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Sekai Bicycle Database

Old 09-01-11, 01:36 PM
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RaleighSport 
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Sekai Bicycle Database


A typical example of a late 70's Sekai 2700.


Sekai Bicycles:was bought out in 1983 by Norco, Production of Sekai Bicycles stopped in 1990 completely.
Sekai was a private label brand that had their frames contract manufactured by a number of sources. One of those sources was Miki, a Japanese manufacturer. Miki manufactured bicycles for several brands, including but not limited to, Centurion, Norco, Raleigh, Sakai, Sekai and Shogun. Your serial number matches the format used by Miki and indicates it was manufactured in the 2nd fortnight of a year ending in 1 (i.e. 1971, 1981, 1991, etc.). The exact year can typically be determined from frame features.
T-mar
The goal:
I'm going to attempt to put as much information as possible about Sekai bikes here in this thread, if you have something to add or correct etc please chime in.

The Information:

Backstory for the company


Article on History/Value in current market


Models Produced

Catalogs/Brochures etc.

Decals


Dating by serial


Known Serials


Credits and thanks for links/info: T-Mar as can be seen throughout this thread, yellowjersey cyclery, retrobike.co, classicrendezvous.com, Don Gillies,re-cycle.com, sekaibmx.wordpress.com and anyone who posted in this thread or PMed me more info..
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Old 09-01-11, 03:29 PM
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do you only want road bike sekai info?
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Old 09-01-11, 03:36 PM
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Models Produced:"The higher the model number, the better the bike was the general rule. You will find though, that you'd be better off referring to this listing below and drawing your own conclusion. (They are not listed by quality, but rather model number, although the general rule applies). Most frames used Tange tubing.

120 Commutor (3 speed - incorrect spelling per Sekai literature, not sure if intentiontial)

150 Cummutor (5 speed)*

175 Folding (3 speed) 16 inch wheels,

350 Superhawk (Tubing 4130)

360 (1980 model)“Firefox” Champion 4130 Cro-Moly 3 Main tubes, 4.6lbs, Chrome Plated. Tange #500W Cro-Moly Fork, Chrome Plated. Takagi One-Piece Crank with a 5-pin Spider and Alloy Ring UKAI “72″ Alloy Rims. Suzue BMX Hubs, Silver. Kashimax Turbo Saddle. 25 lbs Total

380 Viper (Mild Steel/Hi-Ten)

400 – Tange, high carbon, plain gauge tubing; 26.0mm seat post; cottered cranks, Dia-Compe center-pull brakes; Shimano Lark (rear) and Thunderbird (front) derailleurs with stem shifters. This is on par or just above your run of the mill department store bargain buy.

410 Steel rims, cottered cranks, stem shifters, turkey levers (Unconfirmed but highly likely)

500 - Tange, high carbon, plain gauge tubing; 26.0mm seat post; alloy cranks; SunTour Honor (rear) and Spirt (front) derailleurs; Dia-Compe center-pull brakes.

750 Saquatch (MTB)Tange No. 5 Cro-Moly Butted Tubes ,Sun Tour shifter, Front and Back DR Suntour Mountech, Crank Sugino, 18 speed, Dia-Compe Brakes, Araya 26 X 1.75 rims

Sekai Sasquatch. the serial number is Y6A2746.
It is an 18 speed, the size is 18" frame Cro-Mo Tapered Double butted tubing (Infinity), shimano crank, shimano M-5 selectors, Dia-compe Cantilever Brakes, suntour XC sport derailleurs, 26" rims, sakae MT CR-MO Bar with ritchey grips, SR MTS-100 Stem
It's a 1986 model manufactured in January by Yamaguchi of Japan and designed by Norco of Canada, who had acquired the brand about three years earlier. Norco offered the same model in Canada under their eponymous brand. The spec'd geometry is typical for the early ATBs, with shallow angles (68 head & 70 seat) and a long (44") wheelbase. Claimed weight was 32 lbs. Original price was $435 US. I'd classify it as a mid-range model for the era.



1000 Sprint (early 80s) - Tange, hi-tensile, single butted tubing; 26.2mm seat post; SunTour Seven derailleur, alloy bars and stem.

1000 Royal

1400 Magnus GT

1500
Tange High Carbon Standard Gauge tubing, Sugino Cranks, Front derailer: Suntour 7, Rear derailer: Suntour 7 GT,Shifters: Suntour stem friction, Brakes: Dia-Compe Center Pull, Handlebars: SR (Sakae) 'North Road' mustache-like bars, Stem: SR (Sakae)

2000 Super SX (early 80s) - Tange frame, Tange Hi Ten fork, Tange headset, Sugino Gt cranks, SunTour VgT (rear) derailleur, SunTour (front) derailleur, SunTour Perfect 6-speed freewheel, Dia-Compe side-pull brakes, 27 x 1 ” Araya alloy rims, Suzue rear hub, SR stem.

