bottom bracket thread direction.
#2
0^0

Joined: Feb 2001
Posts: 4,056
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From: Rolla, MO
Bikes: Redline Monocog,Surly Crosscheck, Lemond Reno
I always have the same question, no matter how many times I take BB's off I never remember the direction. But I am going to suggest anticlockwise, because you pedal clockwise, so if the BB thread direction was clockwise, it seems like it would be easier for the BB to come loose. So I would try anticlockwise.
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#5
RAGBRAI. Need I say more?

Joined: Apr 2001
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From: West Branch, Iowa USA
Bikes: 1998 Mongoose NX7.1, 2008 Kona Jake, GT singlespeed (year unknown).
I can never remember either. That is why I have saved an old BB for reference. It saves me a lot of time and effort. BB and pedals are not something most people take off very often and it is easy to forget.
#6
What kind of bike are you working on and how old is it?
If it is a BB with free bearings, then the left side bottom bracket bearing cups and lock ring should be normal standard threading - rightee tightee, lefty loosey. (Bear in mind MichaelW's correct info that French bikes CAN BE weird and opposite).
Also, it is the left side which is the removeable side. Don't spend energy, time, and tools trying to loosen the permanent side (right side).
Unless the mechanic who worked on the bike before you was an idiot, the BB parts are usually not put on too tight. They are usually put on just snug. Thus, if it seems you are putting a lot of torque to your tools, you are probably doing something wrong.
Be sure to use the right tools. Bottom Brackets use weird and specific tools. Try to substitute something else and you will do a lot of expensive damage.
If it is a BB with free bearings, then the left side bottom bracket bearing cups and lock ring should be normal standard threading - rightee tightee, lefty loosey. (Bear in mind MichaelW's correct info that French bikes CAN BE weird and opposite).
Also, it is the left side which is the removeable side. Don't spend energy, time, and tools trying to loosen the permanent side (right side).
Unless the mechanic who worked on the bike before you was an idiot, the BB parts are usually not put on too tight. They are usually put on just snug. Thus, if it seems you are putting a lot of torque to your tools, you are probably doing something wrong.
Be sure to use the right tools. Bottom Brackets use weird and specific tools. Try to substitute something else and you will do a lot of expensive damage.
#7
Bottom brackets both tighten by rotating toward the rear of the bicycle.
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#8
Originally posted by Dirtgrinder
Bottom brackets both tighten by rotating toward the rear of the bicycle.
Bottom brackets both tighten by rotating toward the rear of the bicycle.
Some bikes have the "sprocket side" cup fixed and it is not meant to be loosened or tightened. it is threaded and look adjustable, but in fact is fixed in place.
I have seen some destroyed by guys who "couldn't get the damned thing to budge!" Then they bring it to me to see if I could replace or fix the cracked cups.
Last edited by mike; 06-20-01 at 09:57 PM.
#9
Originally posted by mike
Dirtgrinder, you assume that both left and right bracket or cups are move-able.
Some bikes have the "sprocket side" cup fixed and it is not meant to be loosened or tightened. it is threaded and look adjustable, but in fact is fixed in place.
I have seen some destroyed by guys who "couldn't get the damned thing to budge!" Then they bring it to me to see if I could replace or fix the cracked cups.
Dirtgrinder, you assume that both left and right bracket or cups are move-able.
Some bikes have the "sprocket side" cup fixed and it is not meant to be loosened or tightened. it is threaded and look adjustable, but in fact is fixed in place.
I have seen some destroyed by guys who "couldn't get the damned thing to budge!" Then they bring it to me to see if I could replace or fix the cracked cups.
#10
Senior Member

Joined: Sep 2000
Posts: 1,148
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From: Spokane WA
Bikes: Seven Axiom Ti, Trek 620, Masi cylocross (steel). Masi Souleville 8spd, Fat Chance Mtn. (steel), Schwinn Triple Bar cruiser, Mazi Speciale Fix/single, Schwinn Typhoon
Bottom bracket threads are NOT uniform:
English and french threaded , (normally 68mm wide) have right hand thread on the right hand of the bike, (fixed cup), left hand thread on the left of the bike adjustable cup.
Italian threaded, (normally 70 mmm wide) have right hand threads on BOTH sides of the bike.
NOTE:
If you ruin the threads on your english or french threaded bottom bracket you can save it by rethreading it with an Italian thread cutter!!! The Italian system uses slightly larger inside diameters. After rethreading to Italian just use Italian cups and an English spindle
English and french threaded , (normally 68mm wide) have right hand thread on the right hand of the bike, (fixed cup), left hand thread on the left of the bike adjustable cup.
Italian threaded, (normally 70 mmm wide) have right hand threads on BOTH sides of the bike.
NOTE:
If you ruin the threads on your english or french threaded bottom bracket you can save it by rethreading it with an Italian thread cutter!!! The Italian system uses slightly larger inside diameters. After rethreading to Italian just use Italian cups and an English spindle
#11
Junior Member
Joined: Feb 2011
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From: Aberdeen, Scotland UK
Bikes: Dawes unknown vintage(!),1964 Raleigh Rapide, 2011 Ridgeback Voyage
To Tighten:
Pedals - turn top forwards (ie. to the front of the bike)
Bottom Bracket - turn top backwards (ie. to the back of the bike)
That's the only way i can remember; with the fixed end of the BB usually being REALLY solid on older bikes, you start doubting whether you're doing it the correct way!
#13
John Wayne Toilet Paper
Joined: Feb 2006
Posts: 1,952
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From: Roanoke
Bikes: BH carbon, Ritchey steel, Kona aluminum
Might indeed be a record! But since we're here now, this is wrong:
This is the exact opposite. On a BSC/English standard threaded 68mm bottom bracket, the righthand cup is LEFT-threaded and the lefthand cup is RIGHT-threaded. This is because of precession (which happens to be the same reason pedals are threaded opposite BBs - becuase the precession causes different forces on a pedal thread than on a BB thread).
This is the exact opposite. On a BSC/English standard threaded 68mm bottom bracket, the righthand cup is LEFT-threaded and the lefthand cup is RIGHT-threaded. This is because of precession (which happens to be the same reason pedals are threaded opposite BBs - becuase the precession causes different forces on a pedal thread than on a BB thread).
#14
Senior Member


Joined: Feb 2012
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From: Rochester, NY
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I would also add that describing threading directions as "to the left" or "to the right" is not a good practice. It assumes that the wrench, placed on the cup, is pointing one way (up or down). Placing the wrench the other way gets you the opposite direction. Even using "clockwise" or "anticlockwise" as direction descriptions is confusing for many to follow (just one of the things they forgot since they learned to tell time back in kindergarten). So I tend to really dummy down the instruction and reference a light bulb's threading
Andy.
Andy.









