greenbeing

I'm looking at a used bike online and they said it has a "Kink on the top tube" but is still "very ridable". Does anybody know exactly what a "Kink" is?

Thanks!!!

BikeInMN

Kink in frame tubing = not good

Run do not walk away from buying a bike that has a buckled tube.

greenbeing

thank you for the advice, just what i needed to know.

ZenNMotion

This is not necessarily a problem. A dent in the top tube is fairly common from the bars swinging around and whacking the tube in the middle- this is what likely happened, and in that case the tube is not "buckled". These are especially common on track bikes that dont have cables to prevent the bars from swinging around- you will see that some of them have a little bumper around the tube right where this contact would be. You need a good photo to judge. If its a small dent, and the frame is steel, its really OK by itself, but I would ask how it happened, and ask if there is any other frame damage (eg was the bike crashed or did it just fall denting the tube?) A frame builder can fix this by either a little gizmo the wraps around the tube and irons the dent out, or by simply filling it in with auto body filler, or silver braze material. The fix is aesthetic. An aluminum bike could be more of a problem, depending on how big the dent is. It would be unusual to have a buckled top tube with no other damage unless something heavy fell or crashed on top of it, like a garage door. In a crash, anything that buckled the top tube would have otherwised destroyed the frame completly. If the dent is on the side of the tube, then odds are its from the bars. I have a couple of bikes with these dings, one is more than 20 years old, and its really not a problem functionally. Frames don't break on the top tube, when they go, they usually go at the bottom bracket, or near the head tube/downtube meet, or the dropouts, or the fork crown (on Carbon and Alum forks). But the middle of the top tube? Don't worry about it-

va_cyclist

Kinked tube = severely weakened tube, regardless of the cause. Don't buy it unless you want to replace the frame.

islenska

heh...i bet its that surly on ebay...dont do it!

ZenNMotion

The Ebay Surly doesnt show the damage on the tube, request closeup pics of the Headtube showing the ends of the DT and TT, the TT "kink", and the BB area. But the price is already pretty high, probably won't be worth it in the end.
You can get a nice new inexpensive steel frame/fork for $600-700 similar to the Surly from Soma
https://cgi.ebay.com/Surly-Crosscheck...QQcmdZViewItem
Or small builder Lyonsport
https://www.lyonsport.com/web/cross_bike.html

I'd still feel OK with the Surly depending on the photos- it's not superlight steel. Geez, do you guys ever actually race cross? Any bike that's been through a season gets some dings-