Bicycle Mechanics - Why hasn't anybody made...

...titanium shifter and brake cable?

...carbon-fiber zip-ties?

Was admiring a friend's custom titanium bike yesterday. He had just taken delivery. Only two hours old. Hadn't even been ridden. What an uber-nice rig. Titanium even in the axles, and the downtube cable adjuster knobs are also titanium.

I suddenly realized that perhaps there might be a market for titanium shifter and brake cable. Do you think? I mean, people buy titanium rotor bolts, so why not titanium wire?

And then it seemed a shame for him to be attaching his new computer sensor to a carbon-fiber fork using plastic zip-ties.

Carbon-fiber zip-ties are probably a bit extreme, but I'm actually a bit surprised now that no one makes titanium cable.

it would be difficult to measure the difference in weight savings on the zip ties...
maybe you can get some black plastic ones and scuff them up with a scotchbright pad and go into business!

it would be difficult to measure the difference in weight savings on the zip ties...


LOL! I don't think that stops some people. I mean, we see carbon bottle cages, and I just saw my first-ever carbon quick-release lever. Heck, Purely Custom even makes a carbon-fiber clipboard.

I'm actually liking the titanium shifter-cable idea.

they do make kevlar brake cables.

they do make kevlar brake cables.

Actual cable? I've seen kevlar housing, but not the cable itself.

My dentist, an avid cyclist said he has titanium fillings in his teeth, he did the calculations and figured out the weight savings was impressive,

He is currently working on carbon teeth replacements he will start first with his 2 front teeth and work back.

He also reminded the bodys water content and that alcohol is lighter then water....:lol:

Why hasn't anybody made...



...titanium shifter and brake cable?

...carbon-fiber zip-ties?....

Titanium inner cable would not improve power transfer or improve modulation over steel or stainless steel and even though they wouldn't rust, stainless steel is cheaper for the same benefit. Teflon lined housing and Teflon-impregnated stainless steel inner cables are probably as good as it is going to get.

Carbon fiber zip-ties might outlast pure nylon ones that tend to break due to drying out, but if they don't look like they are carbon fiber they probably wouldn't sell very well. Now nylon ones that still dry out and break easily but look like carbon fiber would probably sell like hotcakes....




Actual cable? I've seen kevlar housing, but not the cable itself.

Kevlar wrapped cable housing look cool but don't have any real performance benefit, and a kevlar inner wire would only be rigid when under tension.

My dentist, an avid cyclist said he has titanium fillings in his teeth, he did the calculations and figured out the weight savings was impressive,

LOL! That's good. You know, my own dentist rides some. I wonder whether I could keep a straight face long enough to ask him about replacing all my fillings w/titanium.

Who knows, the next big thing in weight-weenieism could be replacement body parts: carbon-fiber hips, titanium fillings, double-butted femurs, ...

Who knows, the next big thing in weight-weenieism could be replacement body parts: carbon-fiber hips, titanium fillings, double-butted femurs, ...
It's already started. My broken ankle was repaired with a Ti plate and screws years ago.

I think working Ti into cables may be a pricy operation plus it may be uber difficult to cut. Ever try and drill a Ti plate?

How can you have Ti filling? I thought filling material had to me malleable to push into the tooth and make a tight seal?

...a kevlar inner wire would only be rigid when under tension.

how's that different than a traditional cable?

1.6 m of 1.5mm brake cable weighs about 23 grams. In Ti it would weigh 13 grams.

It would be twice as flexible, about half as strong* and have poor abrasion resistance, whilst costing far more. It's also more notch sensitive than steel, so the likelihood of cables fraying / breaking at the pinch bolt would be higher.

Doesn't sound like a value proposition to me.

*Although 6Al4V is almost as strong as stainless steel wire, I don't think that's a valid comparison as I don't think it could be drawn into wire and more malleable alloys like 3Al2.5V are lower strength. Also "stainless" brake cables usually have a stainless sheath wrapped around a high tensile steel core and no Ti alloy approaches half the strength of the best steels.

