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Mudguard Mounting Screw Hole - Stripped

dinyulldinyull Posts: 2,969
edited September 2016 in Workshop
Getting my Planet X London Road ready for winter this weekend I tried to fit some SKS Bluemels.

When coming to fit the front guard I've found that one of the screw holes on the fork is damaged - possibly stripped - meaning I can't screw in one of the bolts to attach the guards.

Bike isn't very old so I'm going to speak in PX about replacement fork, however It's my only bike atm and I commute on it so sending the fork off for inspection would cause some hassle.

Anyone out there with a fix (bodge) that would work and avoid having to send off?

The screw hole I'm talking about is halfway down the fork below:

CBPXLDNRIV_P1.jpg?v=s

Posts

  • tgotbtgotb Posts: 4,714
    1. Get yourself a set of taps, and retap the thread. If you've never use the thread before, it may not be damaged at all but merely clogged with paint, which the tap will clean out.
    2. Drill out the hole and use a slightly longer screw with a nyloc on the other end.
    Pannier, 120rpm.
  • arlowoodarlowood Posts: 2,527
    As above - this might solve your problem

    http://www.modelfixings.co.uk/metric_taps.htm

    Thread is probably M5 or thereabouts.

    Alternatively if you don't want to spend out on a set of taps, call your LBS and ask them how much they'd charge to re-tap the hole.
  • dinyulldinyull Posts: 2,969
    It's definitely not clogged with paint. There was a bit of censored in there so cleaned it out with cotton buds and under close inspection it looks like the half of the screw hole is missing - don't think it would be able to be re-tapped?

    It's really difficult to tell though as the hole is so small trying to inspect with a light created shadows making it hard to see.
  • FishFishFishFish Posts: 2,152
    The one I use on my MTB is called 'muddynutz' or something like that. It is surprisingly small, effective and is held on by velcro - might be the bodge you are looking for. Have a nose around CRC site.
    ...take your pickelf on your holibobs.... :D

    jeez :roll:
  • tgotbtgotb Posts: 4,714
    Dinyull wrote:
    It's definitely not clogged with paint. There was a bit of censored in there so cleaned it out with cotton buds and under close inspection it looks like the half of the screw hole is missing - don't think it would be able to be re-tapped?

    It's really difficult to tell though as the hole is so small trying to inspect with a light created shadows making it hard to see.
    When you say "half the screw hole is missing" what do you mean? Is the hole smaller than it should be, or larger?
    Pannier, 120rpm.
  • dinyulldinyull Posts: 2,969
    The hole is the correct size (as opposite side) but the depth of the thread pattern inside the hole looks much shallower. Looks like half - 2/3's of it are missing.

    I can't even get the bolt to 'bite' at all.
  • 964cup964cup Posts: 1,361
    Drill it out and put in a rivnut?
  • graeme_s-2graeme_s-2 Posts: 3,382
    Dinyull wrote:
    I can't even get the bolt to 'bite' at all.
    Does the bolt just slide freely into the hole with nothing to grip against, or can you not get it to turn into the hole at all because the thread is missing/incomplete?
  • fenixfenix Posts: 5,437
    Ziptie ?
  • dinyulldinyull Posts: 2,969
    Graeme_S wrote:
    Dinyull wrote:
    I can't even get the bolt to 'bite' at all.
    can you not get it to turn into the hole at all because the thread is missing/incomplete?

    This.
  • svettysvetty Posts: 1,904
    Dinyull wrote:
    The hole is the correct size (as opposite side) but the depth of the thread pattern inside the hole looks much shallower. Looks like half - 2/3's of it are missing.

    As long as there is a hole you should be able to cut a thread using a tap.....
    FFS! Harden up and grow a pair :D
  • keef66keef66 Posts: 13,123
    Svetty wrote:
    Dinyull wrote:
    The hole is the correct size (as opposite side) but the depth of the thread pattern inside the hole looks much shallower. Looks like half - 2/3's of it are missing.

    As long as there is a hole you should be able to cut a thread using a tap.....

    + several. Sounds like it just needs tapping properly. If it was like that from new PX should reimburse you for having it done, no?

    Don't try the longer bolt + nyloc nut suggestion above; that would involve drilling right through the fork leg... :D
  • tgotbtgotb Posts: 4,714
    keef66 wrote:
    Don't try the longer bolt + nyloc nut suggestion above; that would involve drilling right through the fork leg... :D
    The bolt/nyloc solution was only intended if the thread's stripped to the point where the bolt goes straight through without engaging the thread. Hard to tell what the OP meant by "half a hole".

    If the bolt doesn't go in at all, either tap it out or get someone to do it for you, it's a 1-min job with the right tool. I had a frame resprayed recently, and had to do this to every thread...

    http://www.screwfix.com/p/carbon-steel- ... 16pc/12080
    Pannier, 120rpm.
  • keef66keef66 Posts: 13,123
    TGOTB wrote:
    keef66 wrote:
    Don't try the longer bolt + nyloc nut suggestion above; that would involve drilling right through the fork leg... :D
    The bolt/nyloc solution was only intended if the thread's stripped to the point where the bolt goes straight through without engaging the thread. Hard to tell what the OP meant by "half a hole".

    If the bolt doesn't go in at all, either tap it out or get someone to do it for you, it's a 1-min job with the right tool. I had a frame resprayed recently, and had to do this to every thread...

    http://www.screwfix.com/p/carbon-steel- ... 16pc/12080

    I was just making the point, tongue in cheek, that this isn't your run of the mill threaded hole behind the dropout, in which you can use a nut and bolt because you can access both sides, but instead a Rivnut type thing half way up the fork leg, just like a bottle cage boss.
  • tgotbtgotb Posts: 4,714
    keef66 wrote:
    I was just making the point, tongue in cheek, that this isn't your run of the mill threaded hole behind the dropout, in which you can use a nut and bolt because you can access both sides, but instead a Rivnut type thing half way up the fork leg, just like a bottle cage boss.
    Ah, sorry, I hadn't spotted that. DO NOT DRILL OUT!

    If it's a Rivnut (or equivalent) it's got paint in it, there couldn't be anything else wrong. Tap it out...
    Pannier, 120rpm.
  • fudgeyfudgey Posts: 854
    What size is the screw you are trying to screw in?
    You can get self cutting screws, let me inow what size you currently have ie M4 and ill see if i have any M5's etc.

    If the mount is halfway down the fork then obviously you wont be able to nut and bolt it.
    My winter bike is exactly the same as my summer bike,,, but dirty...
  • dinyulldinyull Posts: 2,969
    Cheers all.

    Going to attempt to tap it, on inspection there isn't much material to tap but should be enough to get a screw to take.
  • The RookieThe Rookie Posts: 27,748
    When the rivnut was inserted the thread MUST have been fine (the tool screws into it to compress the rivet section), so it's almost certainly just paint.

    Same size as rack and bottle mounts - M5.
  • dinyulldinyull Posts: 2,969
    It's definitely not paint. 2/3's depth of the rivnut (if that's what it is) are missing and damaged - not covered in paint.

    I realise I haven't explained it well - if someone explains how to post pics I'll put some up.
  • arlowoodarlowood Posts: 2,527
    Dinyull wrote:
    It's definitely not paint. 2/3's depth of the rivnut (if that's what it is) are missing and damaged - not covered in paint.

    I realise I haven't explained it well - if someone explains how to post pics I'll put some up.


    Pics would help. Posting is staightforward

    1. Take pic on camera or phone.
    2. Upload pic to web hosting service eg Google+, Dropbox, Flickr etc
    3. Once pic is on the hosting service open it there and right click on it
    4. Select "copy image address" from the drop down list
    5. Open a Reply box in your thread
    6.Add text if you want then select the tab from the horizintal list of options above the reply box 7. Paste the image address from your clipboard between the[img][/img]brackets 8. Check in the preview that the pic is there
  • dinyulldinyull Posts: 2,969
    No pics I'm afraid. Spent the past half hour with 2 posh work camera's and can't get a decent photo. Considering the hole is (I think) only 5mm wide I just can't get the lighting right and zoom in close enough to show what I want.
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