I have purchased an 85 K100 and I am thinking of turning it into a cafe racer style bike. I bought the bike from a friend in need of some cash with the intention of getting it running and selling it for a profit. Long story short, I decided to keep it as a means of transportation to and from school.
The project has just gotten started but the bike will not at this time. I started my journey with poking around on the old inter-web looking at pictures of other K bikes and ran up on a members thread about their trials and tribulations with their cafe (rbarrero) project. I was hooked immediately on turning my tourer into a racer.

So how about sharing any links you get with us. My wife is excited about the idea of my turning my current K75 restoration project into a K cafe. There are a couple of interesting very minimalist K cafe pictures online
One title robock-K100 appeals. Unfortunately I'm still fighting this system trying to figure out how to post jpegs.

One continuing question though is what do they do with that ugly battery? Is it replaced or hidden some where?

best
J.

Jjeffries, I've found the best way to post pics is to upload my pictures to Picasa, and copy the direct link to the JPEG file in Picasa to the image widget in the forum editor.  There is an upload widget provided here but I've had mixed results with it.  The Picasa route is solid and foolproof.

As for the battery, a Shorai lithium ion battery can replace the standard one and be placed in the tail of the bike.  There are limitations to that technology and I'm not 100% certain that the Shorai is compatible with the charging system in the K100.  Maybe others can comment.

That's a mechanical speedo. It's not compatible with the K-bike.  There is Motogadgets, Dakota Digital, Acewell, Autometer and VDO to name a few speedos that are compatible.

wickbimmer wrote:My questions have been ... and what type of speedo can be used.

Main issue is tastes. To supplement my standard K75 speedo I mounted an Avocet 40 (now pase') bicycle speedo. They are battery powered and more accurate than the BMW speedo's. The Avocet 40 is good to about 110 mph. Newer models like the 45TT claim accuracy of .1 mph from 1-400 mph. Here's a link so you can see what they look like:
Avocet Cyclometers

A draw back is the lack of lighting for night time use. But I could see rigging an led easily to deal with that. After dark I just use the inaccurate BMW speedo. I found that the magnet ring (think there are six magnets so you get six pulses per revolution) used for timing can fit over the K-bike's axle. So the main problems with mounting were to cobble together a plastic ring to hold that ring of magnets and then mount the sensor from one of the K-bike's pinch bolts. Really not difficult if you are at all handy with doing small projects. It's programmable to fit different tire sizes and metric or english measurements. It also has other features such as an assortment of trip distances, timing, clock, etc.

Thanks for the info guys.
J.

wickbimmer wrote:I believe that people use the gel type batteries and put them in the tail section. My questions have been "where to relocate the radiator overflow and what type of speedo can be used. I found this one at dime city cycles that I like but not sure if it is comparable with my bike. Anyone know? 
http://www.dimecitycycles.com/vintage-cafe-racer-caferacer-bobber-brat-chopper-custom-motorcycle-electronic-parts-mini-black-face-led-speedo-speedometer-25-7032b.html

Hi,

Regarding the overflow tank, there is plenty of room next to the radiator. I'm having trouble inserting a picture. If you can be bothered looking at my blog about my project, you can see my solution.
http://papajhotel.wordpress.com/2013/07/01/the-k100-project/

Paul

Thanks for the info and link. I had seen your blog before and your bottle idea was awesome. I wondered if the heat that is generated in that area would melt it. I was thinking of using an aluminum water bottle that I had laying around but I still need to harness some way of mounting it that I will be happy with. 
Where did you find the collector that you used? The one eye sore I find on these bikes is the ugly square exhaust. I am a fan of all things BMW but I just can't figure out why they designed it the way they did.

papajhotel wrote:Hi,
Regarding the overflow tank, there is plenty of room next to the radiator. I'm having trouble inserting a picture. If you can be bothered looking at my blog about my project, you can see my solution.
http://papajhotel.wordpress.com/2013/07/01/the-k100-project/

Paul

Yeah, I have trouble with picture insertion as well. I'm guessing that the site owner prefers to have photos hosted elsewhere.

Anyway your blog refers to the overflow tube as "Baby bottle Mark II". So I'm guessing it's literally a modified baby bottle. Any comments about how you arrived at an acceptable size to allow for  or where you obtained it?

J.

Check out the how to https://www.k100-forum.com/t998-posting-pictures-and-movies

wickbimmer wrote:Thanks for the info and link. I had seen your blog before and your bottle idea was awesome. I wondered if the heat that is generated in that area would melt it. I was thinking of using an aluminum water bottle that I had laying around but I still need to harness some way of mounting it that I will be happy with. 
Where did you find the collector that you used? The one eye sore I find on these bikes is the ugly square exhaust. I am a fan of all things BMW but I just can't figure out why they designed it the way they did.

The bottle is attached to the frame, I don't think temp will be a problem. I found the collector on eBay. A guy was selling it as part of  a full system with an aftermarket can. Don't know where he found it.