gitaneusa.com :: View topic

Dubuque75

I have a Gitane Grand Sport Delux I bought in 1972. I like to ride it again, but I'll need to replace the bottom bracket. Any ideas about how to find one?
BTW: I've enjoyed reading the posts on this site.

scozim

I'm working on a 70's bike with Swiss threading (ughh!) and was at a loss on what to do. The bb's I found to fit the bike were really expensive so I decided to go with this - http://www.velo-orange.com/grcruthbobr.html

I installed it today and, while the colors are ugly, the installation was easy and it doesn't feel like it will budge at all. Riding it will be the test, though. that will happen in a couple of weeks.

Scott

vanhelmont

A 1972 Grand Sport Delux probably has cottered cranks. If you change to a square taper bottom bracket you will have to also change the cranks, and if you change the cranks you will need new pedals, I think, because the old ones are probably French thread. On the good side, you would drop some weight, but the cost might be more than you want to spend on the bike.

As an alternative, you might first open up the bottom bracket. What Sheldon Brown said about cottered cranks:

http://www.sheldonbrown.com/cotters.html
and
http://www.sheldonbrown.com/tooltips/cotters.html

Once you get it open (remember, right hand thread on both cups!) you can see what needs to be changed. Ball bearings are easy to get at any bike shop. A little pitting on the cups and/or spindle may not matter. If in doubt you can reassemble with the new ball bearings (cheap) and see if it's reasonably smooth. If you need cups and/or spindle, they can usually be found on ebay. You will probably need new cotter pins, which are available here:
http://sheldonbrown.com/harris/french-cranks.html#bottom

While you have it apart, you might also want to clean and lube the pedals. Again, take a sample ball bearing to the bike shop to get new ones.

A bit of work, but you could save some money, and some of us even think this kind of stuff is fun!

If you decide to go for the sealed bb, the velo orange unit scozim recommends also comes in French thread, which you could use if your threads are OK.

Good luck with your bike!

Dubuque75

Thank you for the knowledgeable advise. I agree, the best start is to open up the BB and see what I've got. I had someone repalce the BB shaft and ball bearing parts a few years ago, but that repair only lasted a few hundred miles. The BB shaft wobbles badly in the BB. The bearing seat on the original shaft and in the BB have worn unevely.
During a brief look on E bay, I did not see any Gitane spare parts.
I think I'll try to get the BB out and then, assuming the frame treads are still good, see what a new Velo Orange BB costs plus pedal/crain ring set.

The question then: Any recommendation on where to buy a pedal set?
and am I going to have issues getting the pedal set to work with my existing derailures and rear casset?

Thanks for the info on the cottered cranks. I remember having a really tough time getting them off many years ago.

sandranian · Site Admin

You won't find "Gitane specific" spare parts on Ebay (with rare exception). You will just need to search for French threaded stuff, which should work.

I may have a spare cottered BB and parts that I could send to you. Once you have it apart, send me a message with the proper measurements, and I will take a look and see what I have.

Regarding your question as to whether a new crankset will be compatible with your existing derailleurs, the answer is likely "yes." But let's see if we can't repair what you've got first.

Dubuque75

Thanks
It looks like the shaft, bearings and cups look OK. I'll have some one else look at them to make sure.
One possibility for my problems: It may be the BB was not tightened properly. I remember the bearing cups had to be adjusted after 200 miles when the shaft started to wobble. It worked for a little while then got loose again. Is there a recommended torque when tightening the bearing cups against the bearings?

Here is what I found when I took the BB apart and compared the original shaft (spindle) with the one the was put in a few years ago.
Cup ID = 30 mm Ball bearing OD 6.5 mm
Shaft OD new = 16.6 mm (original = 16.9 mm)
Distance between the shaft bearing race = 55 mm (same for new and original)
Shaft length 138 mm (both)
Beside the shaft dia, the only other difference between new and original shafts is the distance from bearing race and the recess for the pedal taper pin. The new shaft is 2 mm closer to the bike frame.

Thanks again for the help. Any more thoughts would be appreciated.

verktyg

The bearing surfaces should be smooth with no sign of chipping or pitting or worn out of round.

The tightening torque for BB cups is 20-30 Ft.Lbs.

Go to an auto parts store or bearing supplier and get some Loctite thread locking compound. Get the blue stuff if you can find it so that you can take it apart again. There are some other brands like Permatex too.

Completely degrease the cups and BB threads. When reassembling use a small amount of the thread locker the full length of the threads on the fixed cup and less on the adjustable cup.

Put the fixed cup in as tight as you can. See Sheldon Brown's web site for suggestions (RIP). Tighten the adjustable cup so that there is no play but the spindle still turns smoothly.

You should use 11 new 1/4" bearings on each side with lots of heavy duty water resistant grease - it helps keep the dirt out. Many bearing retainers only have 9 ball bearings. If you can't find any with 11 balls, use loose grade 25 chrome steel balls.

It helps to have the bike on it's side when you are putting loose balls in.

Take and curl up a business card and slide it into the BB shell before you put the spindle in. It will help keep dirt and rust flakes from getting into the BB from the seat and down tubes.

If you use a hammer to put the cotters back in take a small piece of soft 2x4 wood and put a shallow 1/4" hole in it. Hold the 2x4 under the crank arm for support so that you are not pounding shock into the BB bearings.