Finally got it built with modern components (ahenm - still some unfinished parts...) - Serial 77G90047.

Today got to a nice ride after rain has stopped.

Everything came out good imo for a first build and the only part that am not that happy are the breaks - using the original calipers to have room for fenders and they are quite heavy compared with the breaking experience on my Nishiki (all 105).


For the Sekai I got a complete Ultegra 6700 with brifters, crankset (50/30T, 165mm), cassette 12-30T, front and rear derailleur (short cage). Break calipers are not installed.

Shimano A530 pedals, Terry Nitto M1104 370mm, Araya 27" rims with Conti Ultra Sport II 27" 1 1/4 and full SKS fenders with my milk jug flap .

Also my first wheel building for the rear on Shimano RS400 hub (11 speed compatible) - it was somehow easier than I was thinking - still not 100% true though.

Cold set the frame from 120 to 130mm and since the chain stays are not the same on left and right, have to do some jumping on the non drive side .

One of my first projects was a Sekai 2700 and one that I actually completed. A bit large for me but still have it. Mostly original aside from the consumables. replaced the barends with DTs and hoods/levers are new. There is a Sekai database here in C&V.

The Sekai 2700 is one of those fantastic sleeper bikes that few know about. Yours looks like a great example!
Are you still using the over 30-year old pads on those new Ultegra calipers?

The other way, I am using the Ultegra shoes + pads on original Gran Comp calipers - there is still life left on used 6700 set I got.
I've ordered new rubber for breaks but didn't arrive yet.

Started re-building the Sekai GT2700 that got stripped out in favor to Centurion ProTour15 and Nishiki Tri-A.

So, today was trying to re-build the rear wheel with old hub and was pretty sure it was a 3-cross since the front wheel is laced on 3-cross.
Finish all the lacing and something is not right.....
So, got a close look at the pic of when I got the bike and … It is a 4-cross on rear wheel.

Well, more re-do = more fun and dirty hands.

Got a nice Shimano break levers to go with and the Futura saddle that came with the Centurion ProTour15.
The Terry Nitto handlebar, SKS fenders will stay there.

Love old Japanese bikes. They're so easy to modify. Plenty of sources for brand new threaded parts. Good stuff. Have fun.

Yesterday after dinner fixed my wrong 3x lacing to 4x and got my hands dirt, of course.
I have halfway tension-ed spokes and did a spin on the wheel .... boy, never saw a wheel that wobble....

Next, truing fun time

Finished truing the rear wheel, and adjusted front too.
Crankset (52/40T), downtube shifter, derailleurs and rear freewheel 5 speeds, 14-17-21-26-32.
Original freewheel was an 13 to 24 teeth that was disassembled and to provide the core to the big one since that was not screwing right into the hub - it looks like the threading is different.

I did a quick ride (don't have the brakes installed yet) and it shifts ok with the friction levers, but sometimes jumps because of huge teeth difference when trying to go lower.
Going upper moves one by one.

My truing "stand"




Frame, fork, headet + seat post - hunmmm. quite heavy.

Great job, love to see Sekai's modernized.

Actually I am putting the original drivetrain back - this frame is one size big for me.
I will finish rebuilding the pass forward.

My 2500 was too big for me as well... but I stripped it down for spares for my 2700

Finish rebuild of the Sekai and went for a short ride today afternoon. Yes, downtube shifter + friction is really not my thing - I got spoiled with brifters and modern drivetrain, but like very much the old steel frames.
As mentioned the frame is one size big for me - and heavier than other of my bikes. I just posted on CL.

[MENTION=476141]phtomita[/MENTION] you might take a look at the this thread for inspiration of classic steel frames with modern drive trains plenty of racey steel frames out there that will hold their own on the weight side of things

Thank you for the thread link - looks a great thread .
As I mentioned, the Sekai was to be my commuter and have used it from around mid November to February this year. It happens I found the ProTour on my size and am enjoying it on my commute.
Have to open some space on the garage …

I not sure of how this "Bike Forms" works...I tried it a few years ago and recieved nothing but greif form mernbers.....
SO HERE I AM again...I am in need Dia compe breake lever HOODS in the Gum (brown) color. I ordered some from VELO Orange and they are not even close to being a correct ones. The cable opening is way too small for the Cable adjusters to fit through. Any sources (other then E-bay) for the CORRECT ones would be great. I still can't (and not sure how) to post pictures yet....