I’m sure this has been done before, in fact I’ve laughed over others misfortune many times, so I thought it was worth sharing. I regard myself as a decent home mechanic and can generally get everything I need done on my bikes.
Until now!
I replaced the hose on my rear brake last night, it’s a shimano m785, and had got it pretty much bled and feeling stif. So just a few more yanks on the brake lever to get every last little bubble out…. Gnnngh… Crack….psssss…..bugger!
Some how I’ve just cracked the ceramic piston with my own fair hand, mineral oil is now p1ssing out everywhere and the caliper looks proper broken.
Today I found out that shimano don’t make spare parts for the caliper so I now need a new caliper, went for an SLX one in the end as they look the same and are compatible (and cheaper).

So what have you managed to destroy whilst spannering at home?

Everything….mostly more than once.Luckily it was with other peoples bikes.

overtightened a pedal on a brand new XT crankset a few yrs ago – expensive lesson in calibration of tighty tighty…..

Yesterday I stripped the thread out of my brake mount on my fork, one bolt holding my front brake will be fine? Right?

iainc – Member
overtightened a pedal on a brand new XT crankset a few yrs ago – expensive lesson in calibration of tighty tighty…..

😯 good god man! were you actually swinging off the spanner/allen key?

Liking these, some way more expensive than mine!

dabble – Member

Yesterday I stripped the thread out of my brake mount on my fork, one bolt holding my front brake will be fine? Right?

With some araldite in there, it’ll be right as rain, for a bit 😉

“Yesterday I stripped the thread out of my brake mount on my fork, one bolt holding my front brake will be fine? Right?”

Helicoil is your answer .

iainc – Member
overtightened a pedal on a brand new XT crankset a few yrs ago – expensive lesson in calibration of tighty tighty…..
good god man! were you actually swinging off the spanner/allen key?

well, I used to have a crappy pedal spanner and had just bought a Park one, which is about 30% longer, and applied the same force…..with a 30% longer lever arm…..

Brand new chainset and I didn’t do the peddle up properly and completely stripped the thread when I stamped on it.

I have seen a flattened downtube from a mis-timed hammerblow to main pivot bolt.Countless steerers cut too short.Numerous ruined shifters from mis threading the cable.Pringled rims from over tensioning.Forks fitted without crown races.Bent shock shafts from interrupted seatposts.Cross threaded BB’s.External headset cups hammered into integrated headtubes.
Pretty much the full gamut of mechanical incompetence 🙄

And only half of that list was done by you! 😀

…but enough about you Rorschach…;-)

Leaving the shock pump on rear shocks and then sitting on the bike, causing pivot/swingarm to clamp, crush, slice the pump and knacker the shock – not me obviously.

It worked out OK but I spent about an hour trying to rebuild a Fulcrum freehub at the weekend- turned out a part was bent when it came out so rebuilding it with the part still bent was impossible, but I was obsessed with putting it back like it was.

First time I ever spannered on my first motorbike, I turned an exhaust stud the wrong way and snapped it off. Ended up needing the engine out to fix it. I learned quite fast!

Not sure I should admit to this but
Snapped a m-arch bomber lower leg when I slipped removeing a seal
The fork brace folded in two opps

Adjusted a barely used X7 lever as “something wasn’t right”. Ended up taking it apart, then couldn’t get all the springs back in.

Took to LBS and they said “too fiddly, we don’t bother fixing them, we just replace them!”

To my utter shame I stripped a break thread on a set of rockshox once. The moment you hear that slight crack and feel the Allen key spin is a moment of crushing failure as a home mechanic. Once experienced, never to be repeated.

Overtightened and snapped lockring on xt cassette, ruining hope freehub body. That takes some doing but I’d convinced myself it was the source of an ellusive creek. It wasn’t

Didn’t cause any damage but when I first bled my avid brakes I followed the excellent avid you tube guide, I followed it to the bloody letter. After about 45 min I still couldn’t get things going. Started thinking I was going mad then realised I was bleeding the back caliber with the front lever (American video, levers wrong way round innit)

Snapped banjo fitting on a set of Hope mini’s just after the LBS closed
Schrader valve integrated into the base of a fork cartridge while removing

much swearing

ndthornton – Member
Overtightened and snapped lockring on xt cassette, ruining hope freehub body. That takes some doing but I’d convinced myself it was the source of an ellusive creek. It wasn’t

That must have been some force you used to do that! 😯

mineral oil is now p1ssing out everywhere and the caliper looks proper broken.

Glad I’m not the only one covered in mineral oil after the weekend 🙂

Brand new SLX 675 brakes – I began bleeding them for the first time using epic bleed solutions kit and as I pushed the syringe at the calliper fluid pisses out of the lever from the diaphragm seal – lots of it, all over the wood floor in my front room, I don’t yet know how much damage was done.

