Cold setting a Ti frame
 

Anything special I need to know? The frame belongs to someone that wants me to fit an IGH with 132 OLD, and the dropouts are currently at 137.
No name frame, probably Chinese, I don't know the source.
I've cold set many steel frames, so basically, what I need to know is working with ti any different?

I haven't tried it, but, I read something about the reason Litespeed dropouts are so perfectly positioned, is they are too difficult to move once the frame is finished.
It looks to me that both of my Litsepeeds have tubing so thin, that it would dent easily when trying that. I can flex the tubing in some places a little by squeezing as hard as I can with my hand.

I've never seen it recommended to cold set Ti, it just doesn't have the same properties that steel has that allow it to work. Google it, there is more info out there.

I'm no expert on this, but from what I have seen you have a good chance of cracking the frame. Like shoota implied, Ti takes a lot of overload to get a significant amount of deformation. Totally different from steel.

I'm thinking is that 5mm of extra thread on the left end can get a (3mm?) spacer, added,
to increase the hub width , rather than bugger with the frame
the extra mm on each end EZ wheel removal gravy..

I have 2 IGH, (BSR & a Sram i9) I used the extra outside axle widrh, for a Chariot trailer hitch ..

under the nut, to tow my folding Carry - Freedom - City trailer..



..

Yeah, one option is to put no turn washers inside facing out. Not enough axle length to just add spacers. I'm considering that as an option, but the client is still hemming and hawing between a couple of hub options,one of which would have enough axle to do as you suggest.
Meanwhile, I thought I would just check in here for some input from people in the know.

"It looks to me that both of my Litsepeeds have tubing so thin, that it would dent easily when trying that. I can flex the tubing in some places a little by squeezing as hard as I can with my hand. "
Must be the down tube, not the stays. The old Ultimate model had a really thin down tube and it could be flexed with our hands.

Or, ought to pull in , 2.5mm per side, owing to its material elasticity ?

2.5mm is a lot, I would try to space out the hub, as you originally suggested

its probably no big deal to cold set it. they do this on all frames one time or another during the build.

it's not likely that they do any cold setting during the build of a Ti bike. Modern steel doesn't like to be cold set either

from what i have heard pretty much all frames are cold set. except from carbon. this is why builders have flat tables!! to do the cold setting. this is also the most important piece in a bike frame factory.

i wouldn't worry too much to be honest. ti is very bendy. and will no fail just because you bent it minimally.

Ti is bendable for sure. It takes a good bit of deflection to reach the yield point.

Here is an older thread that's worth reading...https://www.bikeforums.net/bicycle-m...-titanium.html

what is this, the bad advice thread?

Yes. Also the dent your seat tube with a long 2x4 thread.

:thumb:

Hey Guys, Lon from Nova here. I've lurked but never commented. The subject of bending Ti among the framebuilders we've worked with has been around for now about 2.5 decades.
To answer the question of whether or not a rear end can be straightened/widened/narrowed, I would ask a simple question: How many Ti bikes have you seen with S-bend chainstays and seatstays ?
How do you think they got that way? The obvious answer is they were formed over dies, just like steel ones are formed. The difference (as already pointed out) is that Grade 9 Ti in CWSR takes a lot of force before it yields.

I've personally taken 4-5 degrees of headtube twist out of a Grade 9 MTB frame. I would not wish it on my worst enemy. I have a large free standing (Blanchard ground 5/8" steel plate) straightening table and solid hardened 1 1/8" shafting rods (each one 5 feet long). It can be done, but it ain't easy.
To the point- Grade 9 3/2.5 Ti is available from most suppliers in 3 hardness conditions: CWSR (Cold worked stress relieved), Annealed and half annealed. Most builders now require the use of annealed material for their rear triangles so the tubes can be manipulated and formed. For main tubes that are built straight (without bends), CWSR is stronger since the stress relief process only is enough to (barely) get the excess stresses from cold working (drawing the tubes by tensile or pilgering)- more of the cold work is left stored in the tube.

Full annealed material is material that has been drawn to wall and o.d. spec and is heated to a specific temp and allowed to soak for several hours and then slowly cooled. This realigns the grain structure to be orderly and fine by dis- assembling the bonds in the lattice and allowing them to reform without stored stresses- (i.e it is now "soft") The same as in steel or aluminum in terms of process, except it must be done in a vacuum. We've used High tech heat treated in the Bay area to anneal Grade 9 in the past, and it has been fine.

So in summary, if the rear end has been shaped, most likely it was done with annealed material and can be straightened/widened/narrowed.
However, without the right tools it could be too much of a PITA ( A Pain where a pill won't reach- as my mother in law says about me:notamused:)

Best Lon/NOVA

Hi there, similar to Lon not much of a commentor but have peeked in to read threads on Ti bikes now and then. Hi Lon...
I worked at Moots for 21 years and before that was a founder of Co-Motion Cycles back in the 80's. Lon has summed things up really well about moving the frame, if you have the right tubes and have done steel it will probably be fine, but I wanted to add a little from my experience and the way we did things at Moots, and they still do.

As Lon pointed out there are generally 2 conditions you can buy grade 9 seamless tubing, Cold Worked Stress Relieved (CWSR) and fully annealed where CWSR has a 30% higher strength with less elongation. I was fortunate to have sourced the material for Moots for 20 years and I got to visit Sandvik, Teledyn Wah Chang (Albany, Oregon input source producer for Sandvik) and a titanium bike factory in Taiwan that anneals, butts and tapers and sells Chinese produced tubing. I have worked with Russia materials as well. Over 20 years there were many ups and downs with titanium tubing supply.

What Lon says about annealed tubes for the rear ends of most builders is probably true, but I did want people to know that at Moots we used CWSR on the rear triangles on all the bikes. We designed and made our own tooling in order to form these tubes into the shape we wanted so that we could use the strongest and lightest weight material possible. If CWSR grade 9 seamless tubing is produced correctly and the tooling is correct it can be bent, swaged and formed quite nicely. The only CWSR tubing I have worked with that holds that standard is tubing that comes from one of the two US tubing mills, Sandvik Special Metals and Haynes International. Both meet and always exceed aerospace standards for elongation, tensile and yield strength. In order to hit the CWSR spec they have to have very tightly controlled input material and very temperature precise vacuum heat treatment ovens to hit the mechanical properties we need to bend

In regards to cold setting the frame in question Lon is dead right, just depends what it is made out of. The most important thing is the diameter to wall ratio. In my experience at Moots, with about 18,000 frames made while I was there, the only chainstays that buckled on the alignment table were some RSL chainstays where the tubing is both larger in diameter and thinner walled (really thin) than any frames that are mass produced. The "beer can" effect is much more of a thing with the larger diameter tubes, as people mentioned with squeezing toptubes and downtubes. From my experience there is a limit to how lightweight a Ti frame can be and last. I know some companies have gone past that limit and then had about a 12% failure rate on a road bike.

Butch