Monday 21 August 2023

Bike Project: 2012 Tomac Flint 29 (Part 2) or: "DON'T THROW AWAY YOUR OLD DEORE XT M739 CRANKSET!!!" or: "A Tale Of Two Chainrings" or: "A Chance Meeting Yields Unexpected Results"

 

2012 Tomac Flint 29
An eclectic mix of old and new working in perfect harmony.

BACKGROUND STORY:

I built up a 2012 Tomac Flint 29 XC frame into a dropper gravel bike a few months ago.  However, I didn't particularly like a few aspects of the end product.  The gearing was centred around a 46/34 crankset, and I really wanted to use a 32.  The 29 x 2.1" tires were great for floating over chunky gravel, but the tradeoff was a lack of agility on firmer ground.  A tire change is simple enough, but running a sub-compact crankset on this frame was tricky due to the wide (pre-boost) chainstays; no problems in installing one, but it was challenging creating an optimum chainline. The problem could have been solved by going to 1X, but I'm stubbornly sticking to 2x.

I was looking for something altogether unrelated, and came across a bunch of old and very dirty Shimano Deore XT M739 parts (circa 1995) in one of my parts bins.

1995 Deore XT RD-M739 rear derailleur
So filthy; even the pivot bolt and internal spring were jammed with mud.

M739 CRANKSET MODIFICATION:

The M739 crankset was the version which integrated the big chainring with the spider.  The concept was ahead of its time, but once the big chainring was worn out (and this one definitely was), you had to replace the entire spider.  I was almost about to recycle it, when I got an idea: What if I could re-purpose the spider to run a sub-compact double inboard of the original triple configuration?


1995 Shimano Deore XT M739 crankset
Deore XT M739 crankset. Integrated chainring & spider, 2 other chainrings removed.

1995 Shimano Deore XT M739 crankset
Pop off circlip, remove lockring using Octalink BB tool or equivalent.

1995 Shimano Deore XT M739 crankset
Cut off chainring, giving you the spider only.

1995 Shimano Deore XT M739 crankset
Extended length 15mm chainring bolts, 5mm chainring spacers, M10 x 14mm washers.

Specialites TA / TA Specialties chainrings
Add beautiful Specialites TA / TA Specialties chainrings, made in France.

1995 Shimano Deore XT M739 crankset
Re-assembled. Note the double vs triple inboard positioning of chainrings.

1995 Shimano Deore XT M739 crankset
M739 crankset modified to 2X completed.

1995 Shimano Deore XT M739 crankset, front derailleur
Circa 1995 Deore XT M739 crankset installed and ready to go for another 28 years.


NEW CLARIS BRIFTERS WITH OLD DEORE XT DERAILLEURS?:

I also wanted to return to an 8-speed system for its cheap, robust chains and mythical mud-shedding capabilities.  Shimano Claris R2000 brifters were used; not the most svelte, but 8-speed, no dangly shifter cables, and relatively cheap.  No worries in compatibility with the M739 rear derailleur, but I reasoned I had two options for the front derailleur: 1) Add a clamp-on pulley to allow the Claris bottom-pull front derailleur to work on the top-pull frame fittings; this would work for sure as as the R2000's longer leverage arm was a mate to the Claris shifter; 2) Use the old top-pull Deore XT front mech, but modify the cable mounting point to simulate the Claris's entirely different cable pull.  To my utter surprise, the Deore XT worked really, really well with the Claris 2x front shifter without any modifications at all!

So, the bike is a 2012 frame with 2017 brifters and 1995 derailleurs, and it all works perfectly fine.

Sometimes, you just take the win and run.


1995 Shimano Deore XT RD-M739 rear derailleur
RD-M739 rebuilt and handling the 32T cog without even maxing out the b-screw.


Shimano Claris R2000 brifters
Shimano Claris R2000 brifters.


Clement X'Plor USH tires
Clement X'Plor USH tires. Tough to mount, hope their ride is worth it.


RIDE REPORT:

2003-08: Massive wildfires in British Columbia currently.  Will test-ride once the sky stops raining ash.



This time, N+0.  Okay, maybe N+0.25.

