BMW K1100 with hub centre steering and sidecar

Someone asked for a build thread in another topic here, so i thought i could copy my build thread from the K100 forum and post it over here!

The K1100 as a cafe racer, going to be some other colors and looks when the whole bike is done though!

I'm drawing som 3D on my spare time so the general idea is coming along nicely:






We've started welding up the single sided front suspension mount now;



Mockup


New saddle on the K1100! The old one was too high to ride the bike comfortable... Going to fit GSXR750 clipons soon too!

New rims for the build ordered! I'm hopefully going to get them from the supplier today!*
Genius Darwin Gunmetal rims for a Smart Car.



More welding and fabrication pic's!
We do not have an advanced drilling machine:*

My dad TIG-welding the frame for the swingarm on the bike.

Tight fit:


Test fitting on the bike:

BMW car bushings for the swingarm mounts:


My dad was not satisfied with the saddle, so a new one was made:



With heat!



Templates for the combined engine/swingarm mounts:


The result!



Double steel thickness at the top mounts:




The engine frame mount for the swingarm is done! Close one though, the Argon bottle is empty...





Sidecar mount:





My dad's been drawing abit:





The sidecar is going to be made out of strips of wood, fiberglass and epoxy, like we made theese kayak's some years ago!




Template for start of the wood building, in our wood shop:
¨


The crossover is where my knees are when sitting like we think we will...

Some more pictures of the wooden sidecar project!




It's going to be coated with fiberglass and epoxy, then smoothed out and painted red.

I'm going to add more pictures to all my three buildthreads on the various forums I'm writing on, got alot more pictures and some writing to do!

Wow

Som more pictures and text from the rebuilding of the bike! We bought a frame for 5000kroner nok. and we had a K100 engine lying around, but we got a K1100 engine for free so now we have a K100 engine lying around still...

My dad has started putting together parts we had lying around to see if we could piece together a K100GS.*
Dad bought a DR750 front fork and rims about a year ago with this build in mind, so when winter came up here, we started some trials. I drew some concept drawings in my spare time some months ago just for fun.













Right now my dad is making new electronics on the bike, pairing together a 1984 K100 fram and handlebars, with a K1100 engine control unit and a KOSO racing lap timer/speedometer. This is going to get studded tires when done to go to Krystall Rally!

Today we started the engine after it's long time rest, and after a complete rebuild of the entire electrical harness. No exhaust pipe and no intake filters at this moment.*
http://www.youtube.com/v/L7YeN2lNdeI
The DR750 forks are to small in diameter to fit the bike so we tried to put on some K1100 forks we borrowed. But that turned out to be a battle, the lover fork bridge have been used on an EZS sidecar rig. so the lover fork bridge is a bit disfunctional for out use. Both holes wouldnt fit the fork legs, so we grinded them to fit, only to find out that the width of the upper fork bridge was about 0,5cm more than the lover fork bridge. so there will be no testruns until we get ahold of a K1100 fork bridge set or a K100. It turns out the K1100 fork legs ar 41,9mm and K100 is 41,3mm for some odd reason...!*:shock:

Some pictures from the new exhaust on the bike, video posted above.




Leo Vince SBK Titanium from a racebike of some kind...

It's going to be a sole seat on the bike, and one seat in the sidecar when we get that far ahead.
We've finally got the right fork bridges for the K1100 front fork, so in the weekend now we get to testride it!

We gave up on trying to fit the DR750 front fork, so now I have a set of forks and rims in spare for my DR750!

Some more pictures!*
K1100 front fork mounted, and it can now be tested in the neighbourhood! But of all days, it started to snow today so...




We also got ourselves a "new" old combined Mig and Tig welder this week! Going to add another Mig feeder case for aluminium too, also got a plasma cutter (don't need that for anything though...) it was free, so we took all of them!***


Some pictures of the new footrest and GSXR750 brake pump and gear shifters, made out of stainless industry steel. Some polishing and grinding left to do!




Today we fitted a Suzuki GS500E headlight and blinkers, just to testride (not yet though, snow...) Dad made a new plate to fit the K1100 tank to the K100 frame, as this is not the same on those bikes. I made some progress mounting my DR750 back together to. Started to make a template for bending an aluminium seat plate for making the seat on. as well as a template for a rear end. We're going to shorten the exhaust pipe by 10cm too we desided!





