Another 'is it crac...
 

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[Closed] Another 'is it cracked?'

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This is in the middle of the top tube and goes about 2/3 of the way round. I'm thinking it's not a crack simply because it would have snapped in two easily, either when riding or when I bend it in my hands. But it feels firm and there's no flex.

Looks like one of those corrosion trails that work their way under the paint on aluminium, but it's a steel frame. There's evidence of rust under the paint. The groove you can see is too small to be felt with a fingernail but it's clearly visible. The reason it's sanded down, btw, is that the frame needs a chainstay repair as well so it's going to be stripped anyway.

https://flic.kr/s/aHsmF8vpDd


 
Posted : 15/07/2019 10:43 am
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It's either a join or a crack.


 
Posted : 15/07/2019 10:48 am
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Crack? No. Tube stretched beyond its elastic limit? Maybe. Note the silver graphic looks like its been stretched and then subsequently has 'relaxed'. I would say that needs to be repaired, or at least looked at. I'd not trust it.


 
Posted : 15/07/2019 10:49 am
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To me, that looks like a crack - at least some of the way round. The other part of it looks like its 'folded', possibly in line with the crack flexing. Have you had a big OTB on the bike?

In all fairness having read your other post about the chain stay, I'd be considering retiring it rather than spending on the chainstay. There comes a point where you're throwing good money after bad...


 
Posted : 15/07/2019 10:50 am
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Was there any cracking in the paint or just the sort of indentation you can see in some of the pics?

I don't think I'd trust it without an expert opinion, some bits of it look like a crack (where you've removed the paint), but I'm not sure how a crack would end up with an indentation above it instead of cracked paint (except for respray post cracking)

I assume the frame isn't built up? I had a frame that went ~90% of the way round the down tube on a lightweight steel road frame before the flex was really noticeable (and even pushing the BB about to find the source of the flex didn't noticeably elongate the crack let alone break the tube), I can imagine a more burly steel frame still wouldn't flex much even if it was 3/4 of the way round, and without wheels, forks, cranks etc. in there to push it about it will be even less noticeable. (my dad broke a chainstay and all he noticed was that the gears wouldn't index correctly, but he is not the most sensitive of riders)

Edit- I think the indentation I saw is actually a protrusion due to rust behind it. I reckon this rust is because the crack's been growing a while. I'm pretty convinced now it's a crack, I can see some cracking in the paint where it's undisturbed too.


 
Posted : 15/07/2019 10:57 am
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Oh and you'll get rust if there's a crack that's been growing for a while. But you'd also get it for other reasons.

Suggestions of a fold seem reasonable, I did think a glued/lugged joint, but that's not a normal way of making steel frames, and the bit you've sanded doesn't look like that.


 
Posted : 15/07/2019 11:00 am
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Tube stretched beyond its elastic limit? Maybe

I'm going to say impossible given the history of the bike. No big crashes, no dents, nothing. The chainstay thing happened at about 3mph and I stopped within a few seconds. The incident was so mild it didn't even bend the seat stay as I was sat on it.

I don't go for the 'good money after bad' idea unless you can prove that the entire frame is somehow compromised. STW is always banging on about steel being repairable and sustainable.

I assume the frame isn’t built up?

It was til this morning yes.

I’m not sure how a crack would end up with an indentation above it

It's a raised track in the paint, exactly like alu corrosion under paint.


 
Posted : 15/07/2019 11:07 am
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I’m not sure how a crack would end up with an indentation above it

It’s a raised track in the paint, exactly like alu corrosion under paint.

Ah, my edit crossed your post, yeah in some of the pics you can see it's raised. Reckon it's a crack.


 
Posted : 15/07/2019 11:09 am
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I don’t think I’d be riding that without getting a frame builder to have a look at it. What frame is it - with a chainstay repair as well as potentially a top tube repair is it worth throwing money at?


