Hi there,

I just bought a used Diamondback Roadbike and now wondered which model it was.
Would be great if anybody could help!

What it says on the upper part of the frame is "Centurion Designed Momentum"

see attached picture!

Thanks

I think the model is Momentum. but the real Centurian experts will know for sure. whats with all the black tape?

also we could use a bit more help. what model are the brakes, Derailleurs, and hubs? something like Exage Sport?

Welcome to BF. IIRC, WSI quit using the Centurion name after 1989, and used DB for road (as well as the mtn bikes) from 1990 on. You can use date codes on some of your components and look at the tables on the www.vintage-trek.com website.

Do you have any tubing stickers?

Thanks for those fast replies guys

Ok, I'm just going to write every label/brand down, I can see:

Brakes: Exage Motion
Shifting: Shimano
Derailleurs: Exage 300 EX
Chainring: Shimano Biopace Bigger: 52 Smaller: 40
Crankset: Exage 300 EX
Front Axle: Super Radius Blades
on Upper Frame: Avenir Equipped
Vertical Frame (top): TANGE CR MO Infinity Tubing
Vertical Frame (bottom): Low Temperature Brazed Hand Finished
Tires Quick Realease: Shimano
Tires: (C) Heng Shin Tire - Nylon - 26 - 622 (700 x 25C) - C-732-5
Rim: Araya 700C Japan
Seatpost Diameter: About 1 inch

Oh, and about the black tape:
There are little spots in the frame (I guess onsetting rust) and since there's a lot of rain over here (Portland, OR) I put some insulating tape over those spots. They're really small and the tape is way exaggerated, just wanted to make sure they're not going to get into the rain...

Shimano is the name of the company that made it, but they make a very wide variety of components from entry-level to professional quality. Is there a model name on the derailleur's? (e.g. 105, Ultegra, Dura-Ace)

Hi, I guess that's going to be "Exage 300 EX"
I wrote it in the next line

well aren't I clever... this might be worth reading.

Link

Let's try this ONE more time

hehe, could happen to anyone
the link is not working..

Hm, I'm not sure about this, just tried it and to me it seems pretty much centered, like you say it should be..
It is true though, that as soon as you don't look straight at them from the side (90°) they look super akward and strange (like I think yours in the picture). But straight from the side they look good.

Infinity was Tange's seamed tubing, so this bike won't be atop the lineup.

And for date codes, on the Shimano bits, you need to look for a 2 letter code, small, usually on the back, something like "PD".

Ok, I found the two-letter codes and also the part numbers:

Derailleurs: NI
Part No: RD-A300

Brakes: NI
Part No: BR-A250

Crankset: NK
Part No: FC-A800

Okey, now I figured out using the list on https://www.vintage-trek.com/component_dates.htm#shimano that my Shimano Parts are from September and November of 1989.

Can anybody tell the bike model from this information?

I still think the Model is Momentum and the phrase "Centurian Design" was to tie the old name to the new Diamond Back rebranding.

if your parts are dated for Sept '89 this is likely a '90 model then. while Infinity is not top of the line tubing it is no dog either, one of my MTBs is built with it (although custome drawn for Bianchi) and it rides great.

with a bit of TLC this will be a great bike

OH PS ditch the tape. remove it clean adhesive off. use a little bit of scotch brite cloth to clean the rust, clean with alchol and touch up with either testors white paint, or some white or clear nail polish

Ok, thanks
Need to register it, my old bike got stolen a week ago and I hadn't registered it... Not this time!

Thanks for the tip, I don't really like the tape to much either, the only advantage it could have I guess is that it looks less interesting for thieves..

I love that bike though

One minor thing I need to fix though is that one of the "caps" on the breaks is missing. Anybody have an idea where I could get one of those (or two in a set, if that's better) for cheap?
It's the grey thing on the picture. As you can see it is still there on one side but missing on the other...

+1. 1990 Diamondback Momentum, $310 US MSLP. Bottom of the line road bicycle but by then the road line had shrunk to only four models.

If Bianchgirll keeps using Centurian, does that mean the rest of us can start using Bionchi?

Looks like the same font and decal style as this one I am holding for Robbie:

That's ok with me then, I paid 200 for it and it's in good condition
Thanks for the Info!

It's the Diamondback Momentum, no doubt. In the first couple of "transition years," DB kept the name Centurion on the top tube, probably to try and hold onto some name recognition. If I was trying to follow up the successful 4-year run of Ironman and Lemans models, I would, too.

Often, there was also an Avenir logo back near the seat tube, I guess in exchange for a deal on the Avenir saddles they used, which almost all were covered in cloth that didn't last very well. As production costs increased, component levels pretty much decreased to maintain a price point.

There was a Diamondback Master and a Diamondback Expert offered, probably to try and keep some of the interest from the earlier Ironman Master and Ironman Expert. Some were lugged, probably only the 1990 or maybe 1991 models, most were not. It appears the DB Master and Expert were close to the Centurion Lemans and Lemans RS. I think the DB Master and Expert evolved into the Master TG and the Expert TG, which were TIG-welded. I had a nice 58cm Expert TG wtih compact triple RSX and Matrix wheels, a nice setup and pretty light, too. The tubing was simply labeledl "100% Chrome-Moly" by then. Seems the tubing decals changed every year around that time.

The Interval and Momentum were not that far apart in component levels, but the Momentum was probably lighter, as the Interval, I believe, was either HiTen tubing or something suitably in that weight range.

Some of the Centurion paint schemes carried forward, as in sjpitt's example above of the marbled treatment, also found on '89 Ironman models. Also offered were some "speckled" paint schemes, much like the early PDG Paramounts.

DB was in the process of putting all their eggs in the MTB market at the time, and not many steel bikes made it through the early 90's without taking real hits, for a variety of reasons.

Right from the beginning, in 1990, the Diamondback Expert and Master were the TG version, using the oversize, TIG welded Tange tubes. While they were intended as replacements for the Ironman models, the components were downgraded one level to make them more competitve in the shrinking road bicycle market. To the best of my knowledge, the only steel, lugged models to bear the Diamondabck logo were the 1990 Momentum and Interval. In 1991 the Momentum would be dropped from the line and the Interval would receive the TIG welded frame with oversize tubing. Diamondback's sole steel entry in the higher end road biccle market would be the Prevail TG, a 1991 model with Shimano 600 Ultegra and Tange Prestige. In 1996 steel would give way to the aluminum Podium series.

That fork if surely bent, see how close the tire is to the downtube compared to later pics in the thread. Don't despair though, Nashbar has a threaded 1" carbon fork for $70-$90 depending on the coupon/discount of the day, a shop should charge maybe $30 to install it and you could get a tuneup at the same time.
Try ebikestop on the internet for the aero brake hoods, they look like Dia-Compe "might" fit, maybe Shimano 105?, search under parts, brakes, road, brake lever parts.

And yes, I do covet sjpitts DBack. I think that stem may well be Tange Prestige. It appears my size, which is 56cm. The smaller tubed models had the pump peg a little higher up, but the oversize tubed models put id pretty much dead center on the 56's. A 54 would be a real bummer....

Note how the white housing disappears along the frame, while black would really stand out. The speckled wrap is perfect for the frame color, and I may have to try that on one of mine. A little upgrading, some deeper aero wheels in silver, and that's yet another bad-ace ride...

The Prevail. Very nice bike. Not my size, or color, but Tange Prestige, full tricolor.