wphamilton

I put an extra bearing in my freehub - I still don't know where it came from. The idiotic part is that even after I felt the binding I still mounted the wheel and took a lap around the parking lot.

shoota 

Good thread idea! I don' think I've been wrenching long enough to make a disastrous mistake yet but I'm sure my time is coming

Go away.

Why??

coasting 

errrrr hmmm.

Carloswithac

After removing some spacers to lower my stem, I over tightened my top cap and had a loose headset. I rode quite a bit in the mountains like this, including 40 mph descents. I didn't know anything was wrong until the lbs mechanic told me.

waterrockets 

I've been building my own wheels for over 20 years. Do you really want me to list these?

Worst case: yes, I have a set of completely unused double-butted spokes that are too short for anything I'd ever build

coasting 

I trued my wheels perfectly until it was out of round.

eja_ bottecchia

Indeed, to err is human...but to keep my knuckles intact is simply divine!

eja_ bottecchia

Why? Because if your hand slips while installing the pedal and it hits the big chainring those teeth will cut you to the quick.

With the chain on, the teeth are "hidden."

merlinextraligh

When the pedal breaks free, or the wrench slips, your hand or arm can bang on the chainring. Hand against chain covering teeth of chainring> hand on teeth of chainring.

Edit: Should have read to the end of the thread Eja beat me to it.

RollCNY

1) Destroyed a new steel fork attempting to install the crown race. I whacked the race, drove the fork out of my hands, and snapped off a fork lug on the concrete floor.

2) Cut a new chain too short. It was a Campy chain, that I couldn't find locally, and had to wait two weeks for the replacement. I had cut probably 15 chains at that point, and never cut one too short previously.

RollCNY

As a follow up, the best home made tool I ever made was a cheater bar out of a MTB handlebar. Cut it in the middle of the oversized center, squashed it flat, and it will serve as a handle to use the small end on allen keys, or go over an open end wrench on the flattened section and not roll off.

Wesley36

+1

Elduderino2412

I either forget to tighten cassette all the way or over tighten freehub. I've actually done both of these twice. If you over tighten freehub you crush your bearings. If you under tighten cassette your freehub body gets chewed up. Not sure why i didn't learn the first time.

shoota 

Makes sense, thanks.

nhluhr

Classic cable friction issue from the extra bends in the housing.

Bah Humbug

Want Di2 so bad. When I get a tri bike, though, I'll likely pick up a regular road bike for road duty anyway.

Long Tom

My worst wrenching debacle was on my '06 Tundra, so this isn't really the place for it, but I cringe every time I think of it and it serves as a stark reminder that, my mechanical hubris aside, I am fully capable of dorking out mechanically.

And I thank the almighty Toyota engineers above for making a bulletproof drivetrain.

531Aussie

Ha! My first car eventually lost all the instruments lights, so I used to drive while holding a cigarette lighter, which i would obviously flick on for a second to see the speedo.

darb85

was on all my bikes, im not a mechanic, i was a sales guy

2 wheeler

About 30 years ago, I was attempting to pull a Campy Super Record crankset off of my bike, but didn't realize that the washer hadn't come out with the crank bolt. I was amazed at the amount of force it took to pull the crank; but the crank didn't come off. In Campy's immense wisdom, they designed their puller to come apart before the crank threads would pull out. They had dumb asses like me in mind when they designed their crank puller.

When I built my first set of wheels (a jillion years ago) I was SO careful to get the rim straight with no discernible lateral run out. The problem was, I forgot to even try to make the wheel round. I took the bike to a group ride and kept commenting on how lumpy the road was! Later I figured out my error and loosened all the spokes and got the wheel straight AND round!

bianchi10

I have stripped or cracked a handful of chainring bolts.

Dang, that reminds me, I need to order another set now that mine dont match anymore.

Leinster

I have done exactly this with Mirage.

Not strictly wrenching, but I did buy an Italian thread Athena BB on eBay. I didn't realise that's what "36x24" meant. I've listed it myself and I have 1 watcher, 0 bids, and 5 days left.

apollored

I wanted to do the Manchester Sky Ride where they close the streets off to vehicles and people can ride on them.

Was cleaning my bike and thought I should take the wheels off and get everything really clean.

All went fine until I tried to put the rear wheel back on and tighten the cable arms.

No the cable decided to shred and no matter what I did,(I even tried to solder it!) I couldnt get it to go under the nut thing and being jobless I didnt have any money to go to the LBS to get another cable.

So had to miss out on the ride tho we did go to the Venue and watched all the events.

I did go to an LBS up the road but they wanted £30 to replace it which I didnt have.

coasting 

i don't get it. What cable? Taking a wheel off doesn't require doing anything to cables.

RomeoTango

One time, I took some links out of a new chain twice...it was too short both times!