I tried to relate the limited niche where having closer together gearing makes a noticeable difference
You appear to be misunderstanding. This isn’t about making gearing be closer together, this is about increasing the range of the gearing by making the low end lower and only reducing the high end by a little.
If anything, the configurations I wrote about would make gear spacing less even as the default is quite nicely spaced.
What I need to know is whether the change in the low end is actually noticeable in an uphill scenario and by how much.
So I prefer to have as wide as my drivetrain supports. If I have any choice, I prefer a tighter set of low gears and a bailout final cassette cog.
It’s the same for me I think. I’d prefer some variety of low gears for uphills and some variety for relatively flat ground. I don’t very much care what’s in between as long as it’s not too far apart.
When I start riding, I usually use one of the lower gears for half a turn and then immediately switch the hub from 64% to 100% (skipping the gear in between) which is a jump from 2.64m to 4.14m or 3.25m to 5.10m and then usually up to 5th gear (6.49m) for a bit and then the 6th gear when conditions allow.
I wouldn’t worry about the total, and would start with the widest cassette that will work with your current setup. Then I would only change the front chainring if you still feel a lack of top speed.
This again appears to be a misunderstanding: This is a 6-speed Brompton.
6-speed here means 6 gears total, including the hub.
The gearing is as follows:
- Hub with 3 fixed ratios (64%, 100%, 157%)
- Derailleur between two sprockets that can be equipped with a maximum of 17 teeth due to size constraints
- One chainring (no derailleur)
I get to choose the two sprockets and the chainring. That’s it; there is no wider cassette that physically fits this frame.
The reason for changing the chainring is merely to shift the gearing down which isn’t possible by changing the sprockets because a sprocket larger than about 17T will physically not fit. Again, this is a Brompton with tiny 16" wheels that folds down to suitcase size.
Someone started working on a Vulkan driver for TeraScale GPUs a few years ago:
https://gitlab.freedesktop.org/Triang3l/mesa/-/tree/Terakan
I believe it can run some demos add even works on windows.