A customer asked me to replace the headset cap on their Cannondale with a lower one.
before
after
Unlike the previous ZS2 job (→here),
this time it's an FSA headset.
Since we have to fit it to the actual bike, it's not always guaranteed to work out the same way,
but this time I installed three 0.5mm microspacers.
Two might have worked too,
but I went with three just to be safe since no visible gap appeared even with three.
The frame is a CAAD10, and it comes with standard headset parts.
Since the recessed dimension on the back of the headset cap is constant,
you might think that the answer should be consistent and fitting shouldn't need to be customized—
but that's not how it actually works.
That said, it's not that Cannondale frames have poor tolerances;
it's just how frames in general are.
If we only lowered the headset cap without doing anything else,
we'd need to buy extra headtube spacers.
But since the customer wanted that difference taken up by cutting the fork steerer,
I cut the fork steerer and moved the spacer that was above the stem down below it.
Strictly speaking, it's now about 2mm lower than the original position,
but the original setup only had 5mm and 10mm spacers,
so those alone couldn't give us the right height.
We could solve this by buying one 2mm spacer,
but since the original position wasn't really locked in anyway,
this works fine for now.
The FSA cap's outer diameter is about 1mm smaller than the frame in diameter,
or about 0.5mm smaller in radius.
If the step is too pronounced, it looks ugly,
but at this level it looks like the same diameter at a glance, so there's no problem.
Oh, I almost forgot to mention this.
The reason they brought it to our shop in the first place was
that when they asked a Cannondale dealer to do the same thing,
they made all sorts of excuses and ended up refusing to do it.
before
after
Unlike the previous ZS2 job (→here),
this time it's an FSA headset.
Since we have to fit it to the actual bike, it's not always guaranteed to work out the same way,
but this time I installed three 0.5mm microspacers.
Two might have worked too,
but I went with three just to be safe since no visible gap appeared even with three.
The frame is a CAAD10, and it comes with standard headset parts.
Since the recessed dimension on the back of the headset cap is constant,
you might think that the answer should be consistent and fitting shouldn't need to be customized—
but that's not how it actually works.
That said, it's not that Cannondale frames have poor tolerances;
it's just how frames in general are.
If we only lowered the headset cap without doing anything else,
we'd need to buy extra headtube spacers.
But since the customer wanted that difference taken up by cutting the fork steerer,
I cut the fork steerer and moved the spacer that was above the stem down below it.
Strictly speaking, it's now about 2mm lower than the original position,
but the original setup only had 5mm and 10mm spacers,
so those alone couldn't give us the right height.
We could solve this by buying one 2mm spacer,
but since the original position wasn't really locked in anyway,
this works fine for now.
The FSA cap's outer diameter is about 1mm smaller than the frame in diameter,
or about 0.5mm smaller in radius.
If the step is too pronounced, it looks ugly,
but at this level it looks like the same diameter at a glance, so there's no problem.
Oh, I almost forgot to mention this.
The reason they brought it to our shop in the first place was
that when they asked a Cannondale dealer to do the same thing,
they made all sorts of excuses and ended up refusing to do it.