1978 Sekai Limited 2400, 62cm, 10 speed (2x5). Tange high tensile steel butted tubes throughout. Upgrades: 42cm bar, bar end shifters, newer wheels. (I have the original shifters and wheels if you want them instead.) Comes with pedals. Good condition. No shifter or water bottle bosses on the frame.

2400 (1981) Sugino Bottom Bracket, V-GT luxe RD, Super Maxy crankset, Suntour DT shifters, tange 1 fork, 27 inch araya aluminum rims.

2400(1985) Tange #2 Frame, suntour adjustable dropouts, suntour ARX derailers, suntour barcon shifters, 27 inch araya aluminum rims.

1981 2400 SER# Y1N2928
Made in Japan

Green Tubing Decal:

" Mangaloy
Butted Manganese Alloy Tubing
Tange Industries Ltd. "

Suntour VGT Luxe Rear Derailleur
Suntour 7 Front Derailleur
Suntour Power Shifters on downtube
Suntour Perfect 6-speed Freewheel
Suzue Juno small flange hubs with quick release Front n Back
Araya 27 1/4" Aluminum rims 36h
Sugino Super Maxy Crankset
MKS Quill-2 pedals
SR stem
SR Road Champion Handlebars
Dia Compe black anodized brake calipers
Dia Compe Q/R Levers with gum hoods
Black Sekai Deluxe Saddle Kashimax
26.2 Aluminum seat post

2500 Grandtour Frame; Tange Champion #2
FD/RD; Suntour ARX w/clamp on DT shifters
Crankset; Sugino GT w/add on triple
Wheels; Suzue hubs/Araya rims

Frame Sekai 2500 Special
Serial # K8H03368
Handlebars Sakae Custom
Shifters Suntour Ratcheting Powerthumb Barcon Shifters
Front Deraileur Suntour Compe V
Rear Deraileur Shimano Crane GS DR-102
Cassette Maeda (suntour) Perfect 8.8.8 PF 5 speed.
Crankset/Arm Sugino Maxy 165 Arm 52
Brakes Silver Dia-Compe 610
Brake levers Weinmann Red Dot Type 500
Bearings Suzue SATN 0.5
Rims Ukai 27"x1.25" W/O LA
Pedals Lyotard 136R
Saddle Selle Italia Touring
Frame Pump Primus

Sekai Grandtour 2500
64cm (25.25")
58.5cm top tube
27 in wheels
27 x 1 3/8 Kenda tires
Suntour AR LI derailer
Suntour Cyclone front derailer
Suntour Power shifters
Moxy cranks
Sekai seat (not so great condition)
Raleigh headset
Raleigh handlebars
Dia-Compe break levers
Dia-Compe front and rear brakes
Serial# 77G90258

Sekai 2500 Grandtour
18 speed
Colour: Dark Red
Frame: 21”.
Front & Rear Derailleur: Suntour Mountech
DT Shifters: Suntour
Crankset: Sugino GT
Chainrings x 3
Pedals: MKS GR8 (Japan)
Hubs: Suzue
Rims: 27” No identifying labels but assumed to be original
Brakes: Dia Compe
Serial No. 365450
Made in Japan sticker

Sekai 2500 1979
Super Maxy Crankset
Suntour Cyclcone RD/FD
Tange Peerless tubing
Serial Number YOL8103

Sekai 2500 GT:
Suntour shift levers, Dia-compe brakes, Sugino crankset, Mountech front, Shimano rear der, Nitto stem and bars.
Tange #2
Six digit serial (!) 365519





2600: 1985 was a club racer that sold for $325. The main triangle is Tange 900, which was a seamed, butted CrMo tubeset. Forks and stays are slightly downgraded with Tange Mangaloy. Angles are typical club racing for the era, with a 73 head and 72.5 seat. Wheelbase is spec'd 39.9", 16.4" chainstays, 1.9" rake, 22.6" top tube. Quoted figures are for a 23" frame.

2600 (1987 model) Tange Infinity Tubing, Mangalloy Fork, 105 components and gold araya rims. Nitto bars and stem.

