MOTOBRICK.COM

TECHNICAL MOTOBRICK WRENCHING In Remembrance of Inge K. => Project Custom Motobricks => Topic started by: stuman on April 12, 2016, 03:54:46 PM

Title: My K75 Project
Post by: stuman on April 12, 2016, 03:54:46 PM
Hi,

I have been posting a few questions and a few parts for sale on this forum recently!  That is because I am balls deep in a K75 modification.  I'm posting this thread as I know I found these things very useful when I was researching my project.  I don't claim to be an expert and won't be commenting on 'How to's etc' but feel free to send me any questions.  I have and will continue to have many questions so if I am back on here asking then at least I can refer members to this thread so they can see what I'm doing.

This may also inspire someone to do the same or similar and it may also inspire an experienced K-Biker to get in touch with suggestions that could help me out.  You know "you don't know what you don't know" sort of thing.  If anyone see's anything that set's off alarm bells or anything for me to be concerned about and pay special attention to then PLEASE do get in touch!  Thanks...

Having always been a BMW fan, both 4 and 2 wheeled, I discovered these bikes a few years ago as well as the earlier airheads.  Whilst I looked at R80/70's etc; romantically the sensible part of my brain said go a bit younger a bit more reliable and without too much maintenance requirement on my part (carbs scare me).

This of course led me to the newer liquid cooled and slightly uglier K bikes.  I use the word ugly as that is what the rest of the word thinks but we love them don't we!  As much as I do like a good stock bike I'm afraid to report that the retro scrambler look in any bike is the vision I fell in love with and wanted right away.

I am pretty good with my hands, have a decent amount of tools and I've worked on many cars of mine and bikes are easier right?  Well I decided that I'm all in and set about finding a good project bike.  A short amount of research also led me to want the K75.  Less power (fine with me) but lighter more agile and because of the later engine improvements a smoother power delivery.  I also preferred the asthetic of the slightly shorter engine block.

After the usual internet searches over a few months I found what looked like a good option a 2 hour drive away from me here in the UK.  A 1991 K75 RT in red with 70k on the clock.  Saw it, rode it and loved it whilst the whole time thinking 'Jesus it weighs a tonne'.  That didn't put me off, I just wanted a good clean bike as my base and I had the picture of the finished bike in my head.  £1,000 handed over and it was mine!  Here she is...
Title: Re: My K75 Project
Post by: stuman on April 12, 2016, 04:05:20 PM
The owner had looked after the bike really well and had lot's of paperwork.  Regular servicing, new head bearings, new progressive front springs and rear shock and pretty much brand new tyres.  Fairing was in good shape as well as the tragkorbs.

So where to start?  Well strip down everything I knew was going.  Anything plastic came off!  Fairing, panels, tragkorbs and handle bar assembly.  Seat and tail section and any day now the ABS units!  I have eBay'd lot's of bits and these have funded various other bits of work and new parts.

Some more pic's!  Non-stock shock and other parts as they fell off...
Title: Re: My K75 Project
Post by: stuman on April 12, 2016, 04:09:14 PM
Pic's...
Title: Re: My K75 Project
Post by: stuman on April 12, 2016, 04:10:20 PM
More...
Title: Re: My K75 Project
Post by: stuman on April 12, 2016, 04:11:21 PM
More...
Title: Re: My K75 Project
Post by: stuman on April 12, 2016, 04:40:35 PM
So next I fitted Renthal Fat Bars with new fitting brackets.  These went straight into the stock holes left behind.  Both sets of handle bar controls were eased off and replaced without removing any of the attached cable and wires.  With a round file and a bit of work on the inside (I must have shaved less than 1mm from the control body) they slid on the new bars easily and tightened up just lovely with new stainless hex bolts of the exact same size and length.

The headlight fitted easily too with some cheap brackets.  They will do for now but I'd like to find some good quality heavy duty ones to swap out.  The headlight is just a fairly cheap one too for now but I'll see how it performs.

