dvald001

I have two that immediately come to mind:

Marathon Supremes. I know, everyone here loves them and thinks they're so great you could mount them on the wall as artwork. But I went from regular Marathons over to the Supremes (both 28s) thinking that my ride was now going to be substantially improved, all the protection of a Marathon at a fraction of the weight. I had gone 3,000 miles without a flat on my Marathons, but within 3 weeks of switching to the Supremes I got a flat each week. They were all from goathead thorns, who didn't seem to give a crap about how space age the Supremes were. They just punched right through. I eventually took off the Supremes and went back to my Marathons. No flats since. My theory is that the only thing that stops a goat head is lots of rubber, which the Supremes lacked.

511 Levi Commuter Pants. Got a pair of 505 Commuters for Christmas--they're FANTASTIC: feel great, have some stretch, have leg openings small enough that the pant leg doesn't get caught in the chain, etc. I was so impressed I bought some 511 Commuter Pants as well (the 505s only come in one color) on Ebay for cheap. The 511s are very similar, but with a MUCH skinnier cut. And they are truly great cycling pants for people who never ever cycle.

Seriously, anyone who has enough leg muscle to walk up a flight of stairs cannot get their thighs into those pants. And it's not like I'm some hardcore roadie, I ride 60 miles a week on average and have a pretty skinny build. But I could barely fit into them at first, and after one wash it was game over.

fietsbob

rain jacket that soaked thru in a couple miles , others that de laminated ..

Now, I use a Rain Cape, that works.

WestMass

I've had similar experiences with both Marathons and Marathon Supremes. My main gripe with both is that I can not for the life of me, even after watching the shop do it, get the 25s onto my rims. I just can't do it. I've only gotten it on once in three tries. The one time I did get the tire on it took me over an hour and I broke 2 tire levers.

With regard to the levi's, I'm 5'10" / 175 and the commuter jeans fit me fine. We're all snowflakes.

SRAM RIVAL disappointed me in comparison to my Shimano 105.

ThermionicScott 

I never ever ever buy clothes without trying them on first. Common sense.

Andy_K 

I'd say my most disappointing upgrade was a Deore XT M770 crank. Don't get me wrong, it's a great component and three years later I'm still using it, only now it's on a mountain bike where it belongs instead of on a commuter bike. I got it to replace some cheapo stock crankset, thinking it would add some really nice bling to the bike. It did look much better, but it screwed up my gearing and didn't really provide any tangible functionality gains. On the other hand, I learned from it and had a nice crankset waiting when I bought a decent mountain bike.

On the flip side, I just installed a set of 700x35 Marathon Supremes and I'm loving them. They weigh about twice as much as the worn out 700x28 GP 4 Seasons I replaced with them, but they roll nearly as well, provide a softer ride, add reflective sidewalls and hopefully will last a bit longer than the Contis did. I've had 700x50 Marathon Supremes before and they provided great puncture protection for me. That said, I'm not surprised to hear that they don't do well against goatheads. The Supremes (like all lightweight puncture resistant tires) use a fabric-based protection system, which works well in a lot of cases but is vulnerable to objects with a fine point that can slip between the weave of the fabric and open it up for the rest of the intruding object. My main enemies are broken glass, nails and screws. Once in a while I get bit by a perfectly pointy piece of glass or a screw that lines itself up just right for a direct hit, but for the most part Vectran can handle these kinds of hazards.

Commodus

My neoprene booties. They don't keep my feet dry or warm.

noglider 

Really! I wonder why. I have neoprene socks, and I can wear sandals with them. I haven't tested this setup in very cold weather, but so far so good, walking in snow.

I can't think of all the disappointments I've had with gear, but I've had many. One that comes to mind is tire levers made of anything but steel. Whose bright idea was that? What was wrong with good old steel? Don't tell me the weight. The bike tire lever was perfected before I was born 52 years ago, so instead of making it better, they had to make it worse. Well, I stocked up on good levers, so I'm OK now.

Velcro-attached bottle cages don't work. Do people even test their products before mass producing them? Sheesh!

