Reaming seatpost tube for dropper post?

Stupidly and wanting to avoid the soda mess I tried to remove a stuck seatpost with a blacksmiths drill. Even with everything clamped down I mullered the seat tube and that was with a drill bit something like 26mm to take out a 27.2mm seat post. I’m not an engineer but am usually pretty careful/handy with making/repairing. I’m sure someone with the ability to clamp the frame and a big enough mill/pillar drill could do the job, however, given the likely use of the bike if a dropper is being fitted I don’t think I’d want to risk weakening the frame.
 
Makes sense to do a post rather than the frame like in the above video. You can always chuck it away if you cock it up.
 
The middle of that seat tube gets very thin.....most of that you will remove trying to ream it.

Riding a fag paper don't sound that good to me or that long lived.
 
No way jose

The reason droppers aren't available in the smaller sizes is the inner post has to be smaller, and not snap or bend.


Get a frame with 26.8 and fit a gravity dropper...

Or bigger, e.g. lots of aluminium frames from the era, or I know Orange P7's have a decent size seat tube if you remove the shim.

I have a '97 M2 stumpjumper that has 30.9 post for this purpose.

I have a '92 steel checker pig that has a big seattube.
 
Think the uncontrolled spinning might be a bit off putting...
Spoilsport. 😂

You know the spinning isnt in the pneumatic unit don't you? Its a bearing underneath it.

They also only come in 27mm diameter. 😁 I've got one in the garage i liberated from a skip rmto play with.
 
Spoilsport. 😂

You know the spinning isnt in the pneumatic unit don't you? Its a bearing underneath it.

Some do, some don't. The one we exploded in the DT lab at school span freely. Until we exploded it.

I'd like to see how fast a saddle would come up on top of one of them, getting your crown jewels in the way would be a whole new type of pain...
 
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