RIDER987

^ Can anyone suggest a model based on that year or do none of those parts look original?

T-Mar

I was under the impression that this is a Yamaguchi branded bicycle. The picture is not clear and the decal on the down tube looks like it could be Yamaguchi . It's certainly too long for Sekai. If it is a Yamaguchi brand then it will not necessarily correlate to a Sekai model.

RIDER987

It's definitely a Yamaguchi and I've attached a photo of the decal.

Both the triathlon decal and Yamaguchi appear to be original as I've also found the same bikes from a Google search.

Any thoughts on this bike as I'm slightly confused?

What is the difference between Sekai, Sakae and Sakai?

That decal says Sakai, seat post has Sakae embedded and what I understand is that Yamaguchi made frames for Sekai?

Would I be right to assume it's a mid-end bike?

T-Mar

It's Yamaguchi built but not necessarily Yamaguchi branded. Triathlon could indicate a brand or model or it could be owner applied.

Sakai, in this case, refers to the Japanese city, though it was also a private label brand for Bloor Cycle of Toronto, Canada. Sakae (Ringyo) is the name of a Japanese component manufacturer, often abbreviated as SR. Sekai is the name of a bicycle brand originally owned and marketed by Velocipede of Seattle and acquired in the in the early 1980s by Norco.

The frame is from 1986.
, not 1985. Tange 900 is a seamed chromium molybdenum alloy, while the Mangaloy 2001 forks (and almost certainly stays) are a lower grade, carbon manganese alloy. During this era, frames with this combination were typically used on upper entry level models but could sometimes be found on lower mid-range models, depending on the components. In this particular case, it is difficult to determine exactly which components are OEM. The wheels and saddle are obvious replacements. Cyclone MK II was still aviailable in 1986 but had been replaced by New Cyclone, which was typically spec'd on new models. I can't identify the 105 and 600 generations form the photo.

Yamaguchi was a contract manufacturer that built for many brands including, but not limited to, Lotus, Maruishi, Norco, Sakai, Sekai, Shogun and Steve Bauer. The large number of possible brands in conjunction with the frankenbike build, makes it difficult to identify the original brand and model.

RaleighSport

and just to muddle things up even further, Sekai and Sakai are sister brands usually distributed by Norco, so while certain models were literally offered by all three.. it also doesn't necessarily mean any connection at all.

RIDER987

Thanks for the detailed response T-Mar. It certainly cleared some things up.

So I think I can conclude that the brand was 'triathlon' and the builder Yamaguchi. This is mainly because whilst researching I've come across a few with the same frame BUT each one had different components.

Perhaps they were sold as a frame only and the owners could choose the parts later on.

Either way it should be a nice ride once cleaned up.

T-Mar

If you've seen this decal on various bicycles, it may well be a brand name. However, if the other examples used the same tubing, it's doubtful that they were marketed as framesets due to the level. Typically, only high grade frames are marketed as framesets.

If it is a brand name, it may be a sister brand to KHS, as they owned the trademark to the name. However, I can't say that I've ever seen any KHS manufactured by Yamaguchi.The other possibility is that they licensed it out, as they did this with Bridgestone, who used it as a model name around this period. However, a Bridgestone Triathlon frame would have been almost certainly manufactured by Bridgestone.

Thespandexkid

Hi! My brother and I just recently got 2 used bikes, both Sekai bikes, I am not a "Bicycle pro" but I just looked up Sekai bikes on a whim and it seems they are pretty mysterious, I have a Sekai 2600 Eurosport and my brother has a Sekai Bush pilot, are they with much? I am not planning to sell mine and my brother is not going to sell his, but I thought I could ask. While I am here...the rims of my bike are painted, green (Looks really cool!) but...they squeak REALLY loud when I brake, I have asked around and people have told me to 1. Chang the brake pads, 2. Sand-paper the area of the wheel the brakes touch, and 3. Toe/turn-in the brake pads (I cant remember the exact words, might not be either of those)...What should I do? I really love mysteries so this is cool that you are collecting all this info!

-Thank you!
Thespandexkid

P.S.
The brakes are Dia-compe 500.
The wheel rims are new, TESSA Eightinch.

P.S.S
The bike frame says SHIMANO SIS, I looked it up and from what I gathered it is the rear gear, well, the company that makes the rear gear.

Sorry for the barrage of questions!

-Thank you!
Thespandexkid

Thespandexkid

Could my Sekai 2600 Eurosport been built and sold after Sekai merged or joined with Norco?

wiab21

I just picked up a Sekai Bigfoot and after going through the forum, I can't find any reference to a serial number starting with "F".

The serial is F7011329

Any suggestions to a conversion of the front axle to quick release?

Thanks!

T-Mar

Welcome to the forums. It's definitely a Norco era bicycle based on the model name, which was also used on Norco branded bicycles. That, in conjunction with the seril anumber indicates a 1987 model manufactured by Fairly of Taiwan.

Most Asain manufacturers of this era used 9 x 1mm threading for both their solid and hollow front axles. So, all you should need to do is buy a hollow axle with the same thread and of the correct length (or buy a longer one and cut it to length). Use use existing cones, locknuts and washers, if they are in good condition, as there are often subtle differences in the cone race profiles that can cause compatibility issues.

