OK, not to throw in a monkey wrench, but a friend of mine just got this:



By the down tube logo and the head badge it appears to be 1975 or earlier:




By the dropouts, lugs, wrap around seat stays, stem/bars and seat post, it appears to be a semi-pro. But this is the serial number:




Is this a different bike with a reproduction Centurion decal?

While a D-code serial number is atypical, I have no reason to believe this is not a legitimate Centurion Semi-Pro frameset. The serial number indicates 1975 and we know the Semi-Pro was produced this far back, even if all the submissions to date have been Miki manufacture. Centurion was a marketing brand owned by Western states Imports. As such the bicycles were all contract manufactured and I've logged well over a dozen different manufacturers for Centurion. If the prime source got into manufacturing difficulties for some reason (i,e, labour disputes, material shortages, equipment breakage, etc.), it was common to resort to a different source until the problem was resolved. Or it could be as simple as the operator grabbing the wrong stamp.

1991 model, manufactured in January by a source believed to be China Bicycle Company, who bought Western States Imports in 1989, and phased out the Centurion brand for the 1990 model year.

There's a 2011 Korn Ferry Institute article on Georgina Terry, where it is reported that her supplier, Tano, copied her frame design for use on Centurion models, which they manufactured for WSI. We know that Centurion introduced the Terry style Ironman Expert Women's model in 1987, followed by the LeMans Proportional in 1988. Samples of these bicycles in my database show them having S/N with N-codes. This would seem to be reliable information suggesting that the N-codes represent Tano. However, the sole 1987 Terry S/N I've found is an S-code. While it's possible that Tano used a different prefix for different customers, this does not appear to have been a common practice among manufacturers and is enough to leave some doubt as to the manufacturer of the N-codes. Still, Tano is currently my leading candidate for the N-codes. In addition to the article statement, Tano is generally cited as being the original Centurion source and is often reported as being WSI's major supplier in the 1980s.

Fun thread, and great info. I'll need to snap a picture of the serial number on my Ironmanwhen I get home.

Here is mine...

Hello T-Mar - I can't get down to the basement to check the serial number because I am in a cast but will in time. I got this Centurion Lemans as a throw in on a purchase I made a couple weeks ago. It's a heavy bike with steel wheels. Please tell me about it since I know nothing of Centurion other than what I read on Wikipedia.

Picked up an Ironman this weekend. Serial number is N5Mxxxx, but the build and livery indicate 1986. Red with white seat tube / head tube, '86-style branding, 600 SIS, etc.

Yes, it would be quite heavy, given the steel rims and hi-tensile frame. The SunTour VGT rear derailleur is the version introduced in 1974 and the frame still bears the North Star style head badge, so it should be circa 1974-1978. At the time, it would have been considered an upper entry level model and was 2nd from the bottom of the line. As you're probably aware from your reading, the Le Mans was the model that established the Centurion brand and was originally intended as a Japanese sourced Raleigh Grand Prix. This one is finished in the Raleigh influenced livery

Thank T-Mar. The look of the frame was familiar to me. Having grown up in small town North Western Quebec, it must have been common enough to have found a spot in my long-term memory.

What you're probably remembering is a Raleigh Grand Prix, as the graphics were very similar (see attached pic). Raleigh was arguably the 2nd most popular brand of 10-speeds in Canada during the early 1970s bicycle boom and the Grand Prix was their best selling model. Raleigh had a wide, well established distribution network and opened a bicycle factory in Waterloo, Quebec in 1972, so they may have been even more popular in Quebec. On the other hand, Centurion were relatively rare in Canada during this period.

Steelnutcase: I have what is probably the same year Semi-Pro that has chrome on the fork and seat and chain stays but not chromed lugs. I haven't posted enough yet to be able to post photos but will do so when I can. The SN on mine is M7C06892. It has all of the original components except the saddle, I bought it a couple of years ago off Craigslist and was thinking it was a Pro Tour,. It's black with no decals. I originally thought it was a repaint but the serial number is in gold as is the lug outlining. It might have been ordered with black paint. The bike has been well used but was rideable even though neglected,. Because it's going to take a lot of elbow grease to disassemble, clean and polish the paint and components, I haven't yet started on it. If the paint is original, I might be able to get it glossy again.


Unlike the 1978 version, none of my components are black (except the tips of the barcons). The Apex chainwheels and brake calipers are alloy, Again, I'll post photos of it when I can,.

