is it worth going "caustic" on this bike ?
 

Hello

I recently have been given a 1990 Trek 750 MultiTrack with a stuck seat post. Someone already spent some hours trying to remove it and did so with a number of tools. I decided it was worth taking the challenge as it would do a great all around bike.
I was about to go "caustic" (use caustic soda to dissolve the leftover of the seatpost) and While I have no problems spending the time and some money to do so, I also noticed that the person that originally tried to remove the seat post damaged a bit the the tube in the process (see attached photos).
What I am wondering now is : is the frame too damaged to even be rideable ? The dent is not that big but still considerable
Will I be able to put a new seat post as the top of the tube seems not to be perfectly round anymore (I suppose some of the tools used make edges and small tiny dents inside the top tube ?

Thanks for your insight.

I would clean up the damage around the opening with rat tailed files and sandpaper. I would try to fix the dent in the seat tube, but I wouldn't expend too much effort on it. Then, I'd put it back together, with some grease on the seat post, and ride the heck out of it.

Personally, if the damage looks like it's gonna chew up any new seatpost, not clamp properly, and fail catastrophically due to serious cracks in the seattube... and from the photos, I'm guessing all three of those things are likely... then no, to me it's not worth the trouble.

Thanks for the feedback, it might not be worth it unfortunately

That's a nice bike (I have a '93) and if you make certain that the seat post extends past the tube damage, I would not be concerned about riding it.

It is a very nice bike and I'm torn in what to do. Now you make me hesitate :P

1. "1990 Trek 750". Assuming you can make it functional, what are you planning to do with it afterward?

2. Until you try to fix this frame, you won't have lost anything on this deal.

I am planning in making this bike my all rounder bike : errands, groceries, touring

Correct, even if I spend time to remove the leftover seat, I will not have lost anything. However, given that the bike only came with the rear derailleur, front derailleur, I'm more wondering if it's worth investing more parts/time/money as I will have to get wheels, etc....

I have a 1997 Trek 750. Great bike for doing just about anything. It's obviously not at any extreme (light weight racer, hard core MTB, etc), but it's a great jack-of-all type bike.

Now that's something else entirely. Wheels aren't necessarily that expensive to procure. If you want to keep it simple, assuming the rear derailleur is a Shimano index-compatible derailleur, you could get a set of Shimano ST-EF51 shift/brake levers (or similar) and get it on the road for less than 100 bucks. I think that bike would have originally come with Suntour derailleurs and, if it's still got them, you could go all friction shifting for even cheaper.

Still probably worth it. Even if you're not pleased with the outcome, you should certainly be able to sell it for what you have in it (or more). At least around me, decent Trek MultiTracks typically go for $150-250.

If a seatpost can inserted properly...or at least far enough for safe operation (you could cut the seatpost if it doesn't get past the dent)...I'd go for it. For a steel frame...that dent doesn't look significant enough to affect the structural integrity. Also, you could consider getting it sandblasted, and then powder coated. I recently had a steel frame powder coated and the process filled in most of the small blemishes around the seats tube and dropouts.

Dan

Have it reamed with a proper sized reamer to smooth out the rough spots and insure the seat tube is round.