2600: Eurosport Dia-Compe 500 brakes

2700 Examples:
Sekai 2700 Gt Deluxe

Color; Blue
Frame; Tange Double Butted/Hi-Ten throughout
FD/RD; Suntour Cyclone w/banded DT shifters
Crankset; Sugino Mighty Tour w/Sugino BB
Wheels; Shimano hubs/Araya rims

Sekai 2700 Gt Deluxe
Color; Tan
Frame; Tange Champion..........decal does not designate any number, Pro, etc.
FD/RD; Suntour Vx w/Suntour barend shifters
Crankset; Sugino Mighty Tour w/Sugino BB
Wheels; Shimano hubs/Araya rims



2750 (MTB)

3000,
Ac 500 brakes ,Suntour Symmetric shifters, suntour arx derailer, sugino gt cranks
techmomic stem, nitto olypaid 115 bars, 12 speed Cro Frame.
1988(Highly likely, but unconfirmed)

Tri-Comp, 3000: Decent quality, 600 components, SN M4B00246 indicates it's Miki manufactured in early 1984. No dealer sticker. Ugly seat and downtube decals a little curled and not perfectly applied. Model name (Tri Comp) on left side top tube only. Champion 2 tubing.



4000 Criterium – (1973) Ishiwata tubing possibly until 1975 when Sekai went to mainly Tange.
Tange Champion #1 Tubing .06x.05 Cr-Moly throughout, Lugs tange short point with cutouts,Shimano SF micro adjusting dropouts, headset tange Falcon,

5000 Tange Professional .06 x .03 double butted Cr-Moly, Lugs tange short point with cutouts, Shimano SF micro adjusting dropouts, Headset Tange Levin Extralight competition, seat lug tange allen key seat pin.

Unnumbered models or unknown numbers
Sekai Magnum S7
Norco era

Tange #2 Cro-Moly
Chocolate brown paint with a cream head tube
Top mounted downtube shifters (with a protruding square boss underneath it)
Two sets of bottle cage bosses on the top and bottom of the downtube
Nitto stem and Nitto Grand Randonneur drop bars
Sella Italia saddle
Dia Comp canti breaks
SunTour Cyclone M-II drive
Sugino triple crank (not sure what model)
Araya 700C wheels (presta valves, 40 spokes)
Magnum GT:
Cranks: Sugino GT 110/74
Serial: Y4A2427 (indicates 1984)
Mountaineer (MTB)
Mountaineer SL (MTB)
Cherokee (MTB)
Bush Plot (MTB)
Everest (MTB)
Kokanee (MTB)
Bigfoot (MTB)

Sekai Bigfoot MTB Welded OS 4130 frame and 4130 fork 31 lbs w/light and kickstand. Shimano Light Action thumbies and derailleurs. Sugino VP triple
Serial number F701***
Oswego(possibly MTB)"

https://www.re-cycle.com/History/sekai.aspx


Sekai Navigation:


Backstory for the company

Article on History/Value in current market


Catalogs/Brochures etc.


Decals

Dating by serial


Known Serials
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Old 09-01-11, 05:47 PM
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I have a sekai 1000 from 83, maybe 82. lugged hi-ten frame, it had suntour honor rd. alloy araya rims, not sure about the rest. it's collecting dust in my parents basement, wheel less. I will check other parts next time I am over there.
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Old 09-01-11, 09:24 PM
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Dating by serial: A large number of Sekai frames came from Kawamura, thus you may find this of use, if your format doesn't match however do not fret simply refer to the information that follows the Kawamura info.
Originally Posted by T-Mar View Post
Kawamura manufactured frames (1972-1987*)

Serial number format XYZZZZZ where:

X is a letter indicating the market using the following codes:
A= Australia
C = Canada (pre-1985)
E = Europe
K = USA (pre 1985)
W = USA (1985-1987*)

Y is a letter indicating the last digit of the manufacturing calendar year, where A =1, B = 2, C = 3… J = 0. Exception is letter S, used on all frames prior to 1975.

ZZZZZ is a five or six digit number, apparently representing a sequential frame manufac turing number for the year (or era in the case of pre 1975 frames)

Example 1: KA24587 is the 24,787th frame produced in 1981 for the US market.

Example 2: CG231117 is the 23,117th frame produced in 1977 for the Canadian market.

Example 3: WE54612 is the 54,612th frame produced in 1985 for the US market.

* Serial number format may extend beyond 1987, but there are no reported examples, to date.

https://www.bikeforums.net/showthread...mber-Database?

70's At least for some Sekais the Y## format and M## one should actually equate ## with the last two digits of their respective year IE. Y77 is 1977, however this does not apply to all Sekai formats.. apparently not even all Mikki or Yamaguchi manufactured frames. Please consult with specs and pictures if you feel your serial is not matching to format.


80's Yamaguchi/Mikki made Sekai frames refer to the quote from T-mar.

