Ibis ti Mojo - drivetrain upgrade?

[Elev12k]

Hi,

Jeroen from the Netherlands had a Bonty Ti repaired with Daryl Crisp in Italy. The Ti had a crack in the seat tube, probably because of no sufficent post in the tube.

If you would like to get in touch with Jeroen and learn of his experiences, PM me and I send you his details.

 

[Elev12k]

Oh I am sorry, it is Darren Crisp, not Daryl. Here his website =>

http://www.crisptitanium.com/bye.htm

Jeroen had also had a frame made with Darren. The site shows some pics.

 

[sylvain]

Cheers guys, I will think about a repair.

Nice site Darren has.

 

[24pouces]

In french : "Putain !" :shock:
A lot of titanium frames have an aluminum tube in the seat tube. Is the weld near the end of this tube ?

Do you have a look in the tube : perhaps, the crack is only outhere, not in the tube.
In France, you have CMT (raymond cycles) who can repair titanium bikes…

(in french (excuse-me, my english isn't technic enough)) : y'a souvent un tube de renfort alu à l'intérieur du tube de selle ti. Est-il assez long, ou s'arrête-t'il au niveau de la soudure. Ce qui expliquerait le mauvais effort et la casse. Peut-être qu'en le rallongeant…
Vérifie tout de même si la fêlure a traversé les tube avec une lampe : s'il s'agit de 2 tubes titanes insérés l'un dans l'autre et soudés ensembles, la fêlure ne devrait pas être si grave (toute proportions gardées, bien-sûr). Normalement, on ne soude jamais 2 tubes bout à bout : (il faut biseauter les extrêmités pour les remplir à la soudure. Je vois qu'ils ont usiné la soudure, ce qui enlève de la matière et fragilise le raccord). Vu le sérieux d'Ibis, je doute qu'ils aient fait cette connerie…)

 

[messiah]

That is such a shame, but absolutely worth fixing... finding someone you trust enough to do the job will probably be the hardest part.

 

[Anthony]

This might be a way forward (not used them but others who have done seem to speak highly of them)
http://www.vernonbarkercycles.co.uk/oth ... rvices.htm

 

[scant]

(ps: no scant I didn't cry. I'm pretty darn upset though ...)

f'kin ell i would! :evil: :shock: gutted for you mate! I remeber you mailing me when you first found it for sale & you were made up. I've heard ti can be fairly cleanly re-welded so I'd look into it. wendly told me they repaired my old fat chance ti & that had a pretty massive crack

(2 frames broken in the last 3yrs, so I appreciate the heartache/annoyance :roll: )

 

[one-eyed_jim]

(in french (excuse-me, my english isn't technic enough)) : y'a souvent un tube de renfort alu à l'intérieur du tube de selle ti. Est-il assez long, ou s'arrête-t'il au niveau de la soudure. Ce qui expliquerait le mauvais effort et la casse. Peut-être qu'en le rallongeant…
Vérifie tout de même si la fêlure a traversé les tube avec une lampe : s'il s'agit de 2 tubes titanes insérés l'un dans l'autre et soudés ensembles, la fêlure ne devrait pas être si grave (toute proportions gardées, bien-sûr). Normalement, on ne soude jamais 2 tubes bout à bout : (il faut biseauter les extrêmités pour les remplir à la soudure. Je vois qu'ils ont usiné la soudure, ce qui enlève de la matière et fragilise le raccord). Vu le sérieux d'Ibis, je doute qu'ils aient fait cette connerie…)

Trans:

There's often an aluminium reinforcing sleeve inside the Ti seat tube. Is it long enough, or does it stop level with the weld? That would explain the breakage. Maybe if it could be lengthened...

In any case, check with a lamp to see whether the crack has penetrated through the tube. If it's two titanium tubes inserted one inside the other and welded together the crack might not be such a big deal (comparatively speaking, of course). Normally you don't butt-weld 2 tubes end to end (you have to bevel the ends. I see they've machined the weld, which removes material and weakens the joint). As Ibis aren't jokers I doubt they've made that blunder...)

 

[scant]

the alu insert in the seattube is used on ti frames as Ti isnt mega easy, or cheap! to accurately ream. its not going to do much if anything re strength.

occasionally a smaller tube is welded into the seattube to allow for a smaller diameter seatpost (original manitou, original fat chance titanium, american comp-lite & probs many others)

sylvain, could you post up some more pics from different angles? seems like an odd place to crack?

 

[sylvain]

Cheers all. I think I will email mr Nicol first try and see what he thinks, and if he has seen this issue before.

No, it is not an alloy collar, the top part of the tube (above the weld) is only ti, the weld seems to be at the junction of that part which is thicker and the bottom part of the tube, which goes down to the BB, and is thinner.

There is no light poking with a torch, as the crack is really thin. From the inside, the difference between wall thicknesses is obvious - there is a straight-edged gap which you can feel with the finger, just as if it was two different tubes end to end.

24p says you don't weld ti tubes end to end, so there might be an overlap - but I am not sure. The crack might even only be on the weld itself, but not through the whole tube, if overlap there is.