Flex Hone

[campy man]

Any experience with a Flex Hone on a Ti frame to open the seat tube dia?

Installed a brand new Campy carbon fiber seat post and had a very difficult time getting in seat tube. Double checked the seat post dia with calipers and I measure 27.18. I always assumed frame seat tube diameters were slightly larger than 27.2. I’m concerned if I leave seat post inside for very long it will seize and nearly impossible to remove at a future date.

Hearing a Flex Hone can be used inside the seat tube to improve fit.

Any suggestions for a Flex Hone dia with a 27.2 seat tube dia?

[Kirk Pacenti]

Get a 1.125 (29mm) flex hone (http://www.walmart.com/ip/33944327?wmlspartner=wlpa&adid=22222222227022514766&wl0=&wl1=g&wl2=c&wl3=34979459221&wl4=&wl5=pla&wl6=63528576781&veh=sem).

Cheers,
KP

[jtakeda]

What frame out of curiosity?

I had the same issue and gave up on the post.

[David Kirk]

The I.D. of the seat tube ideally is 27.2 and this will allow a '27.2' post to slip in. This of course means that a post called '27.2' needs to be smaller than that and unfortunately there is no firm accepted standard of how big 27.2 post should be. Typically they are 27.15 and that allows for a nice fit. Some posts tend to run large (like campy) and some tend to run smaller.

I doubt you will have much luck making the seat tube ID larger with a flex hone......or at least in a timely fashion. They are meant to hone out of the inner surface and give it a consistent surface finish and not so much to remove material. If you have one or two high spots in the inside of the seat tube the hone might take those off but you could hone it for a very long time and have little to show for it aside from a very smooth and shiny surface on the inside of the seat tube.

To take any material off you will need a good sharp reamer..........or you can select a 27.2 post that runs a bit smaller and find one that fits very nicely.

I hope that helps -

dave

[Ken Robb]

will ti and carbon fiber tend to stick to each other? If not why worry unless you need to remove the post frquently?

[cmbicycles]

Some recent discussion and info on the question here...

http://forums.thepaceline.net/showthread.php?t=149579&highlight=reamer

and

http://forums.thepaceline.net/showthread.php?t=147713

I'm still working out my issue. Fixed the compressed tube, now just taking my time getting it smoothed out.

[93legendti]

Ti Campy posts do not fit well in Serotta ti frames, according to my experience...when I used Campy Chorus Ti posts in Serotta's, the fit was really tight and it took some force to get the post in and out, leaving the post scored (sic?). Easton posts fit nicely, which is what I usually used.

I just changed the 27.2 seatpost in my Concours. From an FSA carbon which was very tight, to a Uno carbon which went in just right.

[jtakeda]

What frame out of curiosity?

I had the same issue and gave up on the post.

[gemship]

possibly have the post turned in a lathe with a light skim pass/spring cut, just the part that will be in the frame. Of course this requires buddies and or access to a machine shop.

[11.4]

The I.D. of the seat tube ideally is 27.2 and this will allow a '27.2' post to slip in. This of course means that a post called '27.2' needs to be smaller than that and unfortunately there is no firm accepted standard of how big 27.2 post should be. Typically they are 27.15 and that allows for a nice fit. Some posts tend to run large (like campy) and some tend to run smaller.

I doubt you will have much luck making the seat tube ID larger with a flex hone......or at least in a timely fashion. They are meant to hone out of the inner surface and give it a consistent surface finish and not so much to remove material. If you have one or two high spots in the inside of the seat tube the hone might take those off but you could hone it for a very long time and have little to show for it aside from a very smooth and shiny surface on the inside of the seat tube.

To take any material off you will need a good sharp reamer..........or you can select a 27.2 post that runs a bit smaller and find one that fits very nicely.

I hope that helps -

dave

Dave nails this on several fronts. A flex hone is not the way to change inside diameter, even if you're only talking a few hundredths. And that's especially true in my experience with ti frames or frames with ti liners.