Originally Posted by T-Mar View Post
Apparently, Miki made both Sekai and Sakai frames. Sekai frames were manufactured by Miki and assembled by Sakai Export. It not uncommon for a manufacturer to produce more than one brand. The serial number format should be Myfxxxx, where y is a number designating the year and f is a letter designating the fortnight. The same serial number format shows on on some Norco and Centurion models, though it is unclear whether these frames were made by Miki or another manufacturer with the same serial number format. For instance, Merida of Taiwan uses the same format.
DBSM Serial framesets:
Originally Posted by T-Mar View Post
The DSBM serial numbers in my database indicate that the 1st number is the year of manufacture. Additionally, the 2nd and 3rd numbers may well be the month indicator. To date, there has only been one example where the the 2nd and 3rd number combination fell outside 01 to 12, however that serial number suspiciously had only 7 numbers, as opposed to the standard 8 numbers in all my other samples. Consequently, I suspect a transposition error but never did get corroboration from the owner.
Sekai Navigation:
Backstory for the company

Article on History/Value in current market

Models Produced

Catalogs/Brochures etc.

Decals

Known Serials
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Old 09-05-11, 07:10 AM
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sure thing. next time i'm up there i'll get the number and snap a couple pics. it's in pretty rough shape. last ridden in 93 with an mtb rear wheel (I busted two rims bunny hopping curbs in college)
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Old 09-05-11, 02:25 PM
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https://www.yellowjersey.org/SEKAI75.JPG 1975 catalog at yellow jersey
https://www.retrobike.co.uk/forum/gal...2_itemId=25384 Very cool set of reviews/specs from '77.
Catalog photo dump courtesy of Claegrid
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Old 09-05-11, 03:59 PM
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OEM decals can be purchased here: https://www.yellowjersey.org/sekai.html

A few img files for the industrious.




Sekai Navigation:
Backstory for the company

Article on History/Value in current market

Models Produced

Catalogs/Brochures etc.

Dating by serial

Known Serials
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Old 10-01-11, 08:32 PM
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'80 Sekai 2000 Super SX

Serial Number - Y0F5767

62cm seat-tube cc

Tange frame, Tange Hi Ten fork, Tange headset, Sugino SuperMaxy cranks, SunTour 7 derailleurs/shifters, SunTour Perfect 6-speed freewheel, Dia-Compe center-pull brakes, 27 x 1 Araya alloy rims, Suzue hubs w/Sekai decals, Alps stem and Bars.

Purchased at Valley Cyclery in Auburn, WA

This bike was picked up by a friend and given to me in filthy condition. But, it cleaned up pretty nice. I've put on new tires/tubes and tape. (Mite redo this with blue cloth, as I did a pretty poor job. I'm used to using nicer cork tape). I rebuilt the bottom-bracket and tuned the drive-train. Rides nice but its a bit big for me and won't be ridden in favor of my other bikes. I'd like to sell it to someone that could put it to better use. Anyone want to give an appraisal for me or should I re-post in that section?















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Old 10-01-11, 09:03 PM
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Original front page

Sekai Bicycle Database
Sekai Bicycles were bought out in 1983 by Norco, Production of Sekai Bicycles stopped in 1990 completely.


I'm going to attempt to put as much information as possible about Sekai bikes here in this thread, if you have something to add or correct etc please chime in.


Backstory for the company:
https://www.classicrendezvous.com/Japan/Sekai_main.htm


Article on History/Value in current market https://www.ece.ubc.ca/~gillies/sekai..._VALUATION.txt


Models Produced:


"The higher the model number, the better the bike was the general rule. You will find though, that you'd be better off referring to this listing below and drawing your own conclusion. (They are not listed by quality, but rather model number, although the general rule applies). Most frames used Tange tubing.


120 Commutor (3 speed - incorrect spelling per Sekai literature, not sure if intentiontial)


150 Cummutor (5 speed)*


175 Folding (3 speed) 16 inch wheels,


350 Superhawk (Tubing 4130)


360 (1980 model)“Firefox” Champion 4130 Cro-Moly 3 Main tubes, 4.6lbs, Chrome Plated. Tange #500W Cro-Moly Fork, Chrome Plated. Takagi One-Piece Crank with a 5-pin Spider and Alloy Ring UKAI “72″ Alloy Rims. Suzue BMX Hubs, Silver. Kashimax Turbo Saddle. 25 lbs Total


380 Viper (Mild Steel/Hi-Ten)


400 – Tange, high carbon, plain gauge tubing; 26.0mm seat post; cottered cranks, Dia-Compe center-pull brakes; Shimano Lark (rear) and Thunderbird (front) derailleurs with stem shifters. This is on par or just above your run of the mill department store bargain buy.