Tuesday 4 April 2023

Bike Project: 2012 Tomac Flint 29 (29er XC to Dropbar Gravel)

2012 Tomac Flint 29 gravel bike
2012 Tomac Flint 29 Gravel Conversion



THE BACKGROUND STORY:

My favourite cyclist of all time is John Tomac.  The choice may be surprising as I have always been more of a roadie, but John Tomac in my opinion is a singularly unique talent in the world of professional cycling.  Tomac either dominated or excelled at multiple cycling disciplines (BMX, cross-country, trials, downhill, and yes, even road) throughout an amazing career. Very few can claim his combination of winning with such an incredible level of versatility.

Unfortunately, the branding of his iconic name has not been as successful or enduring.  The third attempt at Tomac-labelled bikes occurred between 2006 and 2013; higher-end bikes were designed and produced under the auspices of Joel Smith (formerly with Answer/Manitou) with direct input from Tomac himself. The bikes generally garnered stellar reviews but failed to find a lasting place in the competitive market.  The iconic name has languished in limbo ever since.

Recently, I was pleasantly surprised to find a Tomac Flint 29 bike frame show up for sale locally. While not rare, Tomac bikes are at least relatively uncommon. Even better, the original owner let the near-mint frame go for a song. Score!!!  This 29er XC frame was the 2012 version and had a standard threaded bottom bracket lacking the earlier Bushnell eccentric bottom bracket system (for singlespeed option).  The AN6 aluminum custom-butted tubing results in the frame weighing a claimed 1400 grams.  I like the look of the white pearlescent paint an awful lot, but I'm not sure if it will stay looking nice for very long.


                                                      2012 Tomac Flint 29 gravel bike2012 Tomac Flint 29 gravel bike2012 Tomac Flint 29 gravel bike                                                  
2012 Tomac Flint 29 gravel bike
1. Sweet head tube badge          2. Downtube sticker          3. Signature of a legend          4. Frame & aftermarket rigid carbon fork

In homage to a classic Tomac-esque move, I decided to convert the XC 29er into a dropbar gravel bike.  I had been riding a budget garage-build dropbar hybrid rig on gravel up to this point.  The process, however, was not without its hurdles. Primary among the issues was the choice of crankset and creating an acceptable chainline.  I had originally hoped to run an oversized integrated spindle 2X crankset using a 110 BCD, but the 73mm BB shell and the very wide chainstays ruled out any road or gravel crank with a ~110mm spindle. Conversely, if I used a MTB crankset with a ~120mm spindle, the 104/64 BCD would not have the chainring sizes I wanted.  The options were to run 1X (which I didn't want) or to run either an interchangeable spider or a DUB crankset and bottom bracket (not in my budget).  I dug deep in my bins for a third option, using a Shimano cartridge bearing square taper BB with a short 107mm spindle and a dog's breakfast of a crankset (Truvativ Touro cranks with a Surly 46T big chainring and a Race Face 34T small chainring).  The frankenstein combo works, but I may switch to a DUB when money and opportunity allows, possibly running a 46/32T.


Chainring / chainstay clearance

I paired some SRAM Red 10-speed brifters I had kicking around with some SRAM X7 MTB derailleurs for a mullet shifting system.  I would have preferred the X9's if only just for the rear clutch mechanism, but beggars can't be choosers.  The front derailleur clamp butts up against the lower seat tube water bottle rivnut and can't be raised any higher; this normally wouldn't be an issue but as Surly chainrings seem to have fairly tall tooth profiles, the front cage just barely clears the 46T. Everything else works pretty much as expected.  The build weight as completed sits at a respectable 11.6 kg.  If I put on some better than entry-level wheels and went tubeless, I could easily shed some weight, but I'm happy with it for now.  I will get back with some feedback once I get a few rides in.


PHOTO GALLERY:

2012 Tomac Flint 29 gravel bike

2012 Tomac Flint 29 gravel bike2012 Tomac Flint 29 gravel bike


SPECIFICATIONS:

Frame: 2012 Tomas Flint 29 (size M), AN6 custom-butted aluminum. Serial # FAT11E0024
Headset: FSA
Fork: Generic aftermarket full carbon rigid, suspension-compensated
Seatpost: Generic carbon, with a 30.9 to 27.2mm shim
Saddle: Synchros
Stem: Kona 50mm
Handlebars: Easton AX70
Brifters: SRAM Red (10-speed)
Front Derailleur: SRAM X7
Rear Derailleur: SRAM X7
Brakes & Rotors: TRP Spyre (160mm)
Bottom Bracket: Shimano UN-52 cartridge square taper, 107mm spindle
Crankset: Truvativ Touro w/46T Survey, 34T Race Face
Chain: Shimano CN-6701
Pedals: Time ATAC Alium S
Wheels: Giant GX28
Cassette: Shimano CS-5700
Tires: WTB Nano 29 x 2.1
Build Weight: 11.6 kg


RIDE REPORT: Pending





N1+1



Thursday 18 August 2022

Bike Project: 1990 Giant Cadex 980C "Carbon For The Masses"

1990 Giant Cadex 980C



*dates indicated are estimated years of production, not introduction of product.

