Mr Beefy (Cotic BFe)

fatboyonabike

Eats Squid
try a piece of steel with some rust converter, maybe an offcut or other rusting frame for comparison.
it has a chemical reaction with the surface oxides that halt the rusting process, achieve desired result then clear coat over the top
355635
 

Calvin27

Eats Squid
It should hold ok, I'll give you some of my engineering notes here, the circumferential cracking suggests this is a bending failure which the thru bolt doesn't really add much more strength to. Not sure what this means for your design the tension is not going to be the one reducing the load. You need tomake sure the wedge is high tolerance so that it mates perfectly with the taper to transfer the bending load. I'd personally just patch weld a cover piece over the entire thing maybe 2mm thick and 50mm width. That bit sits inside the headtube so should clear.
 

Plankosaurus

Hydraulic Jack specialist
It should hold ok, I'll give you some of my engineering notes here, the circumferential cracking suggests this is a bending failure which the thru bolt doesn't really add much more strength to. Not sure what this means for your design the tension is not going to be the one reducing the load. You need tomake sure the wedge is high tolerance so that it mates perfectly with the taper to transfer the bending load. I'd personally just patch weld a cover piece over the entire thing maybe 2mm thick and 50mm width. That bit sits inside the headtube so should clear.
Thanks mate, good input (I'm not too proud to admit I had to read it a couple of times...)

My first thought with the crack was that it was due to expansion/cooling rate differences between to massively different metal thicknesses. I've had similar stuff with steel in the past, but I'm also shit at welding. I would have thought if bending was the issue that it would be open on one side and attached on another? The crack was identical all the way around.

Unfortunately there's two issues with welding - first, the crack is almost bang on bearing height, so there's no way I can externally reinforce it. Best I could do is reweld and grind it back to fit.
And second - I'm shit at welding and have no aluminium welding equipment



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Calvin27

Eats Squid
I'm not too proud to admit I had to read it a couple of times
I think I read it more than you to check I wasn't talking out of my rear end!

In terms of bending it cracks one side if it fails from overload, this one might be fatigue failure meaning the crack grows and grows slowly. Having the bearing right in the crack region would suggest it is a bending failure. If you imagine a simple beam with a bearing clamping the middle it will usually break where it is supported because that is where material shear forces are greatest. Don't stress too much about my comment though, because the solid piece straight through should help with that a lot. I was just making the point that a flush fit for the wedge should be a bigger focus than trying to pull the lot tightly in tension. I would also have a crack at re-welding the external and sanding down but I've had too many 'hole in aluminium' moments to have any authority on that :p.
 

Plankosaurus

Hydraulic Jack specialist
Send it to Dougal at Shockcraft NZ to have thatbusted steerer pressed out and replaced.
I'm not convinced it's worth putting this much effort into fixing a $60 set of forks. If it comes down to it, I'll hunt up an old set of lyriks again or something. This build is more about playing with new ideas than having the best of the best, I just wanna make sure I don't add missing all my front teeth to the crushed vertibrae and fractured ribs

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Hugsy

Likes Bikes
If you want it to rust before painting, use vinegar or an acidic product which will speed up the rust and make it look very uniform and clean rather than patchy. If you are trying to stop rust use fish oil before painting.
 

Plankosaurus

Hydraulic Jack specialist
So a couple of nights of Melbourne weather and a couple of coats of clear and Mr Beefy is starting to take shape...







I liked the idea of a uniform rust pattern but then decided to go for a more natural (less work) look. I like the way it's not the same all round, gives you something to look at.

And I've gone for a satin clear rather than gloss, I was hoping it would look a little less like it's painted and I think that's worked out about right.


Now waiting on a headset so I can fit these forks and get it rolling

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Cardy George

Is not in gaol
So a couple of nights of Melbourne weather and a couple of coats of clear and Mr Beefy is starting to take shape...







I liked the idea of a uniform rust pattern but then decided to go for a more natural (less work) look. I like the way it's not the same all round, gives you something to look at.

