I am a frame builder AMA

Posted on
of 40
First Prev
/ 40
  • Can a 142x12 steel mtb frame be cold set to 148mm? Doesn't sound unreasonable to me but thought I'd get some opinions.

  • While I'm sure you could coldset the frame to rear end to 148, I imagine the difficulty will be getting alignment of the TA dropouts and disc brake mount.

  • Today I managed to fall into/onto a fallen tree branch - it was a pretty big tree - and the branch basically levered off the bottle cage and one of the mounts from the down tube. A bit of a bummer since this bike is only two or three months old.

    Would it be possible to epoxy/glue/rivnut these back in or is it back to a framebuilder to torch the shit out of my almost brand new frame?

    I should add, I'm not a framebuilder...

    1 Attachment

    • 20200509_150826.jpg
  • What’s the width of the hole?

  • Damn thats a bummer, you could braze new ones in and just rattle can the bits where the paint is damaged. Or rivnuts but they're less fun, no fire invoved.

  • A steel rivnut, splined for preference, and a blob of epoxy should be fine. If you want a suitable rivnut, let me know. I have many.

  • If that frame is steel and you want to come down to Putney, I could silver braze one in for you in 5 minutes but obviously you’re gonna lose some paint. Alternatively rivnuts as above

  • Paging @mdcc_tester to tell you off about epoxying a rivnut.

  • I'm not suggesting just using epoxy. Use the rivnut properly, and get it to squish itself into place, but put a bit of epoxy in there just as a belt and braces exercise. There's nothing as annoying as trying to undo a bolt from a rivnut, only to find that the rivnut, while held firmly in place by the squishing of the rivnut, just spins around with the bolt. I've used hundreds of rivnuts in the past on cars I've built, and a blob of epoxy has saved me from much swearing. The splined ones are more resistant to spinning, but even then I'd still prefer a bit of epoxy just to make sure.

  • Thanks for all the advice.

    It's an 853 tube, will that cause any problems?

    I'm guessing it's worth a try for now, maybe when it's a bit easier to get to a framebuilder I'll have someone do it properly.

  • Rivnut doubly-secured with epoxy is how I've replaced bottle cage mounts in the past.

    Got some spare alu M5 rivnuts I'd be happy to pop in the post.

    Edit - just realised it's a steel frame so an alu rivnut may corrode

  • 🤷🏼♂️

  • Should be fine.

  • Did you get that little mill?

  • No, it went for £530 in the end which I couldn't justify given they're $695 brand new.

    Keeping an eye out but I've just invested a chunk in some non-framebuilding equipment for another venture so it'll probably have to wait a while

  • Ah yeah thats a lot for what it is. Oh well im sure something similar will come up at some point

  • Sam at Stayer did a similar repair for me (rack mount had pulled out). For full repair plus new powder coat I think you would be looking at around £80.

  • Which is ridiculously cheap

  • And you get to deal with Sam who’s an absolute gent!

  • You mean you didn't fall onto a tree?

  • Sadly no. I was going to ask more about how that happened, but didn't want to pry.

    Didn't a tree once fall on one of Dimi's bikes in Epping Forest and crush the top tube? Just saying, it could be worse.

  • Yeah that happened:)

    Just a standard bridleway incident really, not enough skills, too many pointy tree bits, etc.

  • Another bottle boss issue;

    Just got this Condor Touring frame, one of the bottle bosses seems to have taken a hit at some point and is slightly angled with a crack in the braze. The hole hasn't spread and no cracks are emerging. Frame is 531 super tourist so I assume it should be easily repairable.

    What's folks opinions?

    1 Attachment

    • 97449276_338094187152130_6126610349111115776_n.jpg
  • As long as the tube isnt cracked, just braze another one in.

    either go to the vaz guy or diy it its not very involved.

  • Post a reply
    • Bold
    • Italics
    • Link
    • Image
    • List
    • Quote
    • code
    • Preview

I am a frame builder AMA

Posted by Avatar for coldharbour @coldharbour