Best Loctite for saddle clamp?

mitchgixer6
mitchgixer6 Posts: 729
edited June 2014 in Workshop
Looking for suggestions for which Loctite to use on my saddle clamp. I managed to partially strip the thread on my 3T side load mechanism the other day. I've currently got a slightly longer bolt in there which is catching enough good thread to tighten to 5nm, but it's loosening off ever so slightly after a ride.

Was thinking of getting some Loctite 222 to help as it has a pretty low loosening torque. Any suggestions or advice?

Obviously the best option is to buy a new clamp but at £50 i'd rather not if at all possible!

Comments

  • sungod
    sungod Posts: 17,351
    are you sure the screw is coming loose? put a mark on the head to see if it is rotating

    if it is coming loose, any low-medium strength threadlock should do, 222, 242 etc.
    my bike - faster than god's and twice as shiny
  • mitchgixer6
    mitchgixer6 Posts: 729
    I will try that with the mark, good call. I'm using my 5nm torque key as a reference, the stripped side is taking about 1/4 turn to get back to 5nm whereas the other side stays at 5nm.
  • imposter2.0
    imposter2.0 Posts: 12,028
    5nm doesn't sound like much to hold a saddle in place...
  • mitchgixer6
    mitchgixer6 Posts: 729
    It's marked on the clamp as 7nm Max. I've seen other 3T posts with the same diff lock mechanism marked as 5nm Max, so after stripping one I'd rather err on the side of caution.
  • Old_Timer
    Old_Timer Posts: 262
    Could you drill out enough to install a Heli-coil? I'm not sure using Loc-tite in this application will hold up well.
    Lets just got for a ride, the heck with all this stuff...
  • mitchgixer6
    mitchgixer6 Posts: 729
    I did buy a heli coil kit with the hope of fitting it, but there's not enough material on the outside diameter of the hole to let me drill it out.
  • frisbee
    frisbee Posts: 691
    You could maybe fit a timesert and drop down a bolt size.
  • mitchgixer6
    mitchgixer6 Posts: 729
    I hadn't heard of timesert before so thanks for another option.

    I had a close look at the clamp today and it looks like I'll have just enough room to fit a heli coil. I'm going to leave it for a bit though and test whether the bolt is actually loosening or not. If it is I'll try the loctite 222, and if that doesn't work I'll consider trying the heli coil, but I don't want to risk making it worse just now when I don't really need to.

    Thanks folks.
  • sungod
    sungod Posts: 17,351
    not familiar with the clamp, but if there's enough room for a helicoil an alternative may be to use a larger self-tapping screw in the hole
    my bike - faster than god's and twice as shiny
  • Old_Timer
    Old_Timer Posts: 262
    mitchgixer6 wrote:
    I did buy a heli coil kit with the hope of fitting it, but there's not enough material on the outside diameter of the hole to let me drill it out.
    Alright, it was just a thought. Could you take a pic and post it here so we can see the item completely? Hope it gets sorted out for you, this must be maddening to deal with.
    Lets just got for a ride, the heck with all this stuff...
  • mitchgixer6
    mitchgixer6 Posts: 729
    I had the clamp off yesterday to inspect it and it looks like I could just about fit the heli coil and leave enough material for it to be sound, but I'm not doing that just now as it seems to be holding OK with the longer bolt.

    In fact while I was inspecting it I realised there was still quite a few threads that hadn't been touched so I've actually ordered an even longer bolt (M5x20mm) to use on that side. I'm sure once I get that in there it should be pretty sound but I'm going to keep an eye on the tension of the bolt. If it does start loosening then I'll try Loctite before I fit a heli coil.

    I was pretty annoyed when it first happened but these things happen. Always more likely to happen with a steel bolt into an aluminium thread. It hasn't stopped me riding the bike so all's good!

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