Sometimes using Ti can be counterproductive. For example, your friends Ti cable adjusters. Since Ti is denser than aluminum Ti hardware with the same dimensions will be heavier than the aluminum parts it replaces. So any place where the same dimension parts would be used Ti doesn't make sense unless higher strength is the goal. (or cool factor).

Similar problem with cables, A Ti wire would need to be thicker than the steel wire it replaces. So while it might save weight it would need bigger housings. Plus thicker wire would have flexibility and metal fatigue problems, where it winds on the drum of the lever. Ti windings on the housings might be practical but it would an expensive way to save a few grams.

And there was someone selling kevlar inner wires a while back, but I don't know if they're still in business. There are a number of technical issues that IMO make it entirely unsuited for brake cable, among which is the reliability of the attachment of the head.

Uhhh, folks, I do think Jonathan was proposing all of these things with tongue firmly planted in cheek. At least i hope so. :)

Uhhh, folks, I do think Jonathan was proposing all of these things with tongue firmly planted in cheek. At least i hope so. :)

Yes, indeed. Tongue-in-cheek. Mostly.

OTOH, cycling is a bizarre world in which people do insane things to shave grams. It would not surprise me too awfully much to find that there might be some who would spend the money for carbon-fiber zip-ties. :eek:

And the idea of titanium wire did seem about as useful as titanium rotor bolts, and plenty of the latter get sold.

Mark, your information about strength and abrasion resistance is interesting. Thanks for posting up with that.

So the zip-tie thing, yeah, I was not real serious about that. The titanium wire, that I was curious about, whether anyone had ever thought of it or made it.

Sometimes using Ti can be counterproductive. For example, your friends Ti cable adjusters. Since Ti is denser than aluminum Ti hardware with the same dimensions will be heavier than the aluminum parts it replaces. So any place where the same dimension parts would be used Ti doesn't make sense unless higher strength is the goal. (or cool factor).

So that's interesting. Hadn't realized that about the density. We aren't 100% certain the adjuster is titanium. The frame is. The finish on the adjuster perfectly matches the frame. My friend and I are presuming it is the same material, but it may not be. Whichever the case, the result is a good-looking bit of hardware.

So that's interesting. Hadn't realized that about the density.

Here's a metal density chart (http://www.simetric.co.uk/si_metals.htm) for comparison. Note that titanium is almost double as dense as aluminum - 45 vs. 27. If you want to make fancy hardware, you want to replace aluminum alloy with magnesium hardware -- that assumes money is no object, because magnesium alloys are difficult to work with.

Actual cable? I've seen kevlar housing, but not the cable itself.

CLB offered aluminum housing back in the 70s; that would be even lighter than titanium.

It's already started. My broken ankle was repaired with a Ti plate and screws years ago.

That's because titanium is more bio-compatible than steel. Bone will bond better to titanium hardware, which lessens the chance of loosening and requiring revision surgery.

If you want to make fancy hardware, you want to replace aluminum alloy with magnesium hardware -- that assumes money is no object, because magnesium alloys are difficult to work with.
Mg is also corrosion prone, even more so than aluminum, and must be annodized or otherwise protected.

Concerning the adjusters Jonathan is describing, I assume the frame is a Litespeed. Both of mine do indeed have Ti adjuster barrels threaded into the Ti bosses welded to the headtube. As above, I assume aluminum was not used due to the corrosion issue.

Concerning the adjusters Jonathan is describing, I assume the frame is a Litespeed.

Actually, it's a Sisu: http://www.sisucycles.com/

Local builder. Have never met him, but I like his work.

Actually, it's a Sisu: http://www.sisucycles.com/

Local builder. Have never met him, but I like his work.
I looked up his site. Apparently the Ti frames are sourced outside and not built by him.

Never heard of it. I did a Google search, and the results seem to indicate Titanium Cable is used in Medical Implants , and maybe Robots. Still, I sent an email to a Swiss based company "Titanex", to ask if such a product exists.

