I've decided to install a seatpost rack to my "racing" bike for commuter use. So far I'm looking at

These two on Nashbar.com:
1. Topeak Trunk Bag and Beam Rack Set

2. Delta Poste Haste Rack and Quick Bag

Performance Bike has TransIt Quick Rack Seatpost Rack

By LBS has one from SunLite but I didn't like it much. Any others I should be considering? Anyone have experience with using a seat post rack. Thanks.

I think I have both the TransIt from Performance and the Delta Poste Haste only one of the ones I have also has stays for trunks with fold out paniers. With the exception of the stays the two racks are basically identical. They are quality construction and as long as you don't over or under tighten them, they both work great.

I have mixed feelings about the Topeak. I've looked at them several times in the past, but always passed because I was afraid of being locked into the Topeak bags. I also prefer the four bolt attachment of the other two to the quick release of the Topeak.

I'm actually attracted to the Topeak rack because of the quick release. I would like to be able to take it off before I do group rides on a Sunday but have it on for my commuting during the week.

I have the Topeak Beam Rack (V-Type). I don't think you'd be locked into a Topeak bag. The track is below the bars on the rack so a normal bag would sit on the bars and just be strapped down I would assume. Worrying about the weight thing would get annoying. I'm thinking about just putting the explorer rack on my Hybrid and finding a used road bike for the fitness and weekend rides I want to do

I used the Performance one for a while with the Transit Metro Pannier. I've since gotten a more dedicated commuter with a Topeak rack and bag system and passed the Performance setup on. For what it was, it was great. I just don't like the low weight limit of a seatpost rack.

I used to use a Bontrager Seat Post rack. It worked really well once I found a better material to put between its clamp and the seat post.

I've since graduated to more "normal" rack systems, but the Bontrager is still serving commuting duty on a buddies Trek.

avoid them all

Why?

I wouldn't trust them at all. The weight capacity of them is suspect in my opinion.

what he said! :-)

I admit its an interesting concept and initially looks like it would be a good idea ... but it isn't

you want a rack? you want to carry stuff? then set one up with at least 3 points of attachment preferably 4. then carry what you want.

I have the Topeak and use it only on my mountain bike for carrying light stuff in the bag. My experience has been that under five pounds or so they are fine. Over that and the thing tends to swing a bit. Some will say they have had no issues with those racks at all. I may be too picky but it never seemed to be lined up with the rear tire in a straight line. I know it sounds crazy but it just bugged me.

Another thing to mention is that even though it h as a "quick release" lever, it has to be cinched down so hard that it hurts my hands just to get it on and off.

Yep, exactly my thoughts and experience. On top of that, it takes away some adjustment from your seat if you need your post down low. Another bad thing is the ease of getting it stolen.

OP you mention it is for your racing bike. Is the reason for the post rack is because of mounting issue? Or perhaps to be able to remove it for weekend ride without the rack? If it is not, then avoid wasting your money on the seat post rack.

I am trying to make my racing bike work for all my riding without going to two bikes - something I can't fit into the budget right now. My commute is 16.5 miles each way, all on roads. The seatpost rack is attractive because I can take it off for group rides which I like to do when I can. (These can go up to ~60miles.)

I only need to carry lunch and snacks which is at most 3-4 fruit/veggies and ziplock ~4 cup container. I have no illusions of using it for loaded touring. I am right now using a XL messenger bag from my college days when I lived up north. Besides the mess of pulls it is making in my jersey, I would like to dispense with the bag before the Florida summer is here in all its humid glory.

I have the luxury of working in a University with my own office so I can bring the bike into the building with me. Security-wise I think I would be ok; although something to think about.

In that case, then yes. Use a post rack. Just be a little careful if your seat post is carbon. After the rack is tight to the post, you may have to tighten your seat post to the bike frame tighter than usual to keep the rack from twisting your seat. It happen often when I swing my leg over the rack and hitting the rack in the process. You most likely will need to use some sticky tape wrap around the post to keep the rack from turning. I usually apply one or two layer of electrical friction tape.

In your list, I like the Topeak rack. They come with several offset height on the clamp which is nice. Also the majority of bag selection is nice.

I also have another bag that has the mounting hardware tighten around the post like a screw clamp. The bag then clip on that mount making it removeable and yet sturdy where it won't twist. Don't have the model off the top of my head at the moment, but it was bought at REI.

Edit: It is a Detours Hightail Seat Post Bag.

Lots of people seem to have good luck with them for small (very small) loads. I think you should be able to carry the stuff you mention in one, though I haven't tried. Of course others say they never could get them to work properly, so who knows?

I would like to put one on my 7.3 FX so I can ride it to work on nice, dry days, but I already have a rack that I took off my other bike that should bolt right on. It would be really nice to take it off when I don't need it, though.

If your seatpost is carbon, then dismiss the whole idea of a seatpost rack. It's just not safe to crush carbon even the slightest amount. I have a Delta seatpost rack and a trunk bag (not sure which type). The bag flops over to the side with very little load- and the delta rack isn't quite level, which gives it a start over to the side. I ended up tying the bag to the back of the saddle to keep it from listing, which kinda defeats the purpose. It sits up too high on my 61 cm frame; hard to swing my leg over the bike. I wouldn't recommend it- if you don't have eyelets, get p-clamps and use a real rack. If your bike is carbon fiber and you can't use p-clamps, then get one of the racks that uses the skewers for the lower mount and the brake bridge for the upper. Get a pannier or two. You'll be glad you did.

Ever considered a front bag? They carry nearly as much as a trunk bag, but *way* more conveniently. You can even remove/pack up stuff while riding. Very handy for food, camera, extra clothes, tools, etc.

My seatpost is carbon wrapped aluminum - no worries there. Now throwing my leg over the bike - I hadn't thought about that problem. I had been planning to mount it high on the seatpost to make room for other stuff.

I like the idea of a handlebar bag - but won't that interfere with the Shimano STI shifter cables?

I have three but can't recommend any of them (although the Topeak would work for small items)

1) A Topeak RX BeamRack with side-frame. This is only rack I've tried which cleared my thighs when cycling, but the side frames are not stiff enough to keep a laptop pannier out of the spokes or long enough to mate to pannier's bottom books.

2) An Axiom Odyssee seat post rack. The huge front clamp did not clear my legs. I had to cut the front off with a hack saw to clear my seat. The pannier supports are fine.

3) A quick-release Delta Post Porter. Both the threaded end of the quick release and the lever rub uncomfortably on my legs. The pannier supports are fine.

I may try the non-quick release Delta post porter next.

I've used my older Topeak rack on my road bike, for long rides to carry extra clothing and food.

It was originally for my old mountain bike, and the clamp was a larger diameter than my road seatpost. ( I think they come with shims, but I didn't have one anymore). I used a few wraps of some leftover roofing rubber, about as thick as a bike inner tube, wrapped around the seatpost. The wrap extended a half inch past the clamp, so the edges of the clamp wouldn't be able to dig in.

It was fine, it didn't slip down. I have the screw clamp, not the quick release. I didn't have to clamp it very hard to get it to stay in place.

Yes, I did hit it with my foot a few times when getting on the bike.

I don't normally use it, partly because the clamp slightly brushes my thighs when pedaling, which is annoying.

no worries if you don't mind crushing the carbon and delaminating the seatpost that is.