ongoing questoins regarding building a bike
 

hi, this is one for the tekkies,

my mate bought a CBR last week, was in great condition, his first bike,

alas he crashed it and its written off. he threw it under a car (silly man)

as he had tpft he is royally screwed.
so were gonna take on the task of getting it back on the road.
the rear end is fine, forks are twisted, plastics are all fecked, headlight assembly is dead, front wheel and discs are all mangled up.

now the generator cover is cracked that spilt out all the oil, |(thats replaceable, only 25 quid for a new generator cover)
but just above the generator cover, there is either a scratch or a hairline crack, were not sure what it is, its about 3cm long, but doesnt join come all the way to the edge of the metal.

http://images6.theimagehosting.com/diag.jpg

the red on the diagram is the big crack gushing oil, while the blue are what we are interested in, am i correct in thinking that if they were cracks, they would go all the way to the edge of the metal ?

would some photo's help ?

how could we test for sure if it is a crack or scratch ?



how can we find out whether its a crack or a scratch ? (a scratch we can live with)

Do you know any welders?

You can test if its a crack using Eddy Current testing. Welders who work on critical stuff will run one of those babies over the weld, and you look at the display, and you can tell what the story with the weld is.

Probably a few minutes in the golden pages will find you one if you dont know any...
(Oh, yeah, I think that just because its not reached to the edge, doesnt mean you are cool. Probably you are ok, but who knows. Weird things happen when you crash bikes.)

If the case distorted under the crash load then a cracks are obviously a possible, if you look on the inside are the marks/cracks visible then?

That area of the case isn't a greatly stressed area, if you find they do reach all the way through, it would be worth considering 'V'-ing the outer side and pressing some Araldite or similar into the grooves thus made - this a definate rough and ready approach, but if your chum truly is potless it may assist. Keep an eye on that area though - if the filler drops out the case is flexing.

cheers mate.
i cant really get the bike a an engineer or a wielder, but they may come to us.
we will have a look on the inside of the case tomorrow and get some pics to post up.

will the filler go on the inside of the case ? or the outside ?

is araldite another word for cold wield ? (to be totally honest, ive never seen it or heard of it before, let alone used it)

used to be sold as Rapid Araldite. Its epoxy resin. Mad strong glue, you have two tubes, one smells manky, you mix them up with a match stick, and daub it on. And robert is your fathers brother.

In fairness, sid is as usual, right, if the line is in the same place on both sides, youre snookered. Otherwise, you are probably grand. Doh.

ok, but if it is cracked, am i still ok to use that epoxy resin stuff to fix the crack ?

How much clearance have you got? If you have a couple of mm, and you can cover the crack nicely with it, yeah, maybe. Epoxy resin is insanely strong. Really clean the suface first obviously, maybe roughen it slightly too.

Find out if its a crack first. Then cross that bridge.
What happens if it leaks? Like, whats your worse case scenario?

I dunno really TBH :?

got about 4inch clearance, loads of room to play with.

what happens if it leaks ? well, from the size of the scratch / crack. . not much its tiny.

will get photo's tomorrow :)

Glue won't work, Alloy is porous and will be full of oil, Glue won't stick.
Looks from the drawing that it's a removable cover, If so just take it off and get it welded. Won't cost very much and is the only way to seal it properly.

The crack is in the crankcase - the blue lines - the red line is the damage to the removable outer cover, which Bikeage has already said costs £25 and will be replaced.

:? Strange that - done it a number of times on cases before - works fine if done carefully, I must not have realised the leaks were still there. :roll: