# Hey literature collectors- 1981-83 question...



## ChattyMatty (Jan 18, 2017)

OK, so long story short, there were two slightly different S/O imported MTB frames available in the early 80's, one eventually making it's way into the accessories page of the 1983 BMX catalog. A couple of us have been trying to chase this little crumb trail over on MTBR and an original owner relates having seen a drawing of it in a 1980 sales rep's catalog, with the first batch of frames arriving in spring '81 (receiving his with the second batch in the the fall). One of the frames is lugged with a forged crown fork, the other a tig'd frame with a BMX-style unicrown fork.

Just curious if anyone out there was bored and felt like flipping through whatever dealer order books or monthly newsletters they might have in a free moment. I have the 1984 Accessories price list, and in the frames price list insert it lists three-

28538 19" Mountain bike frameset SB
28374 Mountain bike 21" SP
28375 Mountain bike 19" SP

Which we think translates to Silver Blue and Silver Pearl.

Thanks,
-M


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## bairdco (Jan 18, 2017)

What is S/O?


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## ChattyMatty (Jan 18, 2017)

Sorry, Special Order. It was sold as a frame set only.


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## Metacortex (Jan 18, 2017)

There is a thread on these framesets over on Bikeforums.net: http://www.bikeforums.net/classic-vintage/376857-id-lugged-schwinn-mtb-frame.html


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## Les (Mar 11, 2018)

Hi, I have been on the MTBR forum and still searching for anything on the lugged Schwinn MTB, or should that be ATB as that is what the MTB was referred to by Schwinn in 1981. With all my searching I have not found anything that confirms the serial number BS367823 stamped to the underside of the BB. The frame is fabricated from Ishiwata MTB tubing that appears to be pre 1980 but is stamped Ishiwata 3.B on the steerer tube. I have been trying to determine what dating systen Ishiwata used, Juilan or Japanese Showa. This makes a difference of about 5 years. Apart from the catalogue page shown above I am posting another page that shows a lugged frame as mine is. This page also refers to a Siera MTB as a different frame and give the Lugged frame no name. The fork does not appear to be a Tange 141 type although I have not seen what the 141 type is. The steerer tube is stamped Ishiwata and the tubing does match the Ishiwata MTB tubing sizes.
Les


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## ABC Services (Mar 12, 2018)

What is your question? I have sales rep catalogs for all those years. Just need to know what to look for and maybe a year.


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## Metacortex (Mar 12, 2018)

Les said:


> I have not found anything that confirms the serial number BS367823 stamped to the underside of the BB. The frame is fabricated from Ishiwata MTB tubing that appears to be pre 1980 but is stamped Ishiwata 3.B on the steerer tube.



The steerer tube stamping indicates Feb. 1983 production. The frame stamping seems to indicate the same as well.


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## Les (Mar 12, 2018)

ABC Services. Thanks for the offer, the Jay Pridmore, Jim Hurd book The Schwinn Bicycle made the comment on page 147 “The Schwinn parts Division brought in some lugged mountain bike frames from Japan. But mostly Schwinn was leaving the new market to others. "  I have seen other comments that this was in 1981. Note it was the Schwinn parts Division. I have looked through all catalogues on the web to no avail but the one I attached is apparently from the 1983 BMX catalogue, one I have not seen as a total catalogue. Therefore anything that is a Schwinn catalogue 1981 to 1983 would be of help. Schwinn cold have advertised them in some other way.

Metacortex, The frame stamping is Feb 1981 by the Schwinn system of 1981, nothing else it can be but it is the location that confuses. The steerer tube indicates Feb 1983 if you follow the Tange stamping system but it is the Ishiwata system in use and that can have 2 dating calenders to follow, the Julian calender or the Japanese Showa calender.  The 3 could indicate year 53 which equals 1978. The steerer tube is BMX size that was common on early MTB`s. The Showa calender is not unusual for older Japanese companies to follow, one of my cars do. The 3.B could have a totally different meaning and this could be lost in history, certainly not proven either way.

My lead to this forum was looking for Jim Hurd and I have seen he passed away in 2004, sadly this does not help me but someone  else may know more or how he came make the comment.
These frames of which I have seen 10 references are not common, they did not receive a model name as they have been sold originally as a frame/fork only. They look more like a 1983 or earlier MTB as made by others from 1980.


