Crack In Aluminium Frame or Lacquer

[Lincs wolds]

Hi I've enjoyed this forum for a long while but this my first post.

I have had a Rose Xeon RS 4400 with an Aluminium frame for about 4 years and done just over 20,000 miles on it, the other day I noticed a small crack/scratch on the top tube near the end of the weld from the seat post.

It may have been there for a long while I have now marked each end of it to see if it gets any bigger.

The welds are not visable on the frame as they have been smoothed, I think it's a crack in the lacquer or frame, I hope someone can offer me some advice or opinion on this.

Is it safe to ride? At 20,000+ miles is it coming towards the end of it's lifespan?

Thank you in advance for reading.

[Keezx]

Looks like a crack to me.
Scratch away the paint and apply dye penetant examination to be sure....

[Brucey]

before you wreck the paint job unnecessarily, just in case it is a scratch....

try polishing the surface with something mildly abrasive ( eg brasso or T-cut). If it is just a scratch it will polish away/ not hold much of the polishing compound. If it is a crack (of any kind) it will soon appear as a much darker line (that can't be wiped clean) when you try and polish it out.

If it is a crack, Keezx's suggestion will tell you what kind of crack it is; in the paint or in the metal.

cheers

[tim-b]

Hi
Do you have the seat post inserted to well below the top tube/seat tube join? (Not necessarily the same as the seat post minimum insertion mark)
Decide what you're dealing with as suggested above; it depends on the frame design, but that join can be subject to quite high loads
Regards
tim-b

[Brucey]

BTW if it is a crack, you may be able to slow its growth (and leave the bike safe to ride whilst you make up your mind what to replace it with) if you fit a longer than normal seat pin.

cheers