OVER THE LAST four years, I've bought on eBay and elsewhere five Centurion-branded bikes of different models and have become interested in their origins and relative quality. I'm not an expert on the subject but since there seems to be no Centurion expert on the Web, I thought I would just throw out what I know. Most of what I've learned has been gleaned from others, including a former regional sales manager for Western States Imports (WSI), the Canoga Park, California company that designed, had manufactured in Japan and marketed in the US and elsewhere its Centurion road bikes and, later, its Diamondback mountain bikes.

The story begins in 1969/70 when WSI was formed by Mitchel Weiner and the first Centurion road bikes were introduced into the US market, mostly on the US West Coast. While Weiner focused on running the business and on marketing, "Cozy" Yamakoshi served as WSI's product development manager, doing most of the frame design work and coordinating and supervising the manufacture of his creations in Japan and exporting them to the US.

The earliest models of the Centurion line had high-tensile steel frames but by the late 1970s and into the early 1980s Centurion's pricier models, such as the Professional and Semi-Professional (late 1970s), Pro-Tour (late 1970s to early 1980s) and the Turbo and Comp TA models (early 1980s) featured Tange's high-end Champion #1 or #2 tubing, a double-butted, seamless chromium-molybdenum (CrMo) steel alloy.

The difference in weight between Champion #1 and #2 tubing (and the later high-end tubing used for Centurions, simply labeled Tange #1 and Tange #2 by about 1985) was so small (less than 3oz for a 58cm c-c frame, all eight tubes) that it seems a bit silly to debate supposed frame quality differences between these two high-end tubesets. The thing to remember is that the high-end Tange tubesets were high-quality CrMo steel which were on a par with high-end Columbus SL/SP (CrMo) and Reynolds 531 (manganese-molybdenum) tubesets.

Source: 1983 Centurion catalog

For more on weight comparison, see Appendices II & III

Tange's seamed Infinity CrMo tubing began replacing high-tensile tubing on mid-priced Centurion models, such as the popular LeMans RS, Super LeMans and LeMans Mixte models, by the early 1980s. Lower- end models of this period featured Infinity tubing for the three main tubes and high-tensile tubing for seat and chain stays and fork blades. In the highly competitive market of the late 1980s, Centurion's mid-priced models boasted Tange #1 and #2 tubing for the three main tubes and use of high-tensile steel became a thing of the past for even entry-level machines as Infinity replaced it.

The Centurion frames of the late 1970s and early 1980s were mostly outfitted with SunTour components or a mix of SunTour, Sugino and other components. Later, as their rival Japanese component maker Shimano came to dominate the market with innovative, quality components at highly competitive prices, WSI switched almost entirely to Shimano, with the lower and mid-priced Centurions sporting the Shimano's OEM "Light Action" parts and higher-priced models sporting Shimano 105, Shimano 600EX (and later Shimano Ultegra) and Shimano Dura-Ace groupsets.

There has been discussion of the relative quality of the many Centurion models. Generally speaking, relative quality among the various models was first determined by the quality of the tubeset and then, within variations of a model, by the relative quality of the groupsets from which one could choose. This included quality wheelsets, which reduced weight significantly.

An example can be seen with the LeMans RS model, Centurion's very popular, income-generating, mid-priced machine. It first appeared in the 1970s as a 10-speed with a high-tensile steel frame, but by the early 1980s appeared as a 12-speed with a Tange Infinity tubeset and a mix of Suntour and Sugino components. By 1987 it boasted the somewhat lighter and seamless double-butted Tange #2 tubeset and Shimano's "Light Action, Light Touch" group. Later still it appeared with the Tange #2 tubeset but fitted out with Shimano Sport LX components. My guess is that this transition reflected the demands of a highly competitive market environment which forced continuous upgrading of both frame materials and components within a single popular model to stay in the game.

Centurions (except the Cinelli Equipe model) have serial numbers on the underside of the bottom bracket shell but as far as I know there are no official records linking serial numbers to years of manufacture. That's the bad news.

The good news is that Tom Marshall (a.k.a. T-Mar), a Canadian engineer, racer and runner, with the help of Centurion owners from around North America and information from his own archives, figured out the serial number date codes for many Centurions. Here's what Tom has to say on the subject:

Japanese Centurions made between 1980-1990 use a serial number format WXYZZZZ where:

Example: N4E0283 indicates the 283 frame made during the period of weeks 9-10 in 1984.

"To date, I have received 19 samples that fit this format. All but one use "N" as the manufacturer indicator.