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## Metacortex (Mar 12, 2018)

Les said:


> The frame stamping is Feb 1981 by the Schwinn system of 1981, nothing else it can be but it is the location that confuses.



BS3xxxxxx would seem to indicate Feb. '83.



> The steerer tube indicates Feb 1983 if you follow the Tange stamping system but it is the Ishiwata system in use and that can have 2 dating calenders to follow, the Julian calender or the Japanese Showa calender.  The 3 could indicate year 53 which equals 1978.




I have several early  to mid-'70s Sports Tourers, Super Sports and Continentals with original Ishiwata forks. They all follow the (same as Tange) date code system YM where the first digit indicates the last number of the year and the second letter indicates the month of production. Here is the stamp on a 4E (May '74) dated Ishiwata fork that came on a EKxxxxx (May '74) stamped Sports Tourer.


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## Les (Mar 12, 2018)

Metacortex
That does seem to show the number to the year 74 of the frame but it is different to the one on my frame in that does not have ISHIWATA as mine and the format is totally different. Mine is Year month. It does appear to have another marking that could be the Japanese manufacturing symbol. Does it have tube manufacturers name on it else where.
The BSnnnn does not fit in with any Japanes makers number system. The S is in a second place, not as prescribed for the Schwinn Japanese manufactured bikes. 
Still confusing
Les


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## Metacortex (Mar 12, 2018)

The Ishiwata forks on my '70s bikes all have the 1970s Ishiwata logo (concentric circles with IS, as seen above the date stamp) to indicate the mfr. and the date code is in YM format. Here is a '74 Ishiwata catalog page showing the logo:






I remain convinced that your frame and fork date from Feb. 1983.


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## Les (Mar 12, 2018)

Metacortex, 
Compare the logo below for what is on your bikes. Most of what it is is not clear, on the photo above. The JIS logo is common on many Japanese items to define a government imposed standard. It can be used by any Japanese manufacturer equally.
The logo that is stamped into the steerer tube of my bike is the Japan Industrial Standard, not Ishiwata`s logo and used in that form until 2008  en.wikipedia.org/wiki/Japanese_Industrial_Standards
The  logo on the 1974 catologue is the Ishiwata logo as it also appears on the pre (not confirmed) 1980 Ishiwata catalogue on the MTB tubing page 
I have had a looked back at a lot of information about Japanese made Schwinn serial numbers (even T-Mar`s listing) and mSnnnnn is not mentioned but it does define February 1981 in the US made bikes. Of all the numbers used for Japanese production S is only used at the beginning for some manufacturers, not all and generally followed by numbers. If a second letter is there it is for the month, difficult to get beyond M for 12 months and why B at the beginning. S should be first to be accepted as Japanese made. If the first letter was S, the second B followed by a 3nnnn, yes it would be Japan made in February 1983 but it is not that stamped into the frame.  
I will just keep looking, if I dont, I will not know. 
Les


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## Metacortex (Mar 13, 2018)

The Ishiwata-built Schwinn forks I've seen only have the earlier ('70s style) Ishiwata logo and no JIS stamp. You appear to be confusing Asian serial numbers with Chicago Schwinn numbers. Your frame serial no. format is MSyxxxxx, which according to the Asian Serial Number Guide was used by several Japanese and other manufacturers and indicates Feb. '83 production. I also checked the '82 and '83 parts catalogs and your frame only appears in the '83 catalog. At this point there is no doubt in my mind your frame and fork date from Feb. '83.


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## Les (Mar 13, 2018)

Hi again
I have had a look at the Asian guide where there is a group under S. 
*S(1)* (Japan *M*S*y*xxxxx
*S(2)* (Japan S*yF*xxxx
*S(3)* (Japan s*My*xxxxx
The only one that could apply is S(1)  I agree it could apply, this guide gives no reference to which Japanese manufacturers used that system and which US clients where involved, These 3 applications are a cover all approach. It would help if these were made clear. Schwinn Le Tour and Super Le Tour models sometimes began with an 'S' followed by the Japan Made numbering system, is clear as you have shown but does not say the S was not or could be in the second place.
Secondly this S(1) is confusing with the Schwinn number system for the US made in 1981 mSnnnnn where the first number could indicate a year. Do all Schwinn bikes made in 1981 with SN mSnnnn get refered to as Japanese made and when the first number is greater than 1 are the dated as 1982 and beyond. 
The other frames the same as mine that I have the numbers of, by using the S(1) application means that these frames where made until 1984 having SN BS367823 3.B Ishiwata,  BS367845,    CS472494,  KS314155,    CS476244.   
The two with CS4 to me indicates March, does the 4 also indicate 1984. This is well after the 1983 selling of the frames.
I am not confusing Asian serial numbers with Chicago Schwinn numbers simply the Asian serial numbers are confusing and are guide only. 
I have seen reference to a Schwinn number GSnnnn where it is said to be a Giant made frame. Schwinn/Giant made frames where Gnnnn only configuration, no other letters appeared. No photo of the frame was included so I will not say I am correct but the Giant explanation is also equally correct.
As I have said before I am not convinced to being correct but I am convinced the date of 1983 is not proven,
Les


