As far as Zorst's go I'd bet parts of your anatomy would twitch if you were to run a three into two and Siamese it up under the tail piece like the V twin Honda's did.
Wont all those lines weight the bike down?

....jury's still out on the exhaust, certainly thought about going under/through the seat unit...

Meanwhile, now that I've an idea of the layout, I've started on the frame. The front legs are shortened 10mm to maintain the same rake after the top rails are shortened. This is where having 2 frames was handy - the spare rear seat hoop gets to donate a piece of tube that slides nicely inside the front legs.



I didn't go for the cut and shut option on the main rails to shorten the frame by the missing cylinder. This was because I could use the gearbox stays from the second frame, which allowed me to import them with a short section of the main rail in order to get a better join. It also makes up a little bit of the reduction in height - the top rails are 10mm closer to the engine anyway. No need to relocate the fuel tank rear mountings either.

I like the way the triangle points now all meet together.


At the moment I've left the stubs of the original gearbox stays in place. This is only to help with alignment of the new section. It'll take a bit of careful work to get the sections fitting well so's everything will line up without pulling after it's welded.

This is what the short - kurz - frame now looks like.

Seeing that stubby thing reminds me of the old Honda ATC 90 three-wheeler.  
Hey, maybe if you got some big, fat, tires...

...I'd rather have the Aston Martin and...and...and



Wouldn't mind the wig either, seeing as I'm making a list

That is coming together so nicely. That is a great solve for the rear triangle. The rear piece isn't going to be stock so you are just going to create the pipework to house that.

This little jigger should really deliver the finest ride going.

Chris! What's with the big hole in the ceiling of the workshop and the electrical wires dangling down?? I didn't think it rained that much in Barnsley.

I'm kind of in the low rent section of the accommodation - been relegated, too many bikes see.

As for the rain, we like that. Not yet got running water in Barnsley.

Hanging gardens of Babylon coming to mind.. indoor because you live somewhere that's cold and wet.

I suppose we can expect to see K75 plants hanging from it.....

Then maybe its Triffid protection.

chris846 wrote:Still squinting. Seat arrived from cafe4racer, very impressed. Note that there's actually 2 (one's upside down on the bench) the first arrived damaged in transit - the second arrived just 36 hours later! Excellent people.
I'll post some details of the seat unit later, but meanwhile I'm just playing with the lines before I start sawing things to bits. I'm thinking of an Avon/Rickman fairing - the one with the big perspex nosecone. The tape line between the forks and the tank is the bottom edge of the fairing..

I keep looking and squinting and I'm not sure what you are cooking up, unless you are going to invert the tubes??

I see a telelever front end in this cooking pot. Had some thoughts on this myself for a K1100LT project.

Frame well on the way - the 'new' seat stay will be the old rear loop tidied up and re-positioned. This could be a first, a K cafe racer that actually retains the old rear loop! A victory for K traditionalists everywhere!

Where did you get my picture from? I want royalties, so I do!!!

Looking good Chris!  You've changed the wheels as well.  I like 'em.  

You're on your second custom build and I have yet to get my non-modified K back together.  Last night I must have spent two hours cleaning my transmission.  When I started I thought it was never going to improve.  When I finished - and I stress that all I got it to was 'good enough' - I was amazed at how many dirt gathering recesses BMW designed into their castings.

looking great!!!

Talking about pictures Dai, I was intrigued by the sign in your avatar. I think I've pinned it down to some highway in India? But I had to stop looking at pictures of it because I started to feel giddy....you actually rode it? I'd have crawled along it inch by inch, digging my fingernails into the gravel.

And Woodie's wheels - The front was kindly donated by my R1100s, but I'm going to try fitting the 25 x 47 bearings from the 3-spoke K fronts, so's I can use a 25mm spindle, which (nearly) fits the KTM/WP forks. Witchcraft*.

The rear is a K1200, but unfortunately it's a 5.5" and needs a little bit too much left offset. So I'm in the market for a 5". I've seen that MW ask over twice as much for the supposedly-rare-as-hen's-teeth 5.5", so I've proposed a straight swap. Still got my hand...and tumbleweed. C'mon MW, this is very important!

*Here's the 'swapping-BMW-bits' design advisory committee, nice people:

A long time ago, on a thread far far away, some optimistic buffoon had a 'good' idea, that sounded so simple:

"So how about:
A K1100 frame, chopped in half and shortened by 78mm around the area of the tank rear mountings."


Just 'chopped in half' right?


Well for a start the seat loop was never going to fit the new seat/tail unit without modification. So the old seat loop is -slightly- repositioned and now runs upwards and rearwards from C. Turns out it needed widening to align with H, so a bit got added at F.

