1986 K100RS before


La Rata del Desierto today (almost done)


It's a scrambler.
It's a rat bike because I built my own intake using two fire extinguishers and the expansion bottle is a water bottle for cyclists, among quite a few other details.
It's an adventure bike because it was built for taking a 7000km ride round trip to Spain next month.

I will be posting detailed pictures in other posts.

I always build my own solo seat. Flat, so that you sit on your butt and not on your prostate. It looks small and hard and it is, but it works great for me on long rides. As usual I make them the base in wood and add a 40mm layer of sound insulating foam. It's pretty hard, that's what you (well, I) need for a long ride.

Last year we took a 1200km trip with a friend on a BMW R1200GS. I rode my 2014 project (XJ900 scrambler) with the same type of seat. On the last part of the trip, he was in real pain while I was still doing fine. 

Welcome to the forum.
Nice to see something different from the usual cafe racer custom.
That's some Sat nav on the tank! 
What is it? We're all dying to know.
I'm planning on some type of rack but intend to shorten the rear frame loop first. Keep us posted on your progress.
I have a GS as well and would agree that for an expensive bike, the standard seat is pretty bad after a 100 miles.
Tell your friend to buy a Sargent seat for his GS.
I picked one up second hand for a reasonable price. It's the lower version which suits my short legs and despite the firmer foam, it's 300 mile in a day comfortable.
A friend and I are planning a trip through France and the Pyrenees at the end of August so will need the comfort. 

Thanks Comberjohn!

This bike is some kind of war machine. The intention is not to have anything fancy on it. Instead, it all should look bellicose, warlike. This is achieved by painting on rough metal, leaving weldings unclean, using stencils for painting, etc. In addition to this, I built a control panel on top of the tank that will wrap up the look I wanted.

It features the original speedometer with a rough/old looking face plate and adds three elements not present in the original bike: Water temperature gauge, digital voltimeter and a USB port. It keeps fuel and oil pressure indicators and features four 3-position military switches, which are solely used as a combination to start the bike. It's only 81 combinations, but it's more than I need. I deeply dislike motorcycle keys!

Last, neutral and choke indicators is something I don't need, and since I have a voltimeter and a thermometer, I thought I could skip those two indicators as well. Tachometer is also something I can live without. 

On the side it reads "Desert Rat" in Russian. I think the Cyrillic letters kicks hostility up another notch (leaving politics aside, of course)



The entire box is lifted from the back, and it comes up along with the fuel cap. Just lift up and refuel. Again, no keys.

I have to applaud your lateral thinking and not conforming to the usual modifications. It's certainly making me rethink some of the things I was planning.
While one or two may question your choice of colour scheme, it's certainly a lot more interesting than painting everything matt black. Not a lot of alloy polishing time required either!
I'm sure that it will get plenty of attention wherever it goes and, after all, isn't that part of the reason to customise a bike.
Is the battery in the ammo box?
What lights are you using?
I'm guessing you are still using the original exhaust. I'm now thinking about cutting it and welding in a section of pipe that can connect to a R1200GS silencer. I don't want a noisy pipe that would be tiresome after riding for a while and the GS silencer is well made and cheap to buy on eBay.
Your method of switching on the ignition is simple and probably as effective as a 30 year old mechanical switch.
I was thinking of something on the lines of a proximity key and a start button on the lines of modern cars but not sure how practical or reliable it could be. Not sure I would trust China's finest but haven't really found anything suitable yet.
Agree with you about having too much info at times.
My first road bike had a neutral light and a high beam light and I managed for decades without a gear indicator!
Until recently I had a K1600GT. Too much information!
Simple is good.
A recent thread talked about how customising K's has become boring with so many cafe racers, not all of them well made.
Maybe practicality instead of art will make a comeback.
Always said that Roland Sands gets paid too much money for turning parts of motorcycles into fresh air. 

Thank you for your kind words, Comberjohn. 

Yes, simplicity goes a long way and that is one think I tend to put focus on. In a 7000km trip you want to minimize points of failure and make the bike as easy as possible to repair. 

My goal is for the bike to look rough, mean. It is a bike that you expect to see in a Mad Max movie, or that you would like to ride when the long awaited zombie apocalypse finally takes place

What's a top priority is that it is reliable, easy to fix and, most importantly: unique. For some reason I cannot enjoy riding a bike that's another one out of thousands made.

The headlamp is from a Kawasaki 250 from the 70s. It reads "Made in Japan" underneath. 

