I’ve done a chunk of googling and ST searching and I guess I’m just looking (hoping) for a second opinion. I put a tiny ding in the drive side seat stay of my p2k the other weekend. I’ve ridden it a few times since then including a hard half iron on Sunday and it’s not collapsed yet or gotten worse in any way but it’s weighing on my mind - the bike is going to get overhauled this winter and I don’t want to throw money away on odd parts (650 wheels, 1" headset etc.) for a frame with a limited life expectency.
So, ding is about 2mm deep and the stay is slightly bent in - if you hold a ruler up to it you can see a crack of daylight on either side of the dent but the bend is not visible to the naked eye. It’s also a “smooth dent” to to the extent that is a good thing. Do you reckon:
the frame is a deathtrap and should be consigned to the trainer immediately;
the frame is fine; or
don’t know but contrary to eveything you’ve read there is a great guy who can repair your frame perfectly and his email is___
About 10 years ago I had an aluminum trek mt bike with a smooth dent (about the size of my pinkie finger) on the down tube. (it was from my u-lock holding tough when someone tried to steal the bike). At the time I was told that as long as the aluminum was not cracked it was still “fine.” I rode that thing for many years of hard mt biking after that and never had a problem.
A lot depends on the nature of the dent. The seat stay is going to absorb impact forces, so essentially your weight coming down on it vs the resistance of the road. Of course, some percentage of your weight is going to be vectored, since you are taking some on the handlebars, and your weight at your butt is essentially applying a vertical force to an angular arm.
So if the dent were elliptical, and the long axis of the ellipse went across the seat stay, I would be somewhat worried that it would eventually buckle. If, on the other hand, the long axis is essentially parallel to the long axis of the stay, then forces will be transmitted around the dent ot a greater extent. The depth is not the only critical issue here, the shape and diameter come into play as well.
I have ridden aluminium bikes with dents in the tubes for years with no problems. I had a bike I just sold with a decent size dent in the seatstay, I raced on the bike for two more years and used it on the trainer, I weigh 180 and ride pretty hard. I would not worry in the very slightest about that dent.
Your experience should be the most common case by far. However, since we don’t have a picture or real description of the dent, my only concern is if the dent can be a preceding condition to forming an actual crease. So there are dents by something hitting the tube pretty much orthagonally, then you would be OK. If the dent was caused by something narrow hitting across the angle of the seat stay, then you MAY have problems want to check it out more carefully.
Thanks for your thoughtful responses - finally got around to taking some photos so any update on the diagnosis? Really appreciate your thoughts http://i9.tinypic.com/4xqlj44.jpg
Not to rain on the parade, I had a cannondale, I dented th etop tube in a crash, I hit a pothole on it a few months later and the top tube buckled, ruined my day.
my unprofessional opinion: the dent appears to be very small, the seat stay’s wall thickness is a lot greater than that of the main frame tubes, the frame is over-designed, and you have the added safety of the other stay (the chain stay) plus the other side of the frame anchoring the rear wheel (i.e., if you had some kind of failure at the dent, the frame’s initial failure will probably be partial, not total).
that said, you could monitor the area for cracks or any changes. me being on the cheap side, i would likely ride the bike for a lot longer. perhaps it may be possible for a pro to lightly sand the area and beef the dented area up with some high-strength aluminum alloy-compatible epoxy. but in the end, the final decision to ride it, replace it, or repair it will be a judgement call, and one only you can make.
My super light alloy Scott Racing MTB has dozens of dents way larger than this pretty much all over it & I kane it as hard as I possibly can most weekends - Its 5(?) years old and just wont die. It is very thin tubing you can flex it with thumb pressure. I used to get stressed out about the dents but now they are just part of its character!!
