So Sekai's serial number system isn't as straightforward as it seems (Y78 = 1977?)?

I have a Sekai that I got for free a few months ago. I pumped up the tires and straightened the handle bars and away I went. Seems to be all original and all was great until the back tire blew out the side because they are original tires. Any idea on what year or model this is? I can get more specs if needed. any help would be greatly appreciated. I'm thinking of selling it as is because I don't have time or know-how to save this bike and would like it listed correctly.

http://spokane.craigslist.org/bik/4116356685.html

This may grant you a little clarity.
http://www.bikeforums.net/showthread...1#post15106813

Thought some of you might be interested in this: It's my Sekai 500 in front of the old location of Velo Bike Shop, who, as I understand it, originally imported and sold these bikes.
http://i1139.photobucket.com/albums/...pse10ed6d8.jpg

HI, I have a bike that has your ver 2 sticker , and curved seat stays.

If you flip the bike onto the seat and handlebars, you can read the serial number which is on the bottom of the bottom bracket

My bike starts with Y79 ------

My bike was built in 1979, and purchased in the spring of 1980

[QUOTE=BlackFoxSees;16148286]
S#: Y79 - 0507051


I believe it's a 1979, based on the serial number and components. Sekai seems to have used a pretty straightforward serial system, which I guess they altered between the late 70's and '81. I'm under the impression that most of the components are original, but a mechanic suggested that the brakes aren't.
/QUOTE]

I strongly believe your bike frame was built in 1979

Updated update: Added navigation links. Update(Compressed my multi-post On this page), navigation on pg 1 is now updated, serial checking updated, a few decal graphics added, and general page 1 clean up.)

I'll do some digging and check to see what the difference in their 70's/80's date codes and get back to this we'll have some confirmation. Too bad T-mars on hiatus he'd have the definite answer.

Compiling. And T-mars still invaluable even if he's not posting any more.

80's format, Yamaguchi and Miki serials should match other than initial letter.
Digging 70's info still.

http://www.bikeforums.net/archive/in.../t-873496.html
http://www.bikeforums.net/archive/in.../t-586624.html

Okay.
80's Mikki's and Yamaguchi's formats SHOULD follow this.
Myfxxxx, where y is a number designating the year and f is a letter designating the fortnight.

At least for some Sekais the Y## format and m ## one should actually equate like eclipsegirl thinks, however this does not apply to all Sekai formats.. apparently not even all Mikki or Yamaguchi manufactured frames. If you would like to contest this assessment, all I really ask is you site sources for me so I can update info accurately.
How can you confirm it was built in 1979? That's another piece of info I'd love to have for the resource.

I had a Sekai 500 from the late 1970's or so. It had very-relaxed frame angles nearly as relaxed as a Schwinn Varsity or Continental!

Good thing then that it was in a very large (for me) frame size, as I was thus able to lean foreward fully on steep hills.

The bike had DB HiTen tubing, steel rims and was heavy, but rode very nicely.
I upgraded the crankset to an alloy half-step triple (with perhaps only a 36t granny) that was at least entertaining to use, that's the way I remember it.

I was able to trade the Sekai 500 for a nice, running Honda MC, so that's the last I saw of it.

I like your story, and good trade man.

I doubt that Andy Muzi has the records that go back far.

I purchased my bike in the spring of 1980. My bike frame is unusual. It is made for small people. I am 5' 2" and have a very hard time large or average size frames. Not a lot of people would have been interested in that tiny frame.

The lug on the front stem is a single lug, not the usual two lugs.

Can I prove that it was built in 1979? No.

I believe that it was built sometime in 1979, and after export to the US, and then to Madison Wi, it was not an immediate seller and was in the shop in the spring of 1980, when I was looking for a bike.

Ah, I apologize if the previous posts appeared confrontational but I am simply seeking facts to attempt to solidify things to move this database forward in helping people. Would have been quite a missing link to be able to verify those points I'm sure you can see.

And did anything materialize on your search for decals?

You are not confrontational. I understood my statement could not be proved.

I did my own searching on the net, as I am sure you did too. There was one long article about the Brothers, helped by about 4 bike shops in the the US. I want to say that article was my source, but I am not sure.

Andy just handed me a nice set of white decals once when I went in there. For any one who is searching for Sekai decals, Andy Muzi and Yellow Jersey are the only one to get decals from. He got his from the widow of one of the Japanese brothers who started Sekai.

Given the right time and place, I will approach Andy about his knowledge of Sekais. Being one of the few dealers, and still in existence, he may have a wealth of info.