410 Steel rims, cottered cranks, stem shifters, turkey levers (Unconfirmed but highly likely)


500 - Tange, high carbon, plain gauge tubing; 26.0mm seat post; alloy cranks; SunTour Honor (rear) and Spirt (front) derailleurs; Dia-Compe center-pull brakes.


750 Saquatch (MTB)Tange No. 5 Cro-Moly Butted Tubes ,Sun Tour shifter, Front and Back DR Suntour Mountech, Crank Sugino, 18 speed, Dia-Compe Brakes, Araya 26 X 1.75 rims


1000 Sprint (early 80s) - Tange, hi-tensile, single butted tubing; 26.2mm seat post; SunTour Seven derailleur, alloy bars and stem.


1000 Royal


1400 Magnus GT


1500 Tange High Carbon Standard Gauge tubing, Sugino Cranks, Front derailer: Suntour 7, Rear derailer: Suntour 7 GT,Shifters: Suntour stem friction, Brakes: Dia-Compe Center Pull, Handlebars: SR (Sakae) 'North Road' mustache-like bars, Stem: SR (Sakae)


2000 Super SX (early 80s) - Tange frame, Tange Hi Ten fork, Tange headset, Sugino Gt cranks, SunTour VgT (rear) derailleur, SunTour (front) derailleur, SunTour Perfect 6-speed freewheel, Dia-Compe side-pull brakes, 27 x 1 ” Araya alloy rims, Suzue rear hub, SR stem.


1978 Sekai Limited 2400, 62cm, 10 speed (2x5). Tange high tensile steel butted tubes throughout. Upgrades: 42cm bar, bar end shifters, newer wheels. (I have the original shifters and wheels if you want them instead.) Comes with pedals. Good condition. No shifter or water bottle bosses on the frame.


2400 (1981) Sugino Bottom Bracket, V-GT luxe RD, Super Maxy crankset, Suntour DT shifters, tange 1 fork, 27 inch araya aluminum rims.


2400(1985) Tange #2 Frame, suntour adjustable dropouts, suntour ARX derailers, suntour barcon shifters, 27 inch araya aluminum rims.


2500 Grandtour Frame; Tange Champion #2
FD/RD; Suntour ARX w/clamp on DT shifters
Crankset; Sugino GT w/add on triple
Wheels; Suzue hubs/Araya rims


2600: 1985 was a club racer that sold for $325. The main triangle is Tange 900, which was a seamed, butted CrMo tubeset. Forks and stays are slightly downgraded with Tange Mangaloy. Angles are typical club racing for the era, with a 73 head and 72.5 seat. Wheelbase is spec'd 39.9", 16.4" chainstays, 1.9" rake, 22.6" top tube. Quoted figures are for a 23" frame.


2600 (1987 model) Tange Infinity Tubing, Mangalloy Fork, 105 components and gold araya rims. Nitto bars and stem.


2700 Examples:
Sekai 2700 Gt Deluxe
Color; Blue
Frame; Tange Double Butted/Hi-Ten throughout
FD/RD; Suntour Cyclone w/banded DT shifters
Crankset; Sugino Mighty Tour w/Sugino BB
Wheels; Shimano hubs/Araya rims


Sekai 2700 Gt Deluxe
Color; Tan
Frame; Tange Champion..........decal does not designate any number, Pro, etc.
FD/RD; Suntour Vx w/Suntour barend shifters
Crankset; Sugino Mighty Tour w/Sugino BB
Wheels; Shimano hubs/Araya rims


2750 (MTB)


3000, Ac 500 brakes ,Suntour Symmetric shifters, suntour arx derailer, sugino gt cranks
techmomic stem, nitto olypaid 115 bars, 12 speed Cro Frame.
1988(Highly likely, but unconfirmed)


4000 Criterium – (1973) Ishiwata tubing possibly until 1975 when Sekai went to mainly Tange.
Tange Champion #1 Tubing .06x.05 Cr-Moly throughout, Lugs tange short point with cutouts,Shimano SF micro adjusting dropouts, headset tange Falcon,


5000 Tange Professional .06 x .03 double butted Cr-Moly, Lugs tange short point with cutouts, Shimano SF micro adjusting dropouts, Headset Tange Levin Extralight competition, seat lug tange allen key seat pin.


