About 5 years ago a local pickup driver "presented me with an opportunity" to replace my 25-year old Galaxy.
After looking around at many bikes, and (almost) being sold gravel bikes, and nice carbon-framed bikes, I came to realise a few things that influenced my decision not sure whether ny thoughts were correct on a technical level, but here goes
- 1) All the bikes I was being shown had gearing that was too high (rule of thumb, at least 2 sprckets that are larger than the smallest chainring)
2) Most of them had an integral mount for the front changer which (I assumed) might limit my ability to have smaller chainring to lower the gearing
3) Most of them had very little tyre clearance
4) Most of them had "trendy" gear setups - widely spaced doubl at the front, 10 or 11 cogs at the back, thin chains which all looked expensive to replace when worn
5) A nice carbon frame might not allow me to put a band-on front changer
6) Common question was "Where are the mudguard/rack mounts?"
7) Will electronic shifters still work in a couple of years without failing due to flat battery or corroded connections
But I did want to upgrade my "tech" as it were
So I deci8ded on a Condor Heritage Disc, fully cable disc brakes, a semi-cheap 8x3 setup (Claris) using a basic square-taper BB, combined brake/gear levers (don't need to bend down any more to the downtube shifters) and plenty of tyre clearance.
Since I had it built I've swopped out the chainset for a nice shiny (well, it was once!) item from Spa, with slightly bigger chainrings, and moved the front changer mount to suit, swopped-out the rear cogs for slightly bigger ones , bolted-on the old rear rack from the Galaxy (disc caliper location doesn't need special rack mounts), put wider, lighter tyres on and a few other tweaks to get it to fit more comfortably.
Overall I feel that the choice of a steel frame and low-level components in some areas at the outset has allowed me more flexibility to tweak things than a super-lightweight carbon jobbie that I'd be afraid of breaking if I messed about with things or tightened up a clamp a bit too far.
So OK its maybe a bit heavier than many bikes, but I can lighten the bike by removing guards/rack, lighte its load by leaving my small change behind and carrying a smaller water bottle, and have lightened myself by about 8 out 9 kg since I bought it (and that last bit cost me nowt!)
I suspect that disc brakes apart, your 531c Orbit would allow some updating of bits, without loads of expense? Or maybe look at an Audax bike or have one built up? (The Spa Audax comes to mind, and the Condor Fratello whhich I was, and still am, tempted by)
Oh, in case the pound note counters were wondering, the original build cost about £1650 plus some bits from the old bike (especially the saddle!), plus about a hundred or so tweaking the gearing and a bit more experimenting with tyres. So somewhere between roubaixtuesdays good value and nice to have (the frameset was the expensive bit!).