Trek 5900 lower headset bearing problem

On Friday, June 4, 2004 at 11:49:17 PM UTC-4, Mike Jacoubowsky wrote:
I have a 2002 5900 with the oversized lower headset bearing. It makes a
small noise when exerting a lot of pedal pressure when standing, e.g.
climbing. I have replaced the bearing and put green loctite in the cup as
recommended, but it still makes the noise.
How was the bearing replaced? It's *very* easy to damage the bearing during
the installation process, or simply install it slightly out-of-plane.
Either one causes trouble. I know; my first installation didn't go so well!
Reason i know the noise is
coming from the bearing/cup is with the old bearing i put some grease in
the
lower cup and it made it quite for a few weeks. But do not really care to
keep doing this.

Questions:
Is the cup susposed to have green loctite in it as was recommended?
Shouldn't be a problem, but you want to make sure you don't contaminate the
bearing with it.
Can the lower cup be replaced, that is can it be extracted like a normal
cup
and a replacement pressed back in. Someone told me, these are glued into
the frame and have to be removed by Trek with heat?
Yikes, the way it's put in I doubt you could remove it without potentially
doing some serious damage to the frame. Don't think I'd go there.
Also, i was told that some company sells a shim/spacer that can be used to
convert this to a standard 1 1/8 inch headset/
Not sure how this would work, but it would be a neat trick. Keep in mind
that it would require a new fork as well, since the reason for the larger
lower bearing is to accommodate the special steer tube the older 5900s have,
which is larger at the bottom and smaller at the top.
Mike J- i know you have some experience with these headsets?
Nah, none whatsoever! :)
PS: It's time to replace my bearings again; with what I put my poor bike
through, they last about a year and a half. Yes, I'll admit it, a Chris
King headset, as allowed by the newer 5900 & Madone designs, would be a nice
thing to have. That'll have to wait a while though, as I rather like my
5900, and tend to keep my bikes for a number of years.
--Mike-- Chain Reaction Bicycles
www.ChainReactionBicycles.com

"dobesh" wrote in message
...
I have a 2002 5900 with the oversized lower headset bearing. It makes a
small noise when exerting a lot of pedal pressure when standing, e.g.
climbing. I have replaced the bearing and put green loctite in the cup as
recommended, but it still makes the noise. Reason i know the noise is
coming from the bearing/cup is with the old bearing i put some grease in
the
lower cup and it made it quite for a few weeks. But do not really care to
keep doing this.

Questions:
Is the cup susposed to have green loctite in it as was recommended?

Can the lower cup be replaced, that is can it be extracted like a normal
cup
and a replacement pressed back in. Someone told me, these are glued into
the frame and have to be removed by Trek with heat?

Also, i was told that some company sells a shim/spacer that can be used to
convert this to a standard 1 1/8 inch headset/

Mike J- i know you have some experience with these headsets?

Thanks.
Duane





April 19, 2021

*** Trek 5900 OCLV 2003-2004 - Headset Bearings for tapered steering tube ***
Steering tube is wider at the bottom
-
Top - ID 30.1mm / OD 41mm - TH Industries ACB 36deg x 45deg - 6.55mm thick
-
Bottom - ID 33.34 / OD 44.45 - 7.14mm thick

33.3mm = 1.311" ~= 1"-5/16" = 1.3125"
44.4mm = 1.748" ~= 1.75"
7.14m = 0.281" = 9/32

Generic replacement - B542-2RS FC
220861 internal trek part # for the bottom bearing

I ordered a new bottom bearing and buffed most of the steering tube to a mirror finish.
I plan to give the steering tube a liberal coating of Phil Wood grease to prevent oxidation & corrosion.
Also will be liberal with grease for the star nut threads and the steerer tube that extends past the
top of the headset. And, finally use clear silicone (RTV) in assembly of the stem and star-nut bolt and cap
to prevent water or sweat from getting into or around the steering tube. I used silicone this way when the bike
was new to me and there was very little corrosion. I am also considering using silicone to set the bearing
into the bottom cup to keep water entering from the bottom. The large bearing itself was more corroded on the top of
the bearing (inside the headset) than it was on the bottom of the bearing assembly exposed to the elements..