One of the reasons we use a K1100 engine; on a K100 there is a airflow measurement unit that isn't able to be rebuilt into theese K&N filters... On a K1100 there is just Air temperature.







Rear end and saddle underlay nearly finished! All in aluminum for lightweigth, and most strenght!


My dad is going on the first longer test trip tomorrow, going to get the tyres studded, and to the annual meeting in Indre Romsdal BMW Eigarlag ("Inner Romsdal BMW Ownerteam")

Testride!



As you see in the picture, we suddenly have a BMW E46 318I car in the family too! Wonder if we could swap engines with the K's....**:roll:*
*A little video from earlier today;
[flash(425,350)][/flash]

Still a lot of work to be done, but it runs and can be driven now! New saddle "pillow" have to be made, shortening the exhaust can, new studded tyre in the rear. And my dad is thinking about making the tank straight at the bottom, cut the lower part of and weld it back together... we'll see how that goes! 3 weeks until Krystall Rally still!

Havent been in here in a while, so here's some pics of the latest progress and work!
It' gotten twin headlights and LED blinkers, new saddle...




My dad tig welding the aluminium rear cover thats on the pictures above:


http://www.youtube.com/v/lnZeFBlDhFo

Fantastic! I look forward to more pictures of the wood side car! Quite an ambitious project on all levels.

Awesome, thanks for the pics

Amazing what a lot of skill and some imagination can produce.

Dette ser kjempefint ut! Jeg er veldig nysgjerrig til ferdige sidevogn. Hvor finner dere denne brukte utstyr?

It's not going to be wood looking though, going to be painted red, or it's allready red mixed into the fiberglass.

No ptoblem! More to come!

Mostly imagination! No drawings or advanced measurements...

Hvilket brukt utstyr? Har mye liggende fra tidligere bygg, og en del kjøper vi fra mc huggere i trondheim og på østlandet. og en god del nytt utstyr også.

Bottom of the sidecar being produced in plywood this time:






Fiberglass and epoxy coating on the inside of the sidecar:


Starting to build the frame inside the sidecar, all pipes are stainless steel.






Some mockup of the control arms on the old K100 engine:


Trying to get the right height:



General look test, before we start to fit it in correct


Turning out a new spacer for the rear wheel to fit the smart car wheel:


You can see the blueprint and drawings of how to turn it on the lathe on the side of the aluminium piece...


Lathe and cutter at dad's work place:



The new front end coming together nicely!


Cross to strengthen the construction and general fitment of the front wheel. The new front bearing mount is coming together too, but i do not have any pictures of that until tonight!


This will be enough turning action


Here is a picture my dad took of the K1100 on Crystal Rally this year:

1st May yesterday, it's a tradition to go on a motorbiktrip at 1st May here, but when i wake up I saw this from my window:


Some more front suspension build pictures:












One old GSXR shock will make do until we get a new one. The shock mount is moveable until we get it on all three wheels and we'll be able to drive it and figure out where to put the shock.












Steering and control arm done, now it's just the tie rods up to the lower fork bridges left! Gotta turn out some new aluminum rods to connect the two fork bridges too.








General setup, and the dog, Guzzi looking it all over!


Trying to figure out where to put the sidecar fork...

This is just an incredible build Only wish I had half the talent.

The mounting choosen for your hub-centre design seems to be a single-action arm which allows the king-pin castor angle to change all through the suspension movement. It there some reason for this decision, rather than to employ a twin-arm fully floating king-pin type as is usual; like below:



and

I'd be chuffed with 10% of the talent.

It's really just for the fun of it being different... We've built two with the usual setup before as seen below here. It's kinda like a Bimota, and a centre hub steering company thats named Kyros build on to som Yamaha bikes.

I really enjoy seeing the Buell like front brake system.

Outstanding

Mathematics and mechanic calculations at school can be transferred a bit into building too, trying to figure out which way it's best to mount the shock on the sidecar.

Some pictures of the steering control arms setup:





It's made at the crooked angle to accomodate the travel of the wheel due to the constant changing angle on the hub. The rods are going to be chaged to stainless BMW E46 318IS stabilisator rods when we get some in the mail in near future!

Some more pictures from earlier on in the build progress from my dads camera:
Pictures from the progress making the hack:
























Top half done, time for the bottom part!