Commuter Bike Frame Material
OK, so I've been commuting 2 or 3 days a week, year-round, for almost 2 years now. I'm pretty sure I'm going to stick with it. Currently riding an old (circa 1978) Trek sport touring bike. I'd like to replace it with a dedicated commuter, and am trying to decide whether to go SS or Ti tubing. Does anyone have recommendations? If so, I'd love to hear why.
If I went with SS, I'd probably get a local framebuilder (the same one who built up my current road bike) to build it to fit; with Ti, I'm leaning to sending the measurements from my current road bike to Moots or Seven, or someone similar.
I'm leaning toward theses two materials for a number of reasons, though the only frame material I'm just dead set against is Al (after riding a C'dale oversize Al frame, I vowed I'd never get an aluminum frame - I see no good reason for changing my mind). I'd consider carbon, but I want this frame to last 20+ years (I bought the Trek new, so yes, I do keep and ride my bikes that long), even though (hopefully) I may not be working that long. I'd even consider steel bike, if it weren't for the issues with scratches, paint chips, etc. (one of the advantages of Ti and SS is the ability to get a brushed finish that can be touched up if necessary).
My current commute is 2 or 3 days a week (unless I'm traveling for work), depending on whether I have Friday off. This likely will increase to 3 to 4 days a week within the next year or so. Round trip is about 30 miles, mostly along a MUP that goes along a river. Pretty flat, except a couple of hundred feet of descending (on the way to work) or climbing (on the way home) to get from the house to the MUP. I'd have the bike fitted with rack and fender mounts, and "climbing gears" so I could also use it for "hilly" rides on the weekend. Still contemplating details like disc brakes, dynamo front hub, Di2/EPS, etc.
BTW, I myself have what could be called "compact geometry", which is one of the reasons I 'm leaning toward replacing the Trek (even at 19-3/4", it's always been, just a bit too big), and I'm running between 140-145 lb (depending on whether I've been good or not).
I'd welcome any thoughts (with the exception of recommending that I reconsider aluminum - not gonna happen).