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## Metacortex (Mar 13, 2018)

Les said:


> ...The only one that could apply is S(1)  I agree it could apply, this guide gives no reference to which Japanese manufacturers used that system and which US clients where involved,



Please look at the guide more carefully and you'll see these entries which conform to the MSyxxxxx aka S(1) format :

SHOGUN (Japan See Mikki, S(1), S(2), N(1), Yamaguchi.
SPECIALIZED (USA See Giant, Miyata, S(1)
TAKARA (USA See Fuji, Kuwahara, S(1), Y(1).
BIANCHI (Italy See Hodaka, S(1)
MIELE (Canada See S(1)

While your frame was stamped in Feb. 1983, based on the numbers I've seen these frames were also made in 1984,


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## Les (Mar 13, 2018)

Mtacortex
Sorry to bare bad news, I have checked the references and,
SHOGUN (USA? See Mikki, S(1), S(2), N(1), Yamaguchi.
MIKI (Japan): MyFxxxx                                NOT AS S(1) or (S2)
YAMAGUCHI (Japan YyFxxxx. There has been some speculation whether Yamaguchi is the manufacturer for this format but samples have been reported with Yamaguchi labels. NOT AS S(1)

SPECIALIZED
Giant  1978-1986: Gyymm on rear dropout.    NOT AS S(1)
            1987-1989: GFyxxxxx                          NOT AS S(1)

TAKARA (USA See Fuji, Kuwahara, S(1), Y(1).  =  AS S(1) SAME AS THE SCHWINN I OWN, I THINK THAT TAKARA FRAME COULD HAVE COME FROM SCHWINN IN 1983
When I saw a Takara MTB of 1983 I did some searching and even emailed Kuwahara and got this reply. 
_Dear Les
Thank you contact to us and visiting to our web site.
At first yes before we produced Schwin bike for OEM business late 70's (not early 80's).
Then your bike serial number 1981 that is not our production actually very sorry we can
not give you any information such bike._

_Best Regards,
Takashi Kuwahara
************************************************************************
Director
 KUWAHARA INTERNATIONAL CO.,LTD_

His only suggestion was Bridgestone as the builder simlpy because of the BS. Not Bridgestone                       NOT KUWAHARA BUILT

FUJI (Japan P designates assumed production facility codes with known characters including F.G. I,J, K and M  
http://www.classicfuji.com/0_Serial_Number_TableAA.htm    The first 3 letters required of which non are included with the B and S for the first 2, the third is not a letter    NOT AS S(1)

KUWAHARA (Japan yy mm xxxx(x)          year could be a B but the month cannot be an S    NOT AS S(1) or S(

BIANCHI (Italy See Hodaka, S(1)  = HODAKA (Taiwan HyMxxxxx          NOT AS S(1)


MIELE (Canada See S(1). The only Miele SN I found is one "bottom of the seat tube with P3361549" comments suggest it may not be the SN  If it it is it is  NOT AS S(1)
www.bikeforums.net/classic-vintage/1058003-miele-road-bicycle-information.html



From all of this you can see why I am skeptical about the Asian Guide
THE OTHER WAY FOR THAT NUMBER TO BE ON THE FRAMES IS THAT IT WAS ADDED BY SCHWINN IN THE USA
Les


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## ChattyMatty (Apr 30, 2018)

Bridgestone or Fuji has always been my guess. The drops on the BMX style forks is identical to the drops on Fuji MTB's and cruisers, and the frame looks a hullva lot like early MB-1 Brigstones.