EDIT: I just looked at yours again and see one key difference. Mine has Dia Compe side-pull brakes instead of center-pull, I'm still not certain what I have, The freewheel and spoke protector are like the 78 Semi-Pro and as are side-pull brakes. The bike is in storage right now. Measuring the wheelbase might give me a definitive answer.

Based on the serial number, you have a 1977 model. A Pro Tour of this period is easily identifiable by the presence of brazed-on posts for direct mounting the centre-pull brakes. Unless, the posts have been removed, you don't have a Pro Tour.

Ignore the forum warnings for posting, While pictures won't attach your post, they will upload to a gallery album where they can be viewed by forum members.

1987 model manufactured in late 1986. Looks like an Ironman Expert based on the colours.

By looking through the history of this thread, I discovered that the 1977 offerings apparently included a Super Elite and it came in black with gold pinstriping. Mystery probably solved.

I tried to post a reply that included photos a few minutes ago and in it seemed to post, but I don't see it here.

I made it through about 15 pages of this thread, tried the Search function, but finally gave up trying to match up my serial number. The bike is most certainly a 1987 Ironman Expert - it has the appropriate color (magenta/yellow), all 105 components, etc. Through the first 15 pages, I can't find a match to my serial number. For those of you who have been on this thread for 13 years, I apologize if this has been already sleuthed - I'll eventually get there! The serial number is: M7K6988. The Centurion will be one of my two daily rides and will get most of the bike path and road time. I'll be rigging it up with a full D-A group (8-speed). Right now, I'm drop-filling the chips and scratches with primer/filler, then I'll sand, mask, and airbrush the bad spots. It'll be ready to go by next Spring!

I have 5 Centurions right now, at least 3 of which I'll be selling. One is an early to mid 70s coffee color Super Le Mans SN Z672083. I'm not familiar with this SN format. The decals on the bike look like 1975 and prior but I'm guessing the SN indicates a later production date. Does anyone have any insight into the year made? I'll post a photo when I have 10 posts.

This is a bit of an anomaly. The M-prefix in this format is representative of Miki. They were a known Centurion source for the mid-range and upper end models but were used in the late 1970s to very early 1980s. The 1987 Ironman variants typically come for Tano, who used a similar format but with an N-prefix. Either WSI used Miki as an alternate source for some Ironman production or somebody at Tano accidentally grabbed an 'M' stamp, instead of an 'N'.

Given the era and format, one possible source is Bridegstone, in which case it would have been built in late 1976. However, typically the number string would only be five characters long and when they did get up to six, the lead number wouldn't be as high as '6'. Another manufacturer using a similar format was Miyata but that would make this late 1971 manufacturer and I have yet to come across any confirmed cases of Super Lemans that are this early. The other way to narrow the date is via the date codes that are often stamped on components, provided they are OEM. Date of Manufacture of Bicycle Components can be used to date a bike: component dating

And I just bought it from your friend.

Have a 75 centurion serial number is m5c00960
can’t upload pics but based on what I’ve read and the sticker on the seat tube that says hi ten high tensile steel made by miki. Any idea of the tubing?

The decal style is consistent with 1985, not 1975. The stamped dropouts and lack of brazed-on features with the exception of the two top tube cable tunnels and chain stay cable stop are indicative of a entry level model. It's definitely typical of mid-1980s, entry level Centurion models such as the Cavaletto and Signet, which used hi-tensile steel. I'm not aware of Miki having manufactured their own hi-tensile steel but have no reason to dispute it. The fork likely says Tange because it came form Tange's pre-fabricated fork facility. It was cheaper to buy complete forks from Tange, than for bicycle companies to manufacture them in-house. The best indicator to confirm hi-tensile steel is to measure the diameter of the seat post. Basic hi-tensile steels typically use 25.4-25.8 mm seat posts, while some lightweight hi-tensile steels use posts as large as 26.2 mm.

I'm not sure if that chain stay Novara decal is a model name or an aftermarket REI decal. I suspect the latter, as it does not have the dark blue outline to match the Centurion decal. The frame doesn't quite match a 1985 Signet, as it lacks the down tube cable stops for stem shifters. However, it's quite close to the 1984 Cavaletto, including the colour. It could be a non-catalogued or non-USA model. It's definitely been frankenbiked to an extent, based on the dual pivot brakeset. The crankset may be a replacement too. The Honor and Spirt derailleurs while more typical of 1975, were still available in the mid-1980s and were actually spec'd on the 1984 Cavaletto. That raises the possibility of a mis-stamp on the year indicator.

Selective photo assist...

Is it possible that the "made by miki" on the label doesn't refer to the steel's manufacturer, but it's their facility-specific decal to denote that they contract-built the frame?