Modern Ti HT frame (warning not actually made yet)

[Neil G]

Look good, TBH for the money does it really matter if the welds aren't perfect!

It matters because its very easy to contaminate titanium welds as the tubes have to be welded in and envioment that is devoid of oxigen (usually the area is floded with an inert gas, although some manufactures weld there frames in a seald air tight bow filled with gas). Titanium welding also demands greater attention to cleanliness and to the use of auxiliary inert gas shielding - if its done incorectly the weld is very brital and will sheare easily.

How did yo come up with measurements?

erm just a mixture of classic uk hardtails really. A bit of on one (head tube) cotic (toptube length) and pipdream (rear triangle).

To be honest i may still change a couple of things prior to ordering/manufacture, the head tube is quite short and its not as renforced as a On ONe Scadal which its baised, so i'm thinking of increasing to 115mm (the extra 10mm between top and down tubes, which will also aid in cable acess). This should aid front end stiffness and steering precision - it wont be as low or 'racey' but it'll also be a trail bike so thats good.

The top tube length is more the equivelent to a 17" or 17.5" frame, Pace and Cotic both use this dim. I'm aiming to use a 70/75mm stem so i'm hoping that this will work well - The top tube length is kinda the dark science bit so its more guess work than any thing else at the mo to be honest, again i dont want it to feel to racey.

Yes, I know about welding Ti

It's not going to be up there quality wise with say a Moots or Dekerf but your not paying £2000 plus for it anyway. That's kind of what I was getting at

 

[skinheadjc]

oh, ok sorry

when you buy a 2k+ ti frame you also pay for the builders geometry knowledge and experiance, which is what you dont get with Xacd.

You ask for a frame with some specifics and the send you a drawing to approve.

If your not proficient in reading CAD drawings its quite easy to end up with some thing you dont want. The first drawing i recived i'd asked for geo baised on a an ON One 456 (just to get an idea on price, tube sizes etc) so i sent a geometry sheet over. 24hrs later they sent back a drawing which looked geat - except that head angle was 69.5 degrees baised on a fork length of 425mm not 500mm like an average 130mm travel fork would be.

 

[Neil G]

Indeed, I imagine you have to be pretty thorough when it comes to checking drawings and getting across what you want. Still cool though having some control over the end product.

 

[SeeingisBelievingGTMuseum]

It matters because its very easy to contaminate titanium welds as the tubes have to be welded in and envioment that is devoid of oxigen (usually the area is floded with an inert gas, although some manufactures weld there frames in a seald air tight bow filled with gas). Titanium welding also demands greater attention to cleanliness and to the use of auxiliary inert gas shielding - if its done incorectly the weld is very brital and will sheare easily.

[

Then you should demand pictures of welds BEFORE the frame has been bead blasted or cleaned after welding. I have seen many broken Ti frames where the welds looked as your picture above, that failed due to oxygen embrittlement.

 

[cyfa2809]

oh didnt know that :shock:

 

[skinheadjc]

Xacd had quite a poor reputaion when it comes to forks produced pre 2004, which had a tendancy to snap (they were made for Sibex and Spicer).

There are various stories around why they snapped, from tube thicknesses to contaminated welds. I think it may be a bit of both, you can see in the picture above that both fork legs snapped at the bottom of the weld joint, so it is proberly a contaminated weld in this case. However there are other examples where they snapped further down on a single leg, so the tube thickness is more likely the cause.

I've not heard of a snapped Xacd frame (yet), only this design of fork which was a bit of a copy and doesnt seem to have any design work go into it.

 

[skinheadjc]

Looks like the ti project is going on hold for a while (well at least untill i sell my house).......

I just couldn't raise enough funds (selling two frames) and then justify the extra spend past the wife.

So i'm going to get a meium Singular Hummingbird which has almost exactly the same geometry as what i want - its right at the top of my revised budget (£380 without the fork suppied) but looks great.

 

[saltyman]

those forks are shocking, bet the unlucky rider got a fright!

 

[Neil G]

Those forks are really bad :shock:

 

[stevet1]

That cad drawing looks almost the same as the design I did for my Setavento a few years ago, took a while to persuade them thats what I wanted.

For info about a year ago the seat-stay/seat-tube weld developed a crack. Had it repaired and its still going strong now.