How I cooked my bike

[zigzag]

some time ago i've added mudguards to my bike and thought that any type of lubricant on mudguard fixing bolts is not a good idea, as it may increase the chance of them rattling loose. so i've attached the mudguards with dry bolts and they stayed fine, until (two years later) i decided to check if they are still tight, and tight they were. i sheared one bolt head, then had to undo another - same story.. doh! they were properly fused with the frame (alloy frame/steel bolts). i've managed to take one out by drilling, dremeling and tapping - yay! not so lucky with another broken bolt. drilled out the 3.2mm guide hole, tried to tap it out with 4mm tap (the original thread is 5mm), and the tap broke off inside! after grinding off the pointy bit of broken tap (so it doesn't foul the chain) i kept on riding with the mudguard attached to the rack mount holes, which was fine. but every time i cleaned the bike i was wondering how can i get this burger out:

then, i found this brilliant advice. there is no harmful/poisonous/dangerous chemicals involved, so a mini lab was set up in the kitchen:

the frame was simmering nicely and the inclusion was dissolving away, to my surprise:

five hours later - ta da!!

the lacquer on the dropout was stained by iron oxide in the water, but barely noticeable:

order and harmony restored! ;D

 

[HovR]

Nice job, never heard of that method before!

Personally I'd have drilled out the sheared bolt and re-tapped it a size larger, although odd sized bolts would be slightly less ideal when fitting/removing the guards.

 

[Peteaud]

One of best / weird / OMG post ever.

I cant say the Mrs would be too happy with me if i tried that tho.

 

[Mr Haematocrit]

Perhaps you need a disclaimer on the post, you just know someone's gonna try that with a carbon bike.. lol

 

[zigzag]

Perhaps you need a disclaimer on the post, you just know someone's gonna try that with a carbon bike.. lol

if i had the same problem on carbon bike's alloy dropout, i'd follow the same procedure - why not? epoxy is cured/baked at much higher temperature.

 

[Mr Haematocrit]

if i had the same problem on carbon bike's alloy dropout, i'd follow the same procedure - why not? epoxy is cured/baked at much higher temperature.

But equally its cured in a mold specific to the frame, the heat is also evenly distributed rather than focused on a localized area. Quite the effects excessively heating a carbon bike would have outside a mold would have on the frame I'm not sure, I'm equally not sure that the epoxy resin is OK with being reheated or not and if this changes its properties any... Damn well interested to know though, just not with my bike, if your brave enough to have a go let us all know what happens.

 

[Peteaud]

if i had the same problem on carbon bike's alloy dropout, i'd follow the same procedure - why not? epoxy is cured/baked at much higher temperature.

.. Damn well interested to know though, just not with my bike, if your brave enough to have a go let us all know what happens.

+1

 

[Svendo]

+1

 

[Sittingduck]

Hah, love it! Nice work my friend

 

[zigzag]

But equally its cured in a mold specific to the frame, the heat is also evenly distributed rather than focused on a localized area. Quite the effects excessively heating a carbon bike would have outside a mold would have on the frame I'm not sure, I'm equally not sure that the epoxy resin is OK with being reheated or not and if this changes its properties any... Damn well interested to know though, just not with my bike, if your brave enough to have a go let us all know what happens.

the heat is less than 100'c, i'm pretty certain it would do no harm to carbon composite frame, but that's a different topic anyway. do your research before experimenting

 

[HovR]

I'm equally not sure that the epoxy resin is OK with being reheated or not and if this changes its properties any... Damn well interested to know though, just not with my bike, if your brave enough to have a go let us all know what happens.

This article may provide some information.

Reading through it it seems like the glass transition temperature (Tg) of the resin used is one of the most important things to take in to account, as this is effectively the temperature at which the resin begins to soften, which presumably would give it the opportunity to become misshapen or expand. The article also seemed to come to the conclusion that after being heated and allowed to return to room temperature, the resin returned to full strength.

Common high temperature resins (that I have seen) tend to have a Tg rating of only around 150 degrees Celsius (ish), and I wouldn't bet on carbon bikes being produced with resin designed to stand high temperatures - So before trying anything like that I'd be contacting the manufacturer to get some information about the properties of the specific resin used!

 

[SomethingLikeThat]

Interesting looking frame.

 

[stuee147]

iv striped bikes down in the kitchen before (and a car engine ) but i would never of thought of cooking it lol great idea i would of drilled and taped it lol

 

[Profpointy]

that is an incredibly useful tip, at least potentially. And not one I've ever heard of either - and despite being merely a gentleman-amateur , I've at least heard of quite a lot these tricks

That said, I've only tended to snap stuff off screwed into steel or iron, but still - bound to need it one day - if only I remember it when that day comes.

 

[Custom24]

Perhaps you need a disclaimer on the post, you just know someone's gonna try that with a carbon bike.. lol

Or a steel bike. Oops.