*any inaccuracies are unintentional and any feedback or corrections are welcomed.


BACKGROUND:


The lugged carbon fibre road bicycles of the late 80’s to 90’s have an undeniable appeal despite being wholly replaced by more modern methods of construction. The appeal is equal parts nostalgia and aesthetic, but an additional factor is owning a bike which at one time was considered state of the art in terms of weight and materials. Granted, there were even earlier carbon frames but they were largely prototypes like the Carlton (1971) or had limited production runs, such as the Mossberg Road X-1000 (1973), and Exxon / Graftek G-1 (1975).  For the most part, the production bikes were typically constructed of carbon fibre tubes bonded into aluminum lugs, and included such iconic models like the Vitus Plus Carbone / Carbone 3 (1983), the Alan Record Carbonio (1984?), the Peugeot PY-10FC (1983), and the TVT / Look KG 86 (1986). At the time, these bikes were exotic superbikes for the pro peloton and certainly out of reach of a neophyte on a budget. Then came the Giant Cadex 980C, which was introduced in 1987 and available for the market in 1989.


The Giant Cadex 980C was one of a wave of bicycles regarded as “carbon for the masses”. Others were the Miyata Carbon Tech models (1987), the Trek 2500 (1987), the Specialized Allez Epic (1988/89), and the Centurion Ironman Carbon (carbon-wrapped aluminum for main tubes; 1988). Now carbon became (somewhat) affordable to Joe Public.  I remember a few of us gathered around a 980C at a shop. Older, wiser heads decried the new technology:


“It’s ugly.”

“It’s gonna snap in half. A guy I know heard that it happened to his 3rd cousin’s riding buddy…!”

“It’s crazy light….too light.”

“It’s GLUED?!!!”


I nodded my head in agreement, but privately, I had a sense of wonderment. The whole thing was hyped by equal parts science and mysticism. I remember a Miyata catalog throwing around terms like “amorphous metal reinforcement” and “stronger than steel”, and touted cool graphs and charts showing how carbon fibre was better.  My science geek brain bought in.


But, alas, the wage of a shop rat did not match up with the lure of carbon. I saved up and raced on a very nice Marinoni Columbus SL frame, then on a Marinoni Columbus SLX, then on a 2nd generation bonded Trek 2000 aluminum; but after a few years, bonding technology was more-or-less done by monocoque construction. Step forward a few decades, dozens of bikes later, and a few pounds heavier later to 2022, and I am on a 2013 Giant Advanced SL ISP frame. It’s a much better bike than I really need for going on a ride or two a week with a buddies followed by a good coffee and talk session.


Yet when a Giant Cadex 980C came up on my local market for a fair deal, I couldn't resist the allure. The original owner bought it during the 90’s triathlon boom, but only used it off and on over the years. There were some normal use clearcoat chips and some nicks and scratches, but the bike hadn’t been abused. Getting it home, I could see it was a 1990 production year 980C, with the “Giant” logo in red text with a blue text shadow - this was supported by serial number # GL002876 (see “CADEX 980C MODELS & SERIAL NUMBERS:” below). The bike came more-or-less fully stock with a fully functional Shimano 105 SC groupset, but I wanted to go Neo-Retro.


Originally, I was planning to go in an all-carbon direction, but after stripping it down to the frame, the phrase “carbon for the masses” stuck in my mind. The challenge was to use more modern parts for improved functionality, but stick to OEM pieces (“components for the masses”) while showcasing the frame’s old-school carbon tubes and aluminum lugs. I used a few colour-anodized parts to emphasize the carbon/aluminum/red/blue colour scheme, but tried to keep it simple.