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## dmarch (Jul 30, 2018)

Hi,David here
I have a Bianchi with Ishiwata fork that has 4E on it and BS583673 (maybe this helps give you some certainty Les for your search) on the seat tube of the bike placing it as a February 85 and it would seem with the fork being produced the year prior. Anyone know of some Bianchi catalogues from that year to look through so i can determine the model?
Thanks


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## Santuri32 (Sep 25, 2018)

ABC Services said:


> What is your question? I have sales rep catalogs for all those years. Just need to know what to look for and maybe a year.



Hello new to the forum here. I have gathered information about the mystery Schwinn Mountain Bike frame that predates the Schwinn High Sierra MTB of 1984. Several people have gathered most of this information and hopefully, I can get all closer to answering the questions. First, I reply to ABC services since he has the sale catalogs.  What would be of geat usefulness from the 1982 catalog is to locate if frame no. 29 265 was offered that year along with the BMX type fork (part no. unknown). Also, if these were offered in 1984 as well (fork no. 54 186)


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## Santuri32 (Sep 25, 2018)

Les said:


> Mtacortex
> Sorry to bare bad news, I have checked the references and,
> SHOGUN (USA? See Mikki, S(1), S(2), N(1), Yamaguchi.
> MIKI (Japan): MyFxxxx                                NOT AS S(1) or (S2)
> ...



Respectfully Les, S(1) which may represent Japan or Import item from Japan, is found on some but not all Specialized, 84 to 86 Specialized Stumpjumper Sport model only on the MTB line used this format as well as Bianchi Grizzly from 1984, I imagine others as well. I do believe this format is the one used in these Japanese frames. Simply the frame is stamped by the manufactures (not Schwinn USA in this case) therefore Schwinn serial number should not apply (the similarity with close dating system used by Schwinn brings a lot of confusion). But catalog offering should be the stronger source of documentation.


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## Santuri32 (Sep 25, 2018)

A post in other forums citing Haaki, describes three versions of this frame offering by Schwinn. I will try to attach the three sources I have. Version 1 appeard on the 1983 Schwinn BMX catalog, ver. 2 on the 1983 Parts and accessories catalog, version 3 I found on the web and lost the link. I will attempt to attached these as pdfs


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## Santuri32 (Sep 25, 2018)

I have dated some frames as I believe is what they represent, but will be useful to have full catalog information on the availability of MTB parts from 1982 and 1984.


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## Santuri32 (Apr 11, 2020)

Retuning to tread after 18 months of inactivity... not much information on these bikes has appeared suggesting these may be some of the rarest Schwinn ever made. I am posting specs of the last year the frame was made, it has some specs, this came from pics I captured online of a brochure or magazine ad. The ad introduces the Schwinn High Sierra on its cover, and inside is this one, below it a list of suggested components for this frame. Schwinn suggested the Suntour Dirt Group or the Shimano Deer Head, the first mountain bike-specific components available in 1983 and '84. 
Tires were suggested to be Maximizers in the 1983 BMX brochure, below of a complete bike as such. Please post anything you know about this early Schwinn model. The number of identified lugged frames remains at 10 with nine serials (Feb '83 to Mar '84), the number of the earlier 1982 prototype frames remain at 4 with only two known serials both Jan '82.


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## Les (Jun 20, 2020)

Santuri32 and others
I have had some spare time available in lock down and I have servived and I am reasonably able to get out, I hope others have also, but your whole world is not now the same.
I have come back to this forum page with the recommended approach of collection and analysing the records that exist. I have transcended the boundaries of the brain within my cortex to consider all that is a record of these frames and approached the record and meanings known and what is accepted as a historical Schwinn record. The evaluation progresses is to eliminate what doubt there is and hopefully accept the result.

The posting of the 1984 advertisement to sell the Schwinn MTB frames with a complete accessories kit. 

This confirms to me it was in 1984 and confirms the further sale of these frames/forks a year later than 1983. It does very much depend on the date the advertisement appeared to confirm the latest SN by year ie a new shipment, or was it a readvertising of the previous year with additional components.

It is interesting the advertisement came from the Schwinn Parts Sales, and this has a link back to the earliest mention of these frame/fork setup being imported and sold through the Schwinn Parts Sales as in 1981 in the Pridmore/Hurd Schwinn book of 1996 and to haaki`s forum entry elsewhere.

