If you look back on previous pages of the thread, I did a Sekai 4000 (different year) made
from Tange #2 that was about the rustiest project I've ever undertaken. It looked like
someone had stored it for thirty years in a storage locker near the beach.

Anyway, I had good luck with this stuff, but blocking the holes in the BB and frame on the
lower end so I could fill up the frame tubes and let it sit was major PIA.

https://encrypted-tbn0.gstatic.com/i...xOulhxiHqlphOA

After letting it sit, warm for about 24 hours, you drain the frame and rinse
(save the evaporust, it's reusable and a little pricey, but sold at Home Depot).

It's very easy to use on your components, just pour in an appropriately sized
and shaped container, and toss in your parts. It works faster when it is warm,
so right now in the summer is a good time to do it, outside, in the sunshine.

I would not do this unless it were my size and I planned to ride it. Like I said
it's a time consuming process, but not more so than a lot of the crazy stuff
we do in the name of bike restoration..........the good thing is the stuff is water
based and relatively non toxic.

After you rinse the frame interior, blow it dry, if you can (compressor or heat gun),
and then coat the tube interiors with something like this stuff.

http://www.plumbersurplus.com/images...330-259386.jpg

It sprays into the tubes as an oil through the red plastic straw that should come
with the can, so you can usuall even get it into the stays through the small brazing holes.
When you get enough of the oil in your tube or stay, swirl it aroune and tilt back and
forth to coat the interior. Let it dry, do another coat, let that dry, and you should have
some success in making the frame outlast you. Unless it's already so severely rusted
in some place like the BB or stays that it is already shakey. Check for that before you
go to all this effort. Most steel tubing with the wall thicknesses of Ishiwata 022 have plenty
of leeway in terms of rust vs failure.

Unfortunately, I was a little over-eager to dismantle it and I did not take any other before photos. But, I did list the components above:

It has a blue swirly Sekai head badge and a "Criterium" badge on the top tube.
Ishiwata 022 tubing.
Serial # K8E10175
Sugino Mighty Comp crankset.
Suntour dropouts and fork ends.
Taihei Compe seatpost and Compe Forged stem.
Suntour Gt rear derailer and Suntour SL front derailer.
Diacompe center-pull brakes.
MKS pedals.
Sakae Custom SR Road Champion bars.
UKAI Alloy QR wheels.

All of the alloy components have a thin layer of oxidation and minor pitting, nothing a quick cleaning and/or polishing cant take care of. However, the steel and chrome components (rear derailer, brake cable clamps, shift cable clamps, etc.) are quite rusty. I am currently giving them a vinegar bath to remove the rust, and I plan on completely overhauling them and then maybe spraying them with chrome/silver paint or getting them re-chromed if it isn't too expensive (I am a grad student so funds are low!). The frame is a bit rusty in spots as well, If I do have a 4000 I think that I might invest in media blasting it. To me, based on this article: http://www.velo-pages.com/main.php?g2_itemId=517 it looks like the frame might actually be a pre-1975 4000 Criterium, but I am new to Sekai.

Look I'm not trying to be rude here, but all the info you would have needed to ID it is in the first post of this thread there's a flat out statement of 4000 being criterium in the models lineup, as well as the link to decode the serial (Which btw is indeed 1978) so second guessing people who are helping you when you aren't willing to invest seconds yourself is not the best way to endear yourself unto others (At least to me). If you will note there is also no confirmation on when tube sets also fully switched between ishiwata and tange as well, your bike proves that the switch wasn't complete anyway.

My apologies RaleighSport, I did not mean to second guess you. I really do appreciate your help. This is my first time on this site and I should have looked at the links prior to posting. I have only had this bike since yesterday (I have never even heard of a Sekia before then) and this site has been a wealth of knowledge for me and I hope to keep learning about these bikes from everyone on this wonderful site.

I also want to thank you 3alarmer for the tips on rust removal. I cant wait to get started on this restoration!

Rechroming on a budget is a non starter, as is spray painting in the traditional Okie chrome.

You can get reasonable results with evaporust and then something like a simple paste wax
on the resulting component to seal out O2 and significantly slow down any recurrence of rust.

Your paint does not look that bad to me, and if you are genuinely on a budget, or even
if you just want to do the best job you can, it's almost always preferable, when that much
of the original paint is intact, to spot treat the rust, (smooth the worst with a little emery
cloth and then use a product called rust converter), and then touch up the spots with a
matched paint (yours seems to be a white). Again, a little wax as your final layer goes a long
way toward shine and preservation.

A lot of beginners get into a project and the first thing they do is pay some guy to media blast
the frame and then do a bargain powdercoat, which 90% of the time comes out looking like
hell, and is usually either sprayed over some component like the fixed cup that you forgot to
remove or is so thidk on the BB and headtube faces that you have to chip it in order to reface
them. My own advice would be to stop, take a deep breath or two, count to ten, and reconsider.