I encourage you to write to Yellow Jersey Privately and get him talking. He can be very intimidating. HE IS VERY OLD SCHOOL about bikes. Give him a chance and he may open up to you.

Andy is also in the middle of a move from Madison Wi to Arlington Wi. Less overhead. as stated, if you know you OLD SCHOOL stuff about bikes, are you are ? deferential to him, he is very informative.

I'd love to talk to either, but I am down here in the bay area and time is a limited commodity for myself trust me though, I've been contemplating a road trip to pick these brains while we still have them around! The nature of this seems much more like a face to face venture to me anyhow.

I would call ahead. Andy has just moved shop from Madison to Arlington. He does the majority of his biz over the net these days.

Serial database added.

Steve,

Any way to get those pics of the Sprint posted again because they are no longer available. I believe that I have a Sprint and was hoping to compare it with your pics because it doesn't seem like there are a lot of Sprints in this forum or anywhere for that matter. Mostly 2500's, 2700's and other randoms ones.

Thanks

http://oldtenspeedgallery.com/blog/w...-sprint-01.jpg
http://oldtenspeedgallery.com/owner-.../#.UmbXGnAw3s4

Same bike pre-fix up

http://farm4.staticflickr.com/3059/2...b1fbd66a_z.jpg


Another sprint can be found here
http://www.flickr.com/photos/mrjoeba...n/photostream/

One more sprint for good measure
http://www.bikeforums.net/showthread...=1#post8555354

http://www.bikeforums.net/attachment...9&d=1237424978

Thanks for the information. I have a Sekai sprint with lug nuts and a different crank than any I've seen and seems like the rest is original. The crank doesn't have a stamp on it at all either. It just seems like my Sprint doesn't meet the same specs as others and I wasn't able to find a serial code on the bottom. I have it listed on Craigslist and was thinking of selling it to get something better but wasn't sure it is worth it or not, or if it would be better to just fix this old Sekai up. Pasted here:
http://spokane.craigslist.org/bik/4116356685.html
any ideas?

Personally I wouldn't buy or sell a 1000 so I doubt I can be of much help.. lowest numbered model I've boughten to date was a 2400 for 20 bucks that I stripped for backup parts for my 2500...

My Sekai Sprint seems different than the others I've seen. It has a 3 Pin Seguino Maxy chainring and the cranks are cottered but I wasn't able to find any markings on the cranks. The serial number I got off of the bike was ID12566. It was stamped on the side of the vertical bar as there was nothing on the bottom like I've seen others. Is the Seguno 3 pin even that good and is it the original by chance? Any input would be great!

I thought I'd add my bike to the database. Got this really nice Sekai 2000 for $90 off of craigslist. Ordered some nos down tube and seat tube stickers from Yellow Jersey. I'll just be doing a light rebuild of this one because it's in such nice shape. S/N is Y0F9054 so based on what I've read that puts it at about 1980. Suntour GT derailleur has a date code of WA so that puts them at about January 1980. The bike has a sticker form the original Velocipede bike shop that sold these bikes in Seattle.

...very pristine and very colorful. You must be happy to have found it in that large size.

Here is a photo of my Sekai 1000 - serial # Y1N1659 I was the original owner but sold it after getting a whiplash from a rear-end type car accident. I found it sitting alongside the road a few blocks from my house - it had A "FREE" sign on it so I picked it up not realizing it was "My" old bike. When I was cleaning it up I found the MN I.D. program number engraved on the bottom of the frame was in my handwriting and was my I.D. number. I took it to my favorite bike shop and had it overhauled - It looks pretty good for something that is at least 30 years old! Can anybody tell me what info is in this serial number? I think I bought this bike sometime around 1975 but can't be sure and I am curious. http://bikeforums.net/attachment.php...hmentid=352491http://bikeforums.net/attachment.php...hmentid=352492 Thanks in advance for any info! 8-)

http://www.bikeforums.net/showthread...1#post13167348

That appears to be a 1981 Serial.

I just picked up a 1983(?) Sekai 4000 off of CL this afternoon. It's in great condition with just a little dirt, grease and paint chips. I'll get photos after I clean it up and it stops raining (so July maybe!). I was surprised that it was Tange Champion #2 tubing, does anyone know when they changed over from #1?

Sekai 4000
58 CM CtT
Color; Dark Silver
Frame; Tange Champion #2
FD/RD; Suntour Cyclone M-II
Crankset; Sugino AT w/2 rings
Serial # on BB; M3C05037