taz777

I’ve had a budget cantilever bike stand for several years. I’ve always secured my bikes using the top tube rather than the seat post. I guess I’ve been doing it wrong! I’ve watched many hours of YouTube videos on bike mechanics recently and have only seen one in which the bike has been secured using the top tube.

I’ve never actually had an issue so far, luckily. The main reason I’ve used the seat post is that it’s easier to lift the bike onto the stand’s clamp and it also means that I don’t need to remove mudguards and lights that are mounted onto the seat post, so it saves a bit of time and effort.

Is it really bad to use the top tube to secure a bike on a stand?

woodcraft

Depends on the frame. Many top tubes, especially aluminum & some carbon, are quite thin. What you're doing has worked so far.

IMO, the upper seat tube that has the seat post inside it is a good place to clamp, but others will disagree.

I dislike moving or removing the seatpost just to work on the bike.

cyccommute 

It's not "good". The middle of the top tube...the middle of any tubes really...is thinner on many bikes than the rest of the tube so you are clamping around a weak part of the frame. The other issue is that the middle of the tube is crushed, the frame is more likely to bend at that point. If you are going to damage a frame in a stand, you are most likely to damage it by clamping in the middle of the tube.

There are also cables running on the top tube of many bikes. Clamping on top of them makes the adjustments you probably want to make more difficult because the cables are bound by the clamp.

How do you feel about taking all the parts off one frame and putting them on another? A seatpost...even a carbon one... is cheap compared to a frame.

Something else to consider is the amount of force you can develop with a clamp on a stand. The co-op I volunteer at has professional quality Park stands. They have a one inch long 1/4" diameter adjustment bolt on them so that you can adjust the clamp size. People regularly bend that bolt because they are trying to force the clamp closed with the clamp jaws closed too small. It will easily crush a frame tube.

Clamp the seatpost. And if getting it back in the same location afterwards is a problem, mark the post before you move it.

JohnDThompson 

Clamping on any decal is asking for that decal to be damaged. Likewise, clamping on fresh paint (e.g. paint that is less than a few months old) is asking for that paint to be damaged. Clamping over any cable or housing can also cause damage and make adjusting whatever component is controlled by that cable problematic. Clamping on non-round tubes seldom works well. Clamping on carbon fiber or thin-wall steel tubes can damage the tube. For all these reasons, I prefer to clamp on the seat post, or use an internal seat tube clamp like the Park ISC-1:



https://www.parktool.com/product/int...be-clamp-isc-1

mcours2006

For adjusting derailleurs, or for just resting on the stand while I work on the wheels or fenders I just clamp lightly on the tt close to the seat tube. It's just easier to put on and take off.

For work that requires some heavy wrenching, I use the seatpost.

SylvainG

+1

Kapusta

I do it all the time, and have for a long, long time. It is just a lot easier on bikes that have a dropper post (which I would definitely not clamp on), or stuff mounted to the seat post.

I just make sure that the clamp can tighten evenly over it's entire clamping area. In other words, no cables, housing, or stops being clamped, and the top tube needs to be a consistent cross-section. Otherwise, I won't do it.

Also, I just clamp it as tight as it needs and no more. And it does not need to be clamped very tight, as that is near the balance point for the bike anyway.

However, I would put this in the "don't try this at home" category when giving others advice. I can definitely see how someone not paying attention to any of the things I mention above could mess up their top tube.

mstateglfr 

Connect to the seatpost. Each time every time.
There is just no benefit to clamping the seat tube or top tube.

The clamp will scratch and blemish paint(have seen)
The clamp could dent tubes(havent seen)