April 19, 2021

On Monday, April 19, 2021 at 12:45:28 PM UTC-7, Eric Halpern wrote:
On Friday, June 4, 2004 at 11:49:17 PM UTC-4, Mike Jacoubowsky wrote:
I have a 2002 5900 with the oversized lower headset bearing. It makes a
small noise when exerting a lot of pedal pressure when standing, e.g.
climbing. I have replaced the bearing and put green loctite in the cup as
recommended, but it still makes the noise.
How was the bearing replaced? It's *very* easy to damage the bearing during
the installation process, or simply install it slightly out-of-plane.
Either one causes trouble. I know; my first installation didn't go so well!
Reason i know the noise is
coming from the bearing/cup is with the old bearing i put some grease in
the
lower cup and it made it quite for a few weeks. But do not really care to
keep doing this.

Questions:
Is the cup susposed to have green loctite in it as was recommended?
Shouldn't be a problem, but you want to make sure you don't contaminate the
bearing with it.
Can the lower cup be replaced, that is can it be extracted like a normal
cup
and a replacement pressed back in. Someone told me, these are glued into
the frame and have to be removed by Trek with heat?
Yikes, the way it's put in I doubt you could remove it without potentially
doing some serious damage to the frame. Don't think I'd go there.
Also, i was told that some company sells a shim/spacer that can be used to
convert this to a standard 1 1/8 inch headset/
Not sure how this would work, but it would be a neat trick. Keep in mind
that it would require a new fork as well, since the reason for the larger
lower bearing is to accommodate the special steer tube the older 5900s have,
which is larger at the bottom and smaller at the top.
Mike J- i know you have some experience with these headsets?
Nah, none whatsoever! :)
PS: It's time to replace my bearings again; with what I put my poor bike
through, they last about a year and a half. Yes, I'll admit it, a Chris
King headset, as allowed by the newer 5900 & Madone designs, would be a nice
thing to have. That'll have to wait a while though, as I rather like my
5900, and tend to keep my bikes for a number of years.
--Mike-- Chain Reaction Bicycles
www.ChainReactionBicycles.com

"dobesh" wrote in message
...
I have a 2002 5900 with the oversized lower headset bearing. It makes a
small noise when exerting a lot of pedal pressure when standing, e.g.
climbing. I have replaced the bearing and put green loctite in the cup as
recommended, but it still makes the noise. Reason i know the noise is
coming from the bearing/cup is with the old bearing i put some grease in
the
lower cup and it made it quite for a few weeks. But do not really care to
keep doing this.

Questions:
Is the cup susposed to have green loctite in it as was recommended?

Can the lower cup be replaced, that is can it be extracted like a normal
cup
and a replacement pressed back in. Someone told me, these are glued into
the frame and have to be removed by Trek with heat?

Also, i was told that some company sells a shim/spacer that can be used to
convert this to a standard 1 1/8 inch headset/

Mike J- i know you have some experience with these headsets?

Thanks.
Duane





April 19, 2021

*** Trek 5900 OCLV 2003-2004 - Headset Bearings for tapered steering tube ***
Steering tube is wider at the bottom
-
Top - ID 30.1mm / OD 41mm - TH Industries ACB 36deg x 45deg - 6.55mm thick
-
Bottom - ID 33.34 / OD 44.45 - 7.14mm thick

33.3mm = 1.311" ~= 1"-5/16" = 1.3125"
44.4mm = 1.748" ~= 1.75"
7.14m = 0.281" = 9/32

Generic replacement - B542-2RS FC
220861 internal trek part # for the bottom bearing

I ordered a new bottom bearing and buffed most of the steering tube to a mirror finish.
I plan to give the steering tube a liberal coating of Phil Wood grease to prevent oxidation & corrosion.
Also will be liberal with grease for the star nut threads and the steerer tube that extends past the
top of the headset. And, finally use clear silicone (RTV) in assembly of the stem and star-nut bolt and cap
to prevent water or sweat from getting into or around the steering tube. I used silicone this way when the bike
was new to me and there was very little corrosion. I am also considering using silicone to set the bearing
into the bottom cup to keep water entering from the bottom. The large bearing itself was more corroded on the top of
the bearing (inside the headset) than it was on the bottom of the bearing assembly exposed to the elements..

April 19, 2021
One of the things to remember about the headset bearings is that they are smoothly rolling bearings because you don't want any friction so that the steering can self correct when you hit road irregulates. There is really no load on a headset bearing and since it can't even turn a full RPM there is really no need for a bearing there other than to get the ultralow friction connection.