I went to Navy Aviation School, and I never heard of Titanium cable. It would have to be available for Aviation use, before it would be used in Bicycles.

Mg is also corrosion prone, even more so than aluminum, and must be anodized or otherwise protected.




These are manageable problems. I'm not suggesting it, just trying to channel dumb ideas in a better direction.

I looked up his site. Apparently the Ti frames are sourced outside and not built by him.

Yes. He's up front about that. He does steel locally. TI and carbon are, I believe, done in Taiwan. Measurements and geometry are all custom though, or at least can be.

I will probably never have a custom frame. I'm "that guy" who likes to change things up every year. This year I am ripping components off from, probably, an Enduro in order to build an El Mariachi. I would not be able to settle down and ride just one frame long enough to make it worth having one custom built.

It might be fun someday to weld my own frame, but I am nowhere near having the tools and shop space and resources in which to do that.

I went to Navy Aviation School, and I never heard of Titanium cable. It would have to be available for Aviation use, before it would be used in Bicycles.

Why would that be?

There are probably numerous examples of where bicycle, and automotive racing applications have been at the leading edge of technical developments. Ultimately it all boils down to balancing weight, reliability and cost. Competitive racing on the ground generally allows a greater sacrifice of reliability to the other two than flying does.

Here is some TI wire: http://www.ti-shop.com/titanium-ti/ti-wire/ti-grade-2/0-80mm-dia-x-coil-ti-gr2-annealed-wire.html

One more link that mentions medical use: http://titanex.ch/tiproducts/titanium-fine-wire-titanium-cable.php

One more link that mentions medical use: http://titanex.ch/tiproducts/titanium-fine-wire-titanium-cable.php

That's structural or mechanical wire. It's either for medical, or welding uses. I'm sure they make mechanical titanium alloy (not pure titanium) wire, but not sure if anyone makes multi-strand Ti cables.

That's structural or mechanical wire. It's either for medical, or welding uses. I'm sure they make mechanical titanium alloy (not pure titanium) wire, but not sure if anyone makes multi-strand Ti cables.

Ah. Ok. You can probably tell that my knowledge in this area is pretty thin.

I've learned a few things from this crazy thread.

Titanium in medicine and dentistry is used these days a lot because bone likes it and will grow to the metal and over time have a much better bond and result in stronger repairs than if simple steel is used.

Cables? For some specialty things maybe. But as noted Ti has more notch sensitivity. Also Ti is not as fatigue resistant as good ol' stainless steel.

Carbon fiber exposed to sun has a life span as well. Not to mention that bare carbon layups get hot as hades in the sun. I don't have a carbon bike but I did windsurf for quite a few years. I made it a point not to leave my unpainted carbon masts out in the sun for longer than I had to. If they sat there for long at all they'd get too hot to handle comfortably. And that ain't good for the epoxy that holds the carbon matrix together. I can only assume that the clear coat used on raw carbon frames has some sort of UV block in it to aid in avoiding this same heat buildup.

Anyhow, I don't know about carbon zip ties but you CAN get carbon cording. Use that instead of the zip ties and just learn to do nice looking knots. Or bind the cables to the frame using a single long running knot like they used to do with wire harnesses in high end and military electronics equipment.... :D

Titanium in medicine and dentistry is used these days a lot because bone likes it and will grow to the metal and over time have a much better bond and result in stronger repairs than if simple steel is used.

Cables? For some specialty things maybe. But as noted Ti has more notch sensitivity. Also Ti is not as fatigue resistant as good ol' stainless steel.
Yes, Ti is compatible with bone and does make a better medical implant but it also has the very important property on not being subject to "chloride stress cracking". Early stainless steel implants were usually 304 stainless steel which is chloride sensitive and they often failed after some time due to cracking from the chloride in body fluids.

Plain, unalloyed Ti (CP grade) is indeed not extremely fatigue resistant as the failure of early Ti bike frames nicely demonstrated. Current 3/2.5 Al/V alloy Ti is extremely fatigue resistant ans is right up there with suitable steels.

