Author Topic: En*gma  (Read 18683 times)

TimC

  • Old blerk sometimes onabike.
Re: En*gma
« Reply #25 on: 17 December, 2021, 03:16:19 pm »
Thermal expansion coefficient of Al is about 3 x Ti, which doesn’t help with opening poorly bonded gaps and encouraging corrosion. Galvanic corrosion can be a significant issue.

Carbon fibre thermal expansion is more difficult to define as it can vary with direction and exact materials but is perhaps 1/6 that of Ti. There is virtually no galvanic corrosion between them.

Casting and machining Ti lugs is expensive and even 3D printing isn’t cheap.

The carbon/Ti interface is an issue that interests me, as I have a Ritchey Break-Away Ti/Carbon frame. Indeed, it's my favourite summer mount and has been ridden all over the world, though perhaps not for the epic mileages that YACF folk would regard as credible. I built the bike with that then-new frame in 2009, and I've rebuilt it a few times since. It's a better ride in every respect other than potential luggage carrying than my 2019 Kinesis GFTi V3, in which I have far less faith for a long life.

Re: En*gma
« Reply #26 on: 17 December, 2021, 04:37:29 pm »
I bloody love my serotta legend from about 2003 or 4.  It did a few 10k mile years, now down to a couple of k at the most as I'm riding less and have a new fast bike and a gravel bike, but if I head out to do a long day on tarmac it's still the only bike I'd chose.  It only fits 25mm tyres but it's a gorgeous ride - just wish I could fit proper mudguards to it.

sam

Re: En*gma
« Reply #27 on: 18 December, 2021, 08:32:32 am »

sam

Re: En*gma
« Reply #28 on: 18 December, 2021, 08:32:44 am »
The aerospace and nuclear industries produce reliable welded Ti by complete exclusion of atmosphere, often by taping clear plastic bags together, purging with argon, and welding with the torch inside the bag and the welder outside.

That must be difficult with things like planes and submarines.


What are our secrets doing on YouTube?!?


"Нам понадобятся сумки побольше, товарищи." (Translation: "We're going to need bigger bags, comrades.")

Steel does seem to cause far fewer headaches all around. I curse the titanium itch.

Within weeks of the Edsel's* crack of doom, my Litespeed had followed suit. (May 2021 = mensis horribilis.) There was a very important difference: the latter was my own fault. Years ago I got someone to drill through its downtube to fit lovely Dura Ace shifters. Rest assured, this is on my list.



Not long afterwards I went completely singlespeed. As you do. I then taped over the holes and forgot about them. Four prime ministers came and went. (Wait a minute, Boris is still there.) Eventually a creak started making its way into the proceedings. That one had me scratching my head for a while, until it occurred to me to remove the bandage and check on the wound.

(click to show/hide)

What was beneath was both horrifying and a relief: horrifying because a crack encircled much more of the tube than seemed possible without a guardian angel involved; a relief because finding the source of a creak is a cause for celebration. Yay.

At that point I wrote off the frame

(click to show/hide)

and put it in the shed as the senior knackered retiree. It seems there aren't many in the UK who can weld a ti frame, and the most convenient provider of that service definitely wasn't getting a call. But it nagged at me for a few weeks – I wanted that bike back on the road, damnit. So I made enquiries.

The guy I found myself talking to sounded as glum as me, as covid had kicked his company into idle. I sent him pics and he said no problem. Turnaround was days.

(click to show/hide)

I happily rebuilt it, adding a cheery band to cover the scar, which like all scars serves as a reminder.



* A little googling tells me the Edsel may not have deserved its lemon status, but the rebadging of my Esprit is fair use.

† PM if you want more details. I'm not entirely certain I wish to be enlightened as to the quality of the weld. If it's not all that, it may be preferable to enjoy our final sweet miles together in blissful ignorance.

LittleWheelsandBig

  • Whimsy Rider
Re: En*gma
« Reply #29 on: 18 December, 2021, 11:46:41 am »
The carbon/Ti interface is an issue that interests me, as I have a Ritchey Break-Away Ti/Carbon frame.

Does it used welded Ti lugs or are they cast/ machined?

Carbon/ Ti should be the nearest thing to a ‘forever joint’, once the poorly-prepared/ -bonded joints have failed. If welded lugs, it should be one of the most-expensive frame construction methods ever, requiring all the preparation, work methods and QA of both carbon and Ti frames.
Wheel meet again, don't know where, don't know when...

LittleWheelsandBig

  • Whimsy Rider
Re: En*gma
« Reply #30 on: 18 December, 2021, 11:51:08 am »
The aerospace and nuclear industries produce reliable welded Ti by complete exclusion of atmosphere, often by taping clear plastic bags together, purging with argon, and welding with the torch inside the bag and the welder outside.

That must be difficult with things like planes and submarines.

