A salutary lesson and yes, I'm an idiot.

[ColinJ]

Ok, forget polishing scratches out of plastic specs!

What about a small electronic device with a flat plastic screen? In the ebay photo it looks usable as it is, but the screen is covered in light scratches. If I thought I could improve it I would have a go, but I wouldn't want to make it worse.

I probably won't win the auction anyway because I am thinking of making an offer at well under the asking price. (I looked at completed auctions and devices in much better condition went for the asking price.)

 

[Vantage]

One of those car paint scratch fixing pens that leaves a clear film might work for that. Get a good one though.
I bought one for scratches on the bike but the stuff never dried.

 

[ColinJ]

From experience of a similar problem: If it's backlit it will have no problem. If you use it in bright sunlight the scratches will be awful.

Hmm... It's a GPS device which I would be using in daylight without a backlight!

I'll make one late, low bid and leave it at that. I don't actually need a new GPS, but the ancient Etrex that I normally use is big and clunky and doesn't do turn-by-turn prompts so it would be nice to retire it.

 

[ColinJ]

I'll make one late, low bid and leave it at that.

Someone has now bid more than I was going to, so I'll pass!

 

[TheDoctor]

Italian BB cups look as if they ought to fit into British BBs.
They really really don't. They're 0.2mm too big, and the fixed cup is threaded the other way round.
It's entirely possible I might be thinking of British BB cups into an Italian BB, cos that doesn't work either...

 

[ColinJ]

Someone has now bid more than I was going to, so I'll pass!

Blimey - a scratched cheapo old Garmin Edge 200 GPS ended up going for £40 including delivery! Others in good condition have gone for £15 on ebay in the past few months.

And now for my bonus bonus stupidity...

I have been trying to service a Campagnolo freehub but made the mistake of buying bearings to fit a modern freehub. Unfortunately, my modern Campagnolo freehub is on a wrecked wheel. The older freehub that I actually want to fix takes smaller bearings...

I ordered 2 more sealed bearings the right size and put them in my spare Campagnolo freehub. I was careful putting them in, not having the tools to do it properly, but seemed to have made a reasonable job of it. I went to put the sprocket back on and it won't go. The spare Campagnolo freehub turns out to be a bloody SHIMANO freehub!

I thought that I had taken it off an old Campagnolo rear wheel, but that was the one with the bigger bearings. I've just remembered a mate dumping a load of old Shimano bits here. I thought I'd keep them in case I ever needed them for some reason...

I don't think that I would be able to get the new bearings out without damaging them. I wrecked the old bearings knocking them out!

I should be able to use the Shimano freehub on my CAADX some time, but now I have to order a 3rd set of bearings for the freehub that I actually want to fix!

 

[AKHiker]

When my neighbor hears "Oh my GOD" in an annoyed voice, he knows it's a bike thing

 

[ColinJ]

I'm just trying to figure out how many other ways there are for me to cock up my freehub bearing replacement! I suppose the next thing would be for me to damage them putting them in. I ordered 2 sets of bearings this time just in case!

Or I might forget to put the cylindrical metal sleeve between them... (or put the wrong sleeve in - the internal one is a slightly different length to the external one. I think the shorter one is the internal one, but I will doublecheck before reassembling the hub).

 

[mickle]

My favourites from my days working in bike shops includes people who:

* Greased the rims/discs to stop the brakes squealing. It does work. It definitely stops the brakes squealing.
* Installed their front derailleur on the down tube. He took it off to clean it, put it back 'exactly as it was' and just needed us to 'do the final adjustment'. Refused to allow us to install it on the seat tube. Told us we were idiots.

The courier who ran into the bike shop (with an urgent parcel on board and the clock ticking) demanding to 'just' borrow a spanner to tighten his crank bolt as his LH crank has fallen off. (We got this all the time, people who weren't customers expecting to be allowed to borrow our tools. So we put in a policy of lending tools in exchange for a £1 in the charity box). there followed a conversation that went along the lines of:
"I don't have a quid"
"OK, sorry I can't lend you a tool then. Shop policy."
"farks sake! I just want to borrow a farking tool!"
"I know Sir, but our tools cost money, people wreck them, expect to borrow them for free without ever supporting our little independent bike shop, so the only fair way is in exchange for a donation to charity blah blah blah"
"FINE, can you break a tenner?"
"No. Sorry. I cant open the till without a transaction. You could wait until someone comes in and buys something or you can purchase something yourself"
"farkSAKE!! I JUST WANT TO... fark it. I'll buy an inner tube then".
"What size? What kind of valve do you need etc"
Transaction complete, he puts a quid in the box, I hand him the tool. He RUNS outside to his bike. Starts frantically swinging away at his crank bolt with the spanner. I watch with interest and I say to him, "You know. Sometimes it pays to step back from what you're doing". He says something along the lines of: "fark Off I Know What I'm Doing!!".