T-Mar

Provided the SIS derailleur is OEM, then it is from the Norco era. Knowing the serial number and posting some pictures would help. The Bush Pilot is definitely Norco era, as that model name was used on Norco branded bicycles in the Canadian market.

As for the brakes, the first solution to prevent squealing is typically toeing the pads so that the leading edge contacts the rim first. The next step would be cleaning the rims, which in your case sounds like removing owner applied paint. Sanding the pads will remove any hardened surface layer. The last step is new pads. Also, check to ensure that all the brake fasteners are secure and that the main pivots move freely without excessive play.

wiab21

Thanks for the info!!! I was in a LBS and they matched the thread pitch to 9.5 x 1 and told me that the front forks are pretty standard at 100mm. They also said that with the forward slant of the rear drop out they don't recommend changing it over to quick release to insure that it doesn't walk and twist under heavy peddling. Thoughts?

T-Mar

I'd be finding anther LBS, immediately! The biggest and strongest professional road cyclists have been using quick release rear hubs since the 1930s without issue. If they're experiencing problems with quick release on the rear hubs of recreational cyclists, then it's because they don't know how to use them properly.

9.5mm is atypical for Japanese front hubs of the era but they are the ones who measured it. 100mm is the most common Over Locknut Dimension (OLD) for front hubs, though 96mm and 91mm are also used. However, the axle has to engage the dropout slots without protruding beyond the outside faces. Consequently, most hollow front axles for 100mm OLD are about 108mm long.

wiab21

Man, big thanks for your help! Just having moved to Portland I'm still looking for a good LBS and haven't been too excited by the help I've gotten in the 2 that I've shopped. It felt like he had an elitist attitude without enough knowledge behind it, but I wanted to give him the benefit of the doubt... He referenced that the forward slanted drop out, vs a vertical one, was the reason for not recommending the quick release.

Anyone out there know the Portland,OR area and recommend a good shop?

I'll take the axle into another shop to match threads, and also measure the fork to make sure I get the correct size. I'm a newbie to bike work so really starting from scratch and just trying to bring a friend's old Sekai back to life.

T-Mar

Vertical dropouts didn't really start becoming popular until the 1990s. Manufacturers realized that vertical dropouts prevented owners from inadvertently altering the chain gap, which is critical to the performance of the indexed shifting systems which had started to appear in the late 1980s and were dominating the 1990s markets. The widespread adoption of vertical dropouts had nothing to do accidentally dislodging a wheel. Horizontal dropouts with quick release rear hubs had been in use for around 60 years before vertical dropouts became dominant.

Most riders have, at one time or another, dislodged a rear wheel due to improper use of the quick release. However, it would be extremely rare to result in a catastrophic incident and you very quickly learn how to adjust and properly operate a quick release skewer, They are very simple mechanisms.

If you're going to be working on bicycles, I suggest you invest in a set of digital calipers. Harbor Freight often discounts them to under $20 US.

I can't help you out with a Portland LBS. To attract the Portlanders, I suggest you open a new thread with a title along the lines of, Anybody Know a Good LBS in Portland?. That should get you several knowledgeable replies and maybe even a wrenching mentor. I would think that a place the size of Portland would also have a few decent bicycle co-ops which usually allow you to use tools and provide some guidance at reasonable prices. Good luck!

richardhashiru

Hi this frame / forks just came my way and I believe its a Sekai 4000 can anyone confirm it is and what year it was made? Top tube cable guides were apparently added when it was repainted (I will be stripping it and repainting it again as I don't like the current paint scheme) Serial number is M5G00255

T-Mar

The frame was manufactured in a year ending in 5. Given the top tube cable tunnels, shift bosses, bottle bosses and cable routing under the BB shell, 1985 would be the obvious candidate. However, given the obvious repaint, it's possible that these were additions and it is 1975. The fork crown style and longer dropouts with eyelets are more indicative of 1975, as are the use of non-recessed brake fittings.

The frame manufacturer is Mikki, who supplied frames for many brands. It may not be a Sekai, let alone a 4000. What size seat post does it take? I'd appreciate detail photos of the fork crown, seat lug and rear dropout. It may help.

richardhashiru

Thanks for the response T-Mar further pics as requested:

T-Mar

Based on the detail photos, I am quite confident that this is a 1975 frame with fittings added. Did you determine the seat post diameter?

Mr.Guy

I just picked up a Sekai 2000 #Y6A0842. I plan on stripping the frame and repainting it since it has a couple rust spots, I just with there were decals still available for it.

RaleighSport

If you talk nice to Velocals they might be willing to turn the 2500 decals into 2000....

nishikiroadace

M1B09061is a framenumber I have on a Alimo, dutch, bike.
That could be a Sekai frame number, not?

T-Mar

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.

nishikiroadace

Yeah, cool. Thank you. It's an '81 frame then. Identical to the pictures of the other 2 from the Netherlands.
Alimo imported Benotto in the Netherlands. But they also sold frames or bikes under the Alimo name. Some of them were Italian, Piazza. Probably the ones with the Benotto style transfers.
Thanks.