# My Titanium seatpost



## JoeandEaston (May 3, 2004)

I've been playing with this for a while. Finally got the first prototype finished. I used an old Litespeed seat post and pulled out the old aluminum seat clamp. I replaced it with something similar to a Thomson head.


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## zipzit (Aug 3, 2005)

J&E,
How did you join the two parts?  Locktite adhesive of some sort? Silver solder? Tight ID/OD interference fit and a press or big hammer? 
--Zip


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## JoeandEaston (May 3, 2004)

J B weld. It's never failed me when properly used. I didn't want to heat the ti unless I welded a ti head on it.


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## buildyourown (Dec 1, 2004)

We used to make them just like that.
Green Loc-tite and a .002 press fit.


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## dRjOn (Feb 18, 2004)

That *is* a thomson head ?

how did you decide on length of insert? 

intersting!....


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## JoeandEaston (May 3, 2004)

It was inspired by my cracked Thomson post. Length was guessed at. I had machined it shorter, then after some thought, decided to make it to the length you see. Small flats were added with a file to allow JB to do it's thing.


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## pvd (Jan 4, 2006)

I prefer Loctite 680.

https://tds.us.henkel.com//NA/UT/HNAUTTDS.nsf/web/461C42048B60E62C882571870000D86B/$File/680-EN.pdf


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## Schmitty (Sep 7, 2008)

Do you know how to weld Ti? If so, just copy the Torque titanium design, and lose the Al and glue.

-Schmitty-


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## JoeandEaston (May 3, 2004)

I do a little ti welding at work, but it's industrial stuff that sees no load. I've done a little reading and research on ti welding and I don't have all of the equipment needed to experiment with it. It would be easy enough to substitute titanium into the manufacturing process instead of the Al, so ti is the goal when I get the time. Ti bar stock is very expensive even from titanium joe, so I'll have to wait until the wife gets a job! I do have a piece of palladium stabilized titanium that I can do a prototype with...


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## forwardcomponents (Dec 2, 2008)

JoeandEaston said:


> J B weld. It's never failed me when properly used. I didn't want to heat the ti unless I welded a ti head on it.


I did something similar with and old Syncros seatpost head. I had the stem of the head turned down for a 0.001" interference press fit. I would trust an interference fit more than I would trust an adhesive.


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## Schmitty (Sep 7, 2008)

Damn, get that wife workin' so you can start making some all Ti posts!

I think the Torque design wouldn't need any bar stock fwiw.

-Schmitty-


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## JoeandEaston (May 3, 2004)

I want to make them one piece like the Al part. From the looks of the Torque post, the ears are welded on.


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## DavidR1 (Jul 7, 2008)

What is the advantage of this setup over the stock Thomson setup? I can only imagine the cost will be considerably higher, with a slight increase in weight. Will the slightly stronger clamp be worth it?


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## Schmitty (Sep 7, 2008)

JoeandEaston said:


> I want to make them one piece like the Al part. From the looks of the Torque post, the ears are welded on.


The ears for the bolts? Yeah, welded on. No head breakage like can sometimes happen with the Thomson/Synchros head style. They get cracks running vertically where the bolts go through. Light, simple, nothing to crack, come loose, etc. Pressed on Al heads can also tend to crack in line with the shaft (Synchros).

Cool project!

-Schmitty-


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## jay_ntwr (Feb 15, 2008)

DavidR1 said:


> What is the advantage of this setup over the stock Thomson setup?


Ti rides way nicer than aluminum, or at least I can feel the difference.

Dude, nice project. I really like that a lot. Looks great and I'm sure it'll ride really nice too. Makes me wish I didn't have two Moots posts already.


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## JoeandEaston (May 3, 2004)

jay_ntwr said:


> Ti rides way nicer than aluminum, or at least I can feel the difference.
> 
> Dude, nice project. I really like that a lot. Looks great and I'm sure it'll ride really nice too. Makes me wish I didn't have two Moots posts already.


That's why I started the project. I like the Thomson posts, I love the machine work on them, but they ride a little rough on a hard tail for me. I had this old Litespeed post that had an aluminum head that IMO is clunky, heavy and creaks.










