
Some better quality bike bearing components are case hardened but they usually have a deep case hardening and the bearing races are ground.
Headsets are a completely different animal. They are thrust bearing designed to support up and down impact rather than rotating forces.
More balls distribute the forces better. Cages keep the balls in the same location within the headset and are more likely to cause indentations in the races (also called brinelling or indexing).
Sheldon Brown wrote some good information on headsets:
http://www.sheldonbrown.com/headsets.html
BTW. if that is a Gitane headset on your bike, it most likely uses 1/8" balls - 23 to 25 of them. Measure the old ones first. Leaving 1 or 2 out is better than 1 too many ball. |
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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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Posted: Sat Jun 25, 2011 4:38 am |
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Signals |
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Joined: 10 Apr 2010 |
Posts: 10 |
Location: New York, NY |
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Purists beware:
looking at these images may burn your eyes. : )
While I realize some of you may frown upon such things, I decided to completely refinish the paint and decals on this '87 Record. Failing finding any realistic way to find old stock decals for this specific model, I went for the next logical step in terms of honoring the history of this model by restoring it as a replica of the Team Pro model of the same year.
Decals were purchased from a restoration guy in Australia, and the paint was done locally by a long time veteran of painting steel frames. He screwed up on the placement of the chain stay decal, unfortunately, despite my meticulous instruction. And, I couldn't get myself to paint over the chrome finish of the fork, so I left that alone even though the Team Pro had a matching blue fork. Nonetheless, it came out pretty nice.
Please refrain from any negative comments; this bike was my first race bike and I am the original owner...I just really wanted to breathe some new life into it. take a look:
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| | | | | | | | | Great Repaint Job | | | | | |
Posted: Sat Jun 25, 2011 8:11 am |
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verktyg |
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Joined: 14 Jan 2007 |
Posts: 2814 |
Location: SF Bay Area |
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Looks great!
Some of my past comments have been aimed at discouraging owners from taking a classic bike and repainting the frame because of a little patina and a few scratches.
For example, I sold this rare 1974 Champion Du Monde frame to someone on the forum. The first thing that they did was strip off the paint and put on a rattle can metallic blue paint job!
It's only "original" once!
Here's what it looked like when I sold it. The paint chips and scratches could have easily been touched up!
The overall rattle can paint job looked good from 5 feet but Gitane used tinted transparent lacquers for the candy apple or flamboyant effect on most of their bikes through the 1970s, not metallic paints.
Whoever painted your bike used tinted lacquer which is harder to apply than metallic paint but it looks more "original". The color looks good.
BTW, I never liked the original style decals that came on your bike.
Additionally, any traces of rust or scratches on the frame show up badly on the original pearlescent white paint and are hard to touch up.
I feel for your decal positioning dilemma. I spent several hours last Saturday working with a local painter installing foil decals on my newly repainted 1972 Super Corsa. He did a great job. |
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_________________ Chas.
SF Bay Area, CA USA
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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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