PHOTO GALLERY:








SPECIFICATIONS:

Frame: 1990 Giant Cadex 980C

Fork: Giant Alloy CAD aluminum

Headset: Tange Vantage

Stem: generic 1” quill with removable faceplate 

Handlebar: MEC compact 

Seatpost: generic carbon

Seat: Giant Contact Neutral

Crankset: Shimano FC-M565 non-series compact

Shifter: Shimano Sora ST-R3000 

Front Derailleur: Shimano Sora RD-R3000-SS

Rear Derailleur: Shimano Sora FD-R3000-F

Brakes: Tektro 540 dual pivot

Wheels: Ritchey Aero OCR Pro rims, Ritchey Zero System hubs, black aero spokes

Cassette: Shimano CS-6500 Ultegra

Pedals: Wellgo Xpedo XRF07MG Magnesium



CADEX 980C MODELS & SERIAL NUMBERS:


In my opinion, and without claiming to be definitive, there appears to be three models of the Cadex 980C manufactured with some production year overlaps before being replaced by the later CFR models:


- 1989-90 (1st generation): White lettering w/red shadow, multi-coloured geometric shapes, “Cadex” on the wishbone, original “G” Giant logo on the head tube, requires a clamp-on front derailleur.

- 1990-? (2nd generation?): Red lettering w/white shadow, “Cadex” on the wishbone, second “G” Giant logo on the head tube (inverted triangle, red/white/black), braze-on front derailleur mount.

- 1990-91 (3rd generation?): Red lettering w/blue shadow, “Giant” on the wishbone, wave “G” Giant logo on the head tube (inverted triangle, sunset fade/blue), braze-on front derailleur mount.


At least some '89 and '90 models had a polished finish on the aluminum lugs. Others look anodized or painted.


There also seems to be several variations in shadow colours (green?), head tube logos, location of decals, black vs grey BB shell, black vs silver Tange Vantage headsets and/or spacers. 


***If you have a 980 C, check the serial number against Giant’s numbering system, and leave a comment with which graphic and serial number you have, so I can either correct or update each generation's production years:


- The first alphanumeric = G for Giant

- The second alphanumeric refers to a 2-week period of production, the year being divided into 26 periods. “A” = weeks 1 & 2 of production; mine is “L” = weeks 23 & 24.

- The third alphanumeric = the year, 0 = 1990.



NOTES OF INTEREST:


The Cadex 980C's have a sloping top tube which gets lower towards the front.  The reason for the design is unknown, but it necessitated the use of a tall headset spacer.


Later versions of the Specialized Allez Epic frames had a dark grey or black coating on their bottom bracket shell, evidently to guard against known galvanic corrosion issues.  The 980C BB shell seem to share this coating - the connection seems to support the theory that Giant also made the Specialized Allez Epic, although some have previously stated it was made by Merida.  I wouldn’t be surprised if various Taiwanese manufacturing facilities had been contracted out, making both theories true.



RIDE REPORT:


2022-SEP-ish: I finally got a few klicks in and was pleasantly surprised by the ride. I've been riding compact frames so long, it took a bit to get used to the traditional triangle frame again.  Other than the weight (my build focus definitely wasn't weight weenie), the 980C felt smooth and handled predictably given its road racing geometry. Off the saddle, the 980C was laterally firm at the bottom bracket while dutifully muting inline road buzz.  I didn't really throw around the bike too much, but replacing the very good-looking stock aluminum fork with carbon would likely improve the downhill tracking.  Overall, it felt stiffer than a Specialized Allez Epic but had a much livelier feel than expected, delivering that nostalgic lugged carbon ride.


2022-DEC: This little piece of cycling history went to Giant Canada, along with the stock Shimano 105 SC groupset, SR Sakae cockpit, plus wheels.  I'm glad I finally got to own and ride one of my bucket list bikes, if only for a short time.