 
Posted : 15/07/2019 11:10 am
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STW is always banging on about steel being repairable and sustainable.

People on STW who like steel are. And it is repairable, but that doesn't necessarily mean it's economically repairable. Did the chainstay crack too? If so, then you could replace those 2 tubes, but you're not likely to find this cheaper than buying a comparable frame unless it's something very fancy (referring back to my dad's case above, it was a custom built frame, he took it to be repaired and they found some damage to the down tube which deemed it uneconomical to repair).


 
Posted : 15/07/2019 11:11 am
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with a chainstay repair as well as potentially a top tube repair is it worth throwing money at?

If you can find me an alternative that's as good, for the cost of a repair, then I'll consider it.


 
Posted : 15/07/2019 11:17 am
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That's a crack. Looks like its dead centre between the welds for the cable guide. The reason it's smooth in some areas after sanding is just due to you accidentally filling in the crack during the sanding process.


 
Posted : 15/07/2019 11:17 am
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New top tube, new seatstay, lick of paint and you'll be good to go.


 
Posted : 15/07/2019 11:20 am
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That would make me nervous.
Looks like a join is corroding from inside.


 
Posted : 15/07/2019 11:22 am
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These are the two cracks you’ve found. Who is to say that there aren’t more, or that you’ll have this work done then it’ll fail somewhere else too. I’m all for fixing up instead of buying new, but there comes a point where you have to ask if it’s worth it. Salsa’s are known for being a bit fragile (said as an ex spearfish owner), maybe it’s time to look for something else?


 
Posted : 15/07/2019 11:41 am
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These are the two cracks you’ve found. Who is to say that there aren’t more

Who's to say there aren't more on any bike?

The chainstay was entirely my fault. Fitted the cranks too close to the stay which caused the chain to get fully jammed in there when chainsuck happened, which gouged the metal.

If you can find me an alternative for less than the cost of one or two tubes so let's say £250, I'm all ears.

70.5 degree HA
Tapered steerer (I want to use my expensive carbon fork)
Full set of bosses
Decent riding frame rather than one people keep describing as 'overbuilt tanks' e.g. Surly
2.4"tyre clearance


 
Posted : 15/07/2019 11:51 am
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Off the top of my head

Sonder

My brother is about to do the French divide on his, he loves it. Head tube is a little slacker than you want, but I've had a go and it's a lovely thing to ride.

On your point - at least with a new frame you'd have a bit of warranty, and it's not seen years of use with fatigue building up over time. Up to you of course but the post seemed like you were asking for advice which is what this is.


 
Posted : 15/07/2019 11:55 am
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Sonder

68 HA though. I was very specific in wanting a steep HA when I bought the bike. It's also boost, which would mean new wheels and cranks 🙁 Looks like repair still the cheapest option by a good way. But it is pretty cheap, and pretty light.

This isn't a criticism.. just not sure it's the perfect replacement.


 
Posted : 15/07/2019 11:57 am
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I was very specific in wanting a steep HA when I bought the bike.

Although the world has moved on in the past few years and a lot of previous 'must haves' seem to have become 'why did we used to insist on thats'


 
Posted : 15/07/2019 12:00 pm
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Worth checking that your fork is a similar length to the Sonder one. If your fork is shorter, it'll steepen the head angle of course.


 
Posted : 15/07/2019 12:01 pm
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Although the world has moved on in the past few years and a lot of previous ‘must haves’ seem to have become ‘why did we used to insist on thats’

That's true, but this is a bike that needs to do 50% of its time on road. It's also by far the best bike I've ever ridden for handling and comfort, so you'll understand why I don't want to deviate much.


