Fork Stem Combo

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12-29-17 | 09:15 PM

mrblue

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Fork Stem Combo

I have a stem which says to torque the bolts, when attaching to the steer tube, to 6nm. However, the instructions that came with the carbon fork said, when installing the stem to the carbon steer tube, to not exceed 5nm.

What should I do, or rather what would you do:

Install the stem using 5nm even though the stem manufacturer suggests 6nm.
Install the stem using 6nm, as suggested by the stem manufacturer, despite the fork instructions saying to not exceed 5nm.
Split the difference and install the stem using 5.5nm.
Get a different stem that suggests 5nm or less.
Get a different fork that suggests at least 6nm.
Tighten the stem bolts until they feel snug, forget about, and go ride.

Thanks.

Last edited by mrblue; 12-29-17 at 09:22 PM.

12-29-17 | 11:33 PM

Andrew R Stewart

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Use 5NM and test the stem's ability to stay put. If the stem stay's tightly in place on the steerer then you're good. Remember that almost any single torque rating is a max not the only amount that works. Carbon paste on the stem's steerer clamp helps. Andy

12-30-17 | 03:32 AM

Bike tinker man

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Quote:

Originally Posted by Andrew R Stewart

Fully agree with above, follow the fork instructions, you could find another stem that may say a different torque value.
Assume you have a suitable torque wrench ?

12-30-17 | 06:42 AM

CliffordK

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Also, choose a stem design that distributes the pressure over the whole clamping area.

The more skeletonized stems may look pretty, but aren't necessarily good for carbon fiber.

12-30-17 | 07:28 AM

HillRider

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Those torque recommendations are maximums, not requirements, and the carbon fork steerer takes precedence so follow and do not exceed it's recommendation. That said, even 5 N-m is more than enough to keep the stem from slipping and that's all you need to accomplish.

12-30-17 | 11:06 AM

fietsbob

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Basically, it just has to be tight enough to turn the wheel , and not let the headset pre-load, slip out of adjustment..

the friction is what the clamping is, add to the friction with carbon assembly paste? .. essentially sand & grease.. combined..

note: we (Mechanics) have long used "Race Tight" for stems ..
tight enough to work normally, but loose enough to move in a crash , to not break so easily.

a good plan for the brake-lever to handlebar bar fitting too..