My latest "project" involves my bike, i.e. I want to perform a complete renovation of it. This involves changing rim, complete shift group, brakes, hubs, carrier etc, just keeping frame, seat post and handlebar & stem.

I wanted to start by stripping down my bike to those bare components, and while I was cleaning and oiling the seat post, I discovered a horrible stench from within the frame. This smell is best described as sewage ( hydrogen sulfide is the chemical behind that I believe).

Since that aluminum frame is roughly 15 years old and heavily used, I now wonder whether this water in the frame causes a risk to the frame?

PS: Please do not discuss whether do-it-yourself is appropriate here, building up the bike from its parts is part of the fun.

  • Aluminum does not rust. It does oxidize but it creates protective layer. But aluminum does fatigue. A heavily used aluminum 15 year old frame is at or near the end of it life. Steel or titanium would be a better project bike.
    – paparazzo
    Commented Mar 8, 2015 at 17:43
  • 1
    Even in an aluminum frame, water in the frame can destroy the bottom bracket cartridge. But note that the odor may be from chemicals used to treat the frame and from the lubricants, perhaps combined with water -- there's nothing in the frame that would "rot" and cause a smell when wet. Commented Mar 8, 2015 at 19:28

3 Answers 3


See this question: How many years an aluminium frame lasts in a touring bike? for an example of an aluminum frame that is showing some cracks. This particular frame had been used for 10 years, but it depends mostly on the number of miles ridden and the type of riding (rough/smooth surface, load, etc.)

There is lots of useful information in the answers to that question. You should read it and form your own opinion on whether what you are planning to do is a good idea.

Personally, I think it might be unwise to buy lots of new components and invest a lot of time building the bike when the frame might already have cracks or may soon develop cracks. It might be better to spend a few hundred dollars/euros/etc to buy a new frame.

  • The question was about water that causes risk to frame, but +1 to this answer as it's objective good answer.
    – Alexander
    Commented Apr 9, 2015 at 12:13

I think you never understand frame condition by smell :). Aluminum and its alloys are great materials, but they could be destroyed by aggressive liquids (salt, acids etc).

If I were you

  1. Check the lowest frame corners (usually here manufacturers make little holes, to let water out). If you able open it and try to look inside or check by hands.
  2. That's all. Actually this is the best you can do. Wash inside the frame, and put on fresh air to make it dry (may be put up side down - water or wash component will flow out fast). Ensure you are using non-aggressive liquid (wait-spirit, warm water with wash chemical).

Store in dry place. Good luck!


You haven't said what the frame material is, but if steel obviously yes. Aluminum (and carbon) not so much, but it will add weight.

However, in any case it will pose a danger to your bottom bracket. Water will eventually seep past seals and into the bearings, leaving you with a stuck or severely degraded bottom bracket.

Your problem could be water getting into the frame somewhere, most likely at the seatpost, and not having a drain hole. It is very difficult to prevent water entry entirely, and this is why many bicycle frames do have a drainhole in the bottom bracket shell.

I would do this: Remove the crank and bottom bracket. If you have a cable guide underneath the bottom bracket, leave that in place and look for an unused hole - frames that do have a drain hole will usually have it co-located with this unused hole in the cable guide. Now, mark that spot, remove the cable guide and drill a 4-5mm diameter hole. Reassemble everything and enjoy.

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