Extending a Steerer Tube

Levi_501
Levi_501 Posts: 1,105
edited February 2011 in MTB workshop & tech
Why does nothing ever fit from one bike to another !!!

Tried slipping the forks up through in to the new Kona frame this evening, however, poxy steerer tube is to short !

It comes through the top bearing by about 10mm, obviously to short to put on a stem.

Are there any 'preferred' methods of lengthening a steerer tube, or is it a no no ?

I did wonder about one of these

http://www.chainreactioncycles.com/Mode ... delID=6254

As the steerer does come up through the top bearing, I thought I might be able to get away with one.

Any thoughts gratefully received.

Comments

  • ilovedirt
    ilovedirt Posts: 5,798
    How will that quill stem adaptor make any difference?

    It's new fork time.
    Production Privee Shan

    B'Twin Triban 5
  • The Rookie
    The Rookie Posts: 27,812
    New fork, unless it has a replaceable steerer and you replace it.

    That adaptor is to allow you to use Ahead stem on threaded steerers and won't help you at all.

    Simon
    Currently riding a Whyte T130C, X0 drivetrain, Magura Trail brakes converted to mixed wheel size (homebuilt wheels) with 140mm Fox 34 Rhythm and RP23 suspension. 12.2Kg.
  • Levi_501
    Levi_501 Posts: 1,105
    It slides down the inside of the steerer tube, where the star nut normally goes, and tightens up with the angled nut.
  • ilovedirt
    ilovedirt Posts: 5,798
    Yeah, it's for a threaded fork/headset, you have an A-headset, I'm fairly sure it won't work...
    Production Privee Shan

    B'Twin Triban 5
  • nicklouse
    nicklouse Posts: 50,675
    Levi_501 wrote:
    It slides down the inside of the steerer tube, where the star nut normally goes, and tightens up with the angled nut.

    threaded steerers were a specific ID. not the same as Aheadset steerers.

    a 1 1/8 threaded steerer had an internal diameter of 1"

    the forks are?
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • allthegearnoidea
    allthegearnoidea Posts: 4,077
    you can get steerer tube extenders but, i dont think i'd be keen on thrashing a bike with said extender on??? :?
    Timmo.
    After all, I am Cornish!
    http://cornwallmtb.kk5.org/
    Cotic Soul, The bike of Legends!:wink: Yes, I Am a bike tart!
    http://www.bikeradar.com/forums/viewtop ... 1#16297481
  • cavegiant
    cavegiant Posts: 1,546
    If the internal is exactly 1", you could just get a bit of 1" pipe, and a some extra spare steerer tube and epoxy everything together. probably be very strong.
    Why would I care about 150g of bike weight, I just ate 400g of cookies while reading this?
  • Deputy Dawg
    Deputy Dawg Posts: 428
    Not sure I even trust Devcon 2 ton to extend a steerer. I've had a loose quill stem un-sieze at the wrong time before & wouldn't wish it on my worst enemy (including the git who loosened it without me noticing).

    If you could get it plugged & welded it might be a goer.
    Statistically, Six Out Of Seven Dwarves Aren't Happy
  • The Rookie
    The Rookie Posts: 27,812
    Anyone else remeber Ayrton Senna's crash when his steering column failed* (and that didn't have front suspension loads from hitting bumps going through it) - no thanks!

    Simon
    *I'm not going into cause an effect, but it had failed and that was welded steel.
    Currently riding a Whyte T130C, X0 drivetrain, Magura Trail brakes converted to mixed wheel size (homebuilt wheels) with 140mm Fox 34 Rhythm and RP23 suspension. 12.2Kg.
  • Matt 24k
    Matt 24k Posts: 186
    If you have Marzocchi forks then Windwave, the UK distributor, offers a stem replacement as an add on to a service on some of the range. I am pretty sure that none of the other brands have this service available. Probably too concerned about product liability.
  • nicklouse
    nicklouse Posts: 50,675
    cavegiant wrote:
    If the internal is exactly 1", you could just get a bit of 1" pipe, and a some extra spare steerer tube and epoxy everything together. probably be very strong.

    right.

    so that is why mine is welded.

    you do come up with some odd ideas.
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • nicklouse
    nicklouse Posts: 50,675
    The Beginner wrote:
    Anyone else remeber Ayrton Senna's crash when his steering column failed* (and that didn't have front suspension loads from hitting bumps going through it) - no thanks!

    Simon
    *I'm not going into cause an effect, but it had failed and that was welded steel.

    if that was steel i will eat my hat.
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • The Northern Monkey
    The Northern Monkey Posts: 19,174
    New fork time!
    Santa Cruz Butcher
  • *AJ*
    *AJ* Posts: 1,080
    Just lol at epoxy!!!!!!
  • Dan_xz
    Dan_xz Posts: 130
    Yes it can work - but theres a couple of points to note.

    Threaded steerers are cut level with the headset, hence why you need this extender to use an ahead stem. The extender does not engage with the threads in any way but goes inside the steerer using an expander bolt exactly the same way the original quill stem would have fastened to the threaded forks

    However, a threaded steerer would be locked into the headset so the strain of keeping the fork attached would not be taken by the quill.

    Thinking of the torque recommendations on aheadset stems we are not talking about massive levels anyway, so what I'd say is would your stem have at least one of the clamp bolts below the extender (so it's at least partiallyclamping on the original steerer)?
    I have this setup on one of my bikes and have had no problem for 2 years and counting.


    The only question, as others have said, is the internal diameter of the steerer tubes. as they can vary a little - not a problem for star nuts as they bend into shape.

    I used my extender on an old set of Judy SL's (1 1/8 alu steerer) and the 1" insert is a nice tight fit and works fine. I do have to say this get the least abuse of all my bikes but it does go off road and has taken a couple of rocky stepped descents on a moorland XC route no probs. By which I'm talking max 6 inch vertical drops at slow/moderate speed, no crazy jumping, racing etc...

    Think about how hard your riding is? If you're a nutcase doing geniune 6 foot vertical drop offs (not a 4" drop off on a gentle 6 foot total slope - we all know what I mean!!!) or riding at over 140mph with the mass and momentum of an F1 car to hold ala Aryton Senna :roll: then I would probably feel happier with new forks, otherwise just get the extender if you feel happy with it.

    Fitting the ahead stem is less easy than normal as the adapter just has a bung on top - theres no cap to screw into a star nut and tighten the stem down, therefore you need to find another way to keep everything tight enough against the eadset while you tighten the stem in place. I got someone to push his weight down on the bars while I tightened it up.

    My advice, first see if your forks can have the steerer replaced as obviously thats the best and strongest option. If you have any doubts about it then get new forks or steerer as you can't put a price on piece of mind.
  • The Rookie
    The Rookie Posts: 27,812
    nicklouse wrote:
    if that was steel i will eat my hat.
    Do you want salt and pepper with that?
    http://www.ayrton-senna.com/s-files/newsfle6.html

    T45 and EN14.

    Simon
    Currently riding a Whyte T130C, X0 drivetrain, Magura Trail brakes converted to mixed wheel size (homebuilt wheels) with 140mm Fox 34 Rhythm and RP23 suspension. 12.2Kg.

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