Saturday, September 18, 2010

Retina-vibrating, skinny-tired time capsule

Yes, that's me in spandex and clipless shoes, not a common sight
UPDATE 18 Sep 2014: I've added a post featuring seatpost size and images of the seat tube cluster, per a reader request. See it here.

This post veers far away from Big Dummying or Daddying. In fact it's about a bike with no provision for fenders or cargo at all. Nevertheless, rest assured it is chock full of the bike nerd-ness you've come to expect.

You may remember my recent encounter with speed on two wheels. I was surprised to find that as non-competitive as I am, I enjoyed racing, at least against myself. I had fun as part of a team triathlon, even though my equipment was not well suited to all-out speed. While all-out speed for me remains a distant possibility, I now have a real road bike.

Enter a 1991 Diamond Back Master TG via Craigslist that I picked up for a mere $6.52 per pound. It has a 60cm center-to-top seat tube and a 58cm center-to-center top tube. The bike has been a garage ornament for the better part of the past two decades. It was obviously un-ridden, with grease having seeped out of every bearing assembly, collecting a translucent encasement of oily dust. 
1991 Diamond Back Master TG as it was when I got it
The Master TG has a full Shimano 105 7-speed group including Look compatible pedals. No unserviceable STI or finicky 9 or 10 speed parts, and it has a threaded headset; all big pluses for me. The tubing is Tange oversized chromium-molybdenum steel, TIG welded together. The bike maximizes use of quality steel with an Avenir 4130 heat treated seatpost and a Tioga Prestige stem. The rims are hard anodized Sun Mistrals, 36 hole front and 32 hole rear.

The previous owner bought it new from Pauli's Bicycle and Lawnmower in Metairie, Louisiana. He later equipped it time trial style, with a Profile aero bar, a Vetta C-10 cyclocomputer and a CO2 cartridge emergency pump. Other than these additions, the bike was stock catalog spec. The original bars were included, as were a pair of size 44.5 Lake shoes (unfortunately a bit too small for me) and a seat pack containing two new tubes with their receipt from a bike shop dated 9/10/91, a bottle of Motrin that expired 6/94 and a multi-tool.

The OEM 22mm Vittoria Zefir tires were flat but in good condition and held air confidently when I pumped them up. I've always liked the look of gumwall tires on dark gray hard anodized rims. I wonder why good gumwalls are so hard to find anymore?
Tange 100% OS CRMO tubing and a slightly askew dealer sticker
Dig the cool matching pink splattered black Paramount bottle cage
Other than old grease, dust and a few paint chips from leaning against things, the bike was immaculate. The photos don't do the intensity of the salmon pink color justice, which I have to admit I quite like. Although the color clashes with current ideals of a proper color for a bike, the paint itself is impressively high in quality, flecked and streaked with gloss black over top. The combo of garish 90s era paint, non-horizontal dropouts, lack of lugs and oversized tubing makes this bike unappealing both for hipsters looking for a fixie frame and collectors looking for a holy grail classic. These features contribute to a lack of respect culminating in low market value for what is really a great road bike, well suited for my purposes.

The frame is a descendant of the highly sought Centurion Dave Scott Ironman road bikes. It was made less than two years after Western States Imports (WSI), the owners of the Centurion brand, apparently decided to capitalize on the name recognition of their Diamond Back mountain bikes by re-branding their road bikes. As a remnant of this lineage, the bike has a decal on the left chainstay declaring it "Designed by Centurion." Sheldon Brown has some info about Centurion bikes, but there is very little info on the web about the short era of high quality steel Diamond Back branded road bikes, starting in 1990 and going to about '94 or '95. 
Furry with dust, prior to cleaning
WSI owned the Centurion and Diamond Back brands
The frameset was made in Taiwan, and appears to be of very similar quality and build characteristics as the two Surlys I own, which were also built in Taiwan. In this respect, it seems a bit like an antecedent to the Surly Pacer road frame. Overall, the welds are clean and the finish work is more than competent, though well short of custom. This is actually preferable to me; I am averse to owning a bike that is too expensive or pretty to ride. That propensity once kept me from buying a Rivendell Atlantis, and I'm glad to now know and acknowledge it.

