Custom Ti frame & seat post clamp

[simonn]

I am thinking of getting a custom Ti frame and have been in contact with XACD. The first draught drawing is below (click for a bigger one) - lots of things need changing, so this is no where near finished.

I want to have a horizontal top tube. I like the look of it and it gives me more space for bottles and pump. However, if you look at the drawing below there is only 16.2mm of seat tube on the front and 36.3mm on the rear.

Never having thought about this before, would this be enough for a normal seat post clamp to function as it should?

[brentono]

I am interested to see how it goes for you. From my research it seems an inexpensive way
to get a Ti Frame. Are you going Ti forks as well?
It is only out of interest, as I have no intention of getting one, as cycling is a done deal for me.
(a pleasant ride for meditation, is all I wish to muster)
Will watch with interest, sorry I can't be of assistance.

[brentono]

edit: sorry double post, weird

[Uncle Grumpy]

Taking a look at the "depth" of some seat post clamps would answer that.

I don't have one on my desk, but I have a ruler and I can see that 16.2mm isn't really a lot, and I'm nearly certain that the seatpost clamps I have would run "deeper" or "taller" than that. I'm sure you can get "shorter" ones but whether they're 16.2mm or less, I don't know.

Is the frame builder cutting a slot or are they welding on tabs for a binder bolt?

Grumps

[simonn]

Are you going Ti forks as well?

No, carbon.

Taking a look at the "depth" of some seat post clamps would answer that.

Just measured the one on my current bike. 10mm of which 1-2mm is above the seat post. The slot is on the rear though which is 36 mm. I do not really want a binder bolt - I like replaceable parts.

[Uncle Grumpy]

10mm is a pretty thin clamp. Bloody weight weenie!

If you can get one that fits then you'll be fine. For some reason 16mm looked pretty tiny on the ruler, but again not having a clamp to measure makes it hard to judge for sure.

Grumps

[simonn]

10mm is a pretty thin clamp. Bloody weight weenie!

Yeah, wallet weight . I just bought the cheapest when I got my last frame... and only because the clamp from my previous frame (also ~10mm) has too large a diameter!

[Crawf]

PM sent.
16.2mm is too small, I'd be thinking closer to 25mm, but I guess it depends on clamp width. Aesthetically you won't notice a difference.

[brentono]

Are you going Ti forks as well?

No, carbon.

As I would have thought, but just thought I'd ask.
Hope it all goes well.

[janus77]

I'm keen to hear how this frame goes when you get it

[ZepinAtor]

Nice looking design in the seat stay area with the subtle curves towards the BB. Are you going with the coupled joins for transportation reasons & if so are you going the whole hog with cable splitters ?

As for the seat clamp all the frames I currently own which vary from Ti, Aluminium, Scandium & carbon all have between 25-40mm of tube protruding above the top tube. Most of the seat clamps such as Salsa, Santacruz & Niner are about 15mm in their profile so 16mm wouldn't be enough as you have to allow 3-4mm for a weld of some description between the seat & top tube. Personally I'd like to see a minimum of 20mm, but preferably 25mm.