I am a frame builder AMA

Ally is not massively pleasant to weld with, needs different welders. There are a lot of really cool steel alloys atm, and not very many ally ones. A lot of this will be to do with fashion, and you may find that it comes back into fashion in the near future, the bike trade is cyclical. Personally, I have the capacity to weld ally, but what with the lack of choice in tubing, drop outs etc, coupled with the pain that it is to repair etc.... have never been particularly drawn to it.

^ This.

Also, if you're doing it properly, you need to heat treat the frame after welding on most decent alloys, which is another PITA and regardless of how it's made the frame will inherently have a limited fatigue life, unlike steel.

@Hulsroy this is a cast one, which I very rarely do now, and they are a bit more of a pain, but the theory remains the same for this as a bent unit. As you can see, my preferred method is to cut everything to length but do all assembly in the jig, tac, check then weld/braze once alignment has shown itself to be fine.

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Yeah I see. Looks smart. I just haven't got that type of fixture on my jig, yet...thanks for sharing

Cyfac does alu as well I think.

Didn't know this existed.

Chuffing hell the wire is expensive!

Yeah, I had only asked bc I had an amazing deal on it from the US (where it's more common), but I let it pass in the end since I didn't think it would work on bicycle tubing. We may never know...

If I was going to have a go at building a lugged frame with a kit from ceeway, can I silver solder the lugs on with MAPP gas and then tig the rear dropouts in?

Drop outs: as long as they aren't carbon that's no issue.
MAPP: Yes, but it's boring and slow. Oxy propane is not much more expensive and way betterer

Ace thanks.
When you say oxy propane, i have seen the small setups you can get for roofing etc, like this?
I know the small bottles aren't so cost effective but this is somewhat of an experiment

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You won't be able to get one lug out of each pair of bottles, I made that mistake 8 years ago! Rent free bottles of oxygen and propane and a second hand torch off ebay would be my suggestion.

ah ok that's that then!
I may profile all the tubes at work then and take everything to the workshop at my parents place over easter where there i can get use of actual oxy acetylene and the TIG.

Or tube blocks on a flat surface and tig the whole thing? Also, make sure the drop outs aren't cast if you want to weld them or you're going to have a bad time.

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Yeah valid, to be honest I could actually just braze or tig the whole thing of I’m going to do it at home.

I was thinking lugged and MAPP has so I could do it at work where I’d never get an oxy setup through the door without a vast amount of HSE

Dear people who know about geometry:
(sorry, cross post from bikefit / correct riding position)

I've found a frame that might work for me as a commuter / winter bike, Spa Audax, which I can use with a Condor Pioggio fork I already own.

Sherritt has fitted me on my Look 586 and by my reckoning I can get the same position on the Spa without too much fuss. Does this make sense?

The Spa has a 71º headtube and a 72.5º seatube, will it handle like a pig compared to my other bikes? (The Look and the SuperSix are racing machines, the Look handles perfectly).

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Seems the Condor fork and Spa frame will give me 71mm of trail...

Lugged and MAPP is fine, slow and you need lots of good quality flux as your'e hanging around hot as the flame is colder than oxy fuel, but I built my first frame with MAPP, lugs and two bits of wood for alignment..... it was wonky, shit penetration and didn't fit, but that was user error not tooling.

I have a surface table i can clamp stuff to to align and join in place, i am tempted to get a kit from Peter and just have a go with mapp as a starting point.

Can you recommend a good suitable flux?

Cycle design silver flux, the blue one. Peter stocks it.

I think someone on here was selling cheap chromor tube sets and lugs, might be worth seeing how juch he wanted for them.

I'm looking to get my 80s Daccorddi Columbus SLX frame cold set at the rear from 126mm to 130mm.

The rear triangle is chromed.

Is there any risk that the bending process will fuck the chrome, making it flake or any other bad side effect?

Google search seems to throw up a lot of results of people bending chrome plated pipes (up to 90 degrees) with no ill effects, but whether that is true for chrome plated steel bikes...

The post from the Russian dude?

I have emailed Peter, he has put together a kit that's lugged oversize tube and a 1-1/8th" head tube so i can use an existing carbon fork i have just repainted.

I just need to tell him whether i want it fixed or geared and to that i want to silver solder rather than brass braze and that's it basically!

I couldn't say for certain, but I would think it risky: chrome is brittle and you have to bend the stays far beyond 130mm to set them.

I can say that if you ride a 126mm frame with a 130mm wheel, then it will eventually "self-set" to closer to 130mm so that getting the wheel in and out becomes easier.

tl/dr
Risk/reward analysis says no.

Also bear (bare?) in mind that chromed stuff tends to rot from the inside out, so it could be being held together by the chrome, so very weak.

Should be pretty straight forward TBH. Seen much older frames go from 120-130 (that's stronging it imho but it can be done).

Remember that the stays will bow from the bridges as the bending will start below. Sometimes this can look completely wank. The pro way is to take the bridges out and cut new ones to fit the wider spacing.