Try as I might I cannot find the differences. My guess is that it is the year of manufacture.
From my investigation it looks like it will be a K25.
Is there a chart anywhere?
N
The numbering by BMW may appear a bit confusing.
From day 1, the bikes where named R-something, where the letter R was a prefix for Rad, translated into Bike. Keep in mind that BMW by then produced engines, mainly for aeroplanes. However, in the aftermath of ww1, they where forced to seek other products, and motorbikes seemed like a great idea.
And they pretty much started with R2 (what happened to R1?) and each new model was numbered whatever came next in line.
The number was also often labeled on the bike.
They kept the numbering sequence until mid-80's, when they for the first time introduced a new, non-boxer engine. And the new series was named K-something.
First K models where numbered by their engine CC, as in K100 was 1000cc etc. But their technical name was K589.
Slowly, all new models where given a Kxx number, and it is my humble guess that this has to do with introduction of computers in their organization.
Now a days, all bikes are still sold with different names depending on engine type and riding style, yet they simultaniously are also given a K-number.
To go back to OP's question, the 1200 boxers that where introduced in 2004 where named R1200 xx, but they where also given a K number, as in K25 to K29 for the different models with this 1200 boxer engine. K12 on the other hand was a prewar bike. Yet, lot's of people shorten the R1200 xx to K12 for simplicity.
And in order to add to the confusion, prior to the K25 R1200GS, BMW , for a short period, used a technical number without a letter prefix. When they introduced the R1100 in -92, it was named 259 in the litterature, and the very first R1200, as in the cruiser nicked named the James Bond bike and a Harley competitor called R1200 CL, they where all numbered 259xx.
If you do a search in the realoem.com, as linked in previous post, you will see the different bikes , where the older ones are found under the 'Classic' selection. The realoem,com lists from R24 and onward.
Earlier models will be found in the link in post #2.
