Trek 5900 Headset Issue

Here's an ongoing issue that I've seen more than once. I recently revisited an issue with a 2003 Trek 5900 headset. Now, this is a nice bike ( I think that I owned on in the past...). Trek did a nice job. Light and stiff. In an effort to save some grams, they utilized a proprietary lower cartridge bearing. This was installed directly onto the crown race of the fork, thus eliminating the use of a crown bearing race. It is my understanding that this bearing was borrowed from Klein. Anyway, to cut to the chase, water likes to collect in the headtube area and cause a whole bunch of problems. This is what I'm talking about...

Well, this mess now only reeked havoc on the lower bearing, it also is evidence of the corrosion/ degrading of the aluminum steertube. Check this...

I needed a plan to stop any further degrading of the aluminum, so I got on the blower to my buddy Dr. J who is like a chemistry god and asked him for advise. He gave me a simplified lesson about what was going on and the nature of aluminum and corrosion and then he told me what to do and I did it. Here's a pic of the steertube and bearing before I installed it back into the headtube... (this is what a $45 bearing looks like...)

Btw... I recommended that the fork not be ridden and should be replaced because there is no way to confirm that the steertube is still structurally sound...
That's it for now. Thanks for checking in. -John

Comments

[Rob]

Trek converted my 5900 to use a normal headset and fork when I sent the original fork into the factory because of a hairline crack. VERY nice of them! I think they cut the headtube and replaced and epoxied a shim? A King headset and Reynolds Ouzo, or similar, make this frame timeless. Peel off some of the gaudy USPS stickers while your at it and it's not so dated to the Armstrong days. I'm still very stoked to ride this 10 year old daily.

[Ming]

I have the 2001 5900 Superlight bike, and it's my favorite bike. Trek has made some converter parts to fit the standard 1 1/8. To use a standard 1 1/8" fork with the 5900, you need part numbers 403215 (bearing) and 403237 (converter crown race). These parts can be ordered through any Trek dealer.

The unfortunate thing about this is that there is a slight wiggle, so it doesn't sit tight, the fork wiggles very very little when picked up by the handle bar. It's enough to be concern.

It's been 2.5 years since your last post, would love to hear your thoughts or if you done anything to replace your fork.

Ming

[RogueMechanic]

Hello B,
Thanks for your kind words. Can you please give me a name of a "local bearing shop" that has this bearing? Obviously, you know more about this bearing than I do. Please enlighten me. If you need the dimensions of this "common bearing that's been around for years". I will watch for your reply. -John

[B]

Nice open end post, would you mind actually explaining what was done and why you installed the bearing and fork back in the bike. Other wise the post seems to have no merit nor responsibility.

BTW the bearing is a lot cheaper if you avoid trek it has been around for years see your local bearing shop.