In addition to p clamps, they also make racks that fit through the quick release clamps of the wheel.

I never use my seat post rack. I can't get it tight enough. I wanted the quick release so I can take it on and off. But it swings too much.

Another problem I don't think anyone else addressed is that it can get in your way when you dismount. If you have something perched on it, your leg can hit it as you try to swing it over when you are stopping.

If you want one bad enough, come to Great Falls, MT and I'll personally hand you mine at no charge.

I've had several carbon seatposts, including a FSA K-Lite, or something, right now. I also have an alum FSA, a Thomson Elite and a Trek something. I change the whole saddle seatpost out when I want something different---it's easier to just set the seat height and go than swapping a saddle and adjusting it.

I can state with absolute honesty that I cannot tell any increased comfort with a carbon post over the others.

But then, I'm just an ol' hardass.
The Thudbuster might make a difference.

The bird appears to come with its own clamps.

+1 on the frame bag idea. I have a new Revelate Designs tangle frame bag that has made my commute much nicer. I carry my lock, keys, sunglasses (before sunrise winter commutes), gym shorts, really anything I can stuff in there. Lunch and clothes are still in a backpack, but it is a much lighter backpack

Sorry I don't have a better pic to offer. I keep the mtn bikes at the summer place and as most of you know this is FAR from summer! Anyway here is a pic I took on a trip to PEI last summer. It was taken on the Confederation Trail near St. George. You can see the beam rack is holding a Topeak bag. It works great as I mentioned earlier in the thread. My only change was to take off the GR lever and use the bolt to tighten it down so it wouldn't move. Didn't need the GR anyway.

I'd take a look at some oversized seat bags. ortlieb makes a decent one. but depending on what all you are carrying might be no match for a pannier or two.

this thread is a great example of the road bike market turning into an "every road bike needs to be a race bike!!" mindset killing the functionality of bicycles. if everyone wasn't so damned concerned with their bike looking like it belongs in the tdf I think we'd have a lot more happy cyclists who used their bikes for more than occasional recreation rides. (not knocking on the OP at all, just a statement on how marketing has made it harder to get a functional road bike these days)

also, my only bike that is currently ridable is a stiff aluminum road bike with no fender/rack braze ons, and can't fit even remotely wide tires

I used to have one, it was the quick release version. I didn't like that it was right next to the seat and had to move my saddle bag else where. Anything over 30lbs would put quite a bit of stress on it. If it wasn't clamped down super tight it would occasionally swing left or right. It was a lot cheaper than getting a rack that would accommodate fenders and disc brakes. I wouldn't say it was terrible, just not as good as a conventional one.

Blech! Quick release is meant to release quickly. This kind of rack makes the quick release into a poor excuse for a bolt. Blech!

This looks like the perfect solution! I think I'll look into this one!

Scratch that, based on reviews it looks like a horrible design for anything other than the lightest of loads.

I have a Topeak QR beam rack that I use with either a pannier or trunk bag (w/wo pannier).
It has the removable side frame to keep panniers out of the spokes.
I swapped out the c/f seatpost for alloy to avoid crimping problems. The original c/f seatpost had an aero profile and didn't fit anyhow.
I tried carrying a laptop in the pannier but climbing uphill rocking the bike was too much. It would be do-able if centered on the rack.
Key is packing light to avoid sway. The bottom line is that the beam rack is only good for up to about 15#. For light commuting that is fine.
I keep shoes, belts, toiletries, sweater at work; and use car days for transporting heavier/bulkier stuff.

Coffee - I carry cold coffee in a plastic water bottle and decant/reheat at work. I also have a coffeemaker in the office.

lol yeah we have a commercial coffee maker with the permanent water line attached to it, and also a Keurig, so coffee is not a problem!

A Dill Pickle seat bag will work well for you.
Lotta storage space and no additional rack.
I use one for randonnuering.

Sadly I just can't afford one of those right now. Plus I would have to mount my rear light to the bag itself which is not an option I care for. I prefer a rigid mounting that will keep the light aimed properly, either the seat post or the rear of a rack.

Why not just get a regular rack and mount it like cycommute suggested? I use a Topeak system and it works great.

I've use regular p-clamps from Fastenal with not problems. They work so well that if the rack/bike combo fits neater I'll use them instead of frame tabs.

I mount my rear lights on my seat stays...but, hey! Whatever suits you.

I agree. This just seems to be one of those things that is more complicated than it needs to be.

I have a seatpost rack and trunk bag I got from Performance Bicycle that I use on my road bike on occassions when I need to bring a change of clothes. It works well and I don't notice the weight nor does it affect handling. I also believe that the Axiom streamliner rack which you nixed would work very well for heavier loads. I don't know what reviews you read but I would not hesitate to hang a couple of small panniers off that rack for commuting purposes. I mean your intent is not loaded touring, right?

As long as you're strapping to the top of the rack, it shouldn't be a problem (within weight restrictions, of course). Panniers are pretty much off-limits, as they'll swing into your rear wheel.

Why do you need to switch posts?

OP said they had a Carbon fiber one , hanging a Beam rack off those is a No-No ..

I don't know... wonder if my local hardware store has some P-clamps with some sort of plastic/rubber protection on it. I like the Tubus attachments, but it appears that the lower attachment only works with Tubus racks.

You do need eyelets ,though the Tubus also does a QR skewer mount , but just for the rear ..
(disc Brake adaptations.. )

Seems a shopping only solution can come up short

and then some Fabricators. creativity is needed ..

cant really down load that ..

They carry them at the big box home improvement stores - in the electrical section.