I have a fairly old, well used and well loved Singular Swift frame.
It developed a crack on the top tube near the head tube.
I retired the frame thinking it was f*cked and Sam sold me the Rooster frame I now use.

The Swift frame has been in the shed attic space for probably 8 years.

I got to wondering if it's repairable by a skilled welder/engineer ( Stu?? )

or is it too unsafe?

It'd only be for relatively light 29er duties, no jumping etc, maybe a bit of bikepacking...

It starts here ...


and ends here ...


and goes round here ...


but not all the way round ...


so should it be permanently retired or could it be safely repaired?

Anything can be repaired its just what it costs
IMHO [ a long long time since I welded] i would want that gusseting personally but it might not be required it would just give me added piece of mind [ probably means you cannot check the weld easily though

A framebuilder could even got a new top tube but it wouldn't be cheap, I'm no engineer but a repair might be a bit messy? But it's steel so there must be a few options...?

Depending on the tube thickness and amount of corrosion present, it could be possible to drill the crack ends, weld the crack up and then apply a plate gusset either side of the head tube/top tube/down tube. Like the old turner fs bikes, Curtis jump frames or mongoose BMX frames...

I've done that to an old Kona cindercone, and it kept going for a couple more years until I snapped the chainstay on it.

It could be tigged up and as John says, I'd likely add another gusset (either plate or tube) over the offending area. The trouble in this instance is that it appears to be the tube itself which has cracked not the weld. Granted, it is on a high stress raiser been just to the edge of the weld but I'd be worried about it going again a little lower down. You could be chasing your tail forever.

Consign it to the wall then
Sam bizarrely has dropped the Swift from the line up.
Thanks for the advice, I did suspect it was BER.

It will give plenty of warning if it fails again - i.e. it will crack rather than snap so maybe worth a go. I guess if it was mine I'd DIY so not incurring any costs, if you are shelling out 100 quid it might not be money well spent....

fatbikephil wrote: ↑Mon Aug 15, 2022 6:20 pm It will give plenty of warning if it fails again - i.e. it will crack rather than snap so maybe worth a go. I guess if it was mine I'd DIY so not incurring any costs, if you are shelling out 100 quid it might not be money well spent....

I'm not a welder ( had a couple of " Can I have a go?" attempts but was crap 'cos it always makes me jump) And I don't know any.
Needs to be someone 'sympathetic'
I sort of hoped it could be brazed as that seems to be able to be smoothed down nicely , though I've no idea if brazing is strong enough.

Brazing would be strong enough ... if it was a true joint between two tubes.

Bearbonesnorm wrote: ↑Tue Aug 16, 2022 10:29 am Brazing would be strong enough ... if it was a true joint between two tubes.

Not a crack then … I’ll try and find a sympathetic welder …
Isla bikes are based in Ludlow but doubt they have a suitable workshop…

Depending on what the other end looks like (TT to ST junction) a complete tube replacement would be the way to go here and wouldn't be hugely costly.
If you wanted to post a pic of the ST end I could let you know if it's worth pursuing. I'm all about keeping stuff like that going so it's a job I'd take on happily.

(for those that don't know, I'm an experienced framebuilder)

Tube replacement will sort the fundamental problem of the original tube being too weak, hence the crack (or did you have a front ender!)

Brazing up a crack like that will be a bit tricky as the tubes are corroded and getting them super clean will be a challenge if there is rust inside. Tig is a bit less fussy for rust.

I know someone who welded a gusset round a frame downtube which had cracked in a similar way but he'd welded round the circumference of the tube and gusset and it kept cracking - he added more and more gussets until he'd chased the crack a few inches up the tube. Eventually he ground it all off and machined up a thick sleeve which he managed to get over the down tube and weld to the head tube and down tube - I told him not to weld it round the circumference but in a v on the shaped gusset and that sorted it, albeit with the addition of about half a kilo!

(for those that don't know, I'm an experienced framebuilder)

We only have your word for that

We only have your word for that

My mate Bob can supply references on request.

I’m away for a couple of days but will supply photos as requested … cheers