 
Posted : 15/07/2019 12:02 pm
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Looks a bit odd but I'd be saying it was a flaw or crack of some description and the tube probably needs replacing. Very weird how it seems to run perfectly through the gap in the centre of the cable boss "feet" rather than starting from one or other foot. Looks like the boss is brazed or silver soldered on (so again less likely to be the start a fatigue crack than a welded boss). Maybe clean off a bit of paint from where the boss is stuck on so I can see the material. If it is brass then will have been more heat than silver (I try to avoid adding too much heat in the thin centre of a tube so always use silver)

If only a hobby framebuilder who works in a fatigue lab with metallurgist colleagues had offered to replace the chainstay!... But with a potential top tube replacement I'm actually quite glad not to be involved now 🙂


 
Posted : 15/07/2019 12:22 pm
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Heh, thanks all the same mick.

I asked bikemonger (from whom I bought it) for their opinion, after they inevitably tell me to naff off I'll probably take it to Argos see what they say.


 
Posted : 15/07/2019 12:37 pm
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dead jim


 
Posted : 15/07/2019 12:58 pm
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Pic of the cable guide - looks like it's soldered on?

There's also more corrosion tracks towards the top of this picture. Also see the bright spot on the right of the cleared bit - I left the rubbing tool on a little and it looks like it's lifting the corrosion a bit..?

I'm not sure it is fatal tbh.

[url= https://live.staticflickr.com/65535/48289459632_1a295876f0_h.jp g" target="_blank">https://live.staticflickr.com/65535/48289459632_1a295876f0_h.jp g"/> [/img][/url][url= https://flic.kr/p/2gzb6Yd ]20190715_124936[/url] by [url= https://www.flickr.com/photos/11569254@N06/ ]molgrips[/url], on Flickr

Quite a bit of rust in evidence though...

Extreme close-up:

[url= https://live.staticflickr.com/65535/48289484307_8de786af45_b.jp g" target="_blank">https://live.staticflickr.com/65535/48289484307_8de786af45_b.jp g"/> [/img][/url][url= https://flic.kr/p/2gzbeiD ]close-up-crack[/url] by [url= https://www.flickr.com/photos/11569254@N06/ ]molgrips[/url], on Flickr


 
Posted : 15/07/2019 1:10 pm
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Hard to tell but colour looks more brass than silver solder (so 100C hotter).

If you've got a syringe or aerosol try squirting some liquid inside the top tube (access hole in head or seat tube?). If cracked through it will seep to the outside. Could try isoprop alcohol, water, wd40, paraffin, diesel etc (the former will be better for not cocking up a repaint, the latter will work better as a crack detect penetrant).


 
Posted : 15/07/2019 1:34 pm
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Good idea. I have IPA.

Place your bets folks, will I get seepage or not?

Oh, I did give it a good soaking with Waxoyl mind when I got it.


 
Posted : 15/07/2019 1:53 pm
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Sonder

68 HA though. I was very specific in wanting a steep HA when I bought the bike. It’s also boost, which would mean new wheels and cranks

Can get a 2 degree angleset to steepen it if you don#'t like it as stock. If it's a 44mm headtube rather than tapered then I might have one for sale shortly. You wouldn't need new cranks either, maybe a new chainring if it doesn't clear the chainstay otherwise run it as standard for a better chainline.


 
Posted : 15/07/2019 3:37 pm
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But I would need new wheels.


 
Posted : 15/07/2019 3:50 pm
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Very odd. Looks more like a joint than a crack, especially as it passes centrally through the braze-on. And no, I've no idea why someone would do that


 
Posted : 15/07/2019 4:08 pm
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If your going to Argos just wait and see what they say before over thinking things. Worst case is £120 for chainstaty and the same for the top tupe. If they paint it another £160 so it comes back like new for £400. £240 if you want to paint it yourself.
I'd be tempted to pay the £400 if it was something I really liked. You've already stated some good reasons for doing so.


 
Posted : 15/07/2019 4:09 pm
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Yeah I think the economics stack up. I don't want Argos to paint it, not heard good things about their paint.