I have continued to study of Serial Numbers from what is on the frames for both ASNG S(1) serial numbers MSYnnnnn and Schwinn MYnnnnnn format serial numbers. Both of these formats can be applied to the serial numbers that are known. There are few SN on frames to be found as most owners appear not to provide serial numbers. Even just the letters MY and the following next 2 numbers. The only Manufacturer approved SN is the Schwinn, from as early as 1965 to 1983.

I will add this explanation that I trust you will patient in reading and discuss with others and that others may make comment as well, I have my views but I will form no conclusion at present.

I have come to address my Schwinn SN format as MYnnnnnn, as it should be, as that is how it is written from when the format started in 1965 at A to its end in 1983 at U, so as a format it can be confused with the ASNG Japan (1) MSYnnnnn when it is visually presented.



I had a small confirmation of my frame when I have viewed a lugged Specialized Stumpjumper of 1982, locally and I could see great similarities to my Schwinn frame.

Tim Neenan has stated, he, in 1981 would have preferred to have used a lugged frame for the first issue of the Stumpjumper in late 1981, but lugs were not to be found, and they did exist by 1982 and were then used for the second order of the Stumpjumper. The Stumpjumper 1982, is built of Tange tubing.

With the ASNG outline it is said an observation as this type is recommended by the ASNG for users to take.

I have searched for confirmation of the Schwinn SN by Schwinn known formats and others is 1980 to 85. This is the list of subjects presented.



The Schwinn MTB frame was reputedly sold as a frame/fork set for the owners to build up a mountain bike as specialist frame builders where at that time providing. They did not receive the Schwinn 4 number stamped head badge to date the final build.

KNOWN FORMATS TO CONSIDER WITH S

Schwinn Formats

Chicago Schwinn SN format MYnnnnnnn

Schwinn Letour format SYnnnnnn

Other Formats

ASNG format Japan S(1) MSYnnnnn

ASNG format Japan S(3) SYnnnnnn



CONCLUSION OF KNOWN FORMATS WITH S

Chicago Schwinn SN format MYnnnnnnn Possible for 1981

Schwinn Letour format SYnnnnnn Not possible as S in wrong location although it is recognised as a Japan built Schwinn but is 1981 was also Chicago built and possibly used for a longer time.

Others

ASNG format Japan S(1) MSYnnnnn Possible for any year.

ASNG format Japan S(3) SYnnnnnn Not possible as S in wrong location although it is recognised as a Japan built.  Schwinn also used it for Chicago built.



Only the Schwinn MYnnnnnnn and the ASNG MSYnnnnnn can be considered to analyse in detail all SNs that can the identified by each format and to the meaning of the format in the early 1980s. All the SN that are known will fit into both formats.



Is there any difference between the ASNG SN Japan (S1) and the Schwinn sn MYNNNN in 1981.

I have referred to Bianchi formats as being one format that has many postings although other brands are referred to this format. The format has not being directly confirmed by Bianchi as Bianchi has never provided a statement of their formats. They appear to have a number of formats used with differing composure used by Bianchi that are not explained.

Also in respect to the ASNG Japan S(1) format I must point out as it is said by ASNG that they have no knowledge of what USA manufacturers as to Serial Number formats they use and don’t want to know therefore do not know about similar based formats. Therefore they will not be aware of Schwinn`s formats that I am to explain. I will try to explain as clearly as I can as the differences are minor but different and detectable.

The Asian Guide I feel is a guide only and is stated not to be not 100% correct and the S means to be Asian made.

The ASNG has been development as a Guide based on a data collection, looking for similarities and distinguishing features thus I have approached my search in the same manner.



The Schwinn is an identifiable format of MYnnnnnn. The SN`s of my Schwinn MTB frame, where S as a year 1981. ASNG S(1)  can also be confirmed used within the Schwinn format format as a year 1983 or 1984 by the first number. There are some ASNG SN that are not identified as a Schwinn MYnnnnnn.

The Schwinn is an identifiable format from 1965 of MYnnnnnn. The SN`s of my Schwinn MTB frame, where S as a year, can be confirmed as 1981. This applied to the Schwinn Mass Produced Chicago cycles where up to 600,000 where built.



Firstly I confirm the ASNG Japan S(1) MSynnnnn appears to be correct for Bianchi SN`s. I have seen that other formats do exist. All of these formats are not confirmed by Bianchi and ASNG but should be.
Most of the Asian made Bianchi SN`s of the 1980s can be identified as a 1981 Schwinn by the Schwinn Lookup Tool. The Bianchi S appears to only apply within the total 1980 decade.

