Last ride 76 

Been on the prowl for one of these for a few years, but wanted to find one cheap, like some of those posted here. It happened yesterday. Nice backdrop, right?

Cadex, as is 100$ 1 1/2 hours away...
One picture and off to work. Yep, I bought another bike at night. Brilliant...
Looks to be in pretty nice shape. And they took 1/2 hour off my drive. Very nice folks.

Last Night, $100, no wheels.

Holy Shimano, wheels do come with it. 600 rear, 105 front, Mavic Open4CD!

7:15 gotta run

Cadex $100 no wheels, 1 1/2 hours away.

easyupbug 

I had a slightly too small 980C find for a while and greatly enjoyed the ride. Sort out that stem funny business, polish up the aluminum, and wax the carbon and that will be a beauty.

T-Mar

Interesting mix of 1990 and 1991 frame features. Serial number? FYI, both years came with Shimano 105SC as OEM. Nice acquisition. Enjoy!

sheddle

Saw one of those on the road a while back and loved it. Didn't notice the wishbone stays until now - pretty unusual for a road bike.

Aluminum-lugged carbon is such a look. I dream for a Vitus Carbone...

Last ride 76 

I have a red 979. Gorgeous bikes... "Didn't notice the wishbone stays until now - pretty unusual for a road bike." Yep, part of my fascination with early carbon- Kestrel, Argos, and now the Cadex. I would love a steel wishbone. I forgot to mention that in my fantasy build.

I was totally sucked in by the George Jetson (not -e Jensen) seat cluster. Still am having seen it in person. Not in love with the graphics. It will always be readily identifiable by the seat cluster anyway.
I plan to refinish the frame like QuangVuong's, though w/o his drill work. Link here: Giant Cadex 980c Build - Ultra Budget and Lightweight He did an amazing job! Keeping it period correct, though not to original specs.
Thanks for the comments, all.
Cheers, Eric

I looked for examples of catastrophic carbon failure with Cadex frames but either there were few of them, or they were so bad, that everything, including the riders, just flashed of into a puff of dust... Hopefully the former. It seems that many early carbon frames were sufficiently over-built, as far as the carbon was concerned, at least, to not have to many catastrophic carbon failures, in normal operation, as opposed to more modern (and waaaay lighter) carbon frames. Not so much invisible catastrophic damage.

Last ride 76 

Yuck, that's pretty foul.

Tmar, it's GC000819 What does this reveal about my new steed? Thank you! 👍

T-Mar

It's hard to say if it's GC0 or GO0. The former would indicate weeks 5-6 of 1990, which would be a 1990 model while the latter would be weeks 29-30 of 1990 and in the grey area where it could be either a 1990 or 1991 model. However, based on the CADEX logo being on the down tube, it should be a 1990 model. Give the serial number a good cleaning and report back.

We had a quite a discussion about the debut year and differences between the 1990 and 1991 models, a few years ago.
Hello! How old is my frame? Thank you!

Last ride 76 

Oh, I'm sure about the GC... Whaddya take me for? Jeez! As soon as I took the picture, I spat on it, and rubbed it with my finger. Thx! Eric

Last ride 76 

My original plan was to remove the somewhat tatty clearcoat and decals, and then reclear with 2x.
Though slightly apprehensive, I removed the tt decal, using a blade, something I have done with re-painted and clearcoated steel frames. The clear-coat peeled up slightly ahead of the blade edge, most but not all of the time. It's the "not all" part that made me try the other method suggested - sanding...

I read that sanding was a safe way to remove the clearcoat, as the carbon used was harder than the paper, and would remain unscathed, within reason. I started to remove the clear, using 3M 320 Blue paper. White powder, coming up nicely, then after a minute or so, (checking ever few seconds) a hint of Gray! Maybe my paper was too coarse, it's also premium, and maybe harder than avg? Ok, I'll try std. wet or dry 600, on a different spot... A little more time, and gray again. How about paper designed for wood? Might be softer, 220 gently as possible... still gray. Now, I know sweet Fanny Adams about carbon fiber.
The gray may simply be some of the epoxy matrix the fiber is embedded in, and removing a small amount will cause no harm.
Then according to this "reasoning" of mine, when the grit hits the carbon, nothing is removed, and all will be well.

Umm, what if that's not the case? I have done no damage yet. So I am at a full stop on this one, until I get more information
Please understand that there is no criticism meant or implied towards anyone. Seriously. The results achieved by the OP whose thread I read, speak for themselves. It's amazing work...
I am frustrated, trying to figure out what is different. I have reached out directly to him, but am also posting this here to see how others have managed, removing clearcoat from bonded carbon tubes,
Hoping to hear of solutions beyond "Don't" presuming they must exist.
Cheers, Eric

unworthy1

I would get a good strong magnifying glass and really look over all the areas you've been sanding to see if any fiber has become exposed.If so then I'd say "too far gone" and retire the frame. But I do not buy that carbon fiber is "stronger" than silicon oxide and cannot be damaged with wet sanding it, likewise any other abrasive you may find on "sandpaper", aluminum oxide, garnet, whatever. But that's just me being ultra cautious around CF, I would not want to tempt fate! Any chemical engineer or industry expert is welcome to contradict my superstitions. And if I was sanding the clearcoat I'd be using nothing coarser than 400 wet-dry to start with, moving along to finer grade if needed as soon as it was "smooth enough" I would not try to remove 100% of the OEM clear but ALSO would find out what the OEM clear was and use the very same over it, if possible. If that cannot be determined then MAYBE would trust a waterborne PU finish like one from General Finishes as being "less likely to cause harm", but...YMMV. here's a link https://generalfinishes.com/wood-fin...urethane-water