Those sorts of problems was why the plastic bag method was developed. They found it was a little impractical to put wing sections into a vacuum chamber.
Wheel meet again, don't know where, don't know when...

sam

Re: En*gma
« Reply #31 on: 18 December, 2021, 12:14:10 pm »
That was mostly a setup for the Russian gag. Here’s another:

Quote from: LittleWheelsAndBig
purging with argon

“Argon is noble like Stalin."


LittleWheelsandBig

  • Whimsy Rider
Re: En*gma
« Reply #32 on: 18 December, 2021, 12:28:04 pm »
Happy to be the straight man…
Wheel meet again, don't know where, don't know when...

sam

Re: En*gma
« Reply #33 on: 18 December, 2021, 12:42:18 pm »
If we didn't have straight men (and women!) we never would have gotten to the moon.



Seriously though, I'm grateful for the knowledge brought to this thread.

rogerzilla

  • When n+1 gets out of hand
Re: En*gma
« Reply #34 on: 18 December, 2021, 03:31:01 pm »
Sam, are you really walking round the country carrying a broken frame, or is some Photoshop devilry involved?
Hard work sometimes pays off in the end, but laziness ALWAYS pays off NOW.

TimC

  • Old blerk sometimes onabike.
Re: En*gma
« Reply #35 on: 18 December, 2021, 06:35:09 pm »
The carbon/Ti interface is an issue that interests me, as I have a Ritchey Break-Away Ti/Carbon frame.

Does it used welded Ti lugs or are they cast/ machined?

Carbon/ Ti should be the nearest thing to a ‘forever joint’, once the poorly-prepared/ -bonded joints have failed. If welded lugs, it should be one of the most-expensive frame construction methods ever, requiring all the preparation, work methods and QA of both carbon and Ti frames.

There are no lugs as such. The frame comes apart so as to fit in a suitcase. The rear triangle is carbon, and the carbon module is fitted into receptors at the rear of the seat tube and bottom bracket. The titanium joints are welded, and the frame splits at the top of the seat tube and bottom of the downtube (as per all BreakAway frames, regardless of construction material). Hopefully this image will make it clearer.


LittleWheelsandBig

  • Whimsy Rider
Re: En*gma
« Reply #36 on: 18 December, 2021, 07:22:42 pm »
OK, so basically a Ti frame with bonded-in carbon seatstay and chainstay yokes. The bonded connections should be fine long-term. The Ti welds are what they are.
https://www.bikeradar.com/reviews/bikes/road-bikes/ritchey-break-away-road-ti-carbon-review

There are some more extreme Ti/ carbon frames that I had in mind.
https://cyclingtips.com/2020/08/bikes-of-the-bunch-firefly-ti-carbon-with-dotted-anodisation/
http://kbedfordcustoms.com/titanium-carbon
http://www.bmedesign.eu/b8-series-frames
Wheel meet again, don't know where, don't know when...

TimC

  • Old blerk sometimes onabike.
Re: En*gma
« Reply #37 on: 18 December, 2021, 08:33:37 pm »
Yes, I thought you were probably thinking of more extreme designs. Interesting that BikeRadar test is 3 years after I built mine (Ultegra 6600 back in those days) and it wasn't new to the market even then. It's still my favourite - and fastest - bike.

LittleWheelsandBig

  • Whimsy Rider
Re: En*gma
« Reply #38 on: 18 December, 2021, 08:52:28 pm »
I think 3D printed Ti lugs and carbon tubes might be both more durable and more customisable than other options, once all the quirks are known and ironed out. 3D printing metal results in some unhelpful material properties alongside the structural design freedoms.

https://www.gravelcyclist.com/videos/bastion-cycles-combining-3d-printed-titanium-lug-carbon-fibre-tubes-melbourne-australia-factory-tour/

Your Ritchey is a nice piece of kit. SRAM Red 11 eTap is a good choice for a travel bike (we have it on our Moultons), I just wish replacement parts were available for the inevitable crash or travel damage. I understand that AXS levers and Blipbox can now be paired with eTap 11 derailleurs but not the other way round.
Wheel meet again, don't know where, don't know when...

sam

Re: En*gma
« Reply #39 on: 19 December, 2021, 03:00:57 pm »
Quote from: Rogerzilla, from YACF News
Sam, are you really walking round the country carrying a broken frame, or is some Photoshop devilry involved?



Those are actual location shots. I even climbed a tree. The only photodevilry – aside from Photoshop itself long since ascending unaffordably into the Creative Cloud® – is the occasional and very obvious "booster".


Shouldn't that be hanging by the headtube, pardner?

The Chamber of Commerce would also like to make it clear that there isn't a gulag in Hastings as advertised upthread. This is the pedestrian reality:



In addition to keeping it real location-wise, I'm committed to showing the unretouched frame, even taking care not to inadvertently widen the crack (which is why the bottom bracket remains installed: it's in there good and tight). Having failed to obtain the satisfaction of a replacement, satisfaction now lies elsewhere.


