M_V's multitude of bikes and adventures in the land of framebuilding

Yup, you got it, the width have changed, the spacing start to change at 9 speed.

8 speed are cheap as chip nowadays, what you can do is set the screw limiter correctly for the 8 speed width, and then indexed the shifter to the smallest to the second biggest cog.

When you need that 8th cog, simply switch to friction and shift up, basically the slowest index shift ever, but it mean you get to use your 7 speed shifter fully on an 8 speed cassette without buying a new shifter.

Good call, alu bottle cage are light but fragile, they're definitely not used to the constant removing/installing of the bottle cages, which tend to get a little loose over time.

When it's upside down, I found the weight of the bottle made the cage a lots looser than it should, after 113 miles, the bottle was rattling away ready to be jettison toward the front wheel for it's final oblivion, it was good fortune I found out then before heading onto a very long tour with a steel cages instead.

Aye, I've found alu cages on a seatpost mount just bend open and drop the bottle, I had forgotten about that when I mounted this one up.

I also hate how alu cages tend to rub off and make your bottle all black.

I like the idea of switching to friction to get into my biggest cog, will definitely be giving that a shot, cheers.