I enjoy working on a bike as much as riding one, so as soon as I had the time I completely disassembled the bike and cleaned, adjusted and rebuilt everything from the bearings outward.
After cleaning and a coat of wax, it's almost factory fresh and completely rust free
The bike rides smoothly and quickly. After reassembly, I took it for a ride to Chatfield on the Platte River Trail and it performed well, with the resilient liveliness and subtle road surface feedback of a good steel frame. It's not the lightest or the quickest thing out there, but neither am I. At about 23 pounds, the Master TG feels like a svelte and nimble rocket after having ridden so many miles on a loaded Big Dummy.
1991 Diamond Back Master TG, resplendent in Pepto-Bismol colored glory
I've never been a fan of lycra-covered gel saddles, so the original Avenir saddle is off in favor of a vintage Flite from my parts box. I also temporarily swapped the Shimano 105 pedals for some SPD compatible units until I have the time to install Look cleats on my shoes. I returned the stock Centurion drop bar to its place, bringing the bike back close to original spec, with the exception of saddle and pedals. I haven't taped the bars yet, because I may exchange the stem with something that has a shorter extension than 130mm. I might go with a 110mm Salsa CroMoto to keep the TIG welded look, but a Nitto Technomic is also a possibility.

It's a little odd for me to ride a bike that doesn't have a utilitarian purpose, but I enjoy it anyway. I'll definitely be doing some more road riding, and who knows, maybe even some casual racing.


  1. What exactly is casual racing? Seems as though "casual" and "racing" are mutually exclusive.

  2. Hmm, you have a point. I may have inadvertently coined a new phrase. In my non sporty mind, I guess I was thinking of participating in a timed event, but not really competing with anyone but myself. I'll have to think about what to call that a bit more...

  3. I have the same frame. I love it for some reason and when I saw it I had to have it. I rebuilt mine with modern Ultegra/105. My frame is not nearly as pristine though. I got it from CL as well but I bought it site unseen and the seller wasn't honest about the condition. Mine has a couple of dents and tons of scratches. If for some reason you ever wanted to part with this frame email me first. (tgrossano at hotmail dot com) I'd love to have a spare in case this one doesn't survive.

  4. tgrossano: will do if I ever decide to let it go. Mine has cleaned up to be in like new condition, with the exception of some chips on the top tube from the bike leaning against things in a garage for 19 years. I've been really enjoying the bike and for some reason, I am hooked on the kooky paint job. I remember these bikes when they were new, and even then in the age of neon, the paint stood out. Beyond that, it has a great ride feel. As you probably know, there is an astonishingly limited amount of info on the web about these bikes.

  5. Just came across this while looking for any info on my Diamondback Centurion Interval TG, which, as near as I can tell, came out in 1991. You're right, there just isn't much information on these bikes, but my frame seems almost identical to yours. Funny story, I picked mine up almost by accident, as a straight-up trade for an almost new (and completely soulless) hunk of single-speed aluminum known as the dreaded Specialized Langster that I had picked up weeks earlier on Craigslist.

    The guy I traded with actually had three bikes he was willing to part with, including a Fuji and a Peugeot that I was convinced I was going to take home, but after test riding all three, there was something about the Interval that just felt ... right. Flash forward almost a year and it's the same feeling I get every time I take it out for a ride.

    I've put God knows how many miles on it, and there's just something about the feel of this bike that makes me want to keep going back out on the road. I feel like I've stumbled across some incredible secret: this bike isn't light by any means, but it's fast, isn't flashy but it's comfortable, isn't equipped (or priced) like a Trek Madone, but can run all day long and hold its own with weekend warriors on far pricier rigs.

    I will say, however, that — unlike you — I don't find my bike, which is black and yellow with decals that have somehow managed to hold on for dear life, appealing in the least from an aesthetic standpoint. It looks like its taken a few whacks from the ugly stick, and I plan on getting it refurbed, with a fresh red clearcoat, any day now. There will be nothing left to identify my sweet ride as a "Designed by Centurion" Interval TG, but that's OK. This incredible bike seemed destined to be underestimated in every regard, so it might as well keep its secrets.

  6. Kamon: I'm glad to hear that there are others who enjoy their obscure and unsung Diamond Back TG road bikes. Sounds like you made a good trade. If I remember correctly, the Interval is one below the Master in lineage, but shares the same frameset, differing only in parts and paint.

    I perpetually notice bikes. I'm also old enough to remember Diamond Back (and Centurion) road bikes from when they were new. A couple of decades later, I found myself in the market for a decent steel road bike for cheap. I've always liked lugged steel from Japan: Bridgestone, Miyata, Fuji, Specialized; even Novara and Giant. A few years ago you could likely have had your pick of Japanese steel on Craigslist. Not so now.

    I then searched out the fabled "magenta and macaroni" '86 Dave Scott Ironman Centurion, once ridiculed for its color scheme. I found the street value was through the roof. The '86 Dave Scott is now apparently embraced by the ironic hipster set. Then I remembered the short era of Diamond Back welded steel road bikes.

    There aren't many around; there never were. People write them off as unworthy because of the low swagger factor. A Master TG will never have the cache of an RB-1, but I've ridden both and for me the Diamond Back is a better bike. That is an incredible secret. I almost feel like hoarding any of the TG line that I find in my size. Good luck with the color swap on yours. I'd be curious to see how it turns out.

  7. BDD:

    Thanks for the kind words. Just wanted to leave a quick update: I've been without my bike for almost three weeks, waiting for its overhaul, but tomorrow I finally pick it up from the shop. Can't believe how well it turned out. According to my bike whisperer (I like to picture him as being like that guy from Toy Story 2 who is called in to repair Woody to pristine condition), the rehab turned out to be far more of a chore than expected. Taking the bike apart was no big deal, putting it back together ... a little more challenging. They ran into corrosion where they never expected it, had to replace far more parts than usual, and finished with a project that's suitable for any showroom floor. My favorite new detail: the tires are red, matching the new paint job, handmade in Germany and so pretty I almost, almost, hate to take them out on the road. Pretty sure I'll get over that about five minutes after getting my bike back tomorrow.

  8. Kamon, if what I see on your user icon is your Interval, it looks like it turned out great. Getting a new bike is fun, but getting a renewed bike that you already know and love is even better. It's good that you were able to find someone adequately detail oriented and precise to work on your bike. I've always worked on my own bikes and can't imagine the trepidation of turning one over to someone else.

    I too recently did a bit of renovating on my Diamond Back, as detailed here:

    Happy riding and congrats!

  9. Wow! I haven't sought more info on this bike since I bought it in 1992. I had a Raleigh Comp GS with a 531 Frame from the Birmingham England factory and loved it. But, I saw this bike at my bike seller and rode it and have loved it since. Heavy, gets plenty of notice, and assures confidence on the short and long ride. Thanks for all your grea info, it is very much appreciated. Cheers!

  10. Hi There,

    I just acquired a Diamondback Interval TG at a garage sale for $40. Its all original (from what I can tell) but in need of some TLC. The paintjob is a pinkish red with raised thin black brush strokes criss-crossing the tubes.

    I think its all original - Shimano Exage 500ex components, Avenir Lycra seat, Araya wheels, Centurion bars and Tioga headstem.

    Going to get stuck into renovating it for the road. Will let you know how it goes.



  11. I'm a cargo bike rider also(Yuba Mundo) and recently fell in love with the orange variant of the Expert TG at a local shop. When researching the bike some more I ran across your blog. Thanks so much for the information!

