cracked frame

mikethemongooserider

i know its nothing to do with downhill but it seems youlot have more common senes then any of the other catogrys
i have had my mongoose fireball for just over 3 years and its starting to form a lovely crack were the head tube joins down tube join

ive asked the farrier/blacksmith and he said alumiliam is dodgy to weld and hes never done anything with heat treated allumiliam so im wondering if its is ok to weld or will it make it worse?

Anonymous

Dont weld. Itwould need to be heat treated again and all sorts. Very dodgy. Just a new frame im afraid.

And how come you have a blacksmith? Are you in the 15th century or something? Or Bradford?

mikethemongooserider

well thats a bum
n the blacksmiths put shoes on horses with theres a lot of round here but blacksmiths are a dieing trade

nicklouse

the crack is easy to fix with the right equipment and knowledge.

But he is right. First you need to get the correct wire for the welder (right grade of aluminum) then weld it and maybe add gussets to re strengthen the frame. then the whole frame will need reheat treating and the a full repaint.

Or buy a new frame.

grantway

You need to take it to a fabricator being this is a specalised job.

I agree with Andy that aluminium needs to be heat treated
When LOL i was at school we had an Aluminium smelt.

The Fabricators may be able to weld it or heat treat it.
Where abouts are you i know a good Fabricator in
Hainault (Essex) or if your in North England take it to Orange
for a small fee they will patch you up

Go to a steel fabricator not a Blacksmith has the Blacksmith only
deals with Wrought Iron and only ferros metals and Aluminium
is non ferros.

Looks i lernt something at school :shock:

Let us know how you get on.

mikethemongooserider

ok thanks

dave_hill

grantway wrote:

Go to a steel fabricator not a Blacksmith has the Blacksmith only
deals with Wrought Iron and only ferros metals and Aluminium
is non ferros.

Eh? Surely he wants an aluminium fabricator then?

Seriously though, aluminium fabrication is a fairly specialist process. Once you've welded the stuff together, the crystalline structure of the joint or repair has to be realigned to maintain it's strength, hence the heat-treatment.

Usually once an aluminium frame is cracked though it is impractical and expensive to repair it so a straight replacement is usually the only answer.

This is one reason that experienced long-distance cyclists choose a steel-framed bike every time - if you snap or crack the frame half way up a mountain in the Himalayas, there's always going to be someone with a brazing kit or welding plant in the next village.

heez29

haha from one question there was like 4 of the same answers each with everybodys opinion on the matter :P so i'll add mine!

2 questions...

have you put larger forks (longer travel) on it?
and do you still have you're proof of purchase?

i dont know about mongoose frames but the frame could still be under warranty. if the crack is on the weld you could get a new frame without splashing. BUT depends how long their frame warranty is!

mikethemongooserider

ive put dj3s on and still hav the resite

heez29

its possible you could get it on warranty but check first. i just noticed its more of a 'jump' bike so chances are it aint. 3 years will probably be maximum.