Bicycle Mechanics - BB size/threading?

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Ochoko
10-26-10, 07:51 PM
I want to replace my bottom bracket on an 80's Miele frame to a closed cartridge one. How do I find the measurements of my bottom bracket? Also, how do i find out which way the fixed bracket is threaded?

My frame is the same model as the one in this picture.
http://lp1.pinkbike.org/p4pb4826832/p4pb4826832.jpg

Jeff Wills
10-26-10, 07:57 PM
STFF! Oh, heck:


I'm 99% certain Miele bikes were Japan or Taiwan made, which means the bottom bracket is standard English threading. To check, look at the bottom bracket cup: it should say something like "1.37 x 24". That's English thread. If it says "36 x 24" it's Italian thread.

If English thread, the fixed cup is left-threaded. If Italian, the fixed cup is right threaded.

The spindle length is the other variable. Measure the old one to find out. You want to know dimension "D":
http://www.sheldonbrown.com/images/spindle.jpg
Ochoko
10-26-10, 08:13 PM
It has a loose bearing bb on it right now and it may just be me but i cant find the measurement anywhere

It does have Italian flags on it, so would it not be made in Italy?

Thanks

Retro Grouch
10-26-10, 08:13 PM
A quick and dirty method:

Measure the width of the frame's bottom bracket shell (excluding the BB flanges). 68 mm = English. 70 mm = Italian.
Ochoko
10-26-10, 08:21 PM
By flanges do you mean the parts of the bb that stick out on each side? It appears to be 68 mm.
I guess I'm going to go with that and hope it works. Thanks
Bezalel
10-26-10, 09:03 PM
It has a loose bearing bb on it right now and it may just be me but i cant find the measurement anywhere

It does have Italian flags on it, so would it not be made in Italy?

Thanks

Meile bikes were made in Canada. Jim Meile was an Italian immigrant who designed Italian sytle bikes. The bikes were actually fabricated by other Canadian manufacturers.
JohnDThompson
10-27-10, 05:52 PM
Most BB cups will be marked in some way to indicate the threading. Most often you find numbers stamped on the cups:
http://www.os2.dhs.org/~john/french-cups.jpg

Sometimes it will be more obscure, like the number or lack of rings inscribed on the cup:
http://www.os2.dhs.org/~john/ta-cups.jpg
badamsjr
10-28-10, 07:35 AM
By flanges do you mean the parts of the bb that stick out on each side? It appears to be 68 mm.
I guess I'm going to go with that and hope it works. Thanks

If you are able to remove the BB, you can measure the BB shell (the part of your frame where the BB mounts). But, having removed the BB, you would know if the drive side cup was left/right thread?:innocent: