Weld breathe holes

Sdao38
Sdao38 Posts: 12
edited July 2018 in MTB beginners
Hi! Just bought a new bike :D

It has on the frame a couple of small holes, are they breathe holes during the weld or maybe holes to mount something?

The holes are just above the rear tyres on the back forks cross piece

On my old bike the paint has started to bubble here, presumably some corrosion underneath?

Does anyone cover up or try to seal these holes or is it not really worth it?

Ta! :D

Comments

  • 02gf74
    02gf74 Posts: 1,171
    Your description is not accurate to be able to say what the it purpose is.

    When you say small, what diameter, 1mm and 5 mm could both be described as small, so which is it?

    Is the hole threaded, that may provide a clue.

    With threaded holes, fill them with an M5 bolt, the weld breather holes cover with tape or fill with epoxy resign.

    There have been cases where water has got inside the frame into the seat stays, not necessarily from these holes as it may have been via the seat tube and when it froze, the seat stays burst, mind you this was in Sweden so not something to overly worry about.
  • cooldad
    cooldad Posts: 32,599
    Presumably small holes in the cross brace between the seat stays. Just ignore them.
    I don't do smileys.

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  • Sdao38
    Sdao38 Posts: 12
    Thanks, the holes aren't threaded and are approx 5mm

    This is one of those things where a picture is more helpful than a thousand words - I'll take a pic when I get back from work and post it
  • tgotb
    tgotb Posts: 4,714
    I'm guessing mounting hole for mudguard - we'll know for sure when we see a picture...
    Pannier, 120rpm.
  • Sdao38
    Sdao38 Posts: 12
    Small holes in the cross brace, sounds about right, ok safe to ignore then

    Reckon there is some corrosion or oxidisation on my old bike at the same point
  • cooldad
    cooldad Posts: 32,599
    And probably other places you haven't noticed. It happens to old stuff.
    I don't do smileys.

    There is no secret ingredient - Kung Fu Panda

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  • CitizenLee
    CitizenLee Posts: 2,227
    Like this?

    Kona-Sutra-LTD-2017-1.jpg

    If so just ignore it, or pop a bit of hot glue/epoxy/grease/bluetac/bogie in it if you want peace of mind.
    Current:
    NukeProof Mega FR 2012
    Cube NuRoad 2018
    Previous:
    2015 Genesis CdF 10, 2014 Cube Hyde Race, 2012 NS Traffic, 2007 Specialized SX Trail, 2005 Specialized Demo 8
  • Sdao38
    Sdao38 Posts: 12
    Yes exactly like that!
  • CitizenLee
    CitizenLee Posts: 2,227
    In that case I wouldn't worry about it if the bike is alu ;)
    Current:
    NukeProof Mega FR 2012
    Cube NuRoad 2018
    Previous:
    2015 Genesis CdF 10, 2014 Cube Hyde Race, 2012 NS Traffic, 2007 Specialized SX Trail, 2005 Specialized Demo 8
  • Sdao38
    Sdao38 Posts: 12
    Yeah it's a bizango, the new one and the old one with some corrosion a rockhopper
  • CitizenLee
    CitizenLee Posts: 2,227
    The Rockhopper will have suffered surface corrosion from salt-water spray from the rear wheel. Was the paint chipped first?
    Current:
    NukeProof Mega FR 2012
    Cube NuRoad 2018
    Previous:
    2015 Genesis CdF 10, 2014 Cube Hyde Race, 2012 NS Traffic, 2007 Specialized SX Trail, 2005 Specialized Demo 8
  • Sdao38
    Sdao38 Posts: 12
    I don't think it was ever chipped

    It is about ten years old though
  • trekvet
    trekvet Posts: 223
    Thats a daft place to put a hole, as all the muck of rear tyre will go straight in and not come out. I would cover or fill it.
    The Wife complained for months about the empty pot of bike oil on the hall stand; so I replaced it with a full one.
  • The Rookie
    The Rookie Posts: 27,812
    May be daft, but a massive number of bikes have it and it doesn't cause an issue, have holes there on both my 1997 steel frames.
    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.