He hands me the tool. He jumps on his bike, to discover the the cranks are at 12 o'clock and 3 o'clock. Comes back in.
I charge him £2 for the spanner plus a crank extractor.

We had the fastest filling charity box in the Scope's history.

 

[Sterlo]

Blimey - a scratched cheapo old Garmin Edge 200 GPS ended up going for £40 including delivery! Others in good condition have gone for £15 on ebay in the past few months.

And now for my bonus bonus stupidity...

I have been trying to service a Campagnolo freehub but made the mistake of buying bearings to fit a modern freehub. Unfortunately, my modern Campagnolo freehub is on a wrecked wheel. The older freehub that I actually want to fix takes smaller bearings...

I ordered 2 more sealed bearings the right size and put them in my spare Campagnolo freehub. I was careful putting them in, not having the tools to do it properly, but seemed to have made a reasonable job of it. I went to put the sprocket back on and it won't go. The spare Campagnolo freehub turns out to be a bloody SHIMANO freehub!

I thought that I had taken it off an old Campagnolo rear wheel, but that was the one with the bigger bearings. I've just remembered a mate dumping a load of old Shimano bits here. I thought I'd keep them in case I ever needed them for some reason...

I don't think that I would be able to get the new bearings out without damaging them. I wrecked the old bearings knocking them out!

I should be able to use the Shimano freehub on my CAADX some time, but now I have to order a 3rd set of bearings for the freehub that I actually want to fix!

Re the prices, I noticed the same. I was bidding for a Garmin 130, some of them ended up going for nearly £100, not in great condition when I could buy one new for £120. Managed to get one for £95 incl postage in the end.

 

[BrumJim]

I've just fitted a brand new rear wheel with Alfine hub. The old one was skipping in more and more gears, until it became difficult to find one that worked, no matter how much I adjusted the cable. I found a wheel and hub already assembled at a good price, and saved the bother of either trying to disassemble the hub, or fitting a new wheel and truing it.

Only I bought a wheel for disc brakes, and I've got rim brakes on the rear. And no suitable bosses on the frame to fit a disc caliper.

So I'm left with the choice of buying a new rim, or recovering the old one. And then swapping them out. Which means wheel building, the very thing I was trying to avoid.

 

[ColinJ]

So I'm left with the choice of buying a new rim, or recovering the old one. And then swapping them out. Which means wheel building, the very thing I was trying to avoid.

You need to find someone who accidentally bought a rim brake wheel, who really wanted one for disk brakes, and then do a swap!

Weirder things happen... I wore out a LH SPD pedal and thought I'd see if anybody was selling cheap SPDs on ebay. I immediately found 2 people selling their LH pedals because they had lost their RH pedals!

 

[silva]

Here's mine: there was a time despite riding them all day long I knew so little about bicycles that one day I decided to buy a spare chain.
2 months later, first ever time I decided to work on a bike (even a flat tyre case I "solved" by walking home and take spare bike to bring the flat tyre wheel to dealer to do the job) - replace the chain with the spare I had bought.
I discovered it as too long, so I rode the bike to the same dealer and said the chain he had given me didn't match the bike, and asked for a good one. He looked at the bike, took my spare chain and disappeared. Couple minutes later he returned, showed me a same box and said this is the good one. I said it was the same box and he answered he had put the good one in it.
Back home I succeeded in replacing the chain and felt Great.
5 years later and a new bike I decided to buy a family size package spare chains.
Somewhat later I realized what that dealer had done back then.

 

[BrumJim]

Recovering the old one is out. It is a 36 spoke design, whereas the new one has 32 spokes, so the flange on the hub gear only has 32 holes.

So off to buy a new hoop!

 

[rockyroller]

my bike stand clamp has grooves for the cables. but yeah I've done plenty of dumb stuff. I've been know to ask Wifey, if you know I'm dumb, why are you surprised when I do dumb stuff?