Japanese Bottom Bracket
06-29-10 | 08:06 AM
#1
Thread Starter
invisible friend
Joined: Jun 2008
Posts: 955
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From: Decatur, Alabama
Bikes: Gary Fisher Tassajara hardtail mtb, '01 Rans Wave, '98 Raleigh R700, Mid-80's Takara Professional, '91 Bianchi Alfana
Japanese Bottom Bracket
I have a mid-80's Takara made with Tange Champion tubing in excellent shape. The cranks are long and I'd like to change them out to a shorter length compact from the 42/53 that's on the bike. Is there any kind of standard BB size from that time period for Japanese manufacturers? Do I just need to take the bike to the LBS and have them take it apart and measure it? I'm watching several auctions on ebay and many come with BB's included, wondering if there's a uniform bb size I can look for.
06-29-10 | 08:15 AM
#2
Cat 6
Joined: Dec 2007
Posts: 7,522
Likes: 236
From: Mountain Brook, AL
BB has 2 match 2 specs
1. Your frame - yours is English 1.37x24 threading
2. Your crank - each crank is specific, so you have to match the BB to the crank. There's not a "standard".
More than likely your current BB will not match any compact you could buy, but I am just making an educated guess here.
If you buy a crank w/BB included, just make sure the BB is English threaded.
1. Your frame - yours is English 1.37x24 threading
2. Your crank - each crank is specific, so you have to match the BB to the crank. There's not a "standard".
More than likely your current BB will not match any compact you could buy, but I am just making an educated guess here.
If you buy a crank w/BB included, just make sure the BB is English threaded.
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72 Frejus (for sale), Holdsworth Record (for sale), special CNC & Gitane Interclub / 74 Italvega NR (for sale) / c80 French / 82 Raleigh Intl MkII f&f (for sale)/ 83 Trek 620 (for sale)/ 84 Bruce Gordon Chinook (for sale)/ 85 Ron Cooper / 87 Centurion IM MV (for sale) / 03 Casati Dardo / 08 BF IRO / 09 Dogma FPX / 09 Giant TCX0 / 10 Vassago Fisticuff
06-29-10 | 08:39 AM
#3
Bianchi Goddess
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From: Shady Pines Retirement Fort Wayne, In
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“One morning you wake up, the girl is gone, the bikes are gone, all that's left behind is a pair of old tires and a tube of tubular glue, all squeezed out"
Sugar "Kane" Kowalczyk
06-29-10 | 08:40 AM
#4
sultan of schwinn
Joined: Sep 2009
Posts: 3,536
Likes: 17
From: Lehigh Valley, PA
I have a mid-80's Takara made with Tange Champion tubing in excellent shape. The cranks are long and I'd like to change them out to a shorter length compact from the 42/53 that's on the bike. Is there any kind of standard BB size from that time period for Japanese manufacturers? Do I just need to take the bike to the LBS and have them take it apart and measure it? I'm watching several auctions on ebay and many come with BB's included, wondering if there's a uniform bb size I can look for.
If you want smaller chainrings keep the crankarms and change the chain rings (possibly you might need a different RD)
If you want shorter arms, look for a crank just like yours (or compatible with your BB, i.e. same make and same time frame ) and just get shorter arms to use. (most Dura Ace/600/and 105 bb work with all 3 kinds of cranks and the reverse - with some exceptions 7410- if made around the same time)
Here is Sheldon Brown's BB size database
06-29-10 | 02:49 PM
#5
Thread Starter
invisible friend
Joined: Jun 2008
Posts: 955
Likes: 0
From: Decatur, Alabama
Bikes: Gary Fisher Tassajara hardtail mtb, '01 Rans Wave, '98 Raleigh R700, Mid-80's Takara Professional, '91 Bianchi Alfana
I am a bit confused... do you want to change the length of the crank arms to shorter ones? or you want to change the chainrings to smaller ones? Both are doable without changing the bottom bracket:
If you want smaller chainrings keep the crankarms and change the chain rings (possibly you might need a different RD)
If you want shorter arms, look for a crank just like yours (or compatible with your BB, i.e. same make and same time frame ) and just get shorter arms to use. (most Dura Ace/600/and 105 bb work with all 3 kinds of cranks and the reverse - with some exceptions 7410- if made around the same time)
Here is Sheldon Brown's BB size database
If you want smaller chainrings keep the crankarms and change the chain rings (possibly you might need a different RD)
If you want shorter arms, look for a crank just like yours (or compatible with your BB, i.e. same make and same time frame ) and just get shorter arms to use. (most Dura Ace/600/and 105 bb work with all 3 kinds of cranks and the reverse - with some exceptions 7410- if made around the same time)
Here is Sheldon Brown's BB size database
Thanks to you all for the great info!
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