fillet seat post binder

[gregclimbs]

someone some time ago posted a link to a framebuilder who made an internal seatpost binder for a fillet brazed frame... ala thomson stem, but in the top tube...

can someone refresh my memory where that is?

g

[fiamme red]

I've seen pictures of lugged Strawberry frames with internal seatpost binders. There's one on the homepage: http://www.strawberrybicycle.com/. Is that what you mean?

[gregclimbs]

yup - thanks!

[mpetry]

Lots of vintage bikes were made like this, with a seatpost that had a "stem bolt" thru it and an internal expander. Be careful - if you do this on just any frame you stand a chance of bulging the seat tube out below the seat lug.

Bikes intended for the expander seatpost had an internal reinforcing collar in the seat tube. I'm not sure what problem it solved - maybe looked cool.

Mark Petry
Bainbridge Island, WA

[gregclimbs]

the strawberry is what I was looking for - I wanted to get a custom stem made that uses a binding system like the strawberry or thomson...

thx!

g

[fiamme red]

Lots of vintage bikes were made like this, with a seatpost that had a "stem bolt" thru it and an internal expander. Be careful - if you do this on just any frame you stand a chance of bulging the seat tube out below the seat lug.

Bikes intended for the expander seatpost had an internal reinforcing collar in the seat tube. I'm not sure what problem it solved - maybe looked cool.

Mark Petry
Bainbridge Island, WAI had that kind of seatpost on an aluminum Schwinn road bike.

The big problem is if you overtighten it and snap the bolt, you'll need a new seatpost, and they aren't easy to find.

[fiamme red]

The random image on the Strawberry home page has changed, so here's the photo I was referring to:

http://www.strawberrybicycle.com/gallery/view_photo.php?set_albumName=Homepage&id=Asphalt_Magazine_036_low_res_jpg

Another frame:

http://www.strawberrybicycle.com/gallery/view_photo.php?set_albumName=Homepage&id=Frame_no_57570307_low_res_012

[rockdude]

Here is another one from Mark Nobilette..

http://www.nobilettecycles.com/pics/curr4.jpg

[David Kirk]

Be sure you are using a stout metal seat post with this design. They work very well but since they don't wrap but apply pressure to one side of the post you can ruin a carbon post and some lightweight alloy ones.

dave

[derosa_guy]

Be even more careful if you are going to use this for a stem! You definitely don't want to clamp a carbon steerer with one of those.