repairable?

[kool maudit]

hi,

i have started this thread over at mtbr, looking for a nishiki alien.

this guy has one, but it's cracked.

if you click on the link, you can see pics.

http://forums.mtbr.com/showthread.php?t=373482

is this repairable?

[/img]

 

[kool maudit]

here it is

 

[Void(EN12-82)]

Yes I think it should be repairable... get the paint off and have a good welder look at it. But probably you could do with using an extra long seatpost to even out the pressure on the seat-tube :idea: :?:

It doesn't look to serious a damage to me, but actually you can only find out when the paint is off. But a descent welder could fix that up and you could smooth out the newly added weld so it won't look horrible ;-)

Void(EN12-82)

 

[JeRkY]

Relatively few frame builders will touch aluminium repairs, and because the crack has spread into the weld i would be a little concerned if it were any where else on the bike. However the location of the crack puts my mind at rest a little.

A super long post and decent tight collar should get you up and riding. If it spreads further then look into finding a repair service.

if its steel...should be no problem.

My O2 has a similar crack (not as large and one side of the forward facing slot only) on the seat tube slot, however it doesnt go into any weld or any where of importance. I have a decent width clamp on it and its held well.

(mine was caused by a previous owner trying to remove a stuck post by seamingly trying to opening up the top of the seatube with a screwdriver as a lever.)

 

[cherrybomb]

If you did just leave it and use a long post, I'd recommend at least drilling the ends of the crack to reduce the stresses and stop any further crack propagation.

Personally I'd want to get it fixed, or I'd leave it well alone.

 

[jacklero]

considering it is at the binder area, not a good idea to repair, subjecting it to further heat or other forms of bonding may weaken the area.

 

[cchris2lou]

Most of the Alien seems to be cracked , a bit like Manitou FS .

I would be carefull as there are probably more cracks .

 

[shovelon]

Yes it is repairable, but you have to watch out for overpenetrating and shrinking the diameter.

I have had to do this same repair on some Proflexes including my own 957 at the seat clamp. An LBS up the road sent me quite a few GT I-drives right after GT's financial woes, as GT would not warranty frames.

What I did is make collapsable mandrels, size 27.2 (proflex), and 31.8(GT), to mount inside to prevent shrinking and overpenetration of the weld. You could cannibalize a cheap steel seatpost, slit down one side and shove in for a mandrel.

Clean the paint yourself, and make sure your welder uses high strength filler, like 5356(most common high strength). Take it to the shop, have them ground on the seat post, you don't have to take apart the bike.

This should fall under the shop's minimum charge. Most tig shops charge a minimum of 1/2 hour. Walk away if they don't know what 5356 is, and they want to charge more than 30 minutes of time. It should take not longer than 10 minutes to weld if you do the prep.

Then reassemble and let the bike sit minimum 1 week, as to let the weld zone age harden somewhat, and then RIDE.

Good Luck,
Terry