"There is a minor variation of the above format, for which I have two samples, both from 1984. This format does not use a letter for the first character and uses a five digit frame number (ie XYZZZZZ format). The first number still appears to be the calendar year of manufacture. It is unclear if the following letter represents a month or fortnight of manufacture. However, given a five digit frame number, it is probably a month indicator.

"Sometime in the late 1980s, Centurion/Diamondback started sourcing Taiwanese manufacturers for some of their lower-level models. The format varies somewhat and I have a limited number of samples, but in all cases the first number appears to represent the year of manufacture. The serial numbers vary from six to nine characters in length and may, or may not, include a letter as the first character."

Tom adds that he did not receive enough samples for 1970s models and does not have enough research material on Centurions of the 1970s to figure out serial number codes from that period. If someone among you, dear readers, has the key to the 1970s serial number date codes, we're all ears!

Another aid in dating Centurions is to look for date codes on the bike's components. Barring a major components upgrade at some point over the bike's history, one can safely assume that the frame was made within a year or so of the dates found on the majority of components in a group.

While dating by serial number and component codes will tell you the manufacture year of your Centurion, these methods will not necessarily tell you the modelyear. This is because model changes were made within a manufacturing year so the next year's model could be made and shipped in time to arrive for sale at retail outlets by the beginning of the calendar year or, in most cases, in time for the Christmas buying season. But all is not lost as model years can still be determined by comparing color schemes, usually varied from year to year, and components groups with those shown in Centurion catalogs, brochures and the advertising pages of period magazines, if you can gain access to such materials.

Centurion frame color schemes seemed to follow the fashions of the times and knowing where a particular color scheme fits on a timeline can aid not only in determining a frame's year of manufacture but also its model year. I do not know for certain what color schemes were used in the early 1970s but all I have seen are a single color throughout. In any case, many of the early to mid-1970s Centurions can be roughly dated by their 5-speed freewheels and/or their frame materials of high-tensile steel. But high-end models of the late 1970s boasted Tange Champion tubing (#1 or #2, etc).

By the end of the 1970s and well into the early 1980s, Centurion frames sported a two-color scheme, with the head tube of one color (eg. black) and the rest of the bike another color (eg. silver gray). In 1986 and 1987, the two-tone feature became more complex, with head and seat tubes of one color (eg. bright yellow) and fork blades and seat and chain stays another color (eg. black). The entire frame on these bikes was first painted the color of the head and seat tubes and then more coats of an another color were added to the other tubes. Light scratching of one of these frame's secondary color will reveal the primary color underneath. I believe it was at this point that clear coating was added, apparently after decals and other artwork had been applied.

Today, some view with shock and horror the pink/purple and pink/yellow two-tone color schemes of 1986-87 but these combinations were the rage at the time. There are often pristine examples of Centurion models with these color schemes (mostly the Ironman Master and Ironman Expert models) appearing on eBay and they often fetch less than similar models with more subdued colors.

Back in the day, these pink and pastel color schemes were attributed to the pervasive image of the TV show "Miami Vice." -- Sheldon Brown

By 1988 the "fade" color schemes had appeared. These were two-tone with most of the frame's triangle of one color (eg. bright red) but as the front of the top tube and top of the down tube approached the head tube, the color faded into a second color (eg. white), with the head tube and the fork blades being completely painted with the second color. Similarly, the tops of the seat stays and the forward portions of the chain stays matched the triangle's primary color but faded into the secondary color, the same as that of the head tube and fork blades. In 1989 this same color scheme was modified slightly with the primary color having a marbled or smoked appearance.

There may have been exceptions to these basic color schemes but the ones described here seem to dominate. It should also be noted that the paint jobs throughout the 1980s, regardless of color scheme, were of very high quality, featuring four primer and finish coats and a sealing polymer clear coat. These durable finishes, along with the high-quality Japanese frames and components of the late 1970s and 1980s, have made Centurions among the favorites of vintage steel-framed bike seekers today.

And now for my rough and ready pecking order of Centurion models.

First in my book is the unique Cinelli Equipe Centurion of 1985, a one-year-only "project bike" joint-venture of WSI and Cinelli of Italy (not Japan). This rare co-branded model has all Cinelli frame components: Columbus SL tubing; Cinelli chromed sloped crown and head lugs; bottom bracket shell; Campagnolo dropouts.

This bike's components were all high-end Italian-made, but not all Campagnolo. The bars and stem were Cinelli (flying C logo); derailers and shifters were Campagnolo Nuovo Record; brakeset was Universal (standard on many Cinellis); headset, bottom bracket and crankset were top-of-the-line Ofmega Mistral, beautifully made and finished to compete with Campagnolo. Freewheel was Regina CX-S; chain, Regina; hubs, Miche; rims, Fiamme; pedals, Ofmega Sintesi (composite platforms with clips and straps); seatpost, Gipiemme, and saddle, Cinelli "Volare."

