M900 SG-X chainring - when did it come out?

[regan_ev]

I’ve hit the Shimano groupset timeline on here but can’t find info I need.

When did this SG-X chainring become part of the M900 group? It superseded the M900 SG outer ring which doesn’t have the pinned shift ramps that the middle ring had, and that the SG-X added.

Curiosity is killing me.

Ta!

M900 SG-X


M900 SG

 

[one-eyed_jim]

1993.

It's in this '93 catalogue:

http://www.retrobike.co.uk/gallery2/v/M ... gues/1993/

Not in '92, obviously, as that was the first year of XTR.

 

[regan_ev]

1993.

It's in this '93 catalogue:

http://www.retrobike.co.uk/gallery2/v/M ... gues/1993/

Not in '92, obviously, as that was the first year of XTR.

Thank you. I struggled with my search, and thought it might be useful to ask here as it may prove useful for others.

Since posting I’ve been told that the photo I posted of the SG-X (I think I just stole from Google Images) may be an M95x era, because of the extra lip/ridge, but the one I’ve bought is definitely M900/110BCD
- with group designation number M900A. I had to check the date just for period-correctness/peace-of-mind:

Cheers

THIS:

 

[boxxer]

Re:

I thought it was 94 just before M910 group launched...

I’ve had both but stupidly never looked at the date stamps on the cranks...

I know my current ones are 92 and it doesn’t have a lip

 

[regan_ev]

Re: Re:

I thought it was 94 just before M910 group launched...

I’ve had both but stupidly never looked at the date stamps on the cranks...

I know my current ones are 92 and it doesn’t have a lip

I was thinking 1994 when I asked, I was linked to MOMBAT via Facebook and it’s listed there as 1993. Not sure what month the updates happened though.

Date stamp might be confusing, especially if cranks were made mid 1992, but not assembled into chain sets till later in the year. Not sure that’s too likely given Japanese production methods, even back then, and the demand for M900 in OE assembly glpbally, but it’s not impossible.

Not sure chainrings get date stamps but I’ll look when I get these.

Cheers.

 

[one-eyed_jim]

Here's a M900 set on sale in Japan. The cranks are stamped PL (December '91) but the outer ring (SG-X) is RF (June '93):

https://buyee.jp/item/yahoo/auction/e305005226

This SG-X ring is stamped RB (February '93):

https://bikemarkt-images.mtb-news.de/ls ... -large.jpg

It's interesting that the SG-X chainring is described as "optional" in the '93 catalogue. That catalogue would have been released in the autumn of '92, so production had presumably commenced by then.

 

[regan_ev]

Here's a M900 set on sale in Japan. The cranks are stamped PL (December '91) but the outer ring (SG-X) is RF (June '93):

https://buyee.jp/item/yahoo/auction/e305005226

This SG-X ring is stamped RB (February '93):

https://bikemarkt-images.mtb-news.de/ls ... -large.jpg

It's interesting that the SG-X chainring is described as "optional" in the '93 catalogue. That catalogue would have been released in the autumn of '92, so production had presumably commenced by then.

LEGEND! Awesome - THANK YOU!

 

[legrandefromage]

Its very short lived.

There are two types as mentioned, stamped and pinned and the machined and pinned. Long term use found the stamped rings a little soft whereas the XT/ XTR machined rings are much tougher.

My own XT equipped bike was built in April 1993 and had the none pinned SG rings. DX and the 'new' low pro LX chainsets had stamped SG-X rings but then the whole 110 BCD was rapidly replaced by the 94bcd groupsets..

It is very common to find XTR chainsets with the stamped rings being passed off as XTR although not always maliciously

Front and back annodised XTR SG-X rings

LX rings

DX Rings

XT Rings

 

[regan_ev]

Its very short lived.

There are two types as mentioned, stamped and pinned and the machined and pinned. Long term use found the stamped rings a little soft whereas the XT/ XTR machined rings are much tougher.

My own XT equipped bike was built in April 1993 and had the none pinned SG rings. DX and the 'new' low pro LX chainsets had stamped SG-X rings but then the whole 110 BCD was rapidly replaced by the 94bcd groupsets..

It is very common to find XTR chainsets with the stamped rings being passed off as XTR although not always maliciously

Front and back annodised XTR SG-X rings
LX rings
DX Rings
XT Rings

Fantastic info. Well I’ve learmed loads from that, thank you.

The power of Retrobike and big cheese is better than MOMBAT’s archive and Google. (Not to diss the late Jeff Arxher, of course.).

 

[one-eyed_jim]

It is very common to find XTR chainsets with the stamped rings being passed off as XTR although not always maliciously

It's interesting to note that the XTR SG-X rings in the '93 catalogue resemble the XT rings in that they lack the "extra lip/ridge" mentioned above:

http://www.retrobike.co.uk/gallery2/v/M ... R.jpg.html

Are these rings ever seen in the wild, or had they been superseded in production by the time the catalogue came out? Are they actually identical to the XT SG-X rings? Can anyone come up with EV part numbers?


PS

Here are XT SG-X rings with QE (May '92) date codes:

https://farm4.staticflickr.com/3814/114 ... eb14_b.jpg
https://farm6.staticflickr.com/5509/114 ... 214c_b.jpg