So I set out to copy the Thomson design that I like and insert it into the old Litespeed ti tube. I did some reading about the Torque post and ti tubing from Titanium Joe and wanted to do ti, but that costs money. I have the Thomson seat clamps and bolts. I can get small pieces of aluminum and I run a horizontal machining center at work. So, put all that together and I have a ti post with a Thomson replica head that I made and like.

Oh, it really all started with wanting a ti Erikson sweetpost. Really nice post and the colors will match my King parts, but they are expensive. Worth the money, but expensive.


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## Schmitty (Sep 7, 2008)

An IRD style would work too. Drill the post for the solid rod that will hold the two bolts, machine a craddle, and miter the end of the tube. Light and easy.

-Schmitty-


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## JoeandEaston (May 3, 2004)

I never liked that style, though I have made some prints to do it in case I change my mind.


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## forwardcomponents (Dec 2, 2008)

*Just so nobody gets accused of stealing an idea.*

Here is something very similar currently in development. The post in the picture is made from 4130 chromium-molybdenum. A 3AL/2.5V version is also planned. The bolt mounting brackets will be welded on, in a manner similar to the Torque Titanium seatpost.

The head tapers up from the main 27.2mm OD shaft(hard to see in this photo), similar to the Torque Titanium seatpost. The tubing walls are 0.036" thick.


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## JoeandEaston (May 3, 2004)

I thought about cro mo too, but did not know where to get tubing. Ti Joe made the choice of ti easy. Now that I have the head worked out I need to get some tubing. I'm thinking of 3/8" ti bar stock for the top clamps. Not sure what to do about the bottom clamp. Ti tubing or Al. Thomson clamps work and are available so I may stick with them for the first few for friends. There is also ti Thomson bolts available.


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## forwardcomponents (Dec 2, 2008)

JoeandEaston said:


> I thought about cro mo too, but did not know where to get tubing. Ti Joe made the choice of ti easy. Now that I have the head worked out I need to get some tubing. I'm thinking of 3/8" ti bar stock for the top clamps. Not sure what to do about the bottom clamp. Ti tubing or Al. Thomson clamps work and are available so I may stick with them for the first few for friends. There is also ti Thomson bolts available.


Black Sheep sells a titanium seatpost with "Thomson style" hardware that is virtually identical to Thomson, but without the logos.

http://www.blacksheepbikes.com/.

It's another variation on the Torque Titanium concept of welded on bolt mounts rather than a pressed in aluminum head. Litespeed made a similar seatpost years ago.

http://www.bikepro.com/products/seatposts/litespd.html

I am surprised that more versions of this basic seatpost design are not available from other manufacturers.


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## JoeandEaston (May 3, 2004)

All good variations of the basic design. BTW, I'm not sure who to give credit to for the original. I am partial to nice machine work like the Thomson, so that's why I went with my copy. The Black Sheep standard post does look nice and simple though.


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## Thylacine (Feb 29, 2004)

forwardcomponents said:


> I am surprised that more versions of this basic seatpost design are not available from other manufacturers.


Because Thomsons only cost 50 bucks and nobody ever asks for anything else?


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## JoeandEaston (May 3, 2004)

Thylacine said:


> Because Thomsons only cost 50 bucks and nobody ever asks for anything else?


But as someone already said, if you use that logic, no one would want to buy one of the many great custom bike frames from one of y'all. The best I can do right now is a measly seat post. Some of the readers here know to build awesome custom frames. Yes, Thomson's are great post's that some of you can get pretty cheap, but they do ride a little rough.


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## Schmitty (Sep 7, 2008)

JoeandEaston said:


> But as someone already said, if you use that logic, no one would want to buy one of the many great custom bike frames from one of y'all. The best I can do right now is a measly seat post. Some of the readers here know to build awesome custom frames. Yes, Thomson's are great post's that some of you can get pretty cheap, but they do ride a little rough.


I agree, they ride like s**t compared to Ti, esp the larger sizes.

-Schmitty-


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## JoeandEaston (May 3, 2004)

:blush: I'd better go ahead and admit it now. My JB weld epoxy did not hold up. I've been testing it pretty hard as often as I can. I started checking it by grabbing the seat and rocking it front to rear. I could feel a slight "knock" in it. I thought (hoped) it would be the seat, but after swapping to another, it still did it. So I twisted it and sure enough, it moved. I removed it and tried again with more JB more liberally applied and I also filed the flats a little deeper to allow more JB to get in. I hope this will do the trick, but if anyone has a better idea for an epoxy for aluminum in titanium I am open to all ideas. As far a using a press fit, my thought was that it would creak eventually.


