[Bluechip]

I purchased a used 5900 on Ebay and it seems to have some sort of headset problem. It can get quite unstable at speed. In a sprint up to 30 mph I don't notice anything but as soon as I start to coast it gets very unstable. It makes it hard to hold a straight line. After doing some research I have found out that there were some problems in this area for this bike. Are my problems similar to the common problems felt by others. What is the cure? I am sure Trek would not honor any warranty since I bought it used. With the standard 1 1/8" upper and a 1 1/4" lower headset how do I replace it if that is the problem? I noticed that Chris King does have a 1 1/4" headset. Will they sell the upper and lower seperatly and would that even be the correct one? Thanks

 

[Folsom Cyclist]

Your headset may be loose. I have had issues with front hub bearings causing this to occur also. As I remember it the issue was the headset getting really tight and the bars would be hard to turn... but I could be wrong..

 

[Bluechip]

I have had three differant stems on it in less than a month so maybe I just have not got the headset adjusted just right yet. It's not the hubs because I have used the same wheels on my other bike with no problems. It's still there though. I had a nice tailwind this weekend and got up to 34 mph and when I strarted to coast it became very difficult to keep it straight. It feels just fine then there is a definate tug on the bars. Kind of feels like riding in a strong crosswind with aero wheels. Thanks

 

[Folsom Cyclist]

REALLY sounds like headset is too loose

You may want to "overtighten" the headset to the point where it is just dragging when you turn the bars. Try a fast ride and see if it goes away. Then loosen until there is no drag. Sounds like a bummer but you can back into the adjustment.

 

[rgr692]

5900 Proprietary Headsets

I purchased a used 5900 on Ebay and it seems to have some sort of headset problem. It can get quite unstable at speed. In a sprint up to 30 mph I don't notice anything but as soon as I start to coast it gets very unstable. It makes it hard to hold a straight line. After doing some research I have found out that there were some problems in this area for this bike. Are my problems similar to the common problems felt by others. What is the cure? I am sure Trek would not honor any warranty since I bought it used. With the standard 1 1/8" upper and a 1 1/4" lower headset how do I replace it if that is the problem? I noticed that Chris King does have a 1 1/4" headset. Will they sell the upper and lower seperatly and would that even be the correct one? Thanks

Bluechip,

Regarding the 5900's headset, I had the same problem and did some research on the problem. The problem is that trek uses a proprietary headset and fork with the 5900 series bike. They did this to decrease weight and increase stiffness. The problem is that the cane creek headset is not very good (IMHO) and if you want to change headsets or forks, it cannot be done by the rider or by the LBS.

There is a solution however, Trek will do the job for you. You have to take your bike a authorized Trek dealership and tell them that you want to send the bike to Trek to have the headset replaced. Trek will modify the bike to accept whatever headset you want (the headsets are epoxied in place on the 5900). The whole process takes about 1 week. I had a Chris King Headset put on my 5900 and couldn't be happier. This is definitely the headset that should have come standard with the bike.

The bottom line is it will cost you 200 dollars for trek to do the work, 75 dollars for postage (round trip), the cost of the headset (Chris King: approx 120 dollars), and whatever your LBS charges to install the headset (Trek just alters the headtube to accept a 1 1/8" or 1" headset, your LBS actually installs the headset.) Everything is about 500 dollars. Expensive, yes...but honestly, the 5900 was/is/always will be my dream bike. I like to have the peace of mind knowing that it is now completely mechanically sound and safe.

I hope this helps...by the way, I have about 4800 dollars in my 5900 so far....not a single regret yet.

Sincerely

Tony