Changing a stem on a carbon steerer.....

[RegG]

Hi everyone,

I need to change the stem on my bike which has a carbon steerer using the expanding type of fitting in the headset.

Can anyone out there advise on the correct method please?

I am thinking I should first of all slacken off the expanding sleeve in the steerer before loosening and removing the stem. Is this correct?

I do have a small torque wrench to make sure I don't over tighten the bolts when I put it all back together.

Thanks in anticipation....

 

[Ian H]

Remove top-cap and bolt. Loosen and remove stem.
Slide the new one on. Refit the top-cap and bolt, tighten until there's no play at the headset (apply front brake and rock the bike forwards and backwards to check). If you can't remove the play then it's possible the new stem is shallower than the old and you need an extra spacer.
There's no need to over-tighten the stem on to the steerer; in fact it's better if it swivels in a crash rather than bending or breaking something.

 

[Racing roadkill]

Turn the wheel 90 degrees, and rock the bike backwards and forwards, when you are preloading the headset. Otherwise you may find you will be be detecting play due to the brake callipers or wheel in the forks as well as the headset. As far as the expander bung in the steerer is concerned, make sure it’s in the position where the stem will be clamping the steerer, and tighten it up to 6N.m. Of torque. Then preload the headset using the top cap, but only tighten that up enough to eliminate any play. When that’s done, tighten the stem bolts to about 5 N.m. of torque. As soon as the stem bolts are tight, you can take the top cap and bolt off and throw it in the bin if you want to save a couple of grammes of weight.

 

[alecstilleyedye]

make sure the stack height is the same.

i once swapped one deda elementi stem for another and needed a 5mm spacer to keep everything tight…

 

[Racing roadkill]

make sure the stack height is the same.

i once swapped one deda elementi stem for another and needed a 5mm spacer to keep everything tight…

Or cut the steerer down.

 

[alecstilleyedye]

Or cut the steerer down.

if y'dare…

 

[RegG]

Thanks for all the advice. I feel a bit more confident now!