The original frame was sawn in two at B, just before the point where it kinked outwards. A-B was then bent upwards by 2' to suit the alignment of the seat unit that rests on  it. It also raises the rear of the tank by a few mm.

B-D was added along with D-E. Most of the added bits came from the spare second frame and so A-G-H imported the frame number from the second frame. Thing is, D-E was cut from the back half of the first frame (stay with me) and it has the first frame frame number on it, so this K75k now has two frame numbers, which I find a bit spooky with the Ronnie/Reggie thing that started it all off. Haven't a clue what I'll put on the application for a log book.

Chris the frame is coming along just fine. Are you planning to change the rear of the tank to resemble to seat's profile? I reckon the frame looks triangulated, a favourite phrase of the road testers of my time. I am envisioning rear-sets on this to carry the peg/seat/bar ratio in a favourable light. The clip-ons will need a fair amount of pull back (you know not just pointing at the ground beside the forks) to give your wrists a fair go. Are you a Geoff Duke or Danny Pedrosa type rider? Not an odd question of you know ergonomics and movement around the bike.

 I must say looking at that frame seat combo I feel you could carry a passenger without any fear of it breaking. Something many before you could not.

Framed up like that I can see why you wanted the R series gearbox and suspension.

The tank/seat gap is there because the seat unit is designed to be further forward than I have positioned it. The seat unit is matched to the rear of the tank (it's made specifically for a K bike) but it would still need a bit of work to be perfect. If you look at Tborosak's 'super clean' build, you can see he's trimmed the horns for a better fit around the rear of the tank.
I decided that it looked better placed more to the rear but, yes, there's now some work to be done to fair it into the tank. I've not done any glassfiber before....

As for Geoff or Danni, I'm more like this guy:

Ah yes I see you sit that bike well.

Golly, 24 days and no progress reports. Well the project is very much Not Dead, if only because it provides me with much needed shed-sanity. Things have been slow though, but all the more determined for it.

Cafe Racer steering lock, that's a big joke. I didn't realise that the whole point of putting a set of clipons somewhere near the front wheel spindle, plus a fairing modelled on Brigitte Bardot's left hooter, was to limit steering lock to something akin to the Torrey Canyon. So it's been a big old challenge to try and produce something that can do a U-turn that isn't visible from space.

The above pic shows full right lock. The fork leg touches the lower frame rail, which pretty much puts the limit on everything, without major major surgery. Steering lock at this point is less than would be obtainable with the standard K1100, high offset/low trail yokes. The KTM yokes have much less offset, so the fork legs are further back, and strike the frame rail much earlier. The fork legs themselves are also much bigger diameter than the original, which compounds this. Despite this, it still gives a measured 70' lock to lock, which is exactly the same as my R1100s, so I'm settling for that (the Madass has a barn owl-like 90' degrees)

Thing is, once the tank is installed, the fork leg strikes the front edge of the tank before it strikes the frame rail. So the tank, and it's welded-on mountings, have had to up sticks and move rearward by 14mm.


(So much for the simple cut and shut job on the frame. Note also the 'dang, the dog's eaten my spanner' approach on the top yoke nut. I had a pal whose favourite saying was "Patience and a maple leaf will make a silk purse", must remember to get a maple leaf or two for my toolbox, they sound useful...I wasn't the chisel-wielder on this occasion, but I don't have a problem with 'means to an end' methods, the chiesel-wielder in this case looks pretty accurate to me, he/she can do my dentistry any time they like...)

The 70' steering lock is now restored, and the tank and frame rails are protected by the installation of a lock stop on the underside of the frame - which picks up the lock stops on the KTM bottom yoke.


Brigitte Bardot is a close old fit on the K, just enough room for a thin-gloved hand around the brake lever and throttle on full lock.

BB's left hooter seems to be doing a remarkable impression of a Dunstall fairing?

Well Chris if you find the steering lock is a bit like the Torrey Canyon try some oil on it. Unless you have cornoil. Some might think that's a scilly idea but if it doesn't work some heat on it might help.

Darn mad we didn't get to meet up with you at K Fest, would have been mighty fun.

I hope your wife's Achilles tendon is coming on ok, that was a bad one but it will keep you close to base and near the workshop. Good time for cleaning parts too as she won't be able to check up on exactly what's in the partsdishwasher.

I love your posts and your projects.

Cheers guys, much appreciated.

  Brigitte Bardot!

  Links hooterbuster!

  Rechts war mein favourite.

And the wheelbase is.....


1466mm!

 1466mm! Das ist mehr kurz als mein hurdlebanger!

 Was ist ein hurdlebanger?