The original airbox, I guess, was designed to shamefully cover the side (now top) of the old Peugeot engine block. I might be wrong, but I personally have no doubt that there has been though put into that (covering up). Removing the airbox reveals the shape of an engine block that was clearly conceived to be used vertically. When laid down, it gets inevitably full of dirt and water that simply stays there forever, and looks quite awkward.

I didn't like the cover up part and I tend to highlights parts of the motorcycle that have not seen before, specially if they look unconventional. Some of these things are the beautiful rear fender and the "Made in West Germany" stamp, both covered by the original seat and fairing and the nice BMW logo in the gear box block, originally covered by the battery and support.



Removing the clunky airbox enables easy access to the fuel pressure regulator and leaves plenty of room for hosting a 14amp gel battery. I built a support for it using some of the screws in the block that originally supported the airbox. The battery is now easily accessible and I carry a set of crocodile cables in the ammo box (and a mini multitester) to ease the pain of any eventual troubleshooting down the road.



Yes, the battery is now close to the radiator, but it lays underneath the fan deflector, which means it won't get direct hot air. I don't anticipate this to be an issue, but I will make a 1200km trip before the long one, so I have time to move it further back if needed. You can clearly see here how many spots will preserve dirt and bugs forever, but you can now easily hose it all away.

As far as the intake, that deserves a new post, which is coming up soon.

I'm not to sure I like the overall design but I do really like the simplistic style you have achieved. Very nice.
I notice the engine block and drive train have been painted. What type of paint have you used for this?

The engine block is NOT a Peugeot. This stupid lie will not die. BMW did use a Peugeot engine in the very first prototype that they made and that IS as far as it went. The K100 engine is ALL BMW.

Think you've annoyed Rick. 

I don't even think it could've been called a prototype. A peugot 104 was used as proof-of-concept... then, I think I read somewhere, the whole thing was destroyed.

Thanks Kaptain Holister. I used Cummings Beige Engine Enamel, by Plasti Kote. 

As far as the Peugeot block, if that was merely used for a proof of concept and then scrapped, then BMW managed to design from scratch an engine that very nicely resembles a 4 cylinder car engine mounted sideways 

Regardless of where does it come from, I love it.

Yes, they designed it from scratch. Their idea was from the start was to design a new m/c engine based on a 4 cylinder car engine but needed to to keep it horizontal. They just happened to use a Peugeot engine to prove it would work in a m/c frame. They then chucked it in the bin . They'd already been building high quality 4 cylinder engines for some time with a huge worldwide reputation, why would they copy a Peugeot?

I've been thinking about eventually painting my engine completely. I think its a good solution to aging alloy and would be very serviceable.

I look forward to hearing about your on-road adventures.
Cheers

I hope your rat scrambler keeps up with the GS boys, cant have you let the side down now mate, good work, you should have a ton of fun on that.

It's a scrambler.
It's a rat bike because I built my own intake using two fire extinguishers and the expansion bottle is a water bottle for cyclists, among quite a few other details.
It's an adventure bike because it was built for taking a 7000km ride round trip to Spain next month.

I will be posting detailed pictures in other posts.

Where did you get this secret russian weapon? 
Very interesting style

Kaptain Holister, gotcha. I promise not to say that it's a Peugeot engine anymore

K75cster, I can easily put 1000km a day (for several days) so I'm sure I'll be ahead of the average GS boy (the K100 will handle that just fine)

спасибо MadRider! The idea was to give the impression of some old Soviet war vehicle, though it has a Made in Japan headlight and a Made in West Germany stamp in the frame . 

"Что русскому хорошо, то немцу смерть "
(old Russian proberv, for MadRider)

For those interested, I do this every year (buy an old motorcycle, customize it the way I like it, take it for a long ride and sell it before the season is over). Some of my previous builds here: 

http://julian.coccia.com/gallery/motorcycles/index.html

An MZ!
I used to have the 250cc version about 42 years ago. An ETS 250 with the one piece tank and seat with the leading link forks.

Yes, Comberjohn, it is an MZ Trophy which still carries the Eastern German license plate and vehicle inspection stamp. It's a present from my bike-dad.

It's time to talk about the intake. The airbox is the first thing I dump when getting my hands on a bike. In this case it's such a big box that I rushed into it. 

It was quite surprising to find inside a MAF the size of Cincinatti, so it was all going to require some serious modifications. When I removed the left part of the airbox (the one that connects to the throttle bodies) and tried to put it back, it was such a pain that I understood I could not live with that. Having everything accessible outside of the engine block is a must in every bike I build. So, I dumped it all and started from scratch.

