Harry, you have guessed correctly i'm sure.
The 98 for me is when they got it just right. Before that there were a few problems with the frames cracking at the headtube,downtube,top tube area hence the gussets on yours.
The earlier ones also had straight gauge tubes and the first butted tubes were around 97 until the M2 ended in 2000. It was the butting when first tried that caused the aforementioned cracking problems.
The frames weigh approx 3.5lbs and the serial numbers are on the dropout, the first two numbers give the year of manufacture.
The frame angles are head 71.5 and seat 73.5.
As you can see i'm a bit of a nerd when it comes to these frames, but I love them and sure you will enjoy what is a classic design that works so well
The 98 for me is when they got it just right. Before that there were a few problems with the frames cracking at the headtube,downtube,top tube area hence the gussets on yours.
The earlier ones also had straight gauge tubes and the first butted tubes were around 97 until the M2 ended in 2000. It was the butting when first tried that caused the aforementioned cracking problems.
The frames weigh approx 3.5lbs and the serial numbers are on the dropout, the first two numbers give the year of manufacture.
The frame angles are head 71.5 and seat 73.5.
As you can see i'm a bit of a nerd when it comes to these frames, but I love them and sure you will enjoy what is a classic design that works so well
a little slideshow of the M2...sorry XT V's off at the time..playing 
