chromenuts

Hi all, my name's Kevin, I ride bikes and need help modifying one of mine. I was too anxious to see if there was a solution to my problem out there to do a formal intro post.

Need to go from slightly over 27.0 mm I.D. to the more common 27.2 mm I.D. seatpost diameter so I can get a more forward position Tri style post in the frame. It's a 58 Columbus SL DeBernardi, about 12 years old...was already reamed by a previous shop to make a bad over spec American Classic post fit when it was built. Now nothing else that size or any size will work in the frame except the AC post.

So how about it...can anyone out there help me out? Loan or rent me an adjustable reamer? Actually do the work for me? I am in central CT. None of the local shops can or want to help me out....liability and all that shiz.

Feel free to drop me an email: chromenuts@hotmail.com

Thanks all.

powers2b

Sorry, I lost interest after Kevin.

Enjoy

Iowegian

Try to find a frame builder in your area or someone who does frame repair. You might also ask over at the frame builders sub-forum.

chromenuts

Thanks...and thanks...yeah I lost interest too...I edited the post to get to the point...guess I needed to vent over a frustrating situation. Oh and I did put a call into J.P. Weigle? A place down in Lyme...35 week wait list on new custom frames...something tells me they have better things to do with their time...and then there's that dreaded liability issue.

FBinNY 

If you don't find someone, (I mean after r-e-a-l-l-y looking) PM me. I'm in Westchester County NY, about 6 miles SW from Greenwich, and I can bail you out. It's just that I'm kinda busy, and would rather you save me for your absolutely last option. (If you bring me the frame and you're forehead isn't totally black and blue from banging your head against the wall, I won't do it).

JohnDThompson 

Unless the frame was built with the seat tube upside-down, a Columbus SL seat tube should take a 27.2 post without any reaming needed. Was the tube overheated during construction perhaps? Can you feel any distortion inside the seat tube, particularly along the lug margins? Something is odd here it seems.

chromenuts

Not sure if you saw my original novel of a post or not. One of the shops I tried to get help from contacted their DeBernardi distributor about the situation. The response from the distributor was that it was common to find thicker wall tubing used for the seatpost tubes on the larger DeBernardi frames of this vintage (approx 12 years old). They also cautioned the shop against reaming the tube for fear that it might weaken it etc. etc. All I know is that the 27.0 American Classic post never fit properly from day one...it wasn't modified in any way, and the measurements I took of it with my calipers this past week puts its average diameter at 27.1 mm...which is barely adjustable in the frame because it is so tightly fit.

Crankycrank

I bought an adjustable reamer here. https://www.wttool.com/category-exec/...ers/page_num/2 Not the highest quality but
cheap and I've used it twice in steel frames and works great.

chromenuts

Thanks for the link...that may be the ticket for me if no one else chimes in with help locally. I am pausing to think it would be nice if someone more experienced with this was to help me out. I am very mechanically skilled and have worked as an auto mechanic as well as built my own bikes, but in my experience any type of machining/taping etc. benefits from someone that has developed a "feel" for the process. This is a little different from most of that type of work that I have done, and I have no desire to make any fatal mistakes on my only current road frame. Did you happen to buy the 27 - 30.25 mm version? How accurately were you able to adjust the tool? The bottom of the range is very close to what I need.

CACycling

What about going the other way and slightly reduce the OD of a 27.2mm seat post to fit your frame? Seat posts tend to be quite a bit thicker than seat tubes.

powers2b

And cheaper, and easier to modify, and there is no risk to ruin your nice frame, and.............
Enjoy

jccaclimber

Alternatively, if it's only 0.1mm large, get the next size down and use a pop can shim. It isn't pretty, but it does tend to work very well. Like everything else, use plenty of grease.

Torchy McFlux

For 0.1mm, you wouldn't have to bother with a shim.
It's crazy to hone out a seattube to match a seatpost. Decent quality frame tubing is somewhere between .5 and 1.0mm thick. You're going to hack up the inside diameter to try and reduce it by another 0.2mm just to accommodate a seatpost you like? Just use a seatpost that fits. There is variability in marked diameters between manufacturers. I remember that AC tended to be on the large size compared to most other brands.