possibly warped seat lug
#1
Thread Starter
Nü-Fred
Joined: Jul 2009
Posts: 1,517
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From: Brooklyn, NY
Bikes: Torelli Tipo Uno (stolen), Peugeot Nice, Mercier Kilo TT
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) :
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) :
#2
Senior Member


Joined: Feb 2012
Posts: 19,359
Likes: 5,492
From: Rochester, NY
Bikes: Stewart S&S coupled sport tourer, Stewart Sunday light, Stewart Commuting, Stewart Touring, Co Motion Tandem, Stewart 3-Spd, Stewart Track, Fuji Finest, Mongoose Tomac ATB, GT Bravado ATB, JCP Folder, Stewart 650B ATB
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.
#3
Thread Starter
Nü-Fred
Joined: Jul 2009
Posts: 1,517
Likes: 0
From: Brooklyn, NY
Bikes: Torelli Tipo Uno (stolen), Peugeot Nice, Mercier Kilo TT
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
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
#5
Senior Member


Joined: Feb 2012
Posts: 19,359
Likes: 5,492
From: Rochester, NY
Bikes: Stewart S&S coupled sport tourer, Stewart Sunday light, Stewart Commuting, Stewart Touring, Co Motion Tandem, Stewart 3-Spd, Stewart Track, Fuji Finest, Mongoose Tomac ATB, GT Bravado ATB, JCP Folder, Stewart 650B ATB
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.
#7
Thread Starter
Nü-Fred
Joined: Jul 2009
Posts: 1,517
Likes: 0
From: Brooklyn, NY
Bikes: Torelli Tipo Uno (stolen), Peugeot Nice, Mercier Kilo TT
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.
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.
#9
Senior Member

Joined: Sep 2012
Posts: 1,751
Likes: 7
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.
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