 

1466! yes!! that's shrunk down nicely. Gawd I think I need some blood pressure pills, This one is exciting A K75 with 5spokes and a Para lever. Man it so works. The shorter the frame tubes are, the thicker they look on the engine.

The present seat height will deliver a gentle bend to the knee when riding, I expect a hands and heels affair as they say???????

Good point about the frame tubes - the K1100 frames have thicker tubes anyway, which adds to the effect.

I've tried to make it compact - here it is next to my 11s


The wheelbase is only 10mm or so less, but the seat, bars and tank are all lower. I like the K engine, I think many people have called it ugly, so I've tried hard to help it become the ugly duckling that turns heads.

The riding position on the K75 is going to make it a good riding companion to your R1100s. The R1100s turns heads so it is just going to have to live with the smaller stablemate taking some of the lime light.

You say the K1100 frame is bigger or thicker in wall thickness than the K75??

Aaaand....

A little light on stock of K75 throttle bodies here in the technological frontier of Barnsley. But we don't even consider that a problem....



     Yay!



 MEIN GOTT!

 Ho ho ho, was do you mean 'Mein Gott', das was exactly what we did back in der tag, remember, der 'Modular Design'...

 Nicht mit ein bleeding hacksaw, ach mein eyes. Was next fur der mad idiot mit der hacksaw, ein 12 valve K75?

 ............!

 ............!

 ............!

Mein Gott! He lives!

Good back Chris but your ideas seem rather 'novel'.

I was going to give you a haircut but couldn't find my angle grinder.

Keep it coming!!!!

Hey Olaf


"Drink!"
"Arse!"
"Fe*k!"
"Good!"
"Back!"


It all makes sense now....

Well it's been a funny old summer. Lots of time spent with the newest plumber/electrician/demolition contractor in the family...

Lots of time spent having staring contests with the local sheep (man are they good!)...

So progress has been proper slow...







Plus, I'm in no rush to throw it together just for a result. I've realised that the pleasure is now in the building so, although it will get finished, it'll be a while...

O-o-o-o-h, that's a proper cafe fairing.  Very nice!

It's no wonder most of the Ks had a fairing, they had to do something to hide the ugly tank. I think that is what spoils most of the cafe conversions is that such an ugly thing stands out so much. You do have a good eye for what looks good as was shown in the madass bike, maybe a paint scheme that changes the hump on the camel. Don't ask me for ideas I like em with a fairing even in stock trim the naked K was not a thing of beauty.

That gap between the tank and the air box gives your project the tall look of a Britten to me (my own secret motorcycle fantasy - "Here Andrew, you like old motorcycles, Alfie died and he had this old piece of junk out in the shed....Do us a favour and make it go away.")  Tell me more about the exhaust.  Did you fabricate that in house?  Love it so far.

John Britten is a hero of mine, up there with Dunlop, Hailwood...the usual roll call I suppose.
Anyway, the exhaust -
These are some of the leftovers. I started with the standard cans from a Triumph Street Triple, which mount as a pair high up either side of the tail unit on the OE bike. The complete one in the above pic is the RH can, which has the wrong bracket orientation (the K75K can goes on the LH side) but the correct angle of dangle for the link pipe. Soooo, it was just a case of disembowelling a LH can (the baffles are cheapo mild steel - unbelievable), cutting off the front end/link pipe, and replacing it with the front end/link pipe from a similarly butchered RH can. The finished item (below pic) just has a perforated pipe down the middle instead of the baffled chambers.
The heat shield is a bit of a bacon slicer with the front overhang, but that's how it was on the OE bike. The link pipe is just a 90 bend joined to a 60 bend, which then replaces the too-small OE link pipe welded to the silencer front end cap.

Today (yes I've managed two days, well, afternoons working on it this week - yay) I've mostly been getting the clutch mechanism all wrong..
The big and clever high level exhaust has elbowed the clutch actuation arm out of the way, so I shortened and re-routed the OE arm, and made a new bracket for the cable, which mounts on the former battery tray mounting holes. (Yep, the new super-duper lithium battery - which weighs the equivalent of two hydrogen atoms - is going to be relocated somewhere more suitable to its puny size - probably inside the handlebar tube or something - where it will be held in place with a cork...)
Anyway, after making sure the butchered actuation arm maintained the same lever length as the OE (only smart people allowed in this shed) I rustled up a cable, connected it up, pulled the clutch lever and....nothing. Turns out that the F800s clutch lever currently deployed to this hare-brained project has a lever length of 26mm, compared the good 'ole K's 35mm. Turns out too, that dumb asses have been in this shed all along...
Anyway, milled a new end for the actuation arm, which is proportionally shorter, and it now all seems to work okay. Still not got the mighty amount of release movement of the OE setup, but that's because the OE K clutch lever is set a bit further from the bars and so has a longer stroke.
Maybe I should have checked all this beforehand, maybe.
Got a query though. I've been googling this and other forums but not really cracked it. The current assembly has a K75 clutch (it came with the engine), but a gearbox which I think is from a K100. The pushrod seems to release the clutch fine, but I know that the K75 is supposed to have its own pushrod. Is this anything to do with the clutch diaphragm spring- do I need to fit one? All clues appreciated, cheers.

