Looking for alternatives to the Kinetix Pro S. My commutes have become longer with some pretty good climbs and descents so I'd like a stronger, faster, and lighter 20 inch wheelset.

The Kinetix Comp wheelset alone (let alone the pro) is a HUGE improvement over the standard equipment found on the Speed D7. The comp wheelset has double walled rims, machined sidewalls, wear indicators, better bearings (imo, possibly subjective), quick releases if you like them, and a much lighter weight to them. The D7 wheels are extremely basic.

Custom,

A rear wheel is easy if you want your own. Cook up a wheel with a 130mm OLD hub, go to town. Nothing particularly out of the ordinary here. There aren't many retail choices out there, you may be best off going to someone like Peter White and simply getting what you want made. Or making it yourself, of course.

The front is trickier. You need that 74mm hub in particular. You can go with a Dahon wheel like the Kinetix Comp or Pro, and there are a few compact hubs I can think of:

Bike Friday has a nice looking 24h front hub they market for the Tikit that would go on your Speed D7.

Brompton 28h hubs are available separately, although they look serviceable, they're not swank. I believe Brompton came out with a better front hub last year, but I haven't personally seen it available separately as of yet.

Phil Wood has a mention on their custom hubs page about Brompton hubs. A compact Phil Wood hub would be one very sweet way to go.

There are few stock options out there. Thanks for the info!

The most cost-effective upgrade may be to buy a Speed P8 (used or new) and sell the Speed D7.

Not a bad idea.

Not a bad idea at all. The P8 has such a wide slew of drastic improvements over the D7. It's a very good bike for the money.

The MU P8 is another thought for just a little bit more. Besides design, what are the improvements of the MU frame over the Speed frame?

After having owned both a Speed and a Mu, not much. One of them is a more traditional folder style steel frame, the other is a curving aluminum frame with some interesting looks. I personally like my Mu SL quite a bit, its a very interesting looking bike and has a good ride. My opinions here are guesswork, but I would personally guess that the Mu frame will be somewhat lighter and the Speed frame somewhat more robust, being of Cromoly steel with a full rear triangle.

I like both frames, enough to the point where it came down to aesthetics for me more than anything.

The two bikes also come with different tires. The Mu has fenders. The Speed comes with a built in derailleur hanger, the Mu has a spot for a hanger but it doesn't come with one.

I think it is mostly aesthetics: design and color. The frame materials are different but opinions vary over which is best. The Mu P8 does not come with fenders, it does come with a derailleur hanger which is occupied by a Neos II derailleur. Equipment wise the two are similar but the Speed has big Apple tires while the Mu comes with Marathon Racers.

I started out looking at the Speed D7, then I convinced myself I could afford the Speed P8, then I fell in love with the look of the Mu P8, then I really fell in love with the transmission of the Mu P24. Finally I decided that the Mu P8 was as much as I could afford and went with that. Of course while I preferred the white color of the P8 I really missed the Dual Drive. A few weeks after I got the bike Dahon offered the Dual Drive rear wheel as an accessory (but alas, no longer) and eventually desire got the better of my wallet and I added that which brought the total cost to more than a P24 would have been. Oh well, it is a bike/train commuter and it replaces a pay per ride shuttle bus service between my destination station and work so it will pay for itself some time this year and I do now have in effect a white P24!

In reality the Speed and Mu P8 models are both ideal for my commuting. There are no hills to speak of on my route so even for out-of-shape-me a Mu Uno would have worked fine too, the 8 speed gearbox was more than enough for that task. I got the Mu and then upgraded the transmission thinking that it would be my bike for everything. I had not ridden for a decade or so and at age 58 it took from July of last year until the end of the riding season before I started getting into any semblance of shape. Once that happened though the Mu just ignited the desire for a more traditional bike and so I picked up a Fuji Absolute a couple of weeks ago to compliment it. If I had any inkling that I would end up feeling that way I would definitely have stuck with the stock transmission on the Mu and probably would have gone with the Speed. Life does not always work out the way we think it will though and I really like my Mu which, as I say, will pay for itself!

Ken