I wouldn't advocate turning down a seat post. You of course have a carbon fiber one, which absolutely rules that out. With a metal post, there's not a lot of wall thickness to work with and the end you want to chuck in the lathe vise is the end you want to be turning down.

I recently returned a frame twice to Moots because it wouldn't fit a Thomson post and, if anything, Thomsons were always traditionally undersized. Turned out that Moots takes the point of view that a 30.9 seat tube should be exactly that, and turned out that Thomson had grown tired of complaints about slipping posts so they adopted the same point of view. If you don't have a few thousandth's difference (in your favor), you won't get the post into the frame. Moots was very gracious and I ended up just getting a different post. I was pretty embarrassed that I had singled out Moots for what appeared to be a manufacturing flaw, when it was a problem shared with Thomson. A different post should preferably be your solution here. If you really want a particular brand of post, then do as Dave said, find a way to inspect a half dozen of that post with a vernier caliper in hand, and pick the one that hopefully will fit.

[gemship]

I have to agree that my suggestion to turn the post is a bad idea for so many reasons. It can be done but more trouble than it's worth. My next crude suggestion was to take some sandpaper to it or it to a beltsander however that's a bad idea too. Given the right conditions these crude ways can be very cheap. I bet honing the frame would work but if you spend the dough to do then it makes better sense to get the right size post and your not messing with your frame at all. :)

[pdmtong]

Dave nails this on several fronts. A flex hone is not the way to change inside diameter, even if you're only talking a few hundredths. And that's especially true in my experience with ti frames or frames with ti liners.

I wouldn't advocate turning down a seat post. You of course have a carbon fiber one, which absolutely rules that out. With a metal post, there's not a lot of wall thickness to work with and the end you want to chuck in the lathe vise is the end you want to be turning down.

I recently returned a frame twice to Moots because it wouldn't fit a Thomson post and, if anything, Thomsons were always traditionally undersized. Turned out that Moots takes the point of view that a 30.9 seat tube should be exactly that, and turned out that Thomson had grown tired of complaints about slipping posts so they adopted the same point of view. If you don't have a few thousandth's difference (in your favor), you won't get the post into the frame. Moots was very gracious and I ended up just getting a different post. I was pretty embarrassed that I had singled out Moots for what appeared to be a manufacturing flaw, when it was a problem shared with Thomson. A different post should preferably be your solution here. If you really want a particular brand of post, then do as Dave said, find a way to inspect a half dozen of that post with a vernier caliper in hand, and pick the one that hopefully will fit.

I tried a variety of carbon posts in my Moots CR and after wrestling with a number of them ended up doing what any sensible Moots owner should do in the first place...I bought a Moots post.

[campy man]

The frame is a Moots Vamoots.

I'm wondering if the collar on the seat tube is causing the issue?

The combination of Campy CF seat posts, Turbomatic saddles and a 73deg seat tube ... hits the sweetspot for me. Campy seatposts have a setback that when the saddle is adjusted correctly, the saddle is perfectly balanced on the seatpost and frame ... all looks good.

Other than the cost of a Moots Ti seatpost, I can't justify buying 2 Moots seat posts to determine if I need a straight or layback seat post.

The Campy seatpost is installed but I got a feeling if I don't remove soon it's going to be nearly impossible to remove in the future.

[pdmtong]

The Campy seatpost is installed but I got a feeling if I don't remove soon it's going to be nearly impossible to remove in the future.

the worst offender was a s-works carbon post I put in there so the shop could clamp to it for the build. we almost destroyed the donor saddle twisting that thing out of there.

The moots post was not cheap but, once I paid the visa bill I haven't looked back. I have the newer curved cinchpost...IMHO it really looks good on that bike especially since I have the integrated seat post clamp.

I too was pretty concerned of a stuck post. Even budging that s-works an inch was effort I don't want to repeat

[David Kirk]

I recently for a 27.2 post in and it measured 27.25 OD....so it was bigger than the hole it was designed to slide into.