Very odd. Looks more like a joint than a crack

It does - as if they joined two tubes when rolling them together. But given that there are other corrosion tracks I think what's happened is that the cable bosses have started to corrode and it's spread - it just happens that that one goes around the tube. Probably not deep enough to write it off.


 
Posted : 15/07/2019 4:14 pm
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The corrosion is probably filiform corrosion, but the pattern is normally much more random than that. Hope it all works out as you obviously like the frame


 
Posted : 15/07/2019 4:40 pm
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Looks like a brazed or welded joint to me.


 
Posted : 15/07/2019 5:49 pm
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The corrosion is probably filiform corrosion, but the pattern is normally much more random than that.

Yeah, there are other random bits to it though. Perhaps there is some kind of join in the tubing or something which guided the corrosion, dunno.


 
Posted : 15/07/2019 6:40 pm
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I’m pro seepage.


 
Posted : 15/07/2019 6:42 pm
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S&S couplings FTW


 
Posted : 15/07/2019 6:54 pm
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There really won't be a butt joint running circumfrentially in the middle of the tube.

Possible there was a flaw but location with boss is very coincidental. I'd go with some combination of:
Flaw in tube.
Cooked a bit during brazing (maybe badly fluxed so oxidised).
Tube on the thin end of tolerance.
Badly prepped so it corroded under the paint.
Ridden a lot.

I've (temporarily) pensioned off the mtb I built in 2012 with a slightly similar looking early stage crack in the DT. That was in the HAZ rather than the joint itself - will find a photo shortly. That frame will be reborn with a new HT and DT to suit a short rigid fork to make a cargo commuter.


 
Posted : 15/07/2019 7:23 pm
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[url= https://i.postimg.cc/1RGJJGjn/DSC-0503.jp g" target="_blank">https://i.postimg.cc/1RGJJGjn/DSC-0503.jp g"/> [/img][/url]

Apologies for bad photo. Crack is the pitted line about 20mm down the DT

Ignore the weirdness inside the Ht - I was experimenting with piercing the TT into the HT to make a stronger(?) joint.


 
Posted : 15/07/2019 7:29 pm
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Is this your El Mar? There was a medium frame on eBay a few weeks ago.


 
Posted : 15/07/2019 7:42 pm
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So Mick do you think it's fatal?


 
Posted : 15/07/2019 8:19 pm
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No way would that be a join. Nor could you bend it with your hands.

I'd go with a frame builder's advice.

And the stress ion it will be low. Just ride it and keep an eye on it


 
Posted : 15/07/2019 9:38 pm
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It looks like a crease, the tube appears to be slightly kinked in this image.

https://i.ibb.co/Qfpht9d/48289456752-f167ac52ca-k.jpg


 
Posted : 15/07/2019 9:45 pm
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Is it fatal? Depends where the fractured tube impails you I guess 🙂

Something is going on with that tube and I'd definitely replace it if I was attached to the bike and wanted it back on the road. Plenty of people ride trigger's broom frames because they have an attachment.

Talk to Argos.

Also measure / draw up the frame on bikecad or similar now before anything is done. You can then at least get a replica made in the future.


 
Posted : 15/07/2019 10:18 pm
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It looks like a crease, the tube appears to be slightly kinked in this image.

Don't think so I've checked it. The paint is really remarkably thick so I think the link you can see is just the amount of paint I've had to sand away.


 
Posted : 16/07/2019 8:26 am
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My gut feeling (as an engineer - I’m meant to say that, aren’t I?) is that that is some kind of fatigue failure and if you’ve got that happening in the middle of the down tube, what’s happening elsewhere?

I’m the sort of person who likes to keep stuff for ages and repair it etc but with the cost of repair I’d buy something new or secondhand to replace it.


 
Posted : 16/07/2019 8:37 am
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There's no way I can get what I want for anywhere near the cost of repair though.


 
Posted : 16/07/2019 1:42 pm
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No WD40 seeped out.


 
Posted : 16/07/2019 9:27 pm

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