As retirement day draws ever close, (26 days) lm just reading back through this thread as l need to be ready to explore the world. Okay mainly Worcestershire at the moment......
But l do have a trip booked for September, Portsmouth to Bilbao, then 10 days exploring!
I've since read about replacement chain rings by
BikeinGreen, so another possible option. At £90 for the pair (30 and 46) its by far the cheapest route.
That said, it was
@T4tomo that suggested the Miche Graffe chainset, which was a great shout.
Okay it is a little more expensive but so much easier to fit that faffing about swapping chain rings over.
The only slight problem l can see, is the drop of the front derailleur to suit the 30/46 chain set. I need to lower the FD 16.2 mm, going from a 50T to a 46T. This isn't a problem as the FD is band mounted.
The issue is the gap from the lowest point of the FD to the top of the chain stay.
With the current set up, 34/50, l have a 16mm gap from the lowest edge of the FD to the top of the chain stay, which is the exact distance l need to lower the FD.
So when the smaller chain rings are fitted, l won't be able to lower the FD quite as much as l would have hoped.
Still l don't think it will present to much on a issue, l guesstimate it would only need to be around 1mm higher than you would normally set a FD to, in order to give a bit of clearance on the chain stay.