I’d actually argue that pound for pound an unbranded tubeset may well be better, an XL frame is going to leave a lot of wasted material in the butts if you have to make it from stock reynolds tubing that has to work in XS frames too, likewise the XL bike may benefit from a tweeked tubeset anyway to gain stiffness.
The problem there is you don’t actually know what you’re getting. As in the above example, it could be an incredibly well thought out and spec’d custom frameset. Or it could be done using bog-standard 4130/T45 tubes spec’d by one of the Tai companies, which then sits firmly in the quandry you describe. I suppose at that juncture it comes down to whether you trust the company specifying the frameset. Going back to Stanton, Dan claims to talk to Reynolds a lot – I’d hope that means he’s getting good advice.
I’d also argue a decent builder should be spec’ing tubes to fit the bikes being built, to avoid excess internal material around the butts (and to increase/decrease tube diameter if applicable). This can be done with both off the peg generic and branded tubes. Now call my a cynic, but I assume most companies will try and squeeze everything they can from a product to maximise the bottom line – in terms of buying a bike frame, this means unless I learn otherwise I assume that the bare minimum has been done to hit the product description. Therefore if a frame is ‘custom butted 4130’ I assume that it’s either single or double butted 4130 – which is a great material – but is ultimately a relatively basic frame, unless there’s some obvious fancy gubbins going on to increase tyre clearance or make more vertically compliant stays (which obviously costs to set-up and construct). Compare that to True Temper, Reynolds or similar where you can find out the exact spec of a tube, I appreciate the added level of transparency and details on material. However this privilege does cost.
Still think this hits the nail on the head though, the way the tubes are stuck together has far far more impact than what those tubes are.
I think the benefit of better tubing is subtle, but there. I think the size of the tubes probably has a greater effect on the ‘feel’ of the bike, because obviously the bigger the tube the less it flexes. Saying that, having owned a fillet brazed frame in the past I’d never own another – by all accounts it’s a far stiffer method of joining than TIG welding, and the frame had all the spring of a brick. Probably great for a TT bike, less so for a steel hardtail.
However, as with all these things I think it’s the sum of parts – there’s compromise everywhere and you have to decide what compromises to make based on your requirements.
