when cutting your fork, how much should you have left? On a carbon steer, what's the max you should have.

Do you mean how tall a spacer stack can you safely have above the headset and below the stem? As a general guide, manufacturers of most 1" carbon steerer forks recommend no more than 25 mm (1 inch) of spacers be used. For 1-1/8" carbon steerers most makers recommend 40 mm maximum and Easton says 50 mm maximum. As to spacers above the stem, anything you like is safe.

BTW, it's a good idea to cut the steerer long enough to require at least a small spacer, say 5 mm, above the stem to assure the steerer tube is fully inside the stem to protect it from the clamping forces.

sorry hillrider.. it was late at night so my wording was off. i did leave about 4mm above the stem so the steer tube is fully inside.

but this is what i had meant. does my stem look too long? when i went to a local LBS, the bikeshop guys said for carbon steerer it's best not to have it longer than 2.5" above the frame (less than 3" max will be safer), which includes the height on the top cap of the headset to prevent any crack into the steerer.

see pics here

Usually the spacer height is measured from the top of the headset's upper race to the underside of the stem rather than from the top of the head tube to the top cap. Anyway, from your photo that distance seems to be about 40 mm which should be fine for a 1-1/8" steerer. And, actually, if you install the stem so 4 mm of steerer projects above it, that makes the spacer stack even more conservative.

+1 The spacer height is just that - the height of the spacers only, not including any part of the headset. In any case I think you have a reasonable level of spacer height.

Not in that picture. It looks like your stem is at the very top of the steerer tube with only the top cap above it.

just a thought... an aluminum sleeve inside the carbon steerer is possible..
still have the look, but adds a safety margin.

[but, not 7000 series Zn alloy aluminum]

ok, so you mean there should be 4mm of fork with spacer above the top of the stem before the top cap is screwed out?

Yes

ah.. got it.. will try that. i have some slim spacers i can use.

Rule 45

what's rule 45?

Rule 45: Thou shalt not display more than 2cm of spacers under thy stem, and no more than a 5mm spacer above it.

Damn silly rule , I imagine it comes from trying to copy the look of factory team bikes ridden by full-time pros. The result is wannabe racers who are not comfortable on their bike for longer rides. They can not fix it because they can't uncut their stem, and they are not psychologically capable of fitting a stem which gives the amount of rise they need.

yup.. i rather have plenty enough fork than not enough... hate to be stretched out that far out for long rides..

And of course, a too long steerer is easy to correct. A too short steerer, not so easy.

You can always cut it shorter but you can never cut it longer.

Unless you are Wookie Jesus.

I you have any steer tube sticking up above the stem you will definitely need a spacer above the stem, and the top of the spacer will need to be at least 1/8 inch above the stem and the clamp bolts loose when setting the cap screw pre-load.

You should be adding not subtracting!

Fixed it.

hi all.. just wanted to let ya'll know that by adding a small CF spacer on top of the stem.. that really did wonders!! now headset don't move and everything is even more rock solid compared to before.

thanks!