Schwalbe commuting tires sound very unappealing to me. I commute on Panaracer Paselas. I don't get an inordinate number of flats, and I'm good enough at fixing them that it's rarely annoying to do a roadside repair.

dynaryder

BOOM

Problem solved.

windhchaser

the bike rack i had it starts with the letter b maybe botanger but most the welds have broke it.even the welds for the tail light broke i was just lucky to find the tail light and other have of the mount.i tryied to reweld it but im doing something wrong

cycle_maven

Neoprene gloves. Ten minutes of riding in a light rain and my hands were colder than if I didn't have them on at all. They are too dense to insulate well. I replaced them with fleece gloves with a gore-tex inner liner, and those things are toasty!

Neoprene shoe covers. Same problem, plus the cutout for the clips was too small, jamming my SPD's randomly. I just wear wool socks now in the cold weather.

Neoprene balaclava. Need I say more?

I think I see a pattern here...

Barrettscv 

Specialized Armadillos. I tried the 700x32 and the 700x38 size. Very flat resistant, but heavy, hard riding and slow. I felt like I was cycling in wet cement. I now Have Vittoria Voyager Hypers. Fast and smooth and no flats after 1000 miles.

Ns1

Do you like the 505's more or the 511's more? I hate skinny jeans so I'm leaning towards the 505's...

for me...

Ortlieb Velocity. god I hated that bag so much. Did nothing for airflow, 1 giant pocket sucked, and it was a pain to get in and out of the messenger.

fietsbob

InoLED 2w headlight for Hub dynamo power.. [ I went to Halogen E6 for a couple years
till the LED headlight Technology improved.]

no1mad 

Topeak Road Morph-G was mine. First time I went to use it to fix a flat at work and the innards were M.I.A.

Gonna have to look at them 505's...

DrakeSuperbus

I got a rain shell that is too hot and a pair of gloves that are too cold. However, I have ended up using the rain shell as cold weather gear, and the gloves as medium weather gear. They both work well in their new roles, so I suppose they aren't that disappointing

ChrisO

Not so much an upgrade, but anything made by Knog. I've tried two of their lights and one of their computers- all absolutely sucked for the few weeks they worked. You'd think I'd learn quicker, but I just really wanted to like their stuff.

Mr. Hairy Legs

I bought a helmet mirror that gives me an excellent view of my backpack. I only used it once.

wayback

Nashbar MTB panniers are high on my list. Seams started to separate within a few weeks. The velcro tabs that hold 'em in place on the rack fell off so they jump around frequently. Worst of all, the stuff I carry has worn several holes in the cheap fabric. Only paid $30 for the pair so it seems I got what I paid for...

alexaschwanden

Walmart M-wave double day pannier, the cardboard started to curve around the rack and the corners got destroyed by the spokes, also loose fitting on to the rack and no adjust ability, it lasted 2 days for 24$ and i learned my lesson.

hueyhoolihan

new bootie can disappoint.

OTOH, i bought a pair of the CHEAPEST (98 cents) gloves that were hanging up on a cardboard rack at the Ace hardware store checout line last year. still wearing them. they are fleece and look like hell now, and the fleece lining (if you can call it that) keeps coming out of the fingers and balls up in the palms. but fiddling with it in order to push it back in does give me something to do at the red traffic lights.

DJ Shaun

I hate helmet mirrors. I've tried at least 2 over the years. I hated having to play with them before every ride to the get the angle just right. Eventually the mirror would break or fall off.

Burton

Profile Design AquaRack Bicycle Water Bottle Cage w/CO2 Mount.

The concept is good, but - they stick their absolute cheapest cages on that and the cages use a rubber O-ring to maintain tension on the bottle. This is supposed to be OK for off-road use.

Those O-rings snap pretty fast and the dealer doesn't keep spares. Doubt that its an isolated case - I had eight snap within a 6 month period. I'd much rather pick my own cages to start with.

dynodonn 

Dynamo power lighted pedals.... poorly made generators that needed McGyvering within a week of their first use, pedal shafts that easily bent, and the extra pedal effort to operate. In the trash after less than a month of use.

Here We Go

Surprised to see hear people struggling with mounting the Marathon Supreme tires. I thought those were supposed to be easy to mount. Anyone else have a problem getting them on, and what's your rim/tire size?

marqueemoon

Jackson & Gibbons rain jacket

It was like wearing a tarp minus the shedding water part. Even with the comically baggy fit and giant pit zips all the way open I overheated. The reflective bits started flaking off within weeks. Utter POS.