180 Frame cracks (or not as the case may be)

TheWrongTrousers

TheWrongTrousers

Senior member
Location
South London
I am going to take my engine out and have the valves seen to so having taken on board what folks say about these frames being prone to cracking I inspected round the headstock area. My thinking is that if the engine is coming out and the frame is cracked then I may as well take the whole bloody thing apart and sort it out from the bottom up.

I was expecting to see some hairline cracks on the assumption drawn from this forum that "they all do it" but I can't see a single crack. Can this be right ? Am I not looking hard enough ? Could the cracks be lurking unseen beneath the silver paint ?



 
Not all 180 frames crack. I've had several go through my hands in the past, and none had cracks.
One even had a head on shunt, bending the spine tube somewhat, but the headstock area was unimpressed.

Gerald
 
If the silver paint is original, then careful inspection should reveal any cracking.  But I'm with Gerald on this - RGS frames are a known candidate, 180s less so
 
Both 180 and 120 frames are prone to crack in my experience.
Here is a crack in my 180 frame that was welded and extensively modified with steering head extension and braced back to the frame.
You can just see where the fractured downtubes have been welded before the bracing was welded on. (below tank mount rubbers)

IMG_5665 by Grant Duguid, on Flickr
 
Ok, thanks guys. I am grateful for your views. I cant see any cracks so I shall work on the assumption that its ok. I think my plan is to strip this thing back to the frame and have it coated/painted. No doubt i shall be bothering you all soon with recommendations as to who i should give it to so as to make it all nice and silver again.
 
TheWrongTrousers said:
Ok, thanks guys. I am grateful for your views. I cant see any cracks so I shall work on the assumption that its ok. I think my plan is to strip this thing back to the frame and have it coated/painted. No doubt i shall be bothering you all soon with recommendations as to who i should give it to so as to make it all nice and silver again.
Click to expand...

If you're going as far as stripping and painting the frame, why not weld reinforcing brackets in for peace of mind?

Paul
 
To check your frame you can use special sprays to make invisible cracks visibly.
If you have a extrem thick painture (plastic coated,...), you schould first eliminate the painture where you want to check.

E.g.: https://www.ebay.de/sch/i.html?_from=R40&_trksid=m570.l1313&_nkw=Risspr%C3%BCfmittel+Risspr%C3%BCfung+Diffu-Therm+Rot+Wei%C3%9F+Entwickler%2C+Reiniger+500+ml+Dose&_sacat=0

For example cracks in SFC-750 piston:
cracks_1_small.jpg


For example crack in the tank of an Eagle:
cracks_2.JPG


Even you can e.g. check the the lower hole of the brake stay of a drum brake. We had several cases with expanded holes and cracks in it.

It is easy to use, cheap and you get more safety.

Best Thomas aus LAU


 
TWT - the technique mentioned by Thomas is known as Dye Penetrant Non Destructive Testing and similar names.  Sorry if I'm teaching granny to suck eggs...

https://en.wikipedia.org/wiki/Dye_penetrant_inspection
 
The dye testing is really only effective on smooth, clean bare metal. I used to use it on truck axles in a previous life. It might work on smooth painted surfaces, but I've never seen it done. You can get false positives if there's any surface imperfections.
 
Hey Wrong Trousers

Familiar story this  :D

I'll just get the valves done, check frame etc.

Months later after major bank balance GBH the full restoration breaks ground.................. :D

                  Cheers
                          Matt
 
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