I don't want to lead the thread in the direction of Ti as bone truss material, but I have a Ti rod and screws running from my right hip to just above my knee (bad femur break). The x-ray picture of the fix is so beautiful that I was moved to comment to my ortho surgeon that it looked like an exquisite piece of architectural/structural work, whereupon my surgeon told me he was an engineering school graduate before going to medical school.

The really weird thing is that the "bum leg" is much stronger and fatigues less quicker than the "good leg" in terms of cycling, hiking and other physically demanding stuff I like to do. It is just unbelievable.

So, maybe Ti has some really good stuff going for it apart from making "noodly" bicycle frames.

I don't want to lead the thread in the direction of Ti as bone truss material

I'll get it back on topic... IMO the ultimate cables use ceramic housings (http://www.vertebr.ae/about/) and prolly kevlar inners; surely the end-fixing issue is solvable, if it hasn't been sorted already.

As for carbon zipties, that's just silly. You want a little elasticity in a ziptie, so you can make it tight enough to stay put on a slightly tapered tube. You wouldn't be able to put any pre-stretch on a carbon ziptie.

Anyway, bugger ziptying speedo cables! You have to think a bit harder than that to do justice to a sexy machine. At the very least, why not just use clear or fork-coloured tape along the wire?

Or how about enlarging the vent hole in the bottom of the blade and running it internally?

Or better yet, why don't speedo manufacturers offer us some tech that befits our machines; say for instance, a 3mm wide stick-on strip containing transparent conductors.

how's that different than a traditional cable?

A stainless steel or steel cable is stiff even when not under tension so it doesn't collapse and fold up when it is released, the kevlar cable would. Now Ti inner cables would be a different story, but as noted they might be susceptible to breakage.



.......As for carbon zipties, that's just silly........

Yes, but silly sells to cycling geeks. Look at Allsop's Softride..... :D

A stainless steel or steel cable is stiff even when not under tension so it doesn't collapse and fold up when it is released, the kevlar cable would.
Brake and shift cables are always under tension from the caliper returns springs or the derailleur's springs so they never go completely slack. I agree that Kevlar cables are silly but they won't be subject to folding up at any time.

Okay, I have received a reply from the email, which was sent to Titanex dot com (my computer put it in the junk mail folder by mistake, but I retrieved it):

"Dear James

There are such cables in Titanium. Not really from stock but made to order
easily. There are several kinds of constructions and Grades in order to
achieve desired Break Load of the cable. Some of the constructions can be
viewed here:
http://titanex.com/tiproducts/titanium-strand-cable-rope-seil.php

Usually Grade 2 or 5 will be used. Also details to Grades are available on
www.titanex.com/tigrades

Anything else I can do for you at this stage? Haven't seen the thread of the
discussion you mentioned - maybe I could add some comments...?

Best Regards
Andreas Fluekiger

--
Titanex GmbH Mr. Andreas Fluekiger
Sternenweg 17 Phone +41 444 635 382
CH-8617 Moenchaltorf Skype titanexch
www.linkedin.com/in/titanex
www.TITANEX.com : Ti, Ta, Nb, Metals
www.ANODURIT.com : anodising - the next level

-----Original Message-----
From: James Donohue [mailto:hotbike@hotmail.com]
Sent: Tuesday, April 03, 2012 5:12 PM
To: afluekiger@titanex.com
Subject: NFA Vehicles Inquiry to Titanex for titanium cable

__________________________________________________
google
titanium cable
SearchEngine
_________________________________________________
Comment Subject came up on a discussion board at bikeforums.net.

Material titanium cable
Application other application
Size Titanium cables for Bicycle Brakes and Gear Shifters? Does
such
an Item exist?
Delivery doesn't matter


Name Mr. James Donohue
Company NFA Vehicles
Address 87 Plymouth Drive North
Glen Head, NY 11545
Phone (516) 342-0826
Fax
E-Mail hotbike@hotmail.com
"