Bottom Bracket Question

HarryB said:

I purchased a used low mileage bike and subsequently discovered that
the cranks were hard to turn. Although the bike has less than 2,000
miles on it, I assumed that I would need a new BB. However, after
removing the BB (TruVativ GigaPipe #BB-04-SPL-SLLT) I discovered that
the spindle rotated freely. When I screwed the BB back in, the spindle
would start to become difficult to turn as soon as the BB was
tightened finger tight and would become progressively worse the more I
tightened it.

If I would leave the BB loose enough that the spindle would turn
freely and then screw in the adjustable cup, the spindle would begin
to get difficult to turn once the cup was tightened past finger tight.

Could it be that the BB shell needs to be chased and faced? I assume
this has not been done since the face is painted and the threads have
paint in them as well. (I was under the impression that facing
normally isn't required with sealed bearings.) If I do need to have
the shell faced, I would only need to have the drive side done since
there is a note on the side of the adjustable cup which reads, "Cup
Will Not Bottom Out on Frame." Correct?

Your suggestions are most appreciated.

TIA,
Harry

Facing and chasing the BB would be my first suggestion. I have also
run into this problem on a few frames and usually facing the BB shell
helped. Good luck.

Steve Sauter

HarryB said:

I purchased a used low mileage bike and subsequently discovered that
the cranks were hard to turn. Although the bike has less than 2,000
miles on it, I assumed that I would need a new BB. However, after
removing the BB (TruVativ GigaPipe #BB-04-SPL-SLLT) I discovered that
the spindle rotated freely. When I screwed the BB back in, the spindle
would start to become difficult to turn as soon as the BB was
tightened finger tight and would become progressively worse the more I
tightened it.

If I would leave the BB loose enough that the spindle would turn
freely and then screw in the adjustable cup, the spindle would begin
to get difficult to turn once the cup was tightened past finger tight.

Could it be that the BB shell needs to be chased and faced? I assume
this has not been done since the face is painted and the threads have
paint in them as well. (I was under the impression that facing
normally isn't required with sealed bearings.) If I do need to have
the shell faced, I would only need to have the drive side done since
there is a note on the side of the adjustable cup which reads, "Cup
Will Not Bottom Out on Frame." Correct?

Your suggestions are most appreciated.

TIA,
Harry

Could be something simple like one of the two bearings not pressed far
enough onto the spindle.

HarryB said:

I purchased a used low mileage bike and subsequently discovered that
the cranks were hard to turn. Although the bike has less than 2,000
miles on it, I assumed that I would need a new BB. However, after
removing the BB (TruVativ GigaPipe #BB-04-SPL-SLLT) I discovered that
the spindle rotated freely. When I screwed the BB back in, the spindle
would start to become difficult to turn as soon as the BB was
tightened finger tight and would become progressively worse the more I
tightened it.

If I would leave the BB loose enough that the spindle would turn
freely and then screw in the adjustable cup, the spindle would begin
to get difficult to turn once the cup was tightened past finger tight.

Could it be that the BB shell needs to be chased and faced? I assume
this has not been done since the face is painted and the threads have
paint in them as well. (I was under the impression that facing
normally isn't required with sealed bearings.) If I do need to have
the shell faced, I would only need to have the drive side done since
there is a note on the side of the adjustable cup which reads, "Cup
Will Not Bottom Out on Frame." Correct?

Your suggestions are most appreciated.

TIA,
Harry

face and chase the BB shell, both sides. have the person doing it
measure to ensure the resulting shell width is 68 MM.

HarryB said:

I purchased a used low mileage bike and subsequently discovered that
the cranks were hard to turn. Although the bike has less than 2,000
miles on it, I assumed that I would need a new BB. However, after
removing the BB (TruVativ GigaPipe #BB-04-SPL-SLLT) I discovered that
the spindle rotated freely. When I screwed the BB back in, the spindle
would start to become difficult to turn as soon as the BB was
tightened finger tight and would become progressively worse the more I
tightened it.

If I would leave the BB loose enough that the spindle would turn
freely and then screw in the adjustable cup, the spindle would begin
to get difficult to turn once the cup was tightened past finger tight.

Could it be that the BB shell needs to be chased and faced? I assume
this has not been done since the face is painted and the threads have
paint in them as well. (I was under the impression that facing
normally isn't required with sealed bearings.) If I do need to have
the shell faced, I would only need to have the drive side done since
there is a note on the side of the adjustable cup which reads, "Cup
Will Not Bottom Out on Frame." Correct?

Your suggestions are most appreciated.

TIA,
Harry

The BB in question is the rear BB on a tandem, so I did a little
experimenting (the BB shells are the same width even though the BB
spindle lengths are different). I swapped the BB's around but didn't
get the results I had expected: Both BB's were a little tight, but a
lot freer than when the rear BB was located in the rear BB shell.

I had expected that if the rear BB was bad that it would also be very
tight when moved into the front BB shell. And, if the rear BB shell
needed to be chased and faced that the front BB, when placed in the
rear BB shell, would be very tight. But, as noted, that isn't what
happened.

This doesn't make any sense to me, but then again, I've never messed
with BB's before. Any further advice would be appreciated.

Harry

HarryB said:

I purchased a used low mileage bike and subsequently discovered that
the cranks were hard to turn. Although the bike has less than 2,000
miles on it, I assumed that I would need a new BB. However, after
removing the BB (TruVativ GigaPipe #BB-04-SPL-SLLT) I discovered that
the spindle rotated freely. When I screwed the BB back in, the spindle
would start to become difficult to turn as soon as the BB was
tightened finger tight and would become progressively worse the more I
tightened it.

If I would leave the BB loose enough that the spindle would turn
freely and then screw in the adjustable cup, the spindle would begin
to get difficult to turn once the cup was tightened past finger tight.

Could it be that the BB shell needs to be chased and faced? I assume
this has not been done since the face is painted and the threads have
paint in them as well. (I was under the impression that facing
normally isn't required with sealed bearings.) If I do need to have
the shell faced, I would only need to have the drive side done since
there is a note on the side of the adjustable cup which reads, "Cup
Will Not Bottom Out on Frame." Correct?

Your suggestions are most appreciated.

TIA,
Harry

This BB is on a tandem and one of the BB's had a lot more drag than
the other. I followed the advice offered and had both of the shells
faced and chased. The result is that the one that had a lot of drag is
much better while the other one improved marginally. But, they both
still have more drag than what I had expected. The mechanic said that
is the nature of cartridge bearings, but I'm not so sure.

I'll post a follow-up question under a new subject to see if others
agree with the mechanic.

Harry