Qing Dao

I'm thinking of building myself a new commuter bike from all the component parts. Other than the tires that I already have, I don't have any specific parts in mind, just a general idea. I live in Shanghai and would buy all of the parts online from Taobao.com. I've only had two road bikes before, or three counting my old Raleigh non-suspension mountain bike with slicks. My road bike a medium 2004 Schwinn Super Sport GL which I have meticulously maintained and is stock besides the tires and toe clips. It is at my parents' house and I only get to ride it now when I am visiting. The other road bike was a piece of crap I bought last year in Shanghai. It was a real road bike, but the components were bottom end and it was assembled horribly. I took it apart completely to rebuild it when I first got it. Also over the course of the first two months of ownership, I replaced about half of the parts on the bike to make it better

Frame+Fork: A sporty road bike frame, preferably aluminum. I would like it to have spots for downtube shifters, but that isn't necessary and I can't actually find any frames that have them that aren't already part of a complete bike being sold. I prefer a shorter sporty frame because of lower weight and quicker handling compared to a longer bike. I also don't want steel because it rusts. I could go with carbon fiber, but I have heard that it isn't very durable.

Tires: This is the only part that is set because I already bought them. Conti GP4000S II that are 25mm wide. On my Schwinn in the US, I currently have 25mm Forte Pro+ tires which are all-around decent tires and I have never gotten a flat with them, but that is riding on hilly mostly suburban roads in the US. On my Chinese bike, I had 23mm Michelin Pro4 Service Course tires. Wider high performance tires are hard to come by and the Chinese bike's rims were already on the narrow side, even for 23mm tires. In hindsight I should have gotten the Pro4 Endurance to get more life out of the tires. They didn't wear out because of too many miles, but because they were torn apart by the roads. I also got a lot of pinch flats with them, and very few punctures. The wider and sturdier Contis, when mounted on a wide rim, should do a lot better. The Pro4 tires felt very fast and handled extremely well regardless of the surface or wetness. I was super happy with them in this regard and definitely want high performance tires. I got very good at quickly swapping out rear tubes, even in the dark, so I am willing to sacrifice a few flats for greater speed, handling, and braking. I probably should have gone with the Contis in 28mm, but I couldn't find any available and got such a great deal on the 25's.

Wheels: I guess anything with 36 spokes, a V shape for strength, made of aluminum, and wide enough to comfortably mount 28mm tires would be optimal. I had gotten flats a few times on my Chinese bike where I just removed the rear tire and tube, and rode several miles home on just the rim. A little loud and uncomfortable, but to my amazement the rims were completely undamaged and not bent at all. Anything like those wheels but a lot wider would be great. My main question with this is what would be the optimal width for wheels to pair with 25mm and 28mm tires? And lets say I go crazy and decide sometime to put on 32mm tires?

Brakes: I want road bike brakes on there. I don't want V brakes or discs on there. Having rim brakes would make it more simple and have the bike stand out less from thieves, but would there be any advantage to disc brakes for a commuter? My Chinese bike came with V brakes which squealed like crazy. I replaced with with Avid SD-7 V brakes and matching levers which I still didn't like, and replaced those with a cheap road bike brake that was just ok but still better. I think I will go with something decent from SRAM or Shimano for this. The Shimano Tiagra brakes on my Schwinn still feel perfect after 10 years. I just need to make sure that the brakes work with fenders and 28mm tires. All the current road brakes from Shimano and SRAM should, right?

Handlebars: My Chinese commuter came with slightly curved/straight mountain bike handlebars. I replaced them with a smaller straight handlebar and placed it as low and as far forward as I could. At the beginning of July I flew off of my bike when the chain came off the main sprocket and I was standing up and pedaling as hard as I could. I landed on my wrists and hurt them pretty bad and need something more comfortable than just a straight bar. I would really like to have either a straight bar with end pieces at right angles for a varied neutral grip OR I would like bullhorn bars which would be very similar to that setup. The only problem with bullhorn bars would be how could I mount brake levers to it? I guess I could really try anything. Maybe mustache/pretzel handlebars?

Drivetrain: This is a big one. Shanghai is very flat, but I still would like some gear changing for bridges, how tired I am, or how fast I want to go. I also really don't want to go fixed gear. My Chinese bike had a single from chain ring and a 7-speed rear cassette with derailer. It was a pretty optimal setup from a performance point of view. However, I had to clean it a lot and the derailer got banged into so I had to adjust. My dad turned me on to the idea of using an internally geared hub for the rear. With how dirty the streets are and the fact that I always keep my bike outside no matter where I go, an internally geared hub paired with a complete chain cover would be pretty sweet in the maintenance department. Now my questions are what rear hub should I go for and with how many gears? What front chain ring should I pair it with? Would it be possible to find some sort of complete chain cover, and if so, what should I look for? I think this idea for the drive train is the most important part for this bike.

Fenders are a requirement in Shanghai. For me it really isn't about the rain. Commuting on my Schwinn in the US was fine without fenders when I did that. Commuting in Shanghai is a totally different ballgame with how absolutely dirty the streets are here. I am assuming that I should also go for plastic instead of metal, right? My reasoning is that a metal fender might be too strong and damage something important if something happens, but that a plastic one will just break apart while leaving everything else ok.

I guess I have a picture in my mind of what I want, but I just want some other people's thoughts on the above items. Also, like I said, I have experience with only two road bikes, so I am sure I am missing something. Thanks!

icepick_trotsky 

There's nothing wrong with aluminum if that's your personal preference, but there are a lot of great new steel frames out there with CX geometries that are ideal commuters -- Surly, Soma, All-City, Kona, et cetera. If you really want aluminum, I'm sure you can find something good, but don't rule out steel. I wouldn't worry about rust at all. There are plenty of 40 year old steel bikes still on the road. Paint protects it from the outside and there are treatments available to the inside if you're worried about it.

A 15 mm rim would fit both 23s and 25s for your tires.

The real advantage disc brakes offer is stopping power regardless of wet weather. That said, I personally don't mind centerpulls in the rain, provided that you have good pads. If your brakes squeal, 90% of the time new pads fix the issue. Get some Kool Stops.

Road handlebars have a different diameter than flat bars, so you need road diameter brake levers. Other than that, handlebars are a matter of personal preference. All road bar, though, have the advantage of offering multiple hand positions to avoid discomfort. Are you averse to drops for some reason?

There are many threads dealing with the IGH, so check those out for the pros and cons. It would lesser your maintenance. Shimano makes a 3 speed and and 8 speed IGh. Sturmey Archer makes a 3, 5, and 8 speed. A lot of people recommend the Shimano 8. I bought one myself, though I haven't built the bike yet. You can pair it with any single crank, though the chainring depends on personal preference. Most people go between 44 and 52.

Both plastic and aluminum fenders are good. If you prefer plastic, SKS makes nice ones.

Good luck!