Bike: "Small Dent" on Aluminum Downtube- deal breaker?

Question

I'm looking at purchasing a used (but VERY high-end...about $2k used) mountain bike. The person selling it has indicated that there is a "small dent on the downtube, where a rock kicked up and hit it". He also states it's "very small and very shallow".

The question is, if it is just a very small ding, could this be a problem? Aluminum is very brittle and has almost zero fatigue strength. Also, I'm about 240 pounds and concerned about aluminum even without dings. Anything to even be concerned about??

Answer 1

A dent in an aluminum frame would be deal breaker for me.  Especially if it is a very high end frame.  It was probably made as light as possible to begin with and even a small dent could grow into a crack in time.  I too weigh about 240lbs and generally stay away from very high end equipment unless it was designed with my weight in mind.  Most high end frames and components were designed around a more typical rider around 170 to 180 lbs.  I do ride aluminum frames but I am wary of really light weight ones.

Answer 2

Hey Robert,

In my opinion If you are going to spend about 2 grand on a used Alloy frame it better not have any dings or dents on it!     For your piece of mind and safety you pretty much answered your own question,  " I'm about 240 pounds and concerned about aluminum even without dings" I would pass on this frame and find a used one with out any dings or dents.  

Even though a small dent is not a biggie, I think one on the down tube would be of concern for me, especially if you weight 240 lbs.  Just my opinion of course.  Good luck.

Kimber

Answer 3

Thats right. High zoot frames tend to be heavily affected by dents. Pass on the deal.