Mguy

I have a Miyata 1000 (s/n MS34733). The decal on it says that it is triple butted. I understand that the M in the serial number indicates that the bike is a 1984. I also understand that triple butting started with the 1985 line. I have also heard that some 1984 bikes were represented as 1985 models. If that is true, were these bikes with the letter M in the serial number actually triple butted? My bike was represented to me at the time of purchase in 1985 as being a 1985 model with triple butting by the bike shop.

Also, not to mix apples and oranges, what does the S signify after the letter M in the serial number? Thank you, I'll take my answer off the air.

T-Mar

Miyata changed it's serial number format during 1984 at the start of the 1985 production. They went from a single letter prefix to a dual letter prefix, where the 2nd letter indicates the fortnight. 'S' being the 19th letter of the alphabet, represents the 19th fortnight (i.e weeks 37-38 or the last two week of Sepetember). This is certainly late enough in the year to represent a 1985 model. Manufacturers typically start building the new models around September in order to build up inventory and allow for time for shipping and distribution so that the new models are in stores for the lucrative Christmas season. New models also have to be available in the fall for the trade shows where many dealers place bookings and also for catalogue layout.

However, there is also possible to misinterpret a "5" for an "s", in which case it would be a 1984 model. But the 1984 version of the Miyata 1000 was spec'd with a double butted tubeset, whereas the 1985 version used a triple butted tubeset. So, things are pointing to a 1985 model manufactured in late September 1984. Others differences between 1984 and 1985 include going from quill to platform pedals, going from over to under BB shell shell cable routing, switching from Dia-Compe to Shimano cantilever brakes, switching from a Sugino to Shimano crankset and the 1985 version having a decal with two diagonal bands at the top of the seat tube.

The Golden Boy 

LOTS of changes across the industry for 1985!!

Mguy

Thank you T-Mar for that excellent information. Between you and Chr0m0ly, I am feeling more connected than ever to my bike that I've owned since '85.

miamijim

I remember a conversation about similar circumstances with our Miyata rep way back then.

Whatever sticker it has is the tubing it has. Sort of. Miyata would occasionally over spec frames, a frame that was supposed to have double butted tubing may have intentionally been built with triple butted tubing and not marked as such. This was a very rare occurrence. The sticker will represent the lowest spec tubing.

The Golden Boy 

So you can look at whether the cables go over or under your bottom bracket to know for sure if it's a "real" 1985 model.

Post some pictures of your bike!!!

I got my Miyata 1000LT late last year- I've been getting some miles in on and hope to load it up and get out for a bit soon.

I wonder how rare of an occurrence it was/is selling a 'last year's model' dressed up for the current model year? I know Trek had unsold 1985 Trek 620s and sold them with 1986 paint as "Trek 620 Cirrus" models. You can see those- they have a silver head tube. But that was a discontinued model and not marketed in the catalog