27.6 post help

[hollowgram5]

Hey ya'll

I am in search of an odd sized seatpost. I recently acquired a Koga-Miyata 'Full Pro S' made of Columbus MAX tubing, and while working through the build, I encountered a bit of an issue. I didn't do all my homework, and I assumed the frameset needed a 27.2 seatpost. Through some diligent research after the fact, I found that the 1995 catalog, which shows the post was a 27.6x220 ITM Eclypse made of Ti.

I also checked on shims, and it seems that Problem Solvers used to make a shim for 25.4-27.6, but that has since been discontinued.

What are the chances that someone has one laying around? Probably not good, but my fingers are crossed..

http://www.koga.com/files/6/1/4/Koga_Brochure_1995.pdf is the link to the PDF for the catalog.

[ultraman6970]

Max with 27.6??? never seen that before. Wonder how will affect the stress in the clamping area. Remember some MTB bikes with that size but IMO you might be able to put a tin can shim in there with a 27.2 seatpost.

The frame uses clamp or has lug ???

[oldpotatoe]

Hey ya'll

I am in search of an odd sized seatpost. I recently acquired a Koga-Miyata 'Full Pro S' made of Columbus MAX tubing, and while working through the build, I encountered a bit of an issue. I didn't do all my homework, and I assumed the frameset needed a 27.2 seatpost. Through some diligent research after the fact, I found that the 1995 catalog, which shows the post was a 27.6x220 ITM Eclypse made of Ti.

I also checked on shims, and it seems that Problem Solvers used to make a shim for 25.4-27.6, but that has since been discontinued.

What are the chances that someone has one laying around? Probably not good, but my fingers are crossed..

Neither USE or PS have a 27.6-27.2 shim. Thompson doesn't make a 27.6 SP either, doubt anybody does. I'd try to find a machine shop that can make you one. A shim, that is.

[jds108]

You can always just make a shim yourself. You're looking for material that's 0.2mm in thickness. The sheet metal used to make home heater/air conditioning ducts is pretty much spot on.

I know this because I have a purple anodized seatpost that I wanted to use in a specific frame. For me it is/was a 27.2 frame and a 26.8 post. I did that years ago and it's been fine ever since. Just use some anti-slip compound between the shim and frame then use grease between the shim and post. That way the shim won't slip down into the frame after you've put it in place.

It takes a bit of time to get the this all put in place in the frame just right but once it's in there obviously you're done. I wouldn't do this (homemade shim) if I was going to be moving the post up and down all the time.

[zmudshark]

Blade type spark plug feeler gauges make perfect shims.

[hollowgram5]

Tin can shim is a last resort..

It's a lug based clamp, and it confused the hell out of me when the post I tried to put in wiggled all over. Knew better than to clamp the bolt down as tight as possible. I found a Kalloy post in Australia that is the right size, and the 25.4-27.6 shims in the Netherlands that say they are in stock. Gonna try to get my hands on a shim and see if I can have a machinist friend cut the ID down to work with either 26.8 or 27.2...

[Mark McM]

USE (a component maker in the UK) makes 25.0 - 27.6 shims. I don't know about their availability from US retailers, but they can be ordered from several UK retailers.

There may also be some low-end 27.6 seatposts available, like this one:

http://www.nycbikes.com/item.php?item_id=588

[hollowgram5]

You can always just make a shim yourself. You're looking for material that's 0.2mm in thickness. The sheet metal used to make home heater/air conditioning ducts is pretty much spot on.
.....

I feel much better about this than using a pop can. Thanks for the suggestion, I'll keep it in mind if I can't get my hands on the other production shims to turn down..

[bicycletricycle]

actual shim stock in specific thicknesses is available here.

http://www.mcmaster.com/#standard-shims/=xr0ei4