SOURCES & ADDITIONAL READING:


Carlton Carbon prototype: http://www.bikeboom.info/carlton/

Trek 2500 Composite: https://www.vintage-trek.com/Trek_timeline.htm

Vitus Carbone 3: https://bicyclingaustralia.com.au/bikes/retro-review-the-legendary-vitus-979/

Peugeot PY-10FC: https://on-the-drops.blogspot.com/2016/12/the-space-ace-racing-bike-peugeot-py.html

Look KG 86: https://velobase.com/Velos/ViewModel.aspx?ID=f54635c9-6a90-4dc2-b862-55bdc2cb9493

Miyata Carbon Tech: https://www.ragandbone.ca/Miyata/miyata_selector.html

Centurion Ironman Carbon: http://www.vintage-centurion.com/models/competition/ironman/88_carbon.shtml

Specialized Allez Epic: https://www.roadbikereview.com/threads/some-specialized-history.190991/

Giant Cadex 980C: http://classiccycleus.com/home/1989-giant-cadex-980-c/

Giant Cadex 980C: https://www.bikeforums.net/classic-vintage/1115437-hello-how-old-my-frame-thank-you-2.html


N+1-1

Sunday 28 February 2021

Bike Project: 2000 Trek Hilo 1000 "Plan 9 Taking Up Garage Space"


2000 Trek Hilo 1000 = "Plan 9 Taking Up Garage Space"


THE STORY: I bought this bike from a retired triathlete on a bit of a whim.  I'll admit I wasn't exactly sure what I was going to do with it.  He had rattle-canned it over the original purple to stamp his own personality onto his bike, but it didn't really fit into a modern day aesthetic.  From a strictly utilitarian viewpoint, the triathlon/TT specific geometry and the 650c sized wheels were somewhat  purpose-specific: 1) the steep 78° seat tube angle created an aggressive seat position less suited to more casual riding; 2) 650c tires are a niche market, and while still available (due to shorter stature cyclists with smaller frames), they were harder to find in anything other than a 23mm or 25mm width.  But I suppose that's why I like doing neo-retro and oddball builds - I find them to be more of a challenge than straight restorations.

Frame as purchased

Bead-blasted

I didn't come up with a theme to the build until the frame was stripped down to raw aluminum.  It occurred to me the frame, and especially the Spinergy Rev-X wheels, were once regarded as the pinnacle of futuristic high-tech.  Nonetheless, items falling in this category always maintain an aura of nostalgic coolness, like Flash Gordon's spaceship, or the famous novels by Edgar Rice Burroughs describing the barbarous splendour of a still-living and still-thriving Mars.  I decided to carry the black & white science fiction theme forward, sticking to a monochromatic colour scheme of silver and black only. My mission was to convert this purpose-specific machine into a more practical everyday rider.


Anyone remember the black-and-white sci-fi/horror movie Plan 9 From Outer Space (1959) by Ed Wood? Infamously labelled at one time as "the worst film ever made", it incorporated all sorts of wildly diverse elements (aliens, zombies, UFOs, vampires, government conspiracies), but nevertheless became a cult classic. I, too, ended up using a rather eclectic mix of parts.  With minimal or subtle branding or logos, the components will hopefully still have a cohesive look as a groupset. Nothing was left stock from the original bike except the Kinesis Aero carbon fork and the Cane Creek headset (which looked too much like a flying saucer to not use).  The tubing sticker (the only deliberate spot of colour on the bike) states the frame is made of Solaronite, a fictional element in the movie which has the potential to "destroy the entire universe". Oddly enough, it rides identically to aluminum.



PROBLEMS & SOLUTIONS: For me, the primary issue is the steep seat tube angle.  I've seen other builds converting triathlon-specific bikes into everyday riders, but they seem to ignore the frame geometry problem; you often cannot get the seat position adjusted back into a more standard road cycling position in relation to the bottom bracket, although you can get close using set back seatposts like the older Easton units. While not everyone is a believer of the K.O.P.S. method of bike fit, it is at very least a ballpark indicator.  The Hilo frame was designed around a forward riding positioning using an aerobar cockpit.  So how can we compensate?  The original Profile Design Fast Forward seatpost was meant to convert a standard(-ish) road bike's 73° seat tube angle into an 78°.  Would turning it around do the reverse here?  It turns out the answer is both yes and no: it has the setback required, but the seat angle adjustment is limited in the wrong direction.  In order to run the saddle +/- from neutral flat, I machined a piece of aluminum into a pivot stack to create increased pitch angle.  Problem solved.  If you are less picky about your fore-aft positioning, any set back seatpost will do.