Not good.

dave

[11.4]

the worst offender was a s-works carbon post I put in there so the shop could clamp to it for the build. we almost destroyed the donor saddle twisting that thing out of there.

The moots post was not cheap but, once I paid the visa bill I haven't looked back. I have the newer curved cinchpost...IMHO it really looks good on that bike especially since I have the integrated seat post clamp.

I too was pretty concerned of a stuck post. Even budging that s-works an inch was effort I don't want to repeat

Yeah. Moots gave me the option of reaming out the seat tube to fit the post of my choice, but in that case it would have been an unorthodox inner diameter that would never have fit anything else. They supplied me with a Moots seat post to try, and I ended up buying it. Great service, and great patience with an awkward problem being handled by remote. It's definitely a great seat post -- it won't fit certain saddle rail types, but it's superb for everything else. When I put a vernier caliper on the post, it was a bit undersized but just enough to make for a very secure fit.

[Kirk Pacenti]

Any experience with a Flex Hone on a Ti frame to open the seat tube dia?

Installed a brand new Campy carbon fiber seat post and had a very difficult time getting in seat tube. Double checked the seat post dia with calipers and I measure 27.18. I always assumed frame seat tube diameters were slightly larger than 27.2. I’m concerned if I leave seat post inside for very long it will seize and nearly impossible to remove at a future date.

Hearing a Flex Hone can be used inside the seat tube to improve fit.

Any suggestions for a Flex Hone dia with a 27.2 seat tube dia?

Fwiw, I wouldn't recommend a flex hone in a shop setting, as DK said, it would take way too long and there a far more efficient ways to get the job done in a frame / machine shop. But if you have an hour, you can get it done with a hone more safely than using a reamer and less expensively than sending the frame back to the manufacturer.

That said I have an adjustable reamer I would be willing to lend you, if you're comfortable doing it yourself.

Cheers,
KP

[soulspinner]

Fwiw, I wouldn't recommend a flex hone in a shop setting, as DK said, it would take way too long and there a far more efficient ways to get the job done in a frame / machine shop. But if you have an hour, you can get it done with a hone more safely than using a reamer and less expensively than sending the frame back to the manufacturer.

That said I have an adjustable reamer I would be willing to lend you, if you're comfortable doing it yourself.

Cheers,
KP

Hell man, ya cant ask for more than that!

[sandyrs]

The combination of Campy CF seat posts, Turbomatic saddles and a 73deg seat tube ... hits the sweetspot for me. Campy seatposts have a setback that when the saddle is adjusted correctly, the saddle is perfectly balanced on the seatpost and frame ... all looks good.

Other than the cost of a Moots Ti seatpost, I can't justify buying 2 Moots seat posts to determine if I need a straight or layback seat post.

I don't understand this last part. Just get the Moots post that has setback closer to the Campy post.

[oldpotatoe]

The frame is a Moots Vamoots.

I'm wondering if the collar on the seat tube is causing the issue?

The combination of Campy CF seat posts, Turbomatic saddles and a 73deg seat tube ... hits the sweetspot for me. Campy seatposts have a setback that when the saddle is adjusted correctly, the saddle is perfectly balanced on the seatpost and frame ... all looks good.

Other than the cost of a Moots Ti seatpost, I can't justify buying 2 Moots seat posts to determine if I need a straight or layback seat post.

The Campy seatpost is installed but I got a feeling if I don't remove soon it's going to be nearly impossible to remove in the future.

???Moots setback is how much different than the set back of the Campagnolo post?

Answer-both 25mm pretty sure.

[Kirk Pacenti]

Hell man, ya cant ask for more than that!

When I get my reamer back from cmg (http://forums.thepaceline.net/showthread.php?t=149579&highlight=Flex+hone), I can forward it on to anyone else who may need it.

Cheers,
KP