Author Topic: Operation Spare Time - K100 "Cafe" Build  (Read 267 times)

Offline Hoffrock

  • Curious
  • Posts: 8
Operation Spare Time - K100 "Cafe" Build
« on: July 16, 2017, 05:18:07 PM »
Hey Guys, I thought I would start a thread seems as I have been taking photos as I have been going along.


This is me: http://www.motobrick.com/index.php/topic,10137.0.html


I bought this K100 recently and have already torn into it. The first image is what I was like when I bought it, and the second is the next day when I had started tearing it down. And the Third is a photoshop image of what I'm looking to acheve.


Plans are:


Chop the tail & fabricate new rear end
[size=78%]Cafe style single seat[/size]
[size=78%]De-tab and clean up frame[/size]
Integrated rear lamps
Clip-on or clubman style bars
Try and reduce the wiring complexity. Possibly M unit if I am brave enough.
Slightly more AT tyres (kind of suits the Swedish weather, and I think they look Cool AF)
Black paint all components apart from cylinder head covers.
Relocate battery
Hide wiring as much as possible
New headlamp
Low profile instruments
Generally refurbish everything - Replacement of all rubbers/hoses etc.




Lets see how it goes.
  • Göteborg Sweden
  • 1984 K100

Offline Hoffrock

  • Curious
  • Posts: 8
Re: Operation Spare Time - K100 "Cafe" Build
« Reply #1 on: July 16, 2017, 05:37:26 PM »
Some progress on the build. This is kind of an assortment of different pictures from a few times at the garage. I was getting familiar with the bike and slowly dissasembling and fabricating. I made the photoshop image as a guide, but I will likely update and change things as I go along. All part of the fun I guess.



  • Göteborg Sweden
  • 1984 K100

Offline Hoffrock

  • Curious
  • Posts: 8
Re: Operation Spare Time - K100 "Cafe" Build
« Reply #2 on: July 16, 2017, 05:42:30 PM »
A few more progress photos.
  • Göteborg Sweden
  • 1984 K100

Offline duckytran

  • ^ Motobrick Curious
  • Posts: 97
Re: Operation Spare Time - K100 "Cafe" Build
« Reply #3 on: July 17, 2017, 10:59:26 AM »
Very cool looking bike you designed. Looking forward to seeing more progress pics.



  • Austin, Texas
  • 1993 K75

Offline Hoffrock

  • Curious
  • Posts: 8
Re: Operation Spare Time - K100 "Cafe" Build
« Reply #4 on: July 17, 2017, 04:29:57 PM »
Very cool looking bike you designed. Looking forward to seeing more progress pics.


Thanks! Hopefully it will turn out similar to the drawing.


I had a few hours this evening at the garage.


I drained off the coolant and disassembled the radiator etc. By the colour of it, it looks like it could even have been the original coolant... probably not but it came out black and smelled like sewer water. Not good when it spills all over your trousers.
The drain bung was seized and unfortunately was quite corroded. The Allen hole rounded off when I tried to Un-do it. I decided to drill it out instead, and then flushed the water pump though with fresh water. The same for the radiator.


I also managed to mask off and sand back the BMW logo and striped on the bottom end cover. Matt black and polished details looks pretty cool IMO.


Also attacked the grime on the throttle bodies. A whole can of brake cleaner and a good wire brush sorted them out. Can't wait to see them back on the engine now.
Will need to give the fuel rail the same treatment.


Has anyone anodised their fuel rails before? Could look quite cool as it's visible all the time.


I used a small hand pump to drain out the tank too. Tried leaving it for a few days to drain before, but it was having none of it.


Anyway, here are the progress pics:
  • Göteborg Sweden
  • 1984 K100

Offline Hoffrock

  • Curious
  • Posts: 8
Re: Operation Spare Time - K100 "Cafe" Build
« Reply #5 on: July 18, 2017, 07:20:11 AM »
I finished off the basic fabrication of the rear frame today. Decided to go for a more squared off look. Partly to do with mot having a decent enough tube bender and also I think the more square section suits the bike as a whole.


I then started using some steel rod to shake up the lines of the rear. Basically just stuck the pieces in a vice and bent and hammered them until I was satisfied. Then just cut and tack welded them.


I am wanted a larger rear section initially but it would have looked a bit too bulky. Also when I sat on it, I would have ended up with too little seat. I want to be able to move around a bit. Save the old gentlemans vegtables.


From this I plan to make some card templates and then shape the plate steel to fit.
  • Göteborg Sweden
  • 1984 K100

Offline duckytran

  • ^ Motobrick Curious
  • Posts: 97
Re: Operation Spare Time - K100 "Cafe" Build
« Reply #6 on: July 18, 2017, 02:16:12 PM »
Are you planning on relocating the battery to the rear seat cowl?
  • Austin, Texas
  • 1993 K75

Offline MaraudeRS

  • ^ Proficient Motobricker
  • Posts: 222
Re: Operation Spare Time - K100 "Cafe" Build
« Reply #7 on: July 23, 2017, 11:20:06 AM »
Cool build! Can't wait to see what you do with the seat.


Sent from my iPhone using Tapatalk
  • Monterey, CA
  • 1992 K100RS

Offline Christopherguzzi

  • My first Beemer🏍.
  • ^ Motobrick Curious
  • Posts: 75
  • It ran when it was parked........27 years ago😳.
Re: Operation Spare Time - K100 "Cafe" Build
« Reply #8 on: July 23, 2017, 11:34:19 PM »
Best of luck with your build.   Very nice work thus far.  For what it is worth, I rather like the stock red color.   
  • Little Canada, Minnesota
  • 1986 K75C
Christopherguzzi