carbon rim crack

MattFT
MattFT Posts: 178
edited May 2014 in Workshop
Hi all,

Noticed a crack today between the fairing and the braking track on my front wheel (Tune Schwartzburners). It's about 2.5cm long. If I squeeze the rim at the crack it noticeably deforms vs. other sections. :(

Dead? :cry:

Reparable? :?

They don't make the rims any more either.

Angry, sad and confused.

Matt
FCN: 4

My Condor R.I.P.

Enigma Echo - everything outside the city
Genesis Day One Disc - commuter

Comments

  • sungod
    sungod Posts: 17,181
    tune still sells schwarzbrenner...

    http://www.tune.de/produkte/laufrader/

    but presumably you have a previous model

    depending on when/where you purchased, you may have warranty or other options

    have you contacted tune?
    my bike - faster than god's and twice as shiny
  • MattFT
    MattFT Posts: 178
    Good idea, I've contacted them. I bought the wheels second hand (from Classifieds here actually) but worth a shot.
    FCN: 4

    My Condor R.I.P.

    Enigma Echo - everything outside the city
    Genesis Day One Disc - commuter
  • Monty Dog
    Monty Dog Posts: 20,614
    Is it a non-structural fairing i.e. the spoke nipples are secured in the bed of the tyre channel rather than the apex of the rim? If so, it should be possible to repair - a structural PU foam is injected and will ensure that the crack will no longer propagate. Ask one of the specialist carbon repair folks for advice - but they tend to avoid anything near a brake track for obvious reasons. I've repaired my own carbon wheels - ordered materials online.
    Make mine an Italian, with Campagnolo on the side..
  • napoleond
    napoleond Posts: 5,992
    If you get no joy from tune try Fibrelyte.
    Insta: ATEnduranceCoaching
    ABCC Cycling Coach
  • MattFT
    MattFT Posts: 178
    Monty Dog wrote:
    Is it a non-structural fairing i.e. the spoke nipples are secured in the bed of the tyre channel rather than the apex of the rim? If so, it should be possible to repair - a structural PU foam is injected and will ensure that the crack will no longer propagate. Ask one of the specialist carbon repair folks for advice - but they tend to avoid anything near a brake track for obvious reasons. I've repaired my own carbon wheels - ordered materials online.

    It is non-structural I guess - the spokes go to the brake track. But the crack is very close to the brake track - would a repair be safe?
    FCN: 4

    My Condor R.I.P.

    Enigma Echo - everything outside the city
    Genesis Day One Disc - commuter
  • ugo.santalucia
    ugo.santalucia Posts: 28,310
    If the crack is in the carbon fairing, which is glued to the alloy rim, I don't know what the big deal is... it's little more than a cosmetic appendix with no function... leave it alone, or epoxy it... the crack will not propagate to the structural metal... If the crack is on the metal alloy, then the rim is good for the bin
    left the forum March 2023
  • sungod
    sungod Posts: 17,181
    there's a big difference between assuming it's a cf fairing on an alloy rim and knowing it's a fairing

    the op hasn't said which model of schwarzbrenner, but was there ever one that was alloy?

    a quick google didn't turn one up, the schwarzbrenner seems to be a lightweight cf wheel

    which is not something for amateur repair
    my bike - faster than god's and twice as shiny
  • damocles10
    damocles10 Posts: 340
    Personally I wouldn't use it until checked by a pro. It's probably fine though.
  • MattFT
    MattFT Posts: 178
    sungod wrote:
    there's a big difference between assuming it's a cf fairing on an alloy rim and knowing it's a fairing

    the op hasn't said which model of schwarzbrenner, but was there ever one that was alloy?

    a quick google didn't turn one up, the schwarzbrenner seems to be a lightweight cf wheel

    which is not something for amateur repair


    yup, lightweight cf
    FCN: 4

    My Condor R.I.P.

