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-   -   Need Help Reaming Seat Tube In CT (https://www.bikeforums.net/framebuilders/643848-need-help-reaming-seat-tube-ct.html)

chromenuts 05-09-10 08:33 PM

Need Help Reaming Seat Tube In CT
 
It was suggested to me in the Mechanics forum that I give you guys a try over here.

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.

Live Wire 05-10-10 04:52 AM

I'm nowhere near CT, but as an FYI, adjustable reamers aren't that expensive http://www1.mscdirect.com/CGI/NNSRIT...99920&PMT4NO=0

chromenuts 05-10-10 04:31 PM


Originally Posted by Live Wire (Post 10789112)
I'm nowhere near CT, but as an FYI, adjustable reamers aren't that expensive http://www1.mscdirect.com/CGI/NNSRIT...99920&PMT4NO=0

Thanks very much for that info...someone else in the Mechanic forum gave a link to a wholesale tool site with reamers that are priced even cheaper than MSC. I do have very good mechanical skills and have worked as an auto mechanic and built my own bikes over the years..however, I'm wondering if this like many other machining processes requires a hand with some experience or a "feel". It is currently my only road frame, I have no desire to render it useless. Any guidance as to how the reamer should be set up and used would be helpful before I consider doing this myself. I want plenty of cutting oil and perhaps a way to set the tool up so that it very gradually reams out to the proper diameter that I need. Any input appreciated here.

erik c 05-10-10 07:04 PM


Originally Posted by chromenuts (Post 10792078)
Thanks very much for that info...someone else in the Mechanic forum gave a link to a wholesale tool site with reamers that are priced even cheaper than MSC. I do have very good mechanical skills and have worked as an auto mechanic and built my own bikes over the years..however, I'm wondering if this like many other machining processes requires a hand with some experience or a "feel". It is currently my only road frame, I have no desire to render it useless. Any guidance as to how the reamer should be set up and used would be helpful before I consider doing this myself. I want plenty of cutting oil and perhaps a way to set the tool up so that it very gradually reams out to the proper diameter that I need. Any input appreciated here.

Easiest way I've been show is to clamp the reamer in a vise on a bench and use the frame itself to spin in a clockwise direction. Start with a just slips in fit and make it larger as necessary till it is reamed to fit the post. It'll be a multistep process with an expandable reamer as they don't self adjust.

ftwelder 05-30-10 10:37 AM

I have a seat tube reaming machine and I am in VT. I can do most modern diameters. Adjustable reamers suck (all low quality junk) and in your case won't work. One size will go 1-1/16" (1.062/27.0) and the next size 1-1/16" + won't really fit in the 1-1/16" hole with out getting "worms" (chips roll into balls and put ridges on the outside surface)

Also, if your seat tube inside diameter isn't over 1.070" (27.2) you will get a very undesirable stress riser (ledge) inside the seat tube causing frame failure. I have my reamers custom made at a cost of about $200 each. You will need a spiral flute for removing material and a straight flute then ball hone finishing.


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