And I've gone for a satin clear rather than gloss, I was hoping it would look a little less like it's painted and I think that's worked out about right.


Now waiting on a headset so I can fit these forks and get it rolling

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Satin is definitely the go. Seen too many auto restoration shows where they've used gloss and it looks like utter shite
 

Plankosaurus

Hydraulic Jack specialist
I've used rust converter a bit on roofs, it changes the colour significantly and I'm not sure that's the effect I wanted. If it continues from here slowly I'll be fairly happy, but if it gets nasty quickly I'll strip it down and try again with converter I reckon.

Sprayed some wax rustproofing into the frame internals and added some forks and wheels. Waiting for bars to hold brakes and shifters etc and cranks to hold pedals but otherwise it's shaping up nicely I think.



Super keen to see how this rides!

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Hugsy

Likes Bikes
I've used rust converter a bit on roofs, it changes the colour significantly and I'm not sure that's the effect I wanted. If it continues from here slowly I'll be fairly happy, but if it gets nasty quickly I'll strip it down and try again with converter I reckon.

Sprayed some wax rustproofing into the frame internals and added some forks and wheels. Waiting for bars to hold brakes and shifters etc and cranks to hold pedals but otherwise it's shaping up nicely I think.



Super keen to see how this rides!

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Looks clean. Still dissapointed I didn't get the bike off of daniel. Happy with my chromag though.
 

Plankosaurus

Hydraulic Jack specialist

Mwahahahhahahahhahaaaa

I've been stuffing around for the sake of stuffing around with this entire build, and today's effort is no different. I bought some Magura mt5 for this build, but I don't like the levers. I have some slx m7000 on hand with mismatched calipers because I've donated the real deal to other bikes. I know they both run mineral oil so I did a little research and it turns out shigura brakes are a thing!

You need to use the Magura hoses, because the banjo is a different diameter.


The hoses have slightly different outer diameters, but the same inner diameter. Olives and barb's seem to work either way, but the nuts have different threads so you have to sacrifice a set.




Bleeding is easy enough, but the Magura calipers seem to dribble a bit when taking the syringe off and putting the nut back in. I just get a little more fluid in the lever reservoir and pump it a few times and she's solid as a rock.



Waiting on a saddle and a chainring now, so close I can taste it!

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Plankosaurus

Hydraulic Jack specialist
Mr Beefy is done!

Having a bit of time on my hands to play with stuff I wouldn't normally bother with has been great, this isn't something I'd normally have built but I'm bloody glad I did! I've only ridden it around the streets and some little kids tracks in the area, but i'm loving the feel of it. Has excellent street manners, pops off the little jumps with ease, and loves a little stair descent. I haven't ridden on a trail yet, but super keen to see what it can do!

Brakes are daresay the best I've felt, definitely more power than my zees, I'd even probably prefer them to my wife's hope v4s.

Frame is brilliantly playful, the geo keeps making me feel like I'm on a dual sus am bike but it just launches when you put the power down. I tried dropping the travel too, but it loves 160 so the talas thing won't get much use.








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fatboyonabike

Eats Squid
you sir are a revolutionary, stand strong my friend!
but please do something about that saddle....comfortable sure, but not nice to look at :(
the rest looks minty
 

Plankosaurus

Hydraulic Jack specialist
Hahahaha
Something to do while I wait for bones to heal. Looks rough but rides smooth as silk, and as long as the rust doesn't dig in too much I'm stoked with the finish.

you sir are a revolutionary, stand strong my friend!
but please do something about that saddle....comfortable sure, but not nice to look at :(
the rest looks minty
Blue wouldn't have been my first choice, but it was decidedly more available than the saddles that weren't. Goes well with the red hubs, specks of green paint I missed, and multi coloured mudguard. I'm thinking some Moar colours maybe - bit of orange? Some purple?

(If I find another comfy saddle I'll grab it)

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