Unnumbered models or unknown numbers
Sekai Magnum S7
Norco era
Tange #2 Cro-Moly
Chocolate brown paint with a cream head tube
Top mounted downtube shifters (with a protruding square boss underneath it)
Two sets of bottle cage bosses on the top and bottom of the downtube
Nitto stem and Nitto Grand Randonneur drop bars
Sella Italia saddle
Dia Comp canti breaks
SunTour Cyclone M-II drive
Sugino triple crank (not sure what model)
Araya 700C wheels (presta valves, 40 spokes)


Mountaineer (MTB)
Mountaineer SL (MTB)
Cherokee (MTB)
Bush Plot (MTB)
Everest (MTB)
Kokanee (MTB)
Bigfoot (MTB)
Oswego(possibly MTB)"
https://www.re-cycle.com/History/sekai.aspx


Catalogs/Brochures etc.
https://www.yellowjersey.org/SEKAI75.JPG 1975 catalog at yellow jersey
https://www.retrobike.co.uk/forum/gal...2_itemId=25384 Very cool set of reviews/specs from '77.


Decals Available:
https://www.yellowjersey.org/sekai.html


Dating by serial: A large number of Sekai frames came from Kawamura, thus you may find this of use, if your format doesn't match however do not fret.
https://www.bikeforums.net/showthread...mber-Database
80's Yamaguchi/Mikki made Sekai frames
Quote Originally Posted by T-Mar View Post
Apparently, Miki made both Sekai and Sakai frames. Sekai frames were manufactured by Miki and assembled by Sakai Export. It not uncommon for a manufacturer to produce more than one brand. The serial number format should be Myfxxxx, where y is a number designating the year and f is a letter designating the fortnight. The same serial number format shows on on some Norco and Centurion models, though it is unclear whether these frames were made by Miki or another manufacturer with the same serial number format. For instance, Merida of Taiwan uses the same format.
Credits and thanks for links/info: T-Mar as can be seen throughout this thread, yellowjersey cyclery, retrobike.co, classicrendezvous.com, Don Gillies,re-cycle.com, sekaibmx.wordpress.com and anyone who posted in this thread or PMed me more info..
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Old 12-14-11, 08:56 PM
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Compiled Serial numbers and years.

1974 Sekai 2500
Serial: K8H03368

1975 Sekai 4000
Serial: M5K02602

1976 Sekai Competition
Serial: 76B91533


1976 Sekai 4000
Serial: M6L37607

1977 Sekai Limited 2400
Serial: Y77-1238515



1977 Sekai Grandtour 2500
Serial: 77B92754



1977 Sekai Grandtour 2500
Serial: 77B92957


1977 Sekai 2500 Grandtour
Serial: 77B92847

1978 Sekai 4000 Criterium
Serial: K8E10175


1978 Sekai 4000 Professional

Serial: M8M 22913

1978 Sekai 2400
Serial: Y78 1218620


1978 Sekai 1000
Serial: Y78-0202306

1979 Sekai 4000
Serial: M9L35487

1979 Sekai 2400

Serial: Y79 - 0507051


1980 Sekai 2000 Super SX
Serial: Y0F5767




1980 Sekai 2700 Gt Deluxe
Serial: YOF9590


1980/81 Sekai 2500 Grandtour
Serial: YOL8103

1981 Sekai 2700, GT Deluxe
Serial: Y1E2677


1981 Sekai 2400

Serial: Y1N2928

1981 Sekai 1000
Serial: Y1B6068



Sekai 1000
Serial: Y1C2664



1983 Sekai 2500 Grandtour
Serial: Y3B2318



Sekai 2500 Grandtour
Serial: 365450


1984 Sekai Magnum GT
Serial: Y4A2427

1984 Sekai Magnum S7
Serial: Y4A2789


1984 Sekai 3000
Serial: M4B00246


1985 Sekai 2500
Serial: Y5C3898

1986 Sekai Sasquatch
Serial: Y6A2746


1987 Sekai 2700 Gt Deluxe
Serial: 7E90194



1987Sekai Bigfoot
Serial: F701***



1988 Sekai GT Deluxe 2700
Serial: 8E90035


Sekai Sprint
IP75053


Sekai Navigation:
Backstory for the company

Article on History/Value in current market

Models Produced

Catalogs/Brochures etc.

