rumrunn6

used Walmart spray chain cleaner, while working on my bike, on a bike stand, on my lawn, near my back patio. it wound up killing a noticeable patch of grass

drlogik 

Being sloppy and not fully checking to see if the bead of my "open tubular" tire had seated all the way around after I installed a latex tube. Pumped it up to 60 lbs and watched in horror as $15 bucks started to blow out of the tire like a bubblegum bubble and burst. I violated my own rule of not checking the bead at three pressure intervals first and got burned. It was all in slow motion of course.....I was yelling NO!!!! frantically trying to let the air out in time. Nope.

SquidPuppet

Great visual. Sorry for your loss.

Darth Lefty 

Installing Campy NR brake pad holders backward

Razorrock

Great to hear i'm not the only one.

silvaeri

[delete]

SHBR

In terms of maintenance, using this.

Sure it will get the outside of your chain clean, but it also does a great job of pushing all of the grit into the pins and rollers, wearing out almost any chain in short order.

Since then I've given up using solvent, I just wipe (thoroughly, one link at a time) relube, and wipe again.

A bit tedious, but unless I have a professional grade parts washer, I won't use solvent.

jonstifler

disassembling... set aside all your bolts and nuts.

after carefully reassembling... why are there extra bolts and nuts left? lol

Clyde1820

Had a small bike shop do some cabling work on my bike, where they installed the trigger shifters backwards. Truth be told, I didn't realize it right away, instead just adjusting to make the shifts how it needed to get done in order to shift effectively. Didn't occur to me for some days that "Gee, these dang things are backwards!" Too much sunshine, or not enough coffee. Hard to say.

europa

I've never done that... but I need the bars so high these days they don't make the steerers high enough

I've also done the chain over the tab on the derailleur thing. Funny how 'well' it works, well enough to have you looking for other reasons for the noise. Considering the ways to screw up rear derailleurs and the problems they can cause, I'm sure the devil has a patent on the things.

Dan Burkhart 

Ha! Could have been the shop I work at except I see by your location it's likely not.
Last week, a bike that we had recently worked on, (not me, another tech), came back with reversed bar end shifters (Sram Red)on tri bars.
It actually worked, friction shifting on rear derailleur and the indexing on the 10 speed shifter worked for the front as well, but my first task of the day was to put them straight.
It was the head tech who had messed up the install, and he's usually pretty meticulous, so anyone can have a "doh" moment.

Semipedersen

I bought new 26 inch tires and tried to put them on a wheel. It took me a while till I realized that the wheel was 28 inches.

europa

Ahh, but the greater the expertise, the less likely you are to let him forget

Dan Burkhart 

Best to save it until I need it. If he starts in on me for some dumb ass move, I can pull out that card.

Paul Barnard

I bought a nice new fork. I installed the headset, inserted the fork, placed the amount of stack spacers in place, marked the fork and cut it.

wipekitty

Oh, thanks: this reminded me of my asploding tube.

'Twas the night of bike maintenance, and all through the flat
Not a creature was stirring, not even a cat
The husband was nestled all snug in his room
When suddenly, the tire bead unseats and goes BOOM!

Trsnrtr

Pro tip: Don't remove the wrong hex head screw on a set of SRAM R2C TT shifters unless you want to spend an hour looking at youtube videos trying to figure out how to put all of the gears, pawls, and washers back in the pod.

martianone

While this is an old posting.
My dumbest thing - not doing maintenance.

BlazingPedals

Speaking of giving blood, once I gave blood at the Red Cross and then tried to do the spinning workout at the club meeting that evening. That's the closest I ever came to exercise-induced barfing. Luckily (for everyone!) I quit before crossing that bridge!

beicster 

Way back in the day when I first bought my Morningstar Freehub Buddy (I still have it!) I thoroughly rinsed my freehub body and injected it with grease. Needless to say, the pawls could not move, much less catch and I had some more fun thoroughly rinsing my freehub body again.

I like to think that if everyone had smart phones back then, there would be video of me pedaling furiously and going nowhere on youtube somewhere.

JLevera

Installed a headset cup backwards. The bike shop mechanic said I was never allowed to work on my own bike again.

rollingsteel

Took apart my rear hub, and put in the cone (cup?) backwards, and cranked it down. It stopped moving and I had to take to to the shop to fix and replace the bearing. Took them awhile to get the cone out.

josh23

Countless. On my current project alone I snapped the front wheel spindle in two trying to remove the handlebars...

Then a few weeks later when converting it to a Fixie I forgot to tighten the chain properly by moving the rear wheel back. First ride, the chain drops off back wheel locks up, and I NEARLY go flying. Luckily, I was anticipating a steep learning curve on a Fixie so was riding slowly on a footpath, but still fun!

Nermal

I couldn't get the nose of my new Champion Flyer angled low enough on the seat. Not for nothing.


So I asked on Bike Forums, rotated the seat post 18o degrees and all was. Thanks to John Thompson, and he didn't even make me feel as dumb as I felt.

Skipjacks

I wanted to keep my daughter's handlebar grips from tearing when they got pushed into the sharp end of the bar. A nickel is roughly the same diameter as a 22mm bar so I thought I'd put a nickel in the grips to keep them from tearing. But she also wanted streamers that stick into the end of the grips, so I need the nickel to have a hole in it to so the streamers could fit through.

So I'm sitting there trying to hold a nickel with pliers while I drill a hole through it.....until my wife walks in and says "Why don't you just use a washer that already has a hole in it"

I desperately searched for a reason that wasn't a much smarter way to go about this. I didn't come up with anything.