bottom bracket size
#1
Thread Starter
Newbie

Joined: Apr 2002
Posts: 3
Likes: 0
bottom bracket size
I am trying to replace the stock crankset on my 99 Rocky Mountain Soul with Deore LX, and I learned that I need to replace the bottom bracket as well.
The options for this bottom bracket range in sizes from 073-118 to 068-113. What do these number represent? I cannot find these specs in my documentation or anywhere on the net. Does anyone know what the proper size would be for my Soul?
Also, will I need to replace any other components to ensure compatibility with this new crankset (i.e. chain etc)?
Any feedback is muchly appreciated!
thanks.
The options for this bottom bracket range in sizes from 073-118 to 068-113. What do these number represent? I cannot find these specs in my documentation or anywhere on the net. Does anyone know what the proper size would be for my Soul?
Also, will I need to replace any other components to ensure compatibility with this new crankset (i.e. chain etc)?
Any feedback is muchly appreciated!
thanks.
#3
feros ferio

Joined: Jul 2000
Posts: 22,397
Likes: 1,864
From: www.ci.encinitas.ca.us
Bikes: 1959 Capo Modell Campagnolo; 1960 Capo Sieger (2); 1962 Carlton Franco Suisse; 1970 Peugeot UO-8; 1982 Bianchi Campione d'Italia; 1988 Schwinn Project KOM-10;
You can narrow it down significantly by measuring the width of your frame's bottom bracket shell, which should be 68, 70, or 73mm. Then, for a triple chainring, the longest available spindle is generally, though not always, the correct one. (As you have guessed by now, the two numbers which specify any BB are the BB shell width and spindle length.)
__________________
"Far and away the best prize that life offers is the chance to work hard at work worth doing." --Theodore Roosevelt
Capo: 1959 Modell Campagnolo, S/N 40324; 1960 Sieger (2), S/N 42624, 42597
Carlton: 1962 Franco Suisse, S/N K7911
Peugeot: 1970 UO-8, S/N 0010468
Bianchi: 1982 Campione d'Italia, S/N 1.M9914
Schwinn: 1988 Project KOM-10, S/N F804069
"Far and away the best prize that life offers is the chance to work hard at work worth doing." --Theodore Roosevelt
Capo: 1959 Modell Campagnolo, S/N 40324; 1960 Sieger (2), S/N 42624, 42597
Carlton: 1962 Franco Suisse, S/N K7911
Peugeot: 1970 UO-8, S/N 0010468
Bianchi: 1982 Campione d'Italia, S/N 1.M9914
Schwinn: 1988 Project KOM-10, S/N F804069
#5
feros ferio

Joined: Jul 2000
Posts: 22,397
Likes: 1,864
From: www.ci.encinitas.ca.us
Bikes: 1959 Capo Modell Campagnolo; 1960 Capo Sieger (2); 1962 Carlton Franco Suisse; 1970 Peugeot UO-8; 1982 Bianchi Campione d'Italia; 1988 Schwinn Project KOM-10;
If it's symmetrically 4mm longer, it will move your chainline outward by 2mm, which will degrade chain efficiency when you use the larger cogs with the middle or outer chainring. For MOST multigear bikes, the best chainline is obtained with the inside ring clearing the chainstay by just a mm or two.
__________________
"Far and away the best prize that life offers is the chance to work hard at work worth doing." --Theodore Roosevelt
Capo: 1959 Modell Campagnolo, S/N 40324; 1960 Sieger (2), S/N 42624, 42597
Carlton: 1962 Franco Suisse, S/N K7911
Peugeot: 1970 UO-8, S/N 0010468
Bianchi: 1982 Campione d'Italia, S/N 1.M9914
Schwinn: 1988 Project KOM-10, S/N F804069
"Far and away the best prize that life offers is the chance to work hard at work worth doing." --Theodore Roosevelt
Capo: 1959 Modell Campagnolo, S/N 40324; 1960 Sieger (2), S/N 42624, 42597
Carlton: 1962 Franco Suisse, S/N K7911
Peugeot: 1970 UO-8, S/N 0010468
Bianchi: 1982 Campione d'Italia, S/N 1.M9914
Schwinn: 1988 Project KOM-10, S/N F804069