Winner of the ironic caption competition

I was particularly pleased with the bin lorry shot, accomplished with the kind permission of the operator (I do find myself having some unusual conversations) who was doubtless amused to watch me set the frame oh so carefully into that great maw.



(click to show/hide)

Much as I would like to travel further afield for photo ops,



go globetrotting like TimC,


"I was in National Geographic, too"*

and best idea yet, turn this into a moveable Instagram feast like the monolith, popping in and out of Google Earth,


"2001"

so far everything has been close to home.


Yo!


* Almost 30 years ago in the dawn of digital photo manipulation, NG infamously moved a pyramid to achieve a more pleasing effect. The editor defended the modification, "seeing it not as a falsification but merely the establishment of a new point of view."

As for my press conference, you need only note the state of the fringes of my hair. My image search history is littered with pleas for subjects with white or preferably transparent backgrounds, for ease of superimposition.

Re: En*gma
« Reply #40 on: 19 December, 2021, 03:09:20 pm »
Does this give rise to the saying 'you have been framed?'
Get a bicycle. You will never regret it, if you live- Mark Twain

T42

  • Apprentice geezer
Re: En*gma
« Reply #41 on: 19 December, 2021, 03:37:38 pm »
IIRC Liam Curran and partner rode a collapsible Ti tandem on the UAF's Paris-Tourmalet run in 2007.  Wish I'd got a bit closer with the camera:



Looks like it broke right down into tubes and lugs.

I remember him stopping halfway down from the Tourmalet to let the discs cool.
I've dusted off all those old bottles and set them up straight

sam

Re: En*gma
« Reply #42 on: 19 December, 2021, 05:27:05 pm »
Does this give rise to the saying 'you have been framed?'


rogerzilla

  • When n+1 gets out of hand
Re: En*gma
« Reply #43 on: 19 December, 2021, 05:33:59 pm »
Ah, that one has a crack in the same place.
Hard work sometimes pays off in the end, but laziness ALWAYS pays off NOW.

sam

Re: En*gma
« Reply #44 on: 20 December, 2021, 04:03:09 pm »
Re: cracks and framing... I call this one TURN IT DOWN.



We don't have many shops in the village, but we've got bare walls covered.



I used to work for a guy who hung his Bianchi up like the work of art it was. It was probably the first time I’d seen anybody do that.* It wouldn’t be the last.



In fact, the very first image that flashed into my head after picking the bones for parts was of the frame exquisitely framed. I then pictured it in a modern art gallery, but didn't quite have the nerve to call the Tate. It was only a matter of time before it occurred to me to make my own gallery.


* Other than Seinfeld - blink and you'll miss it at the end of this clip

rogerzilla

  • When n+1 gets out of hand
Re: En*gma
« Reply #45 on: 21 December, 2021, 08:26:37 am »
I've got Clare Grogan singing "Happy Birthday" in my head now.

https://youtu.be/6t1vaF50Ks0
Hard work sometimes pays off in the end, but laziness ALWAYS pays off NOW.

sam

Re: En*gma
« Reply #46 on: 21 December, 2021, 07:10:41 pm »

I didn't have the letters for Happy Bathday.


PS. Yes I take requests

sam

Re: En*gma
« Reply #47 on: 21 December, 2021, 07:10:53 pm »

sam

Re: En*gma
« Reply #48 on: 22 December, 2021, 07:44:49 am »
Morning has broken


Re: En*gma
« Reply #49 on: 22 December, 2021, 10:14:23 am »
Just read this sorry tale and I was reminded of two separate warning tales. One was the certain french tool firm (not Facom, they have a reputation so don't need guarantees) who gave a "lifetime" guarantee against breakage. We broke one of their expensive tools and tried to get a replacement. "It's broken so its life is finished - beyond lifetime no replacement!" A bit galling for a manufacturer's workshop with almost entirely this make of handtool - the local rep was a bit embarassed as well, he would have liked to,sell us other stuff!
The other tale concerns Ti bits on bikes. Many years ago when Richard Virenque was riding Peugeots for Festina (about the time of the famous Peugeot Power Yoke on their aluminium frames IIRC), his rig was part of an article in a cycling magazine (perhaps Le Cycle, perhaps one of the others devoted to training plans and pro kit for MAMILs). He remarked that he used Ti components (might have been seatpost and qrs). He reckoned to replace them at least once in the season to be sure that they wouldn't fail at a critical moment. I always think of this when I see Ti as a frame material, can't think why ???

Of course nothing beats steel! My tandem frame is coming up for a century (modded all over the place to take modern bits, I ride it and since I don't know what was on it originally I am not trying to dress it up in the wrong period kit). Show me a soot bike of that age! (Mind there are quite possibly a few aluminium frames around from the 20's or even before).