  12. Hey BDD,

    I've wanted to commend you for sharing your insights and info about these great, unsung bikes by Diamondback/Centurion. My story's similar to others posted here: I was searching through a friend's 'bike barn' (he's a low-end trader/dealer) and noticed this black frame hanging upside down from a hook every time I visited but never gave it a second look. Weeks went by and on the third visit, I took it down to inspect it and noticed how light it was and that it had the original bars brake levers, stem, headset, fork, and seatpost still attached to it. He said $10, I said sold! It sat around my garage for a few months until I was out of bikes to ride (constant upgrading/modding/reconditioning) so I planned to build it. As luck would have it, my lbs had a donated road bike with good wheels-for free! I bought a used rear derailleur, cranks, tires, bar tape and cables to fill-in the rest. I had a seat, brakes, and after much attention to the hopelessly stained white synthetic brake hoods, a pair of Dia Comp brake levers.
    Echoing what everyone else says about these bikes and their ride: really, really nice! It's comfortable yet lively with just enough compliance over the rough spots. Having owned and ridden many 'classic' and custom bikes, such as a DeRosa, '78 Masi, custom Japanese track bikes, etc., The only changes I would make over time are: longer cranks and shorter stem (the stock is a 130!). I was surprised to find the tire clearance was tight and wouldn't accept anything over a 32c, but that's what a 'real' roadbike is all about, right? Aesthetically, I dig the 'big 80's' graphics and reflective 'Oakley' sticker on the top tube, but I'm of an age to pine for my younger cycling days when these bikes were brand new. ;)

    My bike is here: if anyone's interested...

  13. I was looking for info on my recently purchased Diamondback Master GT and ran across your blog. I'm in process of rebuilding it with modern Ultegra/105 10-speed components. I had a red/white Dave Scott Ironman expert that I loved, but sold at dirt cheap price to a negibor who had his bike, and sole mode of transport, stolen in San Diego's North Park neighborhood about 2.5 years ago. I felt good helping him out - and no he was not a hipster d-bag - because he was good hard working dude, but man I've missed that bike. It was Tange 1 lugged steel.

    Anyway, the pain struck me right away when I saw the eBay ad for the frame and fork. All told I won it for $100 and have put some more into parts, etc. It's a passion project for me and the first bike I've built up so I'm really digging it.

    Anyway, my question for you BDD, is what is the seat tube diameter on your bike? I'm getting between 26.8 and 27.0mm on my calipers. I think the variation in my measurements is due to me and not any issues with the tube, but I wanted to get a second opinion. Also, any chance you can share a photo of your seat tube cluster? I'm curious about the bolt clamp on your nearly original frame.



    1. Congrats on your new bike. Sounds like you got a good deal. I can confirm that the original Avenir seatpost on my bike is a 27.0 mm. Also, as requested, I just created a new post featuring photos of the seat tube cluster:

      Hopefully it shows what you need. The bolt clamp is a very simple affair.

  14. Boy, it's been a while since I last visited this page, though it appears from the comments as though people still stop by here. To those of you who are discovering or acquiring old Diamond Back road bikes, I hope you enjoy them, and good luck with your rebuilding. They are good, solid old bikes that are still a lot of fun to ride.

  15. Hi Andy,

    Just thought you would like to know the Interval TG I posted about here back in Feb 2012 is still with me, now being ridden by my wife.

    We did a complete renovation on this garage sale find. The thing that stands out most about this bike is its smoothness.

    I am now on the lookout for a Master GT like yours.

    Here is a Photobucket link to a photo of our bike.




    1. That's a great looking bike, Mark! It's undoubtedly better than new. What size of frame are you looking for in a Master TG? It might be that someone who visits here may have a lead for you.


  16. Thanks Andy! Frame size would need to be 58 - 61cm for me.



  17. Wow! What memories this bike has. Stumbled across this page after nostalgically searching for the first real road bike I ever purchased for myself. And there she is.... my Diamondback Master Tg in pepto bismol pink. I was thinking I bought it in 89, but it could have been 90, or 91. Anyway, so many good times and lots o’ miles. The color was fitting for the day for sure. I had added a few chartreuse accents to mine. Anyways, all these years later and I’m still riding with that same passion as I had back in the day.... just on a more awesome, less pink, machine! Thanks for the awesome pics!

  18. If you are the original owner of the bicycle from the Pauli's sticker on the frame I was the one who built this bike at the shop in Metairie La. Great see in that sticker I had the same bicycle thanks for posting it.