I did this and raced a week-long MTB race in the North-Indian Himalayan foothills before realising!

Mine was only a tiny bit noisier than normal, easy to do and not easy to spot! 😁

Don’t worry Flashy. I kept a link for such occasions as Northwind not being here…

I’ve tightened up a cassette lock ring without puting the cassette on…

…twice.

And headbutted a top tube when undoing some serious wedged on square taper cranks.

eldest_oab tried to fit a pedal on the inside of the crank…

Brilliant 😂

I opened this thread to post that I had done exactly the same thing (about a month ago)

Quite possibly on eldest_oab’s old Bike ?? 🤔👍

<My brother managed to put a liter of coolant straight into his engine. Luckily he realised what he done as soon as he’d finished pouring, followed by a hasty phone call to me to help him with an oil change!>

Work in a garage and the worst I’ve seen is someone tried to bleed rear brakes with the pipes clamped off then unclamped with loose bleed nipples and and cylinders failed dumping all the fluid and lost the brakes completely… As you can guess full rear brake rebuild.. High labour, high cost..

Some good ones on here.

I’ve done the pedal on wrong side of crank, flummoxed me for a good minute how it was catching the frame.

I also cut a dropper post wire down and fitted it, the realised I’d not put the cable through the internal routing.

Best one is putting a new dropper behind the car while I put the bike on the roof to take to the shop to have it fitted, forgot to pick it up and put in car and duly reversed over it.

I have carefully measured, re-measured and marked with a scratch line a fork steerer prior to cutting it down.
Set it up in the vice, got the hacksaw, lined up with the mark and cut the fork steerer.
…only to find that I’d cut to another random scratch further down the steerer, leaving it at least 20mm too short to even go through the frame.

That’s a mistake I’ll only make once.

Fitted an 8 speed cassette to a 9 speed bike. Took several days to figure out why the middle gears just would not index.

Was fitting a new stem and had to answer the phone before I was quite finished. Came back and forgot that I hadn’t tightened it all up. Took it for a test ride, made it half way down the alley, but then got to the bit with a hard right turn. Turned the bars but just plowed straight into the fence. Was very glad I found the problem without serious injury.

Thanks, Josh. I’m sure he’d appreciate that.

We’ve all left the front wheel behind the car then reversed over it, yeah?

Luckily it was an old 26er so I got another for a tenner.

1st ride out this year in the Lakes on the Loughrigg Loop i noticed an annoying squeal/squeak coming from the rear wheel.
Got back that night and decided to try and sort the problem with GT85.
Thought it might be the jockey wheels so gave them a bit of a squirt.
Then thought maybe it was the hub, so tipped the bike upside down on it’s saddle and bars and sprayed in between the hubs and qr’s and left it hoping it might do the trick.
Wasn’t till the morning when i had a little lap in Glenridding car park that i realised that the GT85 had dripped down onto my brake pads and contaminated them resulting in zero stopping power.
The problem was we were due to climb up to the top of Helvellyn that day and come back down again.
not a problem going up but definitely an issue on the descent.
So at the top of Helvellyn I had to try and remove the oil with a combination of sand paper from a puncture repair kit and alcohol wipes from the first aid kit, much to my riding buddies amusement.

Never again……..possibly……

We’ve all left the front wheel behind the car then reversed over it, yeah?

Nope, but I did leave a very expensive wheel leaning against a wall and drove home. 3Hrs I went back not expecting to find it, but it was there!

Not left a wheel in the car park but have left a Garmin in the middle of a car space in Afan.
Realised 20 minutes later after returning to our campsite, got a lift back to the car park expecting it to be gone but yep it was still there also with people still milling around too.
Lucky really.

Managed to route the brake hose around a rear spoke and took a minute to realise that it wasn’t a dodgy brake that was stopping the wheel from rotating properly.

We’ve all left the front wheel behind the car then reversed over it, yeah?

Yeah. Luckily it was a strong wheel, and apart from the QR it was fine.

When I used to do motorbike enduros I borrowed a bike as mine had been nicked just before a big event. I thought I would give it a bit of a service so changed the fork oil but misread the units of oil required so used 10x too much oil. Result was riding a two day event with completely rigid forks.I was too dumb to realise immediately what had gone wrong so didn’t even let some out after day1!