Using two 2kg fire extinguishers and some silicon hoses I built a new intake that would connect the four 40mm throttle bodies with the 60mm MAF. 




The word воздух (Russian for "AIR") was written using a stencil (I 3D print all my stencils, BTW, which is quite convenient). What I like about the Russian language is that you write the word AIR with a stencil in a piece of metal and you would think it actually says "Missile launcher" or something like that. Russian language looks quite mean with stencil fonts, which is very cool

The silicone hoses attract dust like it's their job, which is great in this bike. Black hose clamps completed the look I was looking for. 



Note the quick release for the return fuel line. I tried in the fuel supply line, but it won't take the fuel pressure. Now it's just one clamp/hose to remove the tank.

The MAF looks very robust and seems like it could take a lot of pain without any further treatment, so simply sits outside with the plastic cover and cable connector facing back. 

A bit more welding took place to make an adapter from the square MAF window (and four bolts) to a standard 60mm racing air filter. The air filter nicely pops up from the hole left between tank and radiator after removing the fairing. It sits behind the radiator side which means it breaths good while still hiding behind the radiator.


(there is no water leak, but some spilling as I topped up the radiator before taking this picture)

As you can see, after the intake with the MAF, filter, and even the battery, there is plenty of space to make it all very accessible, including the fuel regulator, which was deeply buried into the bike before.

I took a first ride today and it all works pretty well. It feels like some kind of a two week tank. I have some minor adjustments before my 1200km (test) trip next week. 

The 1200km test ride is completed. This is not a bike. She's a hammer!



The stiff, flat seat in combination with the off-road handlebar feels like you are sitting on a wall. Yet, no butt pain after 1200km. The 40mm sound insulation foam has proven, once again, to work a lot better than a standard seat for long rides.

She cruises at 100mph like a champ and has no issue catching up with my friend's R1200GS. We had a blast!



This Sunday we will film a small documentary about her. More info on this to come.

Sounds like a beast.
Would be interesting to see what fuel consumption you get out of her.

How do you ride without front fender?
I tried once in rainy weather, and dirt was everywhere on the bike and me

A fascinating creation. How many hours did it take to create? John

Thanksk100virgin! It took six weeks of my entire free time including weekends. This would have been impossible without my wife's neverending patience

You still haven't told us about the painting.
Did you spray it on?
What kind of paint is it and did you use a primer paint?

I'm not surprised that you find the brick fun to ride. The last one I had, an RT, had the fairing removed from time to time and I found it easy to ride quickly and throw around. Feels like a 250!
Most of the forum members haven't had that pleasure and carrying a fairing, despite its advantages, makes it a bit of a lump to handle. My first K was a naked and the project I have now is the same. Probably with an upright seating position.
Someone else called it a 'funduro'. Like that description.
Not doing much to it over the summer, got the GS to play with, but trying to work out what to do next winter and watching for bits and pieces on eBay in the meantime.
Don't tell the rest of them, but if I was able to build or afford something like the sKrambler, I could part with the GS. Back to the dark side. :pale:

Plasti-kote engine enamel "cummins beige" on bare metal. No primer.

(spray can)

Shooting session today was amazing. Aerial shots using a DJI Inspire-1 (4K)  and moving footage from a car using a DJI Ronin gimbal with a 4K video camera. I will post the Youtube link here as soon as the video becomes available. Here's a frame for now:

Me like. 

The short film is finally here. Enjoy! (watch in HD)

Ahhh.
Mere photographs will never be the same again after watching this.
Lovely little movie.

Thanks Comberjohn 

I like your movie
And here are some Soviet war units from museum, I know you like such things

WOW scramblerftw!

Lovely bike.

Amazing film.

Pick yer game up everybody!

Brilliant - absolutely brilliant.

k-rider

Thank you all for your comments. Those Russian tanks are awesome, and so is that rat. 

Keep all those K100s rolling!  

I really like this build...can you tell me what handle bars you used? and did making the seat lower make the seating position easier to reach the bars?

Martyman, this is the handlebar I used: http://www.biltema.se/sv/Bil---MC/MC/Tillbehor/Styre-och-handtag/Styre-aluminium-286-MX-2000021122/

I'm 6'3" (1.9m) and I love riding with my arms extended. This works fine with me, but due to the height of the handlebar, it makes a hell of a difference if you tilt it a bit.

The low seat somehow sinks you further into the bike, and the raised instrument panel makes you feel you are riding a tank or something like that