gitaneusa.com :: View topic - Bottom Bracket

natprice

Does anybody know the dimensions for the bottom brackets on the old Tour de France bikes from about 1973 or 74'? Is locktight usually needed to keep the bottom bracket from becoming loose? Are the dimensions listed on the Sheldon Brown website (http://www.sheldonbrown.com/bbsize.html)? Also does anybody know what size tools I would need and where I could get them?

Any help would be great!

Thanks

vanhelmont

The bb dimensions are given under the "Threading Standards" section, the "French" line. Ideally loctite is not needed, per the resident expert, Verktyg.
I use a big crescent wrench on the fixed cup, same as I always have on British bb's, and a pin spanner which any bike shop should have on the adjustable cup. My lock ring, which is TA, just has little square indentations to tighten it with a wrench that would probably be similar to a lot of other bottom brackets, but when I get it finger tight I put a block of wood against one of the notches and hit it with my hand to tighten it a little more. I've never had one come loose like that, and it doesn't mar the ring. Removal is just the reverse, tap it with the wood block in the other direction.

Good luck with it.

Dave

verktyg

The threads are 35mm diameter by 1mm pitch (35x1, 35mmx1mm, M35x1.0, etc). Turn counterclockwise to loosen, clockwise to tighten.

All of the Gitanes that I've seen from the 70s and earlier have both sides right hand threads (unlike British or ISO BB cups which have left hand threads on the right hand fixed cup side).

Left hand threads on the fixed cup are supposed to be less likely to come loose. I've had a few French right side fixed cups come loose while riding.

If the fixed cup easily screws all the way in by hand then I'd suggest using a little bit of blue Loctite on that cup. If it's tight don't worry about it.

Does your TdF have Stronglight or Sugino cranks? Sugino BB components are pretty much interchangeable with Campy NR parts from the early 70s.

One suggestion, get a long 1/2" or larger bolt and nut plus several large flat washers at least 1 1/2" in diameter. Remove the adjustable cup and axle and put the bolt through the BB with a washer on each side. Place the wrench or adjustable wrench over the fixed cup and hand tighten the nut.

The washer on the outside of the wrench will help keep it from slipping off the fixed cup as you break it loose.

Chas.

smilingroadrunner

Thanks, Chas for the tip about utilizing a bolt and washers to help hold the adjustable wrench on the fixed cup, a handy way to avoid marring the fixed cup and/or bottom bracket.

Hope your feeling better as the weekend progress.

Not to rub it in Wink

---but before tomorrow's returning wintery blast to the plains, it was a balmy 68 degrees, albeit windy 30-35mph gusts this afternoon. It was nice to get off the Kreitlers and out of the basement, onto the streets today.

At 9pm this evening, 57 degrees and winds moving to the northwest from the southernly flow earlier today. Well it was fun while it lasted.

Again thanks for the tip for the forum members.

Peace & Good Health to all !! Lots of helpful information shared this year, Thanks Stephan, What a great site, and What a great resource.

I Like Steel !!!
________________
C.A. in Salina, Ks.

sandranian · Site Admin

It is freezing here in SoCal. There is actually some frost on the grass on the lawn. Clear blue skies...but it should only warm up to 60 degrees today. Talk about the dead of winter...Brrrrr!!!

verktyg

Stephan,

It's ~50° F here in the Bay Area. It was nice and clear all morning with no wind but the clouds are moving in this afternoon.

I missed the last Classic Rendezvous ride of the year today. Crying or Very sad

Thanks Santa for bringing me the plague. Evil or Very Mad

Chas.

natprice

yeah, it was so warm in St. Augustine, fl that we were out surfing with no wetsuits today. caught some bluefish and whiting too! Cool

natprice

I tried getting it tightened and I tried getting it tightened again with Loctite. After only a couple weeks of short commuting though the bottom bracket is already quite loose.

I took the bike to a shop about a year ago when the bottom bracket was making this grinding noise and they said they "fixed" it but I am not sure what they did but I thought they replaced something in the bottom bracket with a used part. I went back there again after painting and reassembling the frame to get the bottom bracket tightened and they said they didn't have the right size tools to tighten it or take it apart. So this makes me very uneasy about whatever they did when they worked on it a while ago.

My new bike mechanic seems to think the threads are just old and that I should look into a replacement. He is also my age though, 20, so I am not too sure he knows what he is talking about when it comes to these old bikes...haha

Where do I go from here?

verktyg

vanhelmont

How can a shop not have "the right size tools?" Maybe they don't have the right tool for the lock ring, but a resourceful person can somehow pad the jaws of a pliers, if nothing else. They surely have a pin spanner for the adjustable cup and a crescent wrench for the fixed cup. You do have an ordinary old style bottom bracket, with cups, ball bearings, and a shaft with cones on it, don't you? There are a couple of different sealed bearing bottom brackets that might need special tools.

If you are using a normal bottom bracket, the surfaces have to be free of oil and grease for the loctite to stick.

If the threads are worn out (and I doubt that is the case since you seem to be able to assemble it) there is a Mavic sealed bottom bracket that doesn't use the frame's threads. Chas. could probably tell you more about it, all I know is that is exists.

Good luck!

Dave

verktyg

natprice

So about the only thing I know about the bottom bracket is that my bike has one and it won't stay tightened. Mine seems to be loose on the side with the gear on it (adjustable cup?). I can see about 2mm of thread exposed on that side and it is loose enough to be tightened by hand. The other side doesn't really appear loose. There is about 1-2 mm of play from side to side if I press in the pedal arms.

Which side is the adjustable cup and which is the fixed? Where would the brand be engraved?

Here are some pics if that helps and also some pics of the frame after I got the bike painted.
[url]
http://picasaweb.google.com/NatBPrice/Gitane?feat=directlink[/url]

PBR Streetgang

Hi Nat:

The fixed cup is the one that can be tightened with a big crescent wrench. It's on the drive side. The adjustable cup is the one with the lock ring. It's on the other side.

Let The Big Gator EAT!

natprice

So I can just keep tightening the fixed cup with a crescent wrench when it becomes loose and keep on riding it?

I don't think I really have the tools to take apart the bottom bracket in order to clean everything and try the Loctite again.

PBR Streetgang