During my initial search for the origin of my Schwinn lugged MTB SN I had always felt the ASNG Japan S(1) MSynnnnn could be used for its application of the Schwinn SN BS3nnnnn, YES as one number, but COULD IT BE for a similar group of others numbers that are also variation of MYnnnnnn, the month/year/ number application. I at one point gave into the fact it was the ASNG format therefore my frame was February 1983.

As the search went on and between SN BS4nnnnn, CS4nnnnn and KS3nnnnn I have RESERVATIONS on the year application and have continued to search for clarification. In that I have located a difference but needed additional information to confirm 100%.

Schwinn produced many thousands of product with the same SN format over 19 years from A to U that do not include I or O as a year. They stopped at U? in 1983. In 1981 produced around 600000  with MS for year NNNNNN bikes.

Most of the ASNG SN`s Japan (S1) MSynnnnn do qualify as by the Schwinn Lookup Tool as well, bar a few as a Schwinn 1981 production. I consider the Schwinn Look Up Tool seems only to refer to the SN date letters being the M and Y letters, and not the numbers. The numbers in the Schwinn SN have their own meaning an individual sequential product Serial Number.

The Schwinn SN format MYnnnnnn do qualify as ASNG Japan (S1) MSynnnnn but for the MTB`s they spread over February 1983 to September 1984.

I have compared a number`s of both the Schwinn Chicago SN from 1974 to 1984 and the ASNG format (Bianchi in particular). I have broken both formats looking at the detail of the actual letters and numbers, positions and their relationships within each other in the same format and across both formats. I have treated both formats as being within the same year and also different years hypothetically.

Bianchi include I as a month, a letter Schwinn never use as it confuses with 1.

Thus Bianchi months are A to L and Schwinn are A to M, not including the letter I and Bianchi do not include a M.

This is a definable difference between the two SN formats as they are visually read.

Furthermore the FIRST number for Schwinn SN over previous years to 1981 show a close relationship to the M and that the 1st number that is increasing reasonably constant PRODUCTION RATE given there will be fluctuations in the PRODUCTION NUMBERS.

This is another definable difference between the two SN formats as read visually.

These are a definable differences between the two SNs. I have seen ISYnnnnnn in the Bianchi SN but not a MSYnnnnnn . I have not seen on any of our Schwinn MTB frames ISYnnnnnn but one could exist. There is evidence that although Schwinn did manufacture to December (month M) each year and the production number did reach 800000 plus over the normal years, and in 1981 I have seen an MTB frame as KS3nnnnn,. The highest month letter seen in 1981 is L then S then 5nnnnn for the production number indicating November 1981, 5nnnnn as a production number. Higher numbers could exist for December MS?nnnnnn but one has not been seen.
It is reported that Schwinns Production Rate in 1981 dropped by over 30% ie 600000 made approximately.


There is definable differences between the two formats that cannot be ignored as all SN will fit, a different result is determined and neither can be confirmed nor excluded.

The two formats have different formats codes but when written as a SN on a frame appear to be the same. When both are subjected to the Schwinn Look Up Tool all but a few being those ASNG being made in September will not be approved. I consider the Schwinn Look Up Tool does not conider the first number. This should be confirmed.

Les


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## Les (Jun 26, 2020)

C         A RANDOM LIST OF SCHWINN SERIAL NUMBERS AS CONFORMING TO THE SCHWINN CHICAGO FORMAT IN ORDER OF MONTHS FOR YEARS 1974 T0 1984 (YEARS OUT OF ORDER) NUMERAL FIRST DIGITS IN ORDER.

Schwinn SNs M letter fit as corresponding with a series of individual frame SN below organised vertically by month A to M. The first number progressively increases, 1 to 8 as the month letter reference dependent upon the production rate per month. The first number is not a year number for the Schwinn format.

