Shakey headset cups

[Aurora]

I have external FSA headset cups on my MTB, the bottom one has now started to shudder and come loose.

 

 

 

What causes this to happen and how can I fix it?

[techguy]

BAD installation...

 

The fix depending on the clearance between frame and cup you may get away with a retaining compound from loctite...

[Little-Ben]

is the cup loose on the frame itself or is the actual fork and bar only moving within the cup

[Johan Bornman]

The solution is both easy and fun.

 

1) Go to your LBS* and buy an imported beer or six. Take a magnet with you and make sure you don't get a steel can, but an aluminium one.

2) Go home, open the beer and down it.

3) Raid your wife's needlework basket, take the scissors and cut the can into pieces so you end up with a strip as wide as the headset cup's insert part.

4) Wrap this around the headset cup insert part (try say that after six beers) so that it does NOT overlap on the ends.

5) Attempt to press the cup back into the frame whilst keeping this lot in place. It isn't easy but if it slips and shifts, just cut the extra bits off with a knife - your friend's knife since it blunts it a bit.

6) Refit the fork and go for a ride.

 

Many aluminium bikes suffer from this problem. It is caused by a too-loose cup to start off with and then constant braking causes the two to frett against each other, wearing the head tube oval. Frame manufacturers will tell you it is time for a new frame. Screw that.

 

 

*LBS = Local Bottle Store

 

[techguy]

JB's solution can work as well I have done it myself, but it all depends on the clearences betweeen the cup and frame...

[Aurora]

I tried the method, it does move a little less now, think i just need a new headset?

[Mudsimus]

A new headset wont work. Headset cup - Steel. Frame - Alluminium. The play you feel is due to the frame...not the headset. Solution = More beer can.

[Aurora]

the headset used to be tight in the frame, now its loose

[Mudsimus]

Because the headtube on the frame is stretched/worn.