Downtubes

[downhill_rob2@hotmail.com]

Hi, since that other T-mag frame dent thread was started.... iv been thinking, why dont the make the downtube on the bike like this:

(image is of a down tube chopped in half)

Instead of making it totally round, so then the bottom of the frame will take the magoritary of beating cause its thicker!

But they make the frame thn all the way round... why?

Maybe to do with lightness?

But surly it wouldnt weight that much heavier with a slightly thicker bottom??

Whats your theory?

[Krisboats]

i just reckon they must find that the trade off for weight isn't worth it.

i mean, you'll still dent it if it's thicker because of the giant whole in the middle of the tube. but if you make it heavier the lighter riders will find it harder to ride and they won't dent it but the heavier riders will still be able to dent it. :huh:

i bet they just think it'd be easier to let the heavy riders use an armourdillo and keep it light for the light riders.

learn how to weld and then start your own buisness. that way you can try it see what it's like. :lol:

[downhill_rob2@hotmail.com]

learn how to weld and then start your own buisness. that way you can try it see what it's like.  :huh:

←

Good point :lol:

I thnk that the T-rex frames MIGHT be made like this.... my mate has rammed his into skips and all sorts and still isnt dented!!!! lol

[AdamR28]

We suggested this to Onza a while back.

The problem with an offset bore, is that there are NO off-the-shelf tubes like this - so production costs for a totally custom tube (requiring new machinery to be made to manufacture it!) would be astronomical.

Adam

[downhill_rob2@hotmail.com]

Ohhhh, so its a good idea then? :lol: :lol:

But you would have to sell the frames for alot more to pay for the costs of the machinary to make the tubes :huh: :lol: :lol:

Could just get the tube and weld in some steel rods.....

Il make anothe or my fantastic pics for you to show what im on about....

I know its very far fetched and would cost a bomb to do, but it would work a treat!

Edited August 30, 2005 by terror-error

[Michael Hardman]

What about the vunerable ares you put a honeycomb section inside the tubing only prob i see is it is expensive and will trnasfer stress to other areas.

[Dr. Nick Riviera]

good idea , what about the pressurised downtube?

[Brian Bleech]

using a different shaped downtube (teardrop shape) also help to prevent denting - like the planet x zebdi downtube, that was pretty resistant (Y)

mike

[AdamR28]

good idea , what about the pressurised downtube?

←

Yup, that works too.

[Waynio]

that picture which looks like it has bearings in is how onza's come anyway :o has anyone picked a t-rex up????? and shook it all about???? most of the range but the t-rax tends to have loads in (N)

Waynio.......................

its like adam says tooling costs are the problem and its only trials bikes that would use this style/type of tube.

its not as if the downtubes are that weak???? if you look at where trials bikes break it is mostly on the back end (Y) :P where all the torque and the flex goes through it.

[1handedluke]

The T-Mag 05 Downtube is like:

Surely Because of that shape its going to be weaker at the bottom? Compared to a normal circle?

[Pork Pie]

What about the vunerable ares you put a honeycomb section inside the tubing only prob i see is it is expensive and will trnasfer stress to other areas.

←

Doubt that'd be out of the question as the technology's already there. It's been done on some frames. Orange Zeros being one of 'em I think.

[Mr Motivator]

Could just buy a Samourdillo;

;)