Decals

Dating by serial
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Old 12-15-11, 10:52 AM
  #12  
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I just read the OP's article. Sekai continued to be available through Norco until 1990, not 1986. The actual takeover by Norco occured during 1983, for the 1984 model year. The quality did not suffer under Norco and Norco bicycles are not equivalent to Huffy. They are much better. Just search the forum and look at some of the Norco models. Norco did do some consolidation of their brands and the higher end Sekai models do appear to have been dropped, but both entry level and mid-range models were still available. Component selection was comparable to the competition at the various price levels.
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Old 12-15-11, 12:52 PM
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Originally Posted by T-Mar View Post
I just read the OP's article. Sekai continued to be available through Norco until 1990, not 1986. The actual takeover by Norco occured during 1983, for the 1984 model year. The quality did not suffer under Norco and Norco bicycles are not equivalent to Huffy. They are much better. Just search the forum and look at some of the Norco models. Norco did do some consolidation of their brands and the higher end Sekai models do appear to have been dropped, but both entry level and mid-range models were still available. Component selection was comparable to the competition at the various price levels.
You are correct on the date they closed shop/the take over/and the quality as well as far as I know some people even collect Norco's... I found the model to pricing info interesting and a great story about someone who loves the brand.
Edit: T-Mar putting those two years at the top of this thread to solve later confusion.
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Old 12-15-11, 02:33 PM
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Originally Posted by Chuckk View Post
Does anybody have an explanation for the extreme stay deflection in the chart on this page?
I had a beautiful 4000, but it absolutely ate up effort, and I finally sold it when it dumped me hard on a hill.
The 4000 was labeled as Tange Champion tube.


Sorry I don't have an answer for ya >.> but I myself am hunting a 4000, since a 5000 would simply be wall art! I can hazard a probably incorrect guess though as to the stay deflection, because the tubing was so light and thin they had to go so extreme, as is referenced often you could literally pinch the tubing out of shape with your bare fingers.
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Old 12-15-11, 02:45 PM
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Deflection probably due to long chainstays, most of the other bikes on this list are more racey, likely have shorter chainstays. I wouldnt expect that a sekai would have partucularly thin-walled chainstays which would be the other reason for high deflection.
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Old 12-16-11, 09:17 AM
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Originally Posted by Chuckk View Post
Does anybody have an explanation for the extreme stay deflection in the chart on this page?
There are a number of factors which could affect this measurement but the major factor is the thickness of the tubing used for the stays. The tested model is the Sekai 5000, their top line racing model. Given the tubeset, the results are predictable. It used very thin, 0.5mm stays. For comparison Columbus SL used 0.7mm stays (40% thicker).
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Old 12-16-11, 01:11 PM
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Originally Posted by T-Mar View Post
There are a number of factors which could affect this measurement but the major factor is the thickness of the tubing used for the stays. The tested model is the Sekai 5000, their top line racing model. Given the tubeset, the results are predictable. It used very thin, 0.5mm stays. For comparison Columbus SL used 0.7mm stays (40% thicker).
Interesting, I knew that sekai made plenty of hi-ten bikes, didnt realize they had a high-end model. I would imagine that an intact 5000 is a very, very rare frame these days! Scan of full '77 review at;
https://www.retrobike.co.uk/gallery2/...2_itemId=25384
Arcticle quotes a 4.5lbs frame weight. For a frame alone, that is not spectacularly weenie light, wonder if that included the fork weight putting the frame weight down near 3 lbs, just a bit more than todays lightest S3 steel frames.
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Old 12-16-11, 01:18 PM
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Coming soon frame materials!

Originally Posted by T-Mar View Post
Mangaloy is Tange's brand name for their manganese-molybdenum (MnMo)tubesets. These tubesets have tensile strength that is between hi-tensile steels and chromium-molybdenum (CrMo). Consequenty, their weight is also in between the two. However, the real advantage of MnMo tubesets is that they retain a higher percentage of their strength after brazing. As a result, control of the brazing temperature is not as critical as with CrMo and it is more suitable to semi-automated, mass production. Introduction of Mangaloy and similar tubesets was instrumental in lowering the cost of bicycles with butted framesets in the early 1980s.
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Old 12-19-11, 04:17 PM
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Heyeverybody,

As this thread concerns Sekai bikes, I thought I would just throw this out to anybody interested. The early 60's Raleigh Gran Sport I just got came with a Sekai stickered, suzue QR high flange hub laced to a 27 steel Araya wheel that I don't want. It looks to be in good shape.I am trying to find the original one Dunlop lightweight with racelite hub to replace it. When I do, anybody that wants the Sekai can have it for shipping cost. Might not be much of an offer, but depending on where you are and how much original parts mean to you, it might.

Thanks for reading, let me know 3 SS
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Old 12-19-11, 07:26 PM
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I picked up another Sekai bicycle this morning. It is the sixth one that I have owned, unfortunately I have yet to get my hands on a 54cm. I am adding the info I have on the 3 that are still with me.