The more I find out about this bike the more I want to restore this guy back to original (No powder coating). I have restored a midrange 1983 Austro Daimler (Puch) Pacifica and am in the process of finalizing an 1983 Nishiki Century (both are all original save the tires, brake pads, and handlebar wrap) and I agree with you on the results that a good waxing can obtain. I took a look at your previous Sekai 4000 posting, and based on your awesome results I will definitely use the evaporust product.

I will take some more shots of my frame to show the extent of the rusting, it is bad enough where a lot of the chrome has began to peel from the forks and the components and subsequently stained the paint. If worst comes to worst I can always buy or barter the ruined components and brackets and repaint the frame after rust removal. I truly enjoy fixing these old bikes up as much as I enjoy riding them! Why toss them when you can fix them?

Great find, chico81! A Sekai 4000 is a really nice bike. Not a bike I would have expected to see sporting a rack and a kickstand!

Agreed, the subject Sekai 4000 is almost certainly 1978 though I don't see why RS thinks it is a Kawamura manufactured frame. That's not their serial number format.

You are correct sir, I'm just so used to quickly reading Sekai serials now I didn't even notice the deviation. Any idea where it was made?

Alrighty, I finally fetched my junior hs sekai out of the basement. wow, it is not looking pretty. I know i didnt treat it badly but I guess the paint on these wasnt great and the decals were even worse. it's been sitting around for 20 years. barely ridden 10 before that.

anyhow. it's a sekai 1000, either purchased in 82 or 83. I'm going to make it single speed and ride it from the train to office. hope is the aesthetics propel chicago thieves. guess we'll see.

serial number Y1B6068http://bikeforums.net/attachment.php...hmentid=323829http://bikeforums.net/attachment.php...hmentid=323830http://bikeforums.net/attachment.php...hmentid=323831http://bikeforums.net/attachment.php...hmentid=323832

Here's my new-to-me Sekai. I've never owned a decent bike before and I love this thing. Thought I'd throw it into your database even though all I know about it is what I've learned around here. I could list and/or upload images of the components if necessary, but I think it'd be a review of things already covered. Anyway, 1981 Sekai 2400 Limited:

http://bikeforums.net/attachment.php...hmentid=333220http://bikeforums.net/attachment.php...hmentid=333221

Very clean looking. Any questions you might have? If I don't know it, T-mar or Sekaijin might ;)

I'm sure I'll come up with some questions eventually. For now I'm just enjoying the ride. And yeah, it's super clean, and for someone like me (total biking noob) I was happy to pay a little extra to buy it already overhauled and set up. I guess my only question at this point is what's "limited" about it? I'm assuming it's the component setup. Random thought: It's got no head badge at present; I may track down a replacement or may leave it bare. Looks kinda cool this way.

in this case "Limited" is just a model name.

New here.

I have a Sekai 2700 silver.

I am desperately looking for BLUE Sekai 2700 decals. (i know Yellow Jersey in Madison, Wi has white decals -- I live in Madison.)

http://www.velocals.com/servlet/the-...bicycle/Detail

.....if you want to turn it into a 2500, these come in a variety of colors. Otherwise, I got nothin'.

Thank you for responding, but I really would like to find 2700 decals.

go to a sign shop they usually charge $15 or $20 to print out any color you want just bring a digital image of the decal and they can either match the font or print it directly easy peasy

I am also 99% sure they can change the 5 to a 7

DH is a stickler. Only authentic decals will do. The 2700 decals have the "2700" in the same size as the "SEKAI". The "GT Deluxe" is a thin cursive font along the horizontal tube. (That decal is in fine shape on my bike.)

I am thinking of purchasing the white decals from Yellow Jersey just to have a set of replacement decals, but I like look of the blue on silver, rather than the white on silver.

http://www.yellowjersey.org/sekai.html

that's just lazy find the originals you'll never regret not having the best set of decals "Original"

Just be glad there are decals guys thanks to the fact that they exist we can with the style make our own decals that will not be noticeably different than the original style decals my sekais are the hand painted variety of decals so there is no going back for me if you are familiar with vector art you can use Inkscape to make really good Crisp images of the decals to print you can also get your own outdoor grade vinyl to make the decals with or have a sign or print shop print them for you

@ kc0yef --> I am confused. It is lazy to get original decals, albeit the wrong color. I like Andy Muzi (the owner of Yellow Jersey). I don't mind supporting him.
[MENTION=235305]RaleighSport[/MENTION] --> my DH went to Andy Muzi to get replacement Raleigh Competition decals. Perhaps I can use the decals from Andy to help make new blue decals, but wouldn't having a flat reference would be helpful?

Welp I've actually been down this road before, I can save you some hassle but not all of it.
http://i182.photobucket.com/albums/x...oke/sekaio.png

"Lazy" is what I did when I discovered a total absence of Sekai headbadge decals on the interwebs: I went to cafepress and got a vinyl "rising sun" decal instead. Looks pretty sharp on that navy blue bike, and easily removable should the time come:

http://bikeforums.net/attachment.php...hmentid=335937

Nothing a purist would consider, sure, but with my fenders and a copilot baby seat strapped to the rear end, purity is pretty much shot to heck anyway! ;)