Dec 24, 2003 8:03 PM
|Ok, first off, Merry Xmas everyone! I've seen a few(or more) threads that mention never clamoing a frame by the tubes on a workstand. Is this really that harmful? I have a Park CP-1 or 2 or whatever the consumer stand is, and always use the frame tubes to clamp onto. All my bikes are steel, if that matters. In fact, the Bianchi frame I am working on right now doesn't even have a seatpost yet, so I have no choice but to clamp the frame. Is it really that easy to crush a frame doing this? Doesn't using the seatpost put extra forces on the seat tube right below where the post ends? This is very confusing to me, since all the workstands advertise about how they are adjustable to about any size frame tube.|
|Use a seatpost||spookyload|
Dec 24, 2003 8:11 PM
|The walls of a seatpost are very thick and can take the clamping force. The seatpost should be in the frame far enough not to damage the seatcollar joint. As for clamping steel...it isn't a good idea, but it is definately safer than doing it to carbon or aluminum. I always keep a spare seatpost laying around in 27.2 so I can throw it in my frame when I work on it. My seatpost is carbon, and I don't like clamping on that either. I picked up a $5 cheapo post at the LBS just for that reason. I mark the carbon post, and it is in and out no problem.|
|It's a thin tube issue||Kerry Irons|
Dec 26, 2003 4:13 PM
|For example, my Cannondale came with a sticker specifically warning against clamping the down tube, but no problem for the seat tube or top tube. The problem with clamp type work stands is that the clamping force can get pretty high as you press to get the clamp to close. My workstand has a threaded closure, which though it is slower, is also safer as you only need to tighten it enough to stabilize the tube. There's much less risk of having the clamp set too tight without knowing it.
However, all this comes back to only needing to worry if you have very thin walled tubing. If you have a superlight steel frame, then clamping force can be a worry. If you have a normal frame, it is not an issue, especially if you don't use a gorilla grip to tighten things down.