Tech advice for Automatic hub upgrade of Brompton
So I have my Brompton S2L about a year and I love it. I have been thinking recently about going for the upgrade that I was reading about pre-purchase, namely an automatic hub.
Having read around a little, the hub I'm looking at is a Fichtel & Sachs Torpedo AUTOMATIC (A 2110) Blue Band - I've read hear that the OLD is better suited to the Brompton rear triangle. I am a little concerned that the Blue band is designed for a larger diameter wheel. Has anyone any experience with calibrating the spring for a 16" wheel? Also the one I'm looking at is a 36H model. I think I read here a while ago that 36 spokes are difficult to accommodate on such a small wheel. Has anyone any thoughts on this?
I've seen some commentary that coaster brakes aren't ideally suited to the fold but that a derailleur chain-tensioner such as the one on the S2L is the least-worst option.
Lastly, the model I'm looking at looks to be 18T. Are there any physicists out there who can tell me what the difference would be between a 12/16T rear cassette on the bike now and an 18T with 1:1 and 1:1.36 ratios would be in terms of performance. I'm pretty sure I have the standard sized front chainring (44T). I'm embarrassed to say I can't say for sure!
Any advice gratefully received.