I’ve also got a small collection of hose nuts with rounded flats.

Attaching a hose to an elixir 5 calliper I sheared of the head leaving the thread in the calliper. Fortunately I greased the thread before hand other wise I would not have been able to extract it from the calliper.

Using a Hope bleed kit and running it off the tyre pressure from a car spare wheel.

Apparently space saver spares run at very high pressure. I pretty much blew the top cap off the master cylinder.

I had similar woes this weekend. I was cleaning my Saint (m810) caliper pistons with a little mineral brake fluid to rid them of the winter detritus and mistakenly overextended the amusing one of the pistons to pop out. I have managed to replace this within the caller housing, but now none of the pistons are extending when the lever is pulled. I am assured that I just need to replace this and bleed the system, but its frustrating to have done such a stupid thing in the first place 🙁

franksinatra – Member
Didn’t cause any damage but when I first bled my avid brakes I followed the excellent avid you tube guide, I followed it to the bloody letter. After about 45 min I still couldn’t get things going. Started thinking I was going mad then realised I was bleeding the back caliber with the front lever (American video, levers wrong way round innit)

Awsome 🙂

I over tightened my Hope seat clamp the other day, first the ally bolt went pop ( I should have stopped tightening there shouldn’t I ) so I popped in a temporary Allen bolt and proceeded to tighten until the clamp split.. I’m now sporting a £6.99 clamp in Black, ohhh the embarrassment.

Rorschach – Member

I have seen a flattened downtube from a mis-timed hammerblow to main pivot bolt

Was he trying to hammer out the pivot bolt as the bike went past?

2 Chris King bottom brackets…..

but the cases are made of soft cheese in my defence!

Separating the lowers from a set of Fox forks. Instructions said use a rubber mallet, surely nothing wrong with using a normal hammer… Knackered threads on damper rod. D’oh! Luckily managed to sort it, but it was a lesson learnt. 99p rubber mallet was purchased!

I was bleeding the back caliber with the front lever

Thats superb – but didn’t you think ” there isnt much fluid going into the lever” ?

Using a Hope bleed kit and running it off the tyre pressure from a car spare wheel.

Im not a fan of that apparatus – you need at least 3 hands to opperate it properly – but they are so easy to bleed without the kit and just piece of tube. Mine went in the bin after the second failed attempt to use.

Never broke anything while spannering at home, mostly due to lots of ham fisted experience when i used to work at halfords lol

I had a mineral oil issue too… although mine was because my mechanic used mineral oil in my brake instead of brake fluid… destroyed the seals and needed a full seal rebuild top and bottom.

Threads and bolts are my downfall. I hate to think the amount of bolts that I have broken on motorbike or pushbike. Its always the quick and simple jobs too!
The most costly+ annoying was probably my sump bolt on GSXR. I didnt realise they were only meant to be hand tight+1/4 turn, very low torque. I was used to cars and steel sumps. Tightened it up (as I didnt want oil pissing out did I?! and spin, spin, god damn fk it! Saving myself money and it cost me loads for new sump.
Again on motorbike, I jacked the front up on fork stands to remove the mudguard, so I could plastic weld a little bit that had cracked. I forgot to loosen the calipers first, but did so whilst on stand.. big mistake. Stand gave way and bike collapsed whilst wheel was out. Front wheel and mudguard went crashing into front cowl and broke front fairing.. again 00s to replace….

XTR cranks & the crappy plastic lock ring & worn splines – ended up using a lump hammer to get them off & in the process the frame had developed a crack where the seat tube meats the head tube. Thank **** for treks warranty – 2013 remedy frame as replacement

a friend of mine sent me an email about 10pm on a friday night (you are on here and you know who you are….)

Pictured was the crimped end of the shimano hose – i cant get this off – i was shortening my hoses and cut down by the caliper.

so he had a hose out his caliper of about 5cm. – no riding his new bike that weekend.

DOH

Swapping forks before a trip to Afan, I didn’t notice the bottom bearing fall out of my old Zesty headset onto the garage floor.

Wondered why the steering was binding and tramlining all the way round W2 the next day.

Destroyed the bottom cup but thankfully the frame was unscathed. Unlike my ego.

I managed to crack a piston on my brand new SLX after having to give it a bit of force to get it fully retracted on the first bleed after shortening the hose. Decided that I no longer had any faith in something so fragile so I sold the warranty replacement and went back to Avids which have been flawless so far.

Bent the bearing cups on the rocker of my stumpy by ‘saving time’ and trying to insert two bearings simoultaneously, using a threaded bar and nut ‘bearing insertion tool’. Panicky No no no no no no no moment follwed by crushing sense of inadequacy followed by the shame of asking LBS to order a new rocker – I think they sussed what a bufoon I’d been, doubling the humiliation.