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possibly warped seat lug

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possibly warped seat lug

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Old 11-11-12 | 02:27 PM
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possibly warped seat lug

Hi, I have a bit of a problem with my frame and I thought the knowledgeable peeps from the framebuilders forum could help me out. If this is the wrong place to post, moderators, please feel free to move this post.

I have a steel 3rensho frame that originally should accept a 26.8 seat post. After disassembling the bike, packing it (carefully), and shipping it across the nation due to a move, the seat post that I used originally for this bike would not take. Took a caliper to it and sure enough it is uneven. The seat tube now measures 26.8 (from left to right) and 26.2 (from front to back). It seems like the same type of warp due to over tightening but I don't recall the seat post being hard to take off when I disassembled it. And surely it couldn't have been the shipping as the box was not damaged when it arrived.

So here's where I need help. How could I go about having this repaired? I tried googling a solution but it's not giving me results. Would it have to be reamed or is there a better approach to getting it back to a circle again w/o having to ream it?

the seat lug in question (and older pic, since a camera is not close at hand right now) :
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Old 11-11-12 | 06:53 PM
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A few questions- It sounds like the binder part of the seat lug was some how impacted and now is a little bit closed up. This is usually easy to fix. Find a seat post that does fit and using that as a lever/reamer insert and work the post around/back and forth. Try one step larger a post and continue until the origonal post fits. Last step is to tighten the binder bolt and check the post's tightness. The idea is to gently and in a controlled manor expand the seat lug around the binder slot. Andy.
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Old 11-12-12 | 01:55 AM
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Thank you, Andrew!
I'll give that a shot. Will go to the community bike kitchen tomorrow and hopefully they'll have enough different sizes of seat posts for me to work with. Also hope it's as easy as it sounds
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Old 11-12-12 | 10:08 AM
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the way that most seat lugs get bent, it's usually possible open the ears with a large screwdriver and sneak the seatpost in. Don't ream, there really isn't much material there.
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Old 11-12-12 | 02:05 PM
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By the use of the word "reamer" I meant that the post used to pry out the seat lug would be a snug fit. The prying action comes from the post being in the lug by a few CMs and then working the post back and forth. Not that any cutting would actually happen. If the frame is already beat up I'll also use a screw driver to open the lug enough for a post but usually i'll try a less gauge prone method first. Andy.
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Old 11-12-12 | 02:33 PM
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I wasn't referring to your post, Andy, the OP mentioned reaming
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Old 11-13-12 | 01:00 AM
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yes I did which I really hoped wouldn't be the case coz I'ld hate to have to resort to that.

Anyway, thanks for the help! Went down to the bicycle co-op today and used Andrew's method with a seat post gauge. Worked flawlessly!
Glad to have my seat back in place.
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Old 11-13-12 | 06:34 AM
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good news, that's a beautiful frame
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Old 11-14-12 | 09:57 AM
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Originally Posted by Andrew R Stewart
A few questions- It sounds like the binder part of the seat lug was some how impacted and now is a little bit closed up. This is usually easy to fix. Find a seat post that does fit and using that as a lever/reamer insert and work the post around/back and forth. Try one step larger a post and continue until the origonal post fits. Last step is to tighten the binder bolt and check the post's tightness. The idea is to gently and in a controlled manor expand the seat lug around the binder slot. Andy.
Spot on Andrew. I'll add that a steel seatpost will work better for this task as it won't dig in and get stuck. Lube it well also. After you have the post in a ways, you can take a hard nylon faced hammer and go all around the outside of the lug and give it a series of firm taps...not enough to damage the paint, but firm. Goal is to force the slightly flattened part of the lug to reform to the shape of the post.

For Ichlitz, next time; Best advice is to always put a post or a plug in a frame before shipping. For a fork; cut a piece of 2x2" wood or a piece of dowell or broom handle to 100mm and slide it in between the dropouts. Then put a washer on a deck screw and run it into the wood just like an axle would sit (do both sides). A spare hub with QR would be better. For the rear triangle, cut the wood to fit the rear OLN (125, 135, 145 or 160mm) or use a spare rear hub if available... Securing these three areas drastically reduces the chance of damage when shipping
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Old 11-17-12 | 06:26 AM
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Well done gents!
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