Sekai 2700 Gt Deluxe
Color; Blue
Frame; Tange Double Butted/Hi-Ten throughout
FD/RD; Suntour Cyclone w/banded DT shifters
Crankset; Sugino Mighty Tour w/Sugino BB
Wheels; Shimano hubs/Araya rims
Serial # on BB; 7E90194


Sekai 2700 Gt Deluxe
Color; Tan or Gold
Frame; Tange Champion..........decal does not designate any number, Pro, etc.
FD/RD; Suntour Vx w/Suntour barend shifters
Crankset; Sugino Mighty Tour w/Sugino BB
Wheels; Shimano hubs/Araya rims
Serial # on BB; YOF9590
The original owner of this bike had a 2500 that was stolen, so he went out and bought this one to replace it. His recollection was around 1980 in Oregeon. Therefore I'm guessing this was built in '79 or '80. Oh.......and he also claimed to have paid around $500 for it.


Sekai 2500 Grandtour
Color; Dark Grey w/Red HT and partial ST
Frame; Tange Champion #2
FD/RD; Suntour ARX w/clamp on DT shifters
Crankset; Sugino GT w/add on triple
Wheels; Suzue hubs/Araya rims
Serial # on BB; Y3B2318


Two of the others I had were the 1000 and the 500........both with low end components, steel rims etc. and the third I don't have much recollection of.......

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Old 12-19-11, 08:00 PM
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Originally Posted by r0ckh0und View Post
I picked up another Sekai bicycle this morning. It is the sixth one that I have owned, unfortunately I have yet to get my hands on a 54cm. I am adding the info I have on the 3 that are still with me.

Sekai 2700 Gt Deluxe
Color; Blue
Frame; Tange Double Butted/Hi-Ten throughout
FD/RD; Suntour Cyclone w/banded DT shifters
Crankset; Sugino Mighty Tour w/Sugino BB
Wheels; Shimano hubs/Araya rims
Serial # on BB; 7E90194


Sekai 2700 Gt Deluxe
Color; Tan
Frame; Tange Champion..........decal does not designate any number, Pro, etc.
FD/RD; Suntour Vx w/Suntour barend shifters
Crankset; Sugino Mighty Tour w/Sugino BB
Wheels; Shimano hubs/Araya rims
Serial # on BB; YOF9590

Sekai 2500 Grandtour
Color; Dark Grey w/Red HT and partial ST
Frame; Tange Champion #2
FD/RD; Suntour ARX w/clamp on DT shifters
Crankset; Sugino GT triple
Wheels; Suzue hubs/Araya rims
Serial # on BB; Y3B2318


Two of the others I had were the 1000 and the 500........both with low end components, steel rims etc. and the third I don't have much recollection of.......
Thanks for the specs and background! And you also actually fixed a problem that has been nagging me, my "2500" never seemed specced right, I'd often wondered if it was a lower model but it matches with your tan 2700.. only mine's gold.. and I suspect you won't find a 54cm one.. mines 53.
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Old 12-19-11, 08:22 PM
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Perhaps my tan 2700 is considered to be gold. Decal lettering is blue w/white outline. There is a noticable weight difference between the gold 2700 and the Grey/Red 2500. They are spec'd out a
little differently and both are 58cm but I would be interested to know the difference between the Tange Champion and the Tange Champion #2

A 53cm would be fine with me.........and actually, I think the blue 2700 is a 53cm but has the telltale paint cracks behind the HT lugs on top of the TT and under the DT and therefore has become a donor.
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Old 12-19-11, 08:32 PM
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I'm curious now about the tan, I can see how the gold could be seen that way, I know when I bring it inside it's definitely more of a dull silver..does yours seem to change color depending on the light? I happen to have a 2500 as well(confirmed) and I really hope the paint isn't stock, it's this weird metallic dark blueish color.. but lots of things bug me about that bike, like the braze on cable stops...
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Old 12-19-11, 08:43 PM
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I scrounged up a few pics.........The silver 1000 I found last year, Tange Champion decal on the gold 2700 and the gold 2700

It is certainly not a brilliant gold, more of a satin finish I think.
Attached Images
File Type: jpg
Sekai 1000 001.jpg (99.4 KB, 839 views)
File Type: jpg
Tange Champion 001.jpg (56.2 KB, 821 views)
File Type: jpg
Sekai Upgrade I 001.jpg (101.2 KB, 833 views)
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Old 12-19-11, 08:54 PM
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You would have been really handy when I first IDed this bike. Beholdy the 2700 GT Deluxe in gold(or as you call it tan, despite our different lighting camera it seems to be the same paint to my eyes) 53cm, purchased at the dump for 10 bucks as a parts/donor bike for a trashed u-08(that later became a shop stool).

I might have to beg you to take some detailed sticker pics for me, I've been toying with the idea of redecaling mine.

Oh and I really should update the pic, that saddle is gone and replaced with a b-17 and almost all that gear is gone other then the helmet.
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