Second frame build

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  • I've been fabricating for artists and designers for over 10 years but always wanted to build my own frames. Fortunately I have all the kit and some of the skills needed - I think.
    I'm coming at this from a slightly different direction as I have a pretty good welding table and fixture set up, which I'm determined to use.
    I made my first one about 1 year ago. Pictures below. It was about as simple as it could get - TIG welded 653 - with downtube shifter. I worked it out as I went along, tweaking geometry and measurements from my other bikes. I rode it a bit for about 6 months and it was loads of fun.....


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  • Excuse the crap pictures.
    I recently started frame number 1 - I'm calling the first one frame number 0. Ha.
    Some pictures below.
    The main frame is actually not too tricky. The easiest bit is the bottom bracket mitres because they are simple perpendicular and central. I did them on the mill with a fine-tooth hole saw.
    The tricky bits are the seat stays and the down tube which I had to mitre by hand.


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  • I thought I'd share a few pictures as this one gets finished. I started before the lockdown and may not be able to finish for a while. It's just going to be a rack-and-mudgaurds summer cruiser hopefully - Zona tubing and I got a new full tiagra groupset for cheap.

    I'm sure the welding table fixture takes 10 times longer to set up than an expensive frame jig, but I reckon it's far more versatile. It is seriously accurate and made from tool steel. The hole spacing means that the tube clamping in the V-blocks keeps everything central. I'm not fully happy with the rear axle fixture - I'd like it to slide forwards and backwards while keeping straight, so it may need a base plate machining at some point. It's very square and true though.
    The whole fixture is adjustable around the BB shell which is only adjustable up and down.

    I started 12 years ago by spraying bike frames but now only spray a couple of bits for myself.

    Would be keen to hear any suggestions and ideas for the fixture.... I need to sort a brake bridge jig.... and I should sort out a set-up for notching the seatstays on the mill - that would save a couple of hours!

    Thanks!
    Sam

  • Looks nice dude. Always enjoy following your stuff on IG.

  • Ooh, all that sexy metal work on the insta, I think I might have to do some retraining one day.

  • Cheers @Hulsroy - Likewise, I always look forward to your updates!
    Cheers @snottyotter - get yourself a good value R-tech TIG welder and give it a go, you won't look back!

  • Lel, I ain't got welder money, maybe I'll scavenge one post apocalypse.

  • Apocalypse scavenge isn't a bad idea, but I went for a small business loan when I started :) The kit isn't cheap but pays for itself when up and running.

  • awesome! Jig looks cool! and the paint on the first one is great :)

  • Thanks! Thinking of going with pink/orange and black in this one!

  • top stuff, good to see a different approach.

  • Cheers.
    Next I brazed on the seat clamp and roughly finished it and added the slit on the mill.
    I cleaned up all the tubes on the inside and made sure there was no dirt or residue clinging onto any burrs. I clamped everything back in the jig for a final check.
    G-Clamps aren't ideal to hold the tubes as they slightly distort the thin section, but it's fractional and it's ok while I'm still getting my head around all this.


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  • This is the Gas Fluxer set-up I have.
    I did the brazing masterclass at the Bicycle acedemy a couple of years ago now and haven't used it much since - especially on steel. It works REALLY well with thin brass actually. I ususally TIG brass, but tried using the gas fluxer with Sif 101 rod and it was a dream. Perfect colour match with the sheet. Not sure if it was gas welding or brazing to be honest - it was melting the parent material, so assume it was gas welding... The little Harris torch must be what most people are using I guess.
    I've also got this relatively high temp brass solder. I'm not sure if this is ideal for things like braze-ons as it could be running too hot and may compromise the tubes.... I used this to solder on the brake bridge, but the fit was so tight (milled) I think it also has some mechanical strength ontop of the solder strength.
    Also a picture of the heat sinks. The one on the left (the pro looking one) was bought from FiveLand Bikes. They are doing some amazing work so snapped at one of these when I saw they did a batch. So many framebuilders I look up to, they are right up there for me and seem bloody lovely. I made a pretty crude seatpost heatsink from brass I had around. I'ts not very good but seems to have done the job. I'll need to improve this, especially if I want to add back-purging for TIG later on.


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  • To the brazing.
    I'm coming from a TIG background and carry over some bad habits that were acknowledged on the excellent BA course. I tend to dab the filler rod in but find this leads to quite a low bead with a small 'throat' when brazing - as you'll probably see around the BB below. I'm still working out how to build this higher - I'm still running a bit hot at the moment (I think) as I'm keen to see it fully wet into the root, but I could be going a little too far with the heat. Hopefully as confidence comes I'll be able to drop in more brass while still being confident it's flowed properly.
    Also the brazing samples I did on the Bicycle Academy course are much better than the ones I did on this frame. Having somebody standing over and giving pointers really helps. I now just need to put the time in.

    There is so much involved with making an accurate frame. I'm working with metal every day and strive for the best quality, but making a frame is a real test - The level of accuracy required and the amount of things going on keeps the brain working. I'm sure this becomes easier after 10 frames and potentially repetitive when doing a frame per week, hopefully I get to find out.
    Hat's off to frame builders out there.


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  • This is the finished frame sat back in the jig.
    You can spot a couple of low point in the brazing. I need to lay more brass on there. I couldn't be bothered to go back and build this up and I'll loose quite a bit in the primer. I'v got to remember this isn't the one-and-only... I need to make as many frames as possible to get better, so this could only be ridden for 3 months and then join the other one on the wall. No point going crazy with finishing - I only spent 2.5h sanding all the fillets. I didn't do much on the concave fillets ontop of the BB, that takes alot of work.
    The fillet sanding is something I have done alot before on other projects and is something I enjoy. I think my knuckles may think differently though.

    That's where I got to. Just waiting to get back to paint and for the bike shop to do the BB tapping/facing when they open. Tempted to buy the tooling but I'm not sure if the Icetoolz or similar BB kits are any good? Can't spend £500 on a Park Tool one - I know it's a good bit of kit, but it seems to have too much bike-tax added for me.


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  • Very nice.... why are you fillet brazing instead of Tig welding?
    Is it just for a change of technique/fun thing?

  • Cheers. Yeah, just for a change really and I spent a fortune on a gas fluxer so felt I should use it more! Like alot of people I guess, seeing Curtis frames as a teenager has stuck in my mind.
    I still like TIG, I just need to practice on such thin tubes. I can knock out some inoffensive TIG welds on thin tube, but getting that last 10-20% of quality is really hard and I need to come back to that at some point :)
    Got lots to learn with brazing too. So much to practice!

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Second frame build

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