Water inside the bike.

Globalti

Legendary Member
Got caught out in lots of warm wet weather yesterday and since the roads had previously been salted, when I reached home I gave the bike a really good wash down with warm water with car shampoo. I also punctured about 200 yards from home so ended up walking the last bit.

Changing the tyre, a good amount of water came out of the wheel rim through the valve hole. Another dribble came out of the stem cap when I hung the bike up to dry and yet more came from the seat tube when I removed the seat post. Does anybody know if any of this actually does any harm? On a carbon frame I guess the only really vulnerable parts are the steerer bearings, which don't appreciate being in a permanently moist environment.
 

screenman

Legendary Member
If it got in it will dry out in time. You can speed the process up but it is not really needed. I have only seen one bike in all my years that rusted through from the inside, note likely to happen on a carbon^_^
 
Location
Loch side.
It does do harm and plenty of it too. The most vulnerable are carbon frames with screw-in BBs. The fact that the BB is screw-in means that there is an aluminium insert in the frame's BB shell (carbon cannot be threaded) and water in there creates galvanic corrosion that will eat away at the aluminium insert. I've seen bikes where the insert was reduced to what appeared to be pitted foil. The second most vulnerable area is the seat tube. Again, galvanic corrosion eats away at the alumimium part. The aluminium salt molecule produced by this reaction (the white crystals you sometimes see) is many times bigger than the aluminium molecule itself and the seatpost thus expands. It often expands to the point where it cannot be removed without destroying it. This is a difficult and treacherous procedure, especially in a carbon frame. Also, water in the steerer tube could ostensibly corrode the expander plug underneath the stem cap, making it difficult if not impossible to remove too.
The best way to drain water (it cannot be prevented) that enters the seat tube is to have drainage holes in the BB shell. Most people don't like the idea of drilling holes there and will give all sorts of invalid reasons, but that is the best route to take. With modern press-fit BBs the shell area is under no threat other than damaging the bearings in the BB. Nevertheless, on my bikes, there are proper drainage holes and water is thus not a problem.
 

e-rider

crappy member
Location
South West
Got caught out in lots of warm wet weather yesterday and since the roads had previously been salted, when I reached home I gave the bike a really good wash down with warm water with car shampoo. I also punctured about 200 yards from home so ended up walking the last bit.

Changing the tyre, a good amount of water came out of the wheel rim through the valve hole. Another dribble came out of the stem cap when I hung the bike up to dry and yet more came from the seat tube when I removed the seat post. Does anybody know if any of this actually does any harm? On a carbon frame I guess the only really vulnerable parts are the steerer bearings, which don't appreciate being in a permanently moist environment.
the wheels and frame have several entry points for water.
hold the bike upside down and you'll likely see plenty of water come out of it!
water in the rims can help rot certain types of rim tape but otherwise doesn't cause much trouble
in the summer months it all dries out quickyl but during the winter it can stay wet for months at a time
 

T4tomo

Veteran
I washed my bike on New Year's Eve and wiped it down afterwards, hung it upside down in the garage as usual. Getting it out today a load of water spilled onto the garage floor, but I didn't see where it came from. :sad:
It came from inside the bike
 

ColinJ

Puzzle game developer
If it got in it will dry out in time. You can speed the process up but it is not really needed. I have only seen one bike in all my years that rusted through from the inside, note likely to happen on a carbon^_^
I came across the owner of this bike on a local audax event. He had just descended some very steep Yorkshire/Lancashire hills before noticing that the front of his bike had gone a bit wobbly ...! :eek:

dead_forks_large.jpg


It is clear that he did not check his bike very often because the rust on the forks is extremely obvious from the outside!
 
Location
Loch side.
I came across the owner of this bike on a local audax event. He had just descended some very steep Yorkshire/Lancashire hills before noticing that the front of his bike had gone a bit wobbly ...! :eek:

dead_forks_large.jpg


It is clear that he did not check his bike very often because the rust on the forks is extremely obvious from the outside!
My first thought on that one was Wow! But then I looked again and it isn't rust that caused the problem but stress cracks. That originally was an ornamental lug with the lug design purely for aesthetics and not for its intended function of blending the forces from fork legs into the crown without a steep transition.

The metal is still quite thick there, rust usually brings edges down to razor edges. Then, for some reason there were two holes in the blades themselves, right at the 90 degree rearward position. The cracks started there on the horizontal line and propagated sideways over time. The last straw was when the crack reached the lug. You'll see it is still silver in there and therefore fresh. I would have like to compare this photo with an original one before the cracks started. There is more to this fork than meets the eye. On the inner shoulder of the right side crown (right in picture), some material was filed away.

You mentioned audax. MY guess is that the owner drilled the fork to get wires down to the hub, perhaps for a dynamo?
 

ColinJ

Puzzle game developer
My first thought on that one was Wow! But then I looked again and it isn't rust that caused the problem but stress cracks. That originally was an ornamental lug with the lug design purely for aesthetics and not for its intended function of blending the forces from fork legs into the crown without a steep transition.

The metal is still quite thick there, rust usually brings edges down to razor edges. Then, for some reason there were two holes in the blades themselves, right at the 90 degree rearward position. The cracks started there on the horizontal line and propagated sideways over time. The last straw was when the crack reached the lug. You'll see it is still silver in there and therefore fresh. I would have like to compare this photo with an original one before the cracks started. There is more to this fork than meets the eye. On the inner shoulder of the right side crown (right in picture), some material was filed away.

You mentioned audax. MY guess is that the owner drilled the fork to get wires down to the hub, perhaps for a dynamo?
Hmm ... perhaps you are right. I didn't give it a lot of thought, I just assumed that the rust was to blame.

He seems to have ziptied a cable to the left side of the fork as we are looking at it.

I saw him walking the bike and stopped to ask if I could help. He replied that I would not be able to help unless I happened to have a spare pair of forks in my bag. I thought I had misheard him until he pointed out the cause of his bike's wobbly front end! I was pretty shocked and asked if he would mind me taking a picture of the damage.

We had been down a very fast 20% descent about 30 minutes back along the road. It doesn't bear thinking about what could have happened if the forks had snapped coming down that!
 
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