Recently went on a cycle touring trip around Brittany on an old bike I had to make some hasty repairs on whilst my son was in nursery.

New BB in and cranks back on I happily rode off the ferry and put into the French sunshine where the crank pulled away from the chain ring and was left dangling from my cleats… Hadn’t tightened up the crank or put the bung in.

Road bike related there was some fun 2 weeks ago in Bristol. Bike taken apart to travel in the car, wheels out, seat post out of frame. Everything arrived in Bristol in the car from Ipswich.

Wheels back in frame and secured. Seatpost into the frame and tighten clamp, actually over-tighten clamp and break it. Lucky as seat tube is carbon fibre, unlucky as it’s a special order Miche part and still waiting for delivery. Always take the torque wrench for 10Nm clamps don’t rely on the multi-tool to restrict max torque.

2 days of sunny riding went to waste.

Full fork service proudly completed. Everything back together.
Job done.
Then noticed the two shiny spring rings from the dust seals sitting on the bench.

I did once put new pads in and missed the holes in the pads with the pin – hence they fell out on a ride.

11pm Sunday before bank holiday road trip, finished new bike build, freshly oiled chain before I decided that I did need to take a few links out of chain, undid the quick link only for the chain to slip from my hand swinging down to the floor catapulting the quick link off into the garage….couldn’t find it anywhere missed BH on new bike! Did find the 1/2 quick link a year later when we were moving house inside a folded camping chair!!

In my teenage BMX years I got angry when I couldnt undo the rear wheel to fix a puncture as the axle nuts had slightly seized, chucked the bike and punctured the front wheel too…

My biggest mistake was putting the forefinger of my right hand near the front brake caliper disc and slicing it down to the bone just below the nail bed ..lots of blood and a rapid trip to the docs and onward to the hospital to stitch it back together again ..
I won’t make that mistake again 😁

I stuck my foot in my spokes while riding along last night. Trying to dislodge a bush caught in my cassette and rear mech. Made a loud boingboignboignboing noise and I yelped a bit.
Only a tiny buckle in the nice strong Mavic Allroad, luckily. But what a div.
(there was a long version of this but the lovely forum logged me out after I typed it)

I thought of this thread last night when I was removing some cranks, and was reminded of the time I ruined a perfectly good crankset by pulling the threads out with the crank extractor… I’d taken the dust cap out, but forgotten to undo the crank bolt.

Removed the outer bolt from Hope cranks but forgot to remove the inner bolt (the one that spreads the splines out to lock the crank in place). Then proceeded to remove the crank arm by putting massive force onto the bearing preload nut. This did slowly pull the crank off but I kept running out of thread and having to wedge bits of steel plate in the gap to keep it going. After about 30 minutes of swearing, smashed knuckles and cursing the name Hope the crank eventually came off…at which point I immediately realised my mistake. Incredibly the cranks are undamaged apart from a lot of paint removal from the preload ring where the tool kept slipping. More incredibly it was me that fitted the cranks. What a dumbass.

ndthornton

Removed the outer bolt from Hope cranks but forgot to remove the inner bolt (the one that spreads the splines out to lock the crank in place). Then proceeded to remove the crank arm by putting massive force onto the bearing preload nut. This did slowly pull the crank off but I kept running out of thread and having to wedge bits of steel plate in the gap to keep it going. After about 30 minutes of swearing, smashed knuckles and cursing the name Hope the crank eventually came off…at which point I immediately realised my mistake. Incredibly the cranks are undamaged apart from a lot of paint removal from the preload ring where the tool kept slipping. More incredibly it was me that fitted the cranks. What a dumbass.

I’m impressed and amazed that you managed to do that, and that the preload ring and your frame survived.

Not really bad ones but multiple times set up tyres tubeless to find them in the wrong direction. And pretty much every time I remove pedals I take the skin off my knuckles.
I did once shoot an airspring onto the shed roof without noticing and couldn’t understand the lack of internal parts when reassembling.

First time I ever did a lower service on forks. Thought I better do things right so got a torque wrench. Torque wrench didn’t work and I sheared the bottom off the damper.

I’m impressed and amazed that you managed to do that, and that the preload ring and your frame survived.

