Lower Inner Race Bearing siezed onto Canyon CF Frame

robhowson

Hi Everyone

After hitting a large pot-hole and damaging the forks of my Canyon Ultimate CF Frame, I brought a new pair forks. When removing the old fork to fit the new forks the lower headset bearing was corroded and imploded upon removal.
I thought this would have been a straight forward replacement job, but the inner race is seized into the frame (See
photo attached). To make the matter worse there is no protruding lip to get an implement on to, and I dare not hit it with a blunt screwdriver (as is the norm) for fear of fracturing the head tube. Does anybody have any recommendations on how I could possibly get it out.

Bar Shaker

Out of interest, did you have the Canyon open steerer cap?

sungod

there's no photo

if it wasn't lubed before fitting then any corrosion will have jammed it

step one is apply something penetrating like plusgas or acf-50, invert the frame and apply it so gravity helps it seep down, let it seep in for a few hours

ypu should be able to use a couple of picks to apply force, they'll be fine enough to get at the upper face without causing significant damage, i.e.

http://www.amazon.co.uk/dp/B0001K9T5G/

if it's still jammed, try freezer spray *only* on the metal itself, it may contract enough to free it


if that fails, you may be able to degrease it and then superglue/epoxy a suitably sized piece of pipe into it, if the bond holds that might give enough grip to get it out, but you better be careful not to simply glue the race to the frame

francis666

I love giving advice on tech stuff, but with a carbon frame like yours, go to a really good bike shop.

Do you really want to take the chance of messing £1000 frame?

If it were ally or steel no probs, but its so easy to split CF when you get nasty with it.

Bar Shaker

sungod wrote:

there's no photo

if it wasn't lubed before fitting then any corrosion will have jammed it

step one is apply something penetrating like plusgas or acf-50, invert the frame and apply it so gravity helps it seep down, let it seep in for a few hours

ypu should be able to use a couple of picks to apply force, they'll be fine enough to get at the upper face without causing significant damage, i.e.

http://www.amazon.co.uk/dp/B0001K9T5G/

if it's still jammed, try freezer spray *only* on the metal itself, it may contract enough to free it


if that fails, you may be able to degrease it and then superglue/epoxy a suitably sized piece of pipe into it, if the bond holds that might give enough grip to get it out, but you better be careful not to simply glue the race to the frame

Soaking the inner face of the carbon will likely stain it and may soften the resin over time, if the solvents are left to soak in.

It should be removed professionally using the correct pulling tools.

sungod

i've never seen any evidence that oils affect cf resins, afaik it's an urban myth, have you a source for this? one low level ingredient of plusgas is a hardener for liquid epoxy, once cured i can't see it having any effect

aside from the slow effect of acetone, it usually takes much nastier things (i.e. methylene chloride, nitric acid) to badly affect epoxy resins

Bar Shaker

sungod wrote:

i've never seen any evidence that oils affect cf resins, afaik it's an urban myth, have you a source for this? one low level ingredient of plusgas is a hardener for liquid epoxy, once cured i can't see it having any effect

aside from the slow effect of acetone, it usually takes much nastier things (i.e. methylene chloride, nitric acid) to badly affect epoxy resins

I have seen water stain carbon fibre when left exposed to it for long enough, so I wouldn't let any solvents near mine. I nearly bought a carbon fibre Nidecker snowboard some years ago. It looked a thing of beauty and rode really well. Just before buying I saw one that had been used for a week. It was milky and horrible from absorbing water and the salts within it. If it absorbs water, it will absorb solvents much more easily.

I am not a chemist so don't know what effect they would have but I cannot see any good coming from it.

robhowson

Cheers for the reply's everyone, ive managed to get the destroyed bearing out with gently levering it out with a screwdriver. I used a little amount of GT85 but made sure no carbon on the inside of the frame was exposed to it. I now need to replace the bottom bearing. The headset is a Acros Ai-70 1.25in - 1.5in. Does anybody know if a standard 1.5in bearing will fit or will it have to be a Acros bearing? cheers

sungod

Bar Shaker wrote:

I have seen water stain carbon fibre when left exposed to it for long enough, so I wouldn't let any solvents near mine. I nearly bought a carbon fibre Nidecker snowboard some years ago. It looked a thing of beauty and rode really well. Just before buying I saw one that had been used for a week. It was milky and horrible from absorbing water and the salts within it. If it absorbs water, it will absorb solvents much more easily.

I am not a chemist so don't know what effect they would have but I cannot see any good coming from it.

that's going to be the clearcoat/lacquer/paint, aside from cosmetics the coating protects against uv, but it's nowhere near as tough as the resin that bonds the cf

op - bear in mind the amount of oil and grease a bike gets exposed to, you really don't need to worry, even cf makers such as enve tell you to grease cf, e.g. fork crowns, one of the most safety critical areas of the bike, they would not say that if there was even a remote chance of a problem

keef66

sungod wrote:

Bar Shaker wrote:

I have seen water stain carbon fibre when left exposed to it for long enough, so I wouldn't let any solvents near mine. I nearly bought a carbon fibre Nidecker snowboard some years ago. It looked a thing of beauty and rode really well. Just before buying I saw one that had been used for a week. It was milky and horrible from absorbing water and the salts within it. If it absorbs water, it will absorb solvents much more easily.

I am not a chemist so don't know what effect they would have but I cannot see any good coming from it.

that's going to be the clearcoat/lacquer/paint, aside from cosmetics the coating protects against uv, but it's nowhere near as tough as the resin that bonds the cf

op - bear in mind the amount of oil and grease a bike gets exposed to, you really don't need to worry, even cf makers such as enve tell you to grease cf, e.g. fork crowns, one of the most safety critical areas of the bike, they would not say that if there was even a remote chance of a problem

Scott on the other hand tell you not to use grease on their carbon frames / forks :roll: How they expect you to assemble / maintain the bike without it coming into contact with grease is another matter...