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## Schmitty (Sep 7, 2008)

I used to think JBW was the goods as well, but not so much anymore.

3M is your friend. DP-420 is a good place to start.


-Schmitty-

ps I find that taking a heat gun to uncured JBW after the parts are fit really helps to get a good bond.


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## forwardcomponents (Dec 2, 2008)

JoeandEaston said:


> :blush: I'd better go ahead and admit it now. My JB weld epoxy did not hold up. I've been testing it pretty hard as often as I can. I started checking it by grabbing the seat and rocking it front to rear. I could feel a slight "knock" in it. I thought (hoped) it would be the seat, but after swapping to another, it still did it. So I twisted it and sure enough, it moved. I removed it and tried again with more JB more liberally applied and I also filed the flats a little deeper to allow more JB to get in. I hope this will do the trick, but if anyone has a better idea for an epoxy for aluminum in titanium I am open to all ideas. As far a using a press fit, my thought was that it would creak eventually.


A press fit will not creak.


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## JoeandEaston (May 3, 2004)

forwardcomponents said:


> A press fit will not creak.


I'll be making more when I get the ti tubing in and get a hands on measurement of the ID. I'll give the press fit a try and the DP420 a try as well. I have a few friends that want one, so they will be my testers.


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## Schmitty (Sep 7, 2008)

JoeandEaston said:


> I'll be making more when I get the ti tubing in and get a hands on measurement of the ID. I'll give the press fit a try and the DP420 a try as well. I have a few friends that want one, so they will be my testers.


dp420 has a gap requirement... follow the diections.

http://multimedia.3m.com/mws/mediawebserver?66666UuZjcFSLXTtnxf258s6EVuQEcuZgVs6EVs6E666666--

-Schmitty-


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## JoeandEaston (May 3, 2004)

I received the ti tubing in from Titanium Joe. The only problem is that is is over size. I thought it would be the correct size that 27.2 seat posts were made from without any additional finishing. Wrong. The tubing measures 1.072" to 1.0735". All of my 27.2 seat posts measure 1.068". I Tried it in my Misfit frame and it would not go in more than one inch! This may be normal but I don't think so. Could this be seconds? Is this what all the other guys that make seat posts are dealing with?


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## Thylacine (Feb 29, 2004)

Got Lathe?


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## JoeandEaston (May 3, 2004)

I got lathe and a little skill, but shouldn't it be the right size?


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## Schmitty (Sep 7, 2008)

JoeandEaston said:


> I received the ti tubing in from Titanium Joe. The only problem is that is is over size. I thought it would be the correct size that 27.2 seat posts were made from without any additional finishing. Wrong. The tubing measures 1.072" to 1.0735". All of my 27.2 seat posts measure 1.068". I Tried it in my Misfit frame and it would not go in more than one inch! This may be normal but I don't think so. Could this be seconds? Is this what all the other guys that make seat posts are dealing with?


Torque said they used ground tubing. It's my understanding that drawn stock will never nail a given od consistantly. That's all I got.

-Schmitty-


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## JoeandEaston (May 3, 2004)

Well no wonder ti posts are so expensive. The old Litespeed post that I used did not look ground and it is to size. It's a little out of round like the ti joe tubing too. I'm gonna try to get some quotes and tolerances from some other vendors.


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## forwardcomponents (Dec 2, 2008)

JoeandEaston said:


> Well no wonder ti posts are so expensive. The old Litespeed post that I used did not look ground and it is to size. It's a little out of round like the ti joe tubing too. I'm gonna try to get some quotes and tolerances from some other vendors.


Where was the tubing drawn? Are there any mill stamps on it indicating grade and condition?


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## Schmitty (Sep 7, 2008)

I'd be leary about trying to keep that kind of tolerance over the length of a seatpost on a lathe. Maybe if you have a fancy new ltahe and are adept at using it.. at best it would take quite a bit of time, and getting a good surface finish without blowing your od would be tricky.

-Schmitty-


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## Yogii (Jun 5, 2008)

Does titanium shrink when frozen?


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