Awesome Laitch.
That absolutely makes sense - especially Inge K's post - the pushrod does seem 'too long' on my setup. I'll strip the clutch and compare K100/K75 diaphragm springs when I get chance.
Much obliged.

Photos from MAX BMW parts fiche.

K75 diaphragm spring



K100 diaphragm spring

Uberawesome!
In the Mick Walker/Peter Dobson book of the K-series, it mentions the K75 being modified at the development stage in order to cope with the different power pulses. I'm sure that's true, but I'd've thought that a 1000cc clutch would've been just fine in a 750cc motor? 
S'pose that's why BMW are making 1000s of bikes every year and I'm pottering around in an old shed wondering where I've put stuff....

Off to ebayland for a K75 pushrod.
Cheers Laitch

chris846 wrote:Uberawesome!
In the Mick Walker/Peter Dobson book of the K-series, it mentions the K75 being modified at the development stage in order to cope with the different power pulses.

That's a bit of an understatement. Got that book

Thanks Chris.  Is there any engineering science to doing an exhaust other than 'collect it off the engine and get it the hell behind you without it all being too loud"?  Oh and make it look cool while you are at it.

Not in my shed lol.

Seriously though, I've left the standard header well alone - the bit that I've made is very accurately summed up by yourself!

This is a great book:

Well all the main fabrication stuff is more or less done, so it's time to build it up as a working bike, before stripping it again for finishing.
Today I've been mostly faffing with the gearbox. It was finished in black, which I thought would be a pain to strip off, but in the end it wire brushed off easily after just a coat of Nitromors. The ally underneath was in good condition, but I still finished it with Rub 'n Buff, because I think it fills the pores and protects the bare ally. Makes your fingers look like the Tin Man from the Wizard of Oz too.

Part done



Finished

Oh dear:


Cleaning the engine, and....no engine number.
 
Bought when I started this project, for fifty quid on Ebay. Just needed a cheap lump to get started and this came up. I collected it from the seller in Lincoln. He was my age, decent house, and we chatted about the K75 he used to own. This and a few other bits were spares that he had acquired back then, kept under his bench and never used. Seemed pukka enough - said he'd been warned/worried about the oil/water pump failing, hence the spare engine. The other bits were also for sale on Ebay. 

My slipshod excuses: it was slinging it down with rain when I collected it, and the engine was fairly grimy. The dust and scrapes on the outer casings were consistent with it being dragged around a floor quite a bit - it looked exactly like he'd said. I didn't bother looking at the engine number - they're not the clearest on these engines, and what would it have told me anyway?

He couldn't guarantee anything about it - I didn't ask him too - hence the cheap price.

So why no engine number? - somebody has removed a goodly amount of metal where it used to be - they definitely didn't want anyone reading the number that used to be stamped there.

Answers on a postcard please. And no, there's nothing as yet that can prove this engine is/was stolen. I should know, after four years dealing with car and bike thieves and ringers.

No problem - you know better than I do what Swansea think of engine numbers. Or any vehicle numbers.  Talking of which... some years ago when I changed countries and sent my blue Moto Guzzi V1000G5's logbook in for updating, the silly buggers sent it back with the right address but it was now a 'Motto Guzzi'. So, eventually I got round to sending it back for a name correction and it came back as a Moto Guzzi but now it was black in colour. Somewhat annoyed, I sent the V5 back again and this time it returned as a black 'Motto Guzzi'.

Feck me!... I gave up and my blue Moto Guzzi V1000G5 was legally a black Motto Guzzi until the day it was stolen and torched. I still have some tax discs with 'Motto Guzzi' printed on them.

From vocabulary.com: A motto is a short sentence or phrase that expresses a rule for sensible behaviour, especially a way of behaving in a particular situation. Our motto is 'Plan for the worst and hope for the best', or favourite saying, like 'When life hands you lemons, make lemonade.' A motto is something you might see on a t-shirt or bumper sticker — a short sentence or phrase that has meaning for that person. Some mottoes have to do with politics, religion, or another belief.


Since it's a Moto Guzzi I reckon it can't be reasonably called 'sensible behaviour', so it must fall under the category of 'another belief', or possibly something to do with hoping for the best.