I just visited a bike shop and a staff member there felt strongly that 531 tubing was not to be used... too much flex and prone to breaking. I see that 531c is 'extra light' and officially recommended for 'racing or sport touring'. I'm hoping to put an Alfine hub in, so I assume this would create more pressure on the chain stay?
Does anyone have any views on this? Any evidence that it's not reliable tubing for general cycling? Am I worrying about nothing? I'm probably about 13.5 stone and, after a cheap aluminium frame, the flex appeals to me. But I don't want to put in lots of effort to build a bike which will snap!
>>I should also add that I plan to have a pannier rack on the back, not for 'touring' as such but heavy shopping...