All Year letters follow the letter for the year as per the Schwinn

A=1965 to U=1984 format excluding I and O

All Month letters follow the letter for the month as per the Schwinn A=January to M=December excluding I


Frame Serial Number Date Month/Year

These are Schwinn confirmed SN and dates

AK10736 Jan 1974

AR53355 Jan 1980

BR553085 on BB u/s Feb 1980

*BS367823 Feb 1981 My MTB SN position along with others *

BU510679 Feb 1983

CU52824? Mar 1983

CG669707 Mar 1971

CR525040 Mar 1980

CM559963 Mar 1976

DR509170 Apr 1980

DS5071927 on BB u/s Apr 1981 Schwinn Predator

EF015984 May 1970

FT520791 June 1982

FU50293 June 1983

FJ583293 Jun 1975

GR733640 on BB u/s July 1980 Schwinn Predator

HR561039 Aug 1980

KQ503804 Oct 1979

KR80055 Nov 1980

KR800514 Dec 1980 King Sting MTB at Mombat Museum

*KS314155 Oct 1981 MTB*

LJ554886 Nov 1973

LS527689 Nov 1981

MH520056 Dec 1972

MR?????? Dec 1980

MR826184 Dec 1980

MR826498 Dec 1980

MR551380 Dec 1980

MR654499 Dec 1980

Months are generally seen to align with the 1st number that is increasing at a reasonably constant amount give variations in a production rate of each year.

The S year (1981) production reaches LS5 ie 500000 for November, low as in respect to most other years previous.




D THE ASNG FORMAT JAPAN S(1) COMPARISON

The ASNG format presented in a manner of order by month that can be read below.

Serial Numbers been observed. Unless stated they are on the underside of the BB.

AS718273 1987 January On the seat tube, not the BB

BS14121 1981 Feb T-Mar

BS581982 1982? LHS side of downtube T-Mar

BS801036 1988 T-Mar

CS304982. 1982 T-Mar

CS474608 1984 T-Mar

CS480940 Sounds like a 1984/1985 model T-Mar

DS484284 made in Japan in 1984, but could be a 1985 model. No picture

IS513786 confirmed as 86 (not a Schwinn)

IS761045 1988 (not a Schwinn) T-Mar

JS682194 1994 on seat tube

JS763084 1987 Oct T-Mar

JS19084 84 Japanese Bianchi reply by owner not confirmed

KS548867 1984 T-Mar

LS326173 1984 T-Mar

LS285470 No explanation

LS25480 It's definitely a 1983 model manufactured in Japan during very late 1982, based on the serial number

LS285709 1982 T-Mar

LS206786 No reply


For the letter S in the ASNG format it was placed and aligned in the same visual location as with the Schwinn list to be seen below. The months where aligned A to L vertically so the month letter and first number appeared opposite each other to be compared with the same positon as the Schwinn format MYnnnnnn below.

Whichever format is referred to there is a clear indication to which month is being questioned. Firstly, they indicate that if I for month occurs as in a ASNG Japan (S1) MSynnnn it idicates September but as Schwinn did not use I then to be sure the SN is a ASNG format. If M appears the format is Schwinn as ASNG Japan (S1) MSynnnn cannot include an M.

There could be minor variations but it does confirm the ASNG Japan S (1) and the Schwinn MYnnnnnn format are SIMILAR BUT NOT THE SAME, and have a different meaning but must be read giving thought to the formats used. Refer below to the Schwinn comparable listing.



The first Bianchi number presented in the Bianchi SN is not generally similar to the Month code letter, so there is a difference that can be detected. The first number in the ASNG format is the year ranging from 0 to 9. The Schwinn format could reach a number 9 but generally is an 8 at least. There could be 0 but I have not seen so the first Schwinn number may be a 1nnnnn.

By ordering the two SN formats as I have done, it can be seen that two different patterns form of increasing numbers in the Schwinn format but differing up and down greatly for the ASNG format. The Schwinn format provides an obvious increase in the production figure over a year, which varies a little due the fluctuation in monthly production. In 1980 and 1981 saw a 21% and 30% respectively for each year for the annual production.

The ASNG Japan S(1) format has the first number will always be the same for that one year but the months alphabetically increase A to L. The formats as visually presented look the same, but have different distinctive in meanings.

For the Schwinn format I month will not appear and for the ASNG format M month will not appear. The ASNG format S appears to extend over a decade at least whereas the Schwinn S is for one year only, 1981.

The serial numbers need to be judged using a few observations.

Understanding what the ASNG format means its interpretation can be calculated. Understanding the Schwinn format also means the same, but the result is different.

This does not mean we can simply rule out one in favour of the other or say only one format applies for the Letter/S/nnnnnn SN.