Adapter to change the clamp angle

A second issue was the front derailleur.  I had planned to use the matching Sensah MX8 front derailleur, but couldn't mount it because the Hilo's retro-aero shift cable routing had a unique cable stop brazed onto the backside of seat tube above the BB.  So no front derailleur with a MTB-style lowered clamp style could be mounted.  It was designed in any case for road front derailleurs, so I installed a Sora road derailleur.  Here the steep seat tube again created a minor issue, as the angular difference in the mounting point moved the front derailleur both more frontwards and pitched forward in relation to the crankset; not a lot, but enough so that in a low-low (or low-2nd low) gear, the chain is rubbing (or very close to rubbing) the lower connection flange between the cage plates.  I never ride in the extreme low-low gearing anyway, but I still had to adjust the derailleur slightly lower than optimal in order to gain additional clearance.  If I had done a 1X conversion, I would not have noticed this peculiarity.

Retro-aero cable stop, seat tube angle required slight adjustment for chain clearance


The third issue was minor; a stripped rivnut on one of water bottle mounts.  I carefully drilled out the centre and removed the rivnut fragments, then had a shop install a new one as I didn't have the specific tool.  I think that was the first time in decades I paid for any kind of shop work, but they charged a very minimal fee and were kind enough to do it on the spot when I called ahead.

Damaged rivnut removed

NOTE ON THE WHEELS: You can find an awful lot on the internet about Spinergy Rev-X wheels; from catastrophic carbon failures, to the Ginsu-like edge of the spokes loping off body parts, to a European UCI conspiracy to ban the wheels - very dramatic stuff! I won't go into it, but there is always an inherent risk to using any vintage carbon, and it's always wise to regularly inspect older carbon parts prior to use.  But...it's hard to beat the Spinergy Rev-X wheels for pure retro-cool, and they still go for a pretty penny if you check online.  I have a pair of Rolf Vector 650c wheels as a really solid alternative in case I wanted to ride the bike harder.  Back to 650c: the available tire widths are fine for road use, but as a utilitarian build, I could wish for something meatier for the mean urban streets.  One option is to adapt 26" MTB wheels; they are only slightly smaller in diameter than 650c wheels.  It's an easy fix to change out the axle spacing to make it fit in the rear dropouts. The slightly longer brake reach required can be handled by using road brakes like Tektro R539's, or even by using aftermarket brake shoe extenders. Surprisingly, the Hilo can accommodate a pretty fat tire, so fitting 26'ers was entirely viable.  For now, though, I'll stick to the 650c's.


The final result after a bit of polishing:







Frame: 2000 Trek Hilo 100, aluminum frame, triathlon/TT specific geometry
Fork: Kinesis Carbon Aero 650c
Headset: Cane Creek threadless
Seatpost: Profile Design Fast Forward aluminum (with angle modifier)
Stem: Pazzazz threadless
Bars: Kona aluminum straight bars
Shifters: Sensah MX8
Front derailleur: Shimano Sora (FD-3500)
Rear derailleur: Sensah MX8
Brake Levers: Avid FR-5
Brakes: Shimano Sora (BR-3300)
Crankset: Shimano Alfine (FC-S501) with Shimano SG 53-39 chainrings
Bottom Bracket: Shimano external (SM-BB4600)
Wheelset: Spinergy Rev-X carbon fiber (650c)
Cassette: Shimano HG 11-28
Tires: - Michelin Pro Race (650c x 23)
Chain: KMC X8 silver/black
Saddle: Misc
Pedals: Time Link


RIDE REPORT: (2021-04-11) Lately, I've been wrenching far more than riding.  Covid means tons of bike work is available as everyone wants to ride but there is a severe undersupply of both bikes and parts. I finally got to go for a real ride on the Plan 9 in between repairs.  Every time I ride 650c wheels, I am reminded of how agile they feel, but the 9's slacker head tube angle definitely helps with front end stability.  The front hub seems to occasionally produce a tiny squeak when standing up and hammering; I'm thinking the hub bearings probably need replacement soon (under $20), but the wheels felt very stable and solid nonetheless.  The Sensah MX8 shifters and rear derailleurs worked flawlessly and very quietly in SRAM-like fashion.  My modified seatpost did the job, as it replicated my usual seat slammed back position.  Overall, the bike had a really quick and light feel to it, which surprised me because of the substantial airfoil downtube.  I can see how if the bike were set up as a triathlon or time trial rig, it would be an absolute rocket.  I did the test ride during a sunny day, and the raw aluminum finish combined with the distinctive wheels garnered some attention at stop lights and at the local coffee stop.  I'm labeling this build a qualified success.  Now if I can only find some 650c x 28mm tires online, it would be perfect...or some 26" wheels running WTB Thickslicks...hmmm.