    Enigma Echo - everything outside the city
    Genesis Day One Disc - commuter
  • ugo.santalucia
    ugo.santalucia Posts: 28,310
    SO is it all carbon or carbon + alloy?
    left the forum March 2023
  • MattFT
    MattFT Posts: 178
    ugo.santalucia wrote:
    SO is it all carbon or carbon + alloy?

    All carbon. Brake track is carbon. Spokes run through the deep section into internal nipples at the same depth as the brake track though.
    FCN: 4

    My Condor R.I.P.

    Enigma Echo - everything outside the city
    Genesis Day One Disc - commuter
  • ugo.santalucia
    ugo.santalucia Posts: 28,310
    MattFT wrote:
    ugo.santalucia wrote:
    SO is it all carbon or carbon + alloy?

    All carbon. Brake track is carbon. Spokes run through the deep section into internal nipples at the same depth as the brake track though.

    OK, so my guess is that the fairing has been laid onto an existing carbon rim, so basically they are two separate structures bonded together... if that's the case you've got nothing to worry about, if not, then you have to somehow stop the crack from developing. If you shine light inside, is there a crack around the spoke hole?
    left the forum March 2023
  • cycleclinic
    cycleclinic Posts: 6,865
    Call Posh bike's they are tune distributor if they cannot help contact tune direct. No point asking here as we have no idea what these wheels are.
    http://www.thecycleclinic.co.uk -wheel building and other stuff.
  • MattFT
    MattFT Posts: 178
    thecycleclinic wrote:
    Call Posh bike's they are tune distributor if they cannot help contact tune direct. No point asking here as we have no idea what these wheels are.

    Thanks all. I've actually just moved to Berlin so I'm going to contact Tune directly.
    FCN: 4

    My Condor R.I.P.

    Enigma Echo - everything outside the city
    Genesis Day One Disc - commuter
  • Monty Dog
    Monty Dog Posts: 20,614
    As I originally suggested, as the crack is effectively in a non-structural part of the rim, the main concern is simply to stop the crack getting any worse. Sounds like the crack is immediately below the brake track which precludes an external 'patch' repair and therefore injecting some structural foam in there will hold it all together. BTW I have experience with carbon composites going back 25 years - it's just glue and fabric!
    Make mine an Italian, with Campagnolo on the side..
  • MattFT
    MattFT Posts: 178
    Monty Dog wrote:
    As I originally suggested, as the crack is effectively in a non-structural part of the rim, the main concern is simply to stop the crack getting any worse. Sounds like the crack is immediately below the brake track which precludes an external 'patch' repair and therefore injecting some structural foam in there will hold it all together. BTW I have experience with carbon composites going back 25 years - it's just glue and fabric!

    Thanks Monty. Know any carbon specialists in Berlin by any chance?
    FCN: 4

    My Condor R.I.P.

    Enigma Echo - everything outside the city
    Genesis Day One Disc - commuter
  • ugo.santalucia
    ugo.santalucia Posts: 28,310
    MattFT wrote:
    Thanks Monty. Know any carbon specialists in Berlin by any chance?

    If you go the repair route, you have to DIY... any so called specialist will charge you a small fortune and frankly you might as well throw everything in the bin. Provided teh damage is on the largely pointless fairing, any composite repiar kit will be simple to use and effective
    left the forum March 2023
  • MattFT
    MattFT Posts: 178
    ugo.santalucia wrote:
    MattFT wrote:
    Thanks Monty. Know any carbon specialists in Berlin by any chance?

    If you go the repair route, you have to DIY... any so called specialist will charge you a small fortune and frankly you might as well throw everything in the bin. Provided teh damage is on the largely pointless fairing, any composite repiar kit will be simple to use and effective

    Ah bugger. Started playing around and noticed that the internal nipple is putting the weight onto the fairing - in other words the fairing has some structural importance. Off to Tune for their crash replacement service I fear. Thanks everyone for your thoughts and comments.
    FCN: 4

    My Condor R.I.P.

    Enigma Echo - everything outside the city
    Genesis Day One Disc - commuter

Categories