Me too – a testament to Hope build quality I suppose

This one’s easy for me, and a very recent example: I bled two pairs of Hope Tech 3 V4 brakes. Was chuffed to bits that I managed to do it, got them running perfectly… for about a day. Then they seized up. Googled the problem… how was I supposed to know not to use mineral oil which makes the seals swell?!

One of those perfect examples of “it’s obvious once you know”.

Hope rescued me. They serviced each of the 4 brakes at a cost of £55 per brake, so that’s a £220 mistake!!

Rushing pedal removal and forgetting to:

1) Wear a long sleeve top and gloves

2) Put the chain into the big ring, leaving all the teeth exposed.

Now I’ve got a bit of nerve damage on the side of my wrist, a bunch of scar tissue underneath and what looks like a shark-bite scar.

Today’s one.

Dug my old hardtail that I’d been using to ride to work on for a while out of the back of the garage to press into service on my turbo trainer.

Its got 10 speed Shimano on it so its not ancient but its not been given a lot of love either.

Rides fine on the turbo, gear index nicely, except the smallest two sprockets are a bit rough.

Hmm… I look in my assorted drivechain boxes

I’ll change the cassette… Nope runs shitty in four of the sprockets now.
I’ll try another wheel.. The wifes bike is also 10 speed so an easy swap… Nope still runs shit.

I’m kind of at a loss now

Could it be the derailleur? Maybe the jockey wheels are worn… Swapped the derailleur, spent a few minutes moving the limit screws, got it indexing nicely again, quite pleased by how faff free sorting out the shifting was.

STILL RUNS SHIT!!!

So what else have I not changed.

The chain.

OF COURSE IT WAS THE ****IN CHAIN!

Lesson learned. I’m actually quite good at swapping parts. I’m just really bad at figuring out what is wrong in the first place.

Not left a wheel in the car park but have left a Garmin in the middle of a car space in Afan.
Realised 20 minutes later after returning to our campsite, got a lift back to the car park expecting it to be gone but yep it was still there also with people still milling around too.
Lucky really.

TTOTD is a really useful under-documented feature of most modern Garmins:
https://www.dcrainmaker.com/2013/08/display-number-garmin.html

(tl;dr: edit “startup.txt” in your /Garmin folder to include your contact details and it will display them every time the thing is turned on. No, it won’t stop a tea-leaf, but if you’ve been a muppet and just left it behind, it may well just get it back to you again…)

Also (and this is much lower tech), find the lanyard in the box that noone uses, fit it to the device and make a point of *always* looping it round your handlebar before locking it to the mount. It makes it almost impossible to accidentally knock it off and lose it. And, for a last tip, print a few sticky labels with your contact details, and stick ’em to the back of the device underneath the silicon case.

(Spot the rider who nearly lost a brand new Edge 1000 in the woods once!)

I took my old rear mech off one night. Removed the old fancy breakaway bolt I had in in too, what a pain that was. Swapped it onto my shiney new mech, another pain then fitted it with new cables, got the indexing absolutely nailed on, then realised I had the actual new mech sitting beside me untouched…

I am very proficient at shortening cable outers with the inner still in place, lost count of the times I have done this

done the hodgynd finger in the rotor trick
built up di2 adventure beastie.stick it on a turbo, pedal awsy, no shifting.
check the junction box – no lights. checked all the connections are good. pull
the seatpost out to check the batt…. hang on, isn’t that the battery over there
on the table ….. d’oh …. put the bike back together again 🙂

Spent several hours over a weekend trying to sort out the grinding sound from the BB on my singlespeed when I was hammering up the climbs.
Couldn’t sort it.
Rode with my mate who said it did t sound like the BB.
He loosened the rear QR, tightened it again and the noise was gone as my mighty powers (!) no longer caused the rear disc to bind slightly.

I am no longer allowed to fit pedals, have ruined 2 cranks.

Also not maintenance per say, i managed to touch my bare leg against my brake disc following a long hard descent. It branded the shape into my leg, just before a beach holiday. It proper hurt and the mark was there for weeks.

I did once shoot an airspring onto the shed roof without noticing and couldn’t understand the lack of internal parts when reassembling

Don’t sell yourself short, that is a cracker.

My worst offence was riding the whole W2 loop at Afan cursing my bike for steering oddly.

Later found the lower headset bearing on garage floor, where it had fallen out while in workstand.

I’m slightly more competent now, honest.