An advertisement in the December 1984 issue of Bicycling Magazine, introducing the Cinelli Equipe Centurion, states:

"The frame is designed by Cino Cinelli and production is coordinated and supervised by his staff."

The ad also states that that the suggested retail price was $995.00 (1984\85 dollars; 2006=$1,942) with an introductory price of $789.95 (1984\85 dollars; 2006=$1,540).

I have seen six Cinelli Equipe's on eBay in four years and the best of them is sitting in my living room ready to ride. A few others advertized as new-old-stock might still be found at CyclArt.com and bike123.com.

My subjective opinion is that this all-Italian model, unique among Centurions, sets the Cinelli Equipe apart from the rest and earns it the number one place in the line.

But at about the same level in quality and performance as the Cinelli Equipe and introduced at about the same time, was the Centurion Prestige. It boasted Tange's high-end Prestige tubeset and was fitted out with Shimano's top-of-the-line Dura-Ace group. Later in the 1980s, the Prestige was offered with Shimano's Ultegra 600 and 105 groupsets.

I've seen two Web references claiming the Prestige fetched $1,000 and $1,100 new in the late 1980s. But price comparisons alone are not a perfect measure of quality for bikes from this period because as the Japanese Yen skyrocketed against the US dollar during the late 1980s, US-dollar prices of Japan-made bikes consequently soared across the board. Prices also varied across the US.

After the Prestige came the Centurion Turbo and Comp TA models, appearing in 1983 and 1984, respectively. The Turbo had a Tange Champion #1 tubeset and the Comp TA had Champion #2 (all eight tubes for both). The Turbo was a bit more expensive than the Comp TA, perhaps reflecting the difference in tubesets and varied group offerings. Turbos boasted top-of-the-line Sugino Mighty Competition and SunTour Superbe Pro components, while the Comp TA was fitted out with the very nice Shimano "New" 600EX groupset. The Turbo weighs in at 21.75lbs; the Comp TA at 22.7lbs.

The Comp TA (short for Competition Tri-Athlon) first appeared on the market in 1984 with a frame design identical to that of the Turbo. This bike was sold under the Comp TA name only in 1984. WSI had to drop the Comp TA model name because B.F. Goodrich owned the Comp TA trade name (a tire model still available).

The Ironman Dave Scott model name replaced Comp TA in 1985 and with the name change came indexed shifting with an upgraded Shimano "New" 600EX group. In 1987 the economy Ironman Expert Dave Scott model, with its Shimano 105 groupset, appeared and the "Master" designation was added to the original Ironman Dave Scott to distinguish it from the "Expert." The frames of both models were identical, featuring the same Tange #1 tubing, itself renamed from Champion #1. At about this time, a TIG-welded fork crown replaced the more graceful, semi-sloped investment cast fork crowns of the Comp TA and the earlier Ironman models. My 1988 Expert weighs about 21lbs.

These models were marketed as "triathlon specific" designs, but their geometry is not at all like newer triathlon bikes. These bikes are more like general high-performance "road" bikes. They were reputed to offer a ride that put less strain on the rider's arms, on the assumption that the rider would have tired arms after the two mile swim... -- Sheldon Brown

In 1988 the Ironman Carbon model was introduced. It boasted a carbon fiber frameset and Dura-Ace components. This model sold for around $1,500-$1,600 and was the highest-priced Centurion of the period. I have not ranked it at the top of the heap only because it falls outside the steel-framed category.

I want to take a step back to the late 1970s for a moment to mention a few very nice Centurions of the late '70s and early '80s. These are the Professional, the Semi-Professional, the Pro Tour and the Trac.

The 10-speed Professional and Semi-Professional models can be seen as predecessors of the Turbo and Comp TA as they were phased out as Centurion's top racing models just as the Turbo (1983) and the Comp TA (1984) appeared. The Pro and Semi-Pro, however, like the later Ironman Dave Scott Master and Expert models, had identical frames of the same Champion #1 (a.k.a. Tange #1) tubing. They also had a similar mix of Sugino and Suntour components but the Semi-Pro's components were a step down from those of the Pro. Both had beautiful chromed head tube lugs, not unlike in appearance those found on 1970s Cinellis, and their look was further enhanced with pin striping. The Pro weighed 23lbs; the Semi Pro 24lbs.

The Pro Tour also appeared in the late 1970s and survived into the mid-1980s. It is a gem, perhaps the nicest mass-produced touring bike ever. It can be seen as the touring version of the Semi-Pro but with a slightly stronger Champion #2 frameset and the touring versions of the Semi-Pro's nice mix of Sugino and Suntour components. It weighed in at 26lbs, not bad for a touring bike of its day.

There was also the Trac, a Tange Champion #5 plain gauge CrMo "all-purpose competition machine," according to Centurion's 1983 catalog. The Trac was WSI's response to the rise in popularity of velodrome racing in the early 1980s. It was a single gear with drillings for brakes (optional). The Trac had a mix of lightweight Sugino and Suntour components. It weighed 19lbs.

And now back to the lesser models of the late 1970s and 1980s. Down the food chain from the models mentioned above were the Super Elite and Elite, the Signet touring/triathlon model, the Omega, the Sport, the Custom and the Commuter. These appeared in the late '70s or early '80s and sport Tange Infinity CrMo or high-tension tubing and a mix of SunTour, Sugino and other Japanese components.

The Elite RS and Elite GT appeared in the mid-1980s and, like the Super LeMans and LeMans which followed them in the pecking order, appeared with progressively improving frame materials and components over the years. These two Elite models were a step down from the Comp TA and Pro Tour, respectively, with only their three main tubes of Champion #2.

The Sport Deluxe and Accordo were lower-end models of the 1980s with the lesser Tange Infinity seamed tubesets, and the Caveletto, among the least expensive of the line of this period, had a high- tensile steel frame.

For more on these and other models and when they appeared, see Appendix I , A Quick Reference to Centurion Models, contributed by Tom Marshall, whose knowledge of Japanese bicycles runs broad and deep. Much thanks to Tom for his contributions and constructive criticism.

Some time in 1990 WSI dropped the Centurion name, using the Diamondback trade name instead for both its mountain and road bike lines. Eventually, after nice Japanese-made bikes got too expensive for the US market because of exchange-rate and other cost factors, Diamondback was sold to Raleigh, USA. Production shifted to Taiwan. I don't know what happened after that.

So that's it as I "know" it. There are gaps in what I think I know and there are certainly inaccuracies but I believe nevertheless that this introductory overview is a useful start to learning more about this very nice line of American-designed and Japanese-made bicycles.

Appendix I

A QUICK REFERENCE TO CENTURION MODELS

By Tom Marshall

Following is a summary of popular Centurion models sorted by purpose and chronological order. An attempt has been made to identify the level of model, though this is somewhat arbitrary and, in certain cases, evolved over the life span of the model. The designated years indicate the first and last known occurrences of the model to the author, but may extend beyond the designated period. Where the design was relatively stable for a period of time, an attempt has been made to document some of the major components.

COMPETITION MODELS:

TURBO (1983 -1984): Mid- to high-end model featuring a Tange #1 frame. The 1983 version featured SunTour Cyclone but was upgraded to SunTour Superbe Pro for 1984.

Comp TA (1984): Mid-range model aimed at triathletes and featuring a Tange #2 frame and Shimano New 600EX components. This model was the subject of an infringement lawsuit brought by B.F. Goodrich, who had an automobile tire of the same name. It would evolve into the Ironman for 1985.

CINELLI EQUIPE (1985): One year only, high-end model. Designed by and manufactured under the supervision of Cinelli, it featured a Columbus SL frame, Campagnolo Nuovo Record derailers, Ofmega Mistral crankset and Universal AER brakes.

PRESTIGE (1985-1989): high-end model featuring Tange's Prestige tubeset. The 1985 version used Shimano Dura-Ace components, while the 1989 version was downgraded to Shimano 600 Ultegra. Components unknown for intervening years.

Ironman Dave Scott (1985-1986): Mid-range, triathlon model that replaced the Comp TA and featured the Tange #1 frame and same Shimano New 600EX components. SIS on 1986 model.

FACET (1986): Mid-range, aluminium-framed model, featuring SunTour Sprint derailers.

IRONMAN EXPERT DAVE SCOTT (1987-1989): Lower, mid-range, triathlon model. Prompted by the success of the Ironman Dave Scott, it was a more economical version that used the same Tange #1 frame but featured more affordable Shimano 105 components.

IRONMAN MASTER DAVE SCOTT (1988-1989): Mid-range, triathlon model replacing the Ironman Dave Scott. The Master designation was added to differentiate it from the lower Ironman Dave Scott Expert. Tange #1 frame and Shimano 600 Ultegra components.

IRONMAN CARBON DAVE SCOTT (1988): An attempt at a high-end triathlon model by pairing Shimano 600 Ultegra components to a carbon fiber frame and aluminum fork. Believed to be a one year model.

GRAND TOURING MODELS:

ELITE GT (1984): Entry level touring model with a single butted, Tange #4 frame, SunTour MounTech derailers, Sugino triple crank and Dia-Compe cantilevers.

PRO TOUR (1976-1984): Mid-range model featuring Tange #2 tubing. Early models were only 10 speeds but featured wide range gearing. Rather than cantilevers, these models featured center-pull brakes with the calipers mounted directly to brazed-on frame bosses to reduce flex. Later versions (Pro Tour 15) featured triple cranksets and cantilever brakes.

GENERAL PURPOSE/SPORTS/RECREATIONAL MODELS:

LeMANS (1970-1989): The model which introduced the Centurion brand and probably the most popular model through 1984. It evolved constantly over the years, with 1970s versions being entry level with hi-tensile frames, while the late 1980s LeMans RS models were more upscale with Tange #2 main tubes paired with lesser grade Mangaloy or CrMo stays and forks. Components varied significantly, depending on the year.

SPORT (1976-1985): An entry level model, positioned just below the LeMans, early versions featured hi-tensile frames and SunTour/SR/Dia-Compe component mixes. By the time of its last appearance in 1985, it was designated Sport DLX and sported seamed, Tange Infinity, butted main tubes and was equipped with SunTour Arx derailers, Sugino cranks and Dia-Compe 500 brakes.

ELITE (1983-1984): The 1983 Elite 12 was a mid-range model with a Tange #2 frame and SunTour Cyclone derailers. For 1984 it was renamed the Elite RS and downgraded to Tange #3, but still sported Cyclone derailers.

COMMUTER 5 (1984): Entry level, 5 speed, commuting/city bicycle with Tange #5 main tubes.

CAVALETTO (1985): Entry level model with hi-tensile frame, Shimano Z derailers, Sugino crankset and Dia-Compe 500 side-pull brakes.

ACCORDO (1985-1989): This upper, entry level model featured a Tange Infinity main triangle with stays and forks that varied from hi-tensile steel to CrMo, depending on the year. derailers were Shimano Light Action for 1985-1987, with Exage used in 1989.

SIGNET (1987): Apparently, a bottom of the line model with hi-tensile frame and Shimano Skylark derailers.

  Appendix II

CHAMPION TUBING No 1 & No 2 BIKE FRAME WEIGHTS:

All eight tubes for 58cm c-c (23.5" c-t) frame

Champion No 1 Double-butted chromoly tubes throughout for road racing. Tang's lightest "street legal" tube set. Complete set weight: 2.22Kg.

Tube wall thickness

Top 0.8 - 0.5 - 0.8mm
Down 0.8 - 0.5 - 0.8mm
Seat 0.9 - 0.6 - 0.9mm

Example: Turbo (complete set)

Champion No 2 Double-butted chromoly tubes for touring. Lightweight but slightly thicker to accommodate heavier load factor of touring. Complete set weight: 2.29Kg.

Tube wall thickness

Top 0.9 - 0.6 - 0.9mm
Down 0.9 - 0.6 - 0.9mm
Seat 0.9 - 0.6 - 0.9mm

Examples: Comp TA and Pro Tour 15 (complete sets) Elite 12: (3 main tubes)

Source: 1983 Centurion catalog

  Appendix III

TANGE TUBESETS: WEIGHT AND USE COMPARISONS

This information was compiled from sales catalogs and correspondence with tube manufacturers and importers in the early 1980s. The use and rider weight notations are intended to be only rough guidelines. Each of these can vary depending upon frame size, expected frame life, desired performance characteristics, weight, etc.

Prestige
Tubeset Weight: 1987 grams
Use : Road racing/track
Max Rider Wt. : 150lbs

Champion #1
Tubeset Weight: 2220 grams
Use : Road racing/track
Max Rider Wt. : 175lbs

Champion #2
Tubeset Weight: 2290 grams
Use : Road racing/track/touring
Max Rider Wt. : 200lbs

Champion #3
Tubeset Weight: 2360 grams
Use : Touring
Max Rider Wt. : 200lbs

Champion #4
Tubeset Weight: 2270 grams
Use : Touring
Max Rider Wt. : 175lbs

Champion #5
Tubeset Weight: 2460 grams
Use : General purpose/road
Max Rider Wt. : All weights

Mangaloy 2001
Tubeset Weight: 2415 grams
Use : Road racing/touring
Max Rider Wt. : 200lbs

MTB
Tubeset Weight: 3207 grams
Use : Off-road
Max Rider Wt. : All weights

Source: This is an excerpted and edited text version of data originally posted on Jalon Hawk's website.

Jalon Hawk builds high-end frames to order