Eric F 

I'm starting the process of rebuilding a '77 (ish) Nishiki ONP. Does anyone know the correct seatpost size for this frame? T-Mar

drewellison 

I’m thinking it’s 26.8. Can’t remember for sure. I had an ONP back in the ‘70s, I still have a soft spot for it in my heart for those. Please post some photos!

T-Mar

A handful of ONP have been reported but I don't believe the owners have mentioned the seat post diameter. It's definitely not mentioned in the road test and catalogue. Regardless, it would appear that there are multiple correct answers, as the ONP were built with a couple of different tubesets. The early version was built with Tange Champion Pro, which had two different seat tube options that used a 27.2mm or 26.8mm post. Later version used a Tange #1 tubeset, which typically used a 26.6mm post. Consequently, you're probably best off measuring the internal diameter or test fitting various post sizes.

Members who have reported owning ONP include @Ouldog @tcarl @JZEH @cirp @ed b @soderbiker @VeloVeg @Kevindale @mainstreetexile

I know that some of them are still active, so hopefully they still have their ONP, will respond to their mention with post sizing data.

Eric F 

Thanks for the info. It's definitely not 27.2. Based on what I have gathered from the posts I've found on this site and others, I'm pretty sure my ONP is the later version with the Champion #1 tubeset (0.8-0.5-0.8). I don't remember which one it was, but someone's S/N was just a few digits different than mine, and still had the original decals.

I posted the story of the frame and pics of its current state in the Nishiki Serial Number thread...https://www.bikeforums.net/21318242-post2191.html

T-Mar

Just be aware that Tange #1 isn't 0.8-0.5-0.8 in all three of the main tubes. The seat tube is actually shared with Tange #2 and is 0.9-0.6-0.9. Of course, they also could have spec'd a mixed set or reamed out the top butt.

BTW, I'd appreciate your S/N for my database. If you don't want to post it, you can send it via PM. TIA.

Eric F 

Thanks for the additional info.

Here's the S/N pic. This pic and a bunch of others were posted in the Serial Number thread a few days ago (link to post...https://www.bikeforums.net/21318242-post2191.html)

cirp 

I have a ‘77 ONP. I’m on the road right now and won’t be back until tomorrow (Thursday).

I’ll measure everything and look at the seatpost let you know.

Jim H
Las Vegas

Eric F 

TIA for your help!

mainstreetexile 

Unfortunately, I don't have mine anymore. I was short on storage space at the time and I regrettably got rid of that frameset (and a very nice Koga Miyata Terra Liner Carbon!!).

Mine was a 1974 champagne colored frameset, and I found the old text for my for sale ad, where I noted that mine took a 26.6 seatpost:

From what I've read, these were Nishiki's top end frames and they were handmade at a separate factory/location. They were trying to make a Japanese frame that would rival hand-built british or italian racing frames. Tubing is marked as "Cro-Mo 0.8-0.5-0.8 double butted", but from reading it sounds like it may use Tange Champion 1 double butted tubes, with suntour fork ends and vertical suntour dropouts. Some nice filing / cutouts / details in the lugs, fork crown, brake bridge, and bottom bracket shell. ... Takes a 26.6 seatpost and a standard bottom bracket (there was a bottom bracket in there when I got it, so the threads are good).

I have some other Nishiki ONP info saved from that time, a 1978 ad and magazine review of one. The ad had frame measurements and a note that stated:

* Please install the seat pillar of 27.0 or 26.8 (620mm or 640mm)

So maybe the seatpost size or tubing widths changed depending on the year or frame size?

Eric F 

This is very awesome historical info for my frame!!! Thank you

T-Mar

Thxs for posting. I had not seen this advertisement.It was a fairly common practice to use heavier gauge tubing that required a smaller seat post, on larger frames, as taller riders were typically heavier and stronger. However, this is the first time I've seen it on Nishiki, outside of their Italian sourced frames. It's strange that the advertisement gives more information that the 1978 catalogue.

cirp 

Eric,

Just measured everythink and took pictures. The seatpost is a SR Laparde and is stamped 27.0. The inside diameter of the seat tube measures 26.86 (never exact).

Hope this helps.

Eric F 

Thank you for your efforts in trying to resolve this for me. Your info matches up with the Kawamura ad posted above. This helps a ton!

Beautiful bike, too