Flipping the stem

friedpizzainbatter
friedpizzainbatter Posts: 166
edited April 2013 in Workshop
Hi,

I was going to flip the stem on my bike and drop a spacer or two, but some words of warning were given to me by the guy who sold me my bike, not to touch the headset bolt(?), as it needs to be tightened correctly with a torque wrench, and over or undertightening can cause damage. I've noticed posts where people have done this, so for those of you that have, is it necessary to have a torque wrench to do this kind of work?

Thanks.
Trek Domane 4.3. Merida One.forty 7.700. Merida CX 3. Voodoo Bizango
"When the vulture flies sideways the moon has hair on his upper lip"

Comments

  • itsnotarace
    itsnotarace Posts: 518
    The headset bolt is purely there to adjust pre-load on the headset bearings, you do not need a torque wrench to do it up
  • nicklouse
    nicklouse Posts: 50,675
    not really.

    dont forget to add the spacers above the stem if you do take any out. you need to keep the same stack height.
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • redvee
    redvee Posts: 11,922
    The headset bolt only sets the bearings in the headset. No need for a torque wrench, best done by feel. Can be as little as 1/4 turn to get it right.
    I've added a signature to prove it is still possible.
  • friedpizzainbatter
    friedpizzainbatter Posts: 166
    Thanks for the quick replies, so I'm safe going for hand tight with an alan key?
    Trek Domane 4.3. Merida One.forty 7.700. Merida CX 3. Voodoo Bizango
    "When the vulture flies sideways the moon has hair on his upper lip"
  • g00se
    g00se Posts: 2,221
    Is the fork steerer aluminium or carbon?

    Once you have the pre-load on the top cap, you tighten up the stem bolts. If the steerer is carbon, there can be a risk of overtightening the stem blots and pinch or crush damaging the steerer - so a torque wrench can be useful in getting the bolts done properly. The seller may have been referring to that?

    The stem will have a given max-torque for these bolts. Usually 4-5NM but can sometimes be 8-10NM. With a bit of experience, you can judge this by hand.
  • friedpizzainbatter
    friedpizzainbatter Posts: 166
    It's a carbon fork, so a bit of caution is required then?
    Trek Domane 4.3. Merida One.forty 7.700. Merida CX 3. Voodoo Bizango
    "When the vulture flies sideways the moon has hair on his upper lip"
  • keef66
    keef66 Posts: 13,123
    You can still over-tighten it using an allen key. Do it up gently then tighten the stem clamp bolts and check for knocking when you apply the front brake and try to rock the bike backwards and forwards. Any knocking and you'll need to loosen the stem clamp bolts, tighten the top cap bolt a bit more and repeat the process. Keep going till you have a knock-free steerer that rotates freely / smoothly.
  • friedpizzainbatter
    friedpizzainbatter Posts: 166
    Nice one, thanks, I'll try that
    Trek Domane 4.3. Merida One.forty 7.700. Merida CX 3. Voodoo Bizango
    "When the vulture flies sideways the moon has hair on his upper lip"
  • g00se
    g00se Posts: 2,221
    And get some carbon paste too - you smear a little between the steerer and the stem. It'll mean you'll need less torque to hold the stem in place so less change of over tightening or not tightening enough...

    If you don't tighten the stem bolts enough, you'll notice it'll start to pick up the smallest bit of play after a few days/weeks. Like Keef said, stand over the bike, put the front brake on and rock the bike forwards and back, you'll feel it knock. Don't use the back brake at the same time, otherwise you won't be able to rock the forks enough.
  • itsnotarace
    itsnotarace Posts: 518
    friedpizzainbatter wrote:
    It's a carbon fork, so a bit of caution is required then?

    If it's an Allez Elite you ride, it's carbon blades with an aluminium steerer so don't worry about it too much, as long as the stem bolts are tight enough (ie you can't rotate the bars and stem with the front wheel clamped between your legs) then you're good to go. If it was a carbon steerer, you need to pay more attention to the torque ratings, but still many people see the torque ratings as a target, not a maximum.
  • friedpizzainbatter
    friedpizzainbatter Posts: 166
    itsnotarace wrote:
    If it's an Allez Elite you ride, it's carbon blades with an aluminium steerer so don't worry about it too much, as long as the stem bolts are tight enough (ie you can't rotate the bars and stem with the front wheel clamped between your legs) then you're good to go. If it was a carbon steerer, you need to pay more attention to the torque ratings, but still many people see the torque ratings as a target, not a maximum.

    Thanks, It's not the Allez it's a Trek Domane 4.3. I think it's all carbon.
    Trek Domane 4.3. Merida One.forty 7.700. Merida CX 3. Voodoo Bizango
    "When the vulture flies sideways the moon has hair on his upper lip"

Categories