The result to this point is the all SN we know fit both formats and the Year determined are from 1981 (Schwinn) to 1983 and 1984 (ASNG)



E THE SCHWINN LUGGED MTB FRAMES SN ANALYSED AS SCHWINN FORMAT MYnnnnnnn

 MTB SN known.

No consideration is given to the meaning of the numbers or order except they could be a consecutive production order for the frames as compare with normal yearly Schwinn PRODUCTION numbers. In 1981 there appears to be a total production of less than 600,000 bikes in the USA by Schwinn

BS357553 B=February 1981 The 2nd to last numbers form a consecutive

BS367578 B=February 1981 order for 1981 ie 57553 to 476244

BS367823 B=February 1981

BS367845 B=February 1981

BS440296 B=February 1981

CS472494 C=March 1981

CS476244 C=March 1981

KS314155 K=October 1981 If 314155 as a consecutive number for 1983

is completely out of order being aligned to K

for 1983 considered as a consecutive number that would align to a month. As it does not.



Refer to a similar analyse of the same numbers for ASNG format MSYNNNNN below.


F THE SCHWINN LUGGED MTB FRAMES SN ANALYSED AS AN ASNG FORMAT JAPAN S (1) MSYnnnnnn


These are the 8 MTB SN known.

No consideration is given to the meaning of the numbers or order except they could be a consecutive production order for the frames as nothing has been stated by ASNG.



BS357553 B=February 1983 The 2nd to last numbers form a consecutive

BS367578 B=February 1983 order for 1983 ie 57553 to 67823,

BS367823 B=February 1983

BS367845 B=February 1983



KS314155 K=October 1983 If 14155 as a consecutive number for 1983

is completely out of order being aligned to K

for 1983 considered as a consecutive number that would align to a month. As it does not.



BS440296 B=February 1984 The 2nd to last numbers form a consecutive

CS472494 C=March 1984 order for 1984 ie 40296 to 476244

CS476244 C=March 1984

For E and F sections at this point I still have variation with both formats with no conclusion.



G THE SCHWINN FORMAT AND THE ASNG FORMAT JAPAN S(1) COMBINED FOR COMPARISON

The both formats presented in a manner of order by month that can be read below. The numbers following the 1st number 3 or 4 indicating the year 1983 and 1984. The following 5 numbers in the Schwinn SN are in a comparable order not including KS14155. The ASNG numbers serial numbers are for years 1983 and 1984 years only. CS304982 is completely out of order as CS3 does not exist in the Schwinn SNs and 304982 as a number would precede all the Schwinn BS3 SN, and also KS314155. CS474608 can fit the order but CS480940, DS484284 are beyond the Schwinn SN but could fit. LS326173 is out of order but much like Schwinn KS314155


BS357553 B=February 1981 Schwinn

BS367578 B=February 1981 Schwinn

BS367823 B=February 1981 Schwinn

BS367845 B=February 1981 Schwinn


CS304982. 1982 ASNG T-Mar


BS440296 B=February 1981 Schwinn


CS474608 1984 ASNG T-Mar



CS472494 C=March 1981 Schwinn

CS476244 C=March 1981 Schwinn



CS480940 1984/1985 model ASNG T-Mar

DS484284 1984, ASNG



KS314155 K=October 1981 If 314155 as a consecutive number for 1983

is completely out of order being aligned to K

for 1983 considered as a consecutive number that would align to a month. As it is out of sequence with the K and 3 its question of how that happened is not known.

Schwinn


LS326173 1984 ASNG T-Mar



The comparative two groups of the Schwinn SN is evident but the no grouping is evident with the ASNG SN


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## Les (Jun 28, 2020)

ChattyMatty said:


> OK, so long story short, there were two slightly different S/O imported MTB frames available in the early 80's, one eventually making it's way into the accessories page of the 1983 BMX catalog. A couple of us have been trying to chase this little crumb trail over on MTBR and an original owner relates having seen a drawing of it in a 1980 sales rep's catalog, with the first batch of frames arriving in spring '81 (receiving his with the second batch in the the fall). One of the frames is lugged with a forged crown fork, the other a tig'd frame with a BMX-style unicrown fork.
> 
> Just curious if anyone out there was bored and felt like flipping through whatever dealer order books or monthly newsletters they might have in a free moment. I have the 1984 Accessories price list, and in the frames price list insert it lists three-
> 
> ...



Matty
I have added some SN research regarding the Schwinn MTB 1981-1983/4 BS3-CS4 etc
Les


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