N+1-1

(2021-02-26) 


Monday 22 February 2021

Bike Project: 1994 Giant Cadex CFM2 "The Purple People Eater Meets The Blue Meanies"

1994 Giant Cadex CFM2 = "The Purple People Eater Meets The Blue Meanies"

1994 Giant Cadex CFM2 updated


As purchased - utterly trashed

THE STORY: I bought this bike from a landscaper who quite literally pulled it out of a pile of landfill.  Visually, the bike looked utterly trashed, with warped wheels, bent handlebars, rotting rubber, a frozen suspension fork, and generally rusted parts.  I particularly liked the carriage bolt and nut securing the seatpost along with a soup can shim.  But the kicker was the bodge to work around a stripped pedal threading on a crankarm (see pic below).  Nevertheless, I eyeballed the frame and it seemed relatively straight, so I gambled and took it home.  I couldn't resist - I remember these Giant CFMs and CFRs back in the heady early days of production carbon fiber bikes and always wanted one.  These frames were made well before one-piece moulded frames, and like others in the era, were carbon fiber tubes bonded into aluminum lugs.

Definitely a WTF?! moment

A long way from home
 
Interestingly enough, the dealer sticker indicates the bike was bought at a Bicycle Superstore located in Dandenong, Australia.  I emailed the company with the serial number, but that particular location closed years ago, and records were no longer available.  I wonder how the bike ended up in Kelowna, BC, Canada?  If only bikes could tell stories....

Straightened up
 
A mite rusty

THE BUILD: Of course, there are always a few build obstacles.  The rear derailleur hanger was torqued off alignment.  There was little chance I could find a NOS replacement or even to cannibalise one, so I considered getting a new one cut from aluminum plate.  In the end, I managed to carefully straighten it without resorting to undue force.  When I removed the bottom bracket, I found a nice slush of water, dirt, and rust inside.  I cleaned out the insides of the tubes and inspected the BB joints; there was no signs of either notch failures or bonding issues.  The clearcoat was peeling, scratched up, or entirely rubbed off in some spots.  I carefully sanded off the old clearcoat and re-applied it.  I wanted to keep the purple fade graphics and left any flaws to give it some character.  The uniquely-shaped aluminum lugs were a Giant signature; I sanded out the scratches and chips, and matched the original silver paint.

Ready for assembly

The entire bottom bracket lug was impressively beefy, creating a solid wishbone structure for the chainstays.  The seatstays and the chainstays were made of a carbon fiber and kevlar composite; the material gave them a yellowish mesh look.  Small nubs in the chainstays indicate they were pinned as well as bonded into the bottom bracket, possibly for extra integrity.  I cut out some carbon-pattern vinyl to use as a chainstay protector.  Here is the finished result:


    

Frame: 1994 Giant Cadex CFM2 Carbon fiber/kevlar 18"
Fork: Tange Struts rigid fork
Headset: Dia-Compe Aheadset
Seatpost: Kona
Stem: Tioga
Bars: Kore
Shifters: Shimano Deore LX
Front derailleur: Shimano Deore LX
Rear derailleur: Shimano Deore LX
Brake Levers: Shimano Deore LX
Brakes: Tektro 865A cantilevers (purple anodised)
Crankset: Shimano Alivio with XT chainrings
Bottom Bracket: Shimano UN-52 sealed cartridge
Rear wheel: Sun Rims Rhyno Lite rim, Shimano Deore LX freehub
Cassette: Shimano 11-32
Front wheel: (Unknown) blue rim, Shimano Deore LX hub
Tires: -
Chain: Shimano HG
Saddle: WTB
Pedals: Time ATAC

RIDE REPORT: The first impression is that the bike is surprisingly stiff - it certainly is no noodle.  The CFM rode almost like oversized aluminum except there was a bit of a muted springiness to it that kept it from being harsh.  I tested it on the road and on the gravel, and I almost couldn't believe the ride quality of this thing.  By modern standards, the frame is far from the lightest.  Still, very impressive for a frame over 25 years old and manufactured by obsolete assembly methods.  I'm glad to see it lived up to the hype from the 90's.

This one sold quickly and went into an industry collection.

N1+1-1.

(2020-09-30)

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