Last ride 76 

Excitement dimmed a bit...
I will certainly check, (I actually have a low power microscope that might work well) but the total amount of "gray" dust was perhaps equal a few normal grains of sugar, (from 3 different spots) before I called a halt.. I doubt that the fabric was adversely affected. I agree, erring on the side of caution is a good idea. That Urethane looks good, hard to see how it would be reactive. Thx

Chombi1 

Quite a few lugged CF frame restorations had come through this forum in the last few years and most of them came out even better than most expected and I never heard of these restored frames failing on the owners.
I also noticed that these Cadex framesets in particular, take very well to sanding and refinishing, looking really nice after a new clearcoat, decals and a polish to the aluminum lugs........ I'd watch out more for any signs of any CF tube separation from the lugs, especially on frames that have evidence of living a hard life or being abused by previous owners. So don't give up on this one yet.

Last ride 76 

Jinx...

Pretty happy with the results. The razoring was actually less nerve wracking than removing the decals on most painted frames, and went quickly and smoothly, no carbon scraped or cut, and no black residue on the sand paper.

After about 5 hours of scraping, (and enough 600/1000 wet sanding to keep checking that the carbon layer was safe). There are some chain drop scrapes, that go beyond the clear coat, on the DS chainstay but the other chips which I was concerned with, turned out not to go into the carbon.

Giant apparently clear coated the whole frame as a finished unit, perhaps with the goal of limiting water penetration. So I scraped the flaking clear coat off the DS dropout. Done, and see below.

Not happy. At all. Seems like it aught to be repairable, hopefully something better than just stuffing some JB Weld in. I'm wondering if it might be possible remove the stay to repair the chain damage or just make new one and reinsert/re-cement. While I can't speak about the rest of the bonds, the tubes and lugs seem in excellent condition. Certainly pretty 👍😃
Not sure what my next step is. Reassemble the bike and put it aside, or pack the parts in a box and wrap the frame and put in storage till... Bother. I was so close, (I thought). More to come..

Jimbo1983

Sucks about the end result with the dropout. I am curious to know more about that nice looking pink frame and matching pump in the background though?

Salamandrine 

That would probably work, if you can get the pieces apart enough to prep the surfaces. There is however probably a somewhat more optimal 3M epoxy.

easyupbug 

Terrible news. I would be very uncomfortable with a shade tree mechanical approach of just gluing it. Searching for expert repair services with a good track record is where I would look and hopefully getting comfortable with letting them do the work. I have a 979 which are known to have similar issues and saved this site in case disaster ever strikes:
https://www.guywires.com/vitusmain.htm

Last ride 76 

Thx for this. I was not really contemplating a "shade tree mechanic" approach to this... I have a v2 979 with the set screw, and also a v1 979 frame with a hairline crack that runs part way through the NDS seat lug ear. I bought a quill seat post for it, but also was planning to install one of those threaded aluminum repair pieces to reinforce the lug. Since getting the new 979, and it being summer, project is back burnered. The 979 led to more lugged Aluminum... Cue the Alan thread...

unworthy1

I don't know how much I would trust a re-bonded frame BUT if I was going to tackle this I would try to remove the DO from both chainstay (easy since it's loose) and seatstay (unknown) so I could prep both joints both aluminum and CF without stressing any parts. My object would be clean all bond surfaces of ANY and ALL old adhesive (if SAFE to use solvents then acetone and denatured alcohol) roughen up at least the AL plugs and pick one of the super epoxy products from Hysol/Loctite or MasterBond, I suggest you read up and make your own choice about which you trust. I have nothing against JB Weld (use it a lot) but this would NOT be a repair I would trust to that product, YRMV

Last ride 76 

Sorry, that really was a flippant suggestion. A pro-grade industrial marine epoxy adhesive, spec'ed for carbon and aluminum, would likely be my go to... Auto folks use alcohol, to clean CF not too sure about Acetone. Removing the chainstay was to entertain the possibility of replacing it due to nicks behind chainrings... If everything went well, by my estimation, it would become an around town, riding the mups type of bike until I felt more secure, if ever, and never a descender... Not that I'm a descender any more, except on skis. So... the Alan thread, seriously.

unworthy1

[QUOTE=. So... the Alan thread, seriously.[/QUOTE] What is "the Alan Thread"? Is it about repairing ALAN frames? Oh, NVM, I think I just stumbled on it, you got an ALAN Carbonio, huh? FUN!

Narhay

I am assuming the frame was prepped and glued with the same glue on all the joins. If one is noticeably failing the others may or may not be far behind.

Last ride 76 

All sorts of possible scenarios. They don't really matter, since, as already stated, this project is on indefinite long- term hold. (Unless someone knows how to resurrecti safely and cost-effectively now). Perhaps there is a way to cannibalize the good bits, somewhere down the road. Thx all.