Ignition was cut out of the foam panel as well as the now not required switches...
Title: Re: My K75 Project
Post by: stuman on April 12, 2016, 04:42:25 PM
Heated grips are gone because they were crappy and I can always add more modern ones later should I regret that move!

Title: Re: My K75 Project
Post by: stuman on April 12, 2016, 04:44:12 PM
A few more views...
Title: Re: My K75 Project
Post by: stuman on April 12, 2016, 04:47:13 PM
I have a new single digi speedo for my bike so this had to go and is currently up for sale.  I'm going to take the mammoth task of re-wiring my new speedo as almost the last job so stand by for questions...
Title: Re: My K75 Project
Post by: stuman on April 12, 2016, 05:00:56 PM
Ok so this last post or two brings me up to date.  I won't list what's coming soon I'll just add as I go but my latest jobs have been:

Fuel tank off and to the paint/repair shop
Cutting of the rear frame
Grinding off now not needed frame tags including the sprung lifting handle - (It's so light now and the ABS units are still attached!)
Stock exhaust removed and dumped! 
Rear pegs removed and plates modded (New rear pegs will be added - maybe)
Rear inner mudguard cut

So the frame needs some tidy up and will get it as well as some protective paint work.  It might be worth saying that at this stage I'm not going for a full frame off, engine re-build restoration.  I will do some patch work re-freshing here and there but the bike is quite clean so at the moment I want it to look the way I want it and I'll run it for a while. 

I've not run it really apart from a few good long test rides and it runs great.  I went straight into stripping down and starting to modify it so I need to run it for a few months, see if anything occurs then further down the line it will be done properly.

Some last pic's taken just this past weekend...
Title: Re: My K75 Project
Post by: stuman on April 12, 2016, 05:05:35 PM
Pic
Title: Re: My K75 Project
Post by: stuman on April 12, 2016, 05:07:11 PM
Pic
Title: Re: My K75 Project
Post by: stuman on April 12, 2016, 05:08:29 PM
BTM I'm having issues adding pic's for some reason hence the stop start posting!!
Title: Re: My K75 Project
Post by: stuman on April 12, 2016, 05:26:47 PM
New braided brake lines on their way so I'll be bleeding out the current lines and ABS system and then fitting the new ones.  During this process I'll also be removing the rear mudguard, taking out the battery an it's securing assembly out and having a good look and clean around the back end.  Anything ABS related will go so it will look a lot cleaner and feel lighter still.
Title: Re: My K75 Project
Post by: Scud on April 12, 2016, 10:42:12 PM
Lots of pics  :2thumbup:

I deleted my ABS recently. It is a surprising amount of weight. There are a lot of little differences between and ABS and non-ABS bike. Here's a few differences from memory:

Rear brake master cylinders - one has a 12, the other a 13 on it - don't recall which is which.
Rear brake caliper - has an extra bracket on it to hold the ABS sensor
Footpeg plates - the non-ABS bikes have a guard where the ABS unit bolts up - I think mostly to keep passenger's feet away from wheel.
Battery tray rubber mounts are different between ABS/non - becuase the battery tray sit on top of the ABS bracket.
Front brake line routing - On the ABS bike, it goes Master to frame to ABS, back to frame and finally to wheels. You'll need a totally different routing.
Front brake RH caliper and rotor - caliper has extra bracket for sensor, rotor has ABS ring on it (so does rear rotor)

Keep the thread so we can see what you're up to.
Title: Re: My K75 Project
Post by: K1300S on April 12, 2016, 11:03:54 PM
maybe it is just me, but if you actually use the bike, i don't see why one would delete an operating ABS system.  even though it is first gen technology, it works.  i have used mine a bunch to get the feel of how it works and in braking exercises.  even had it kick in on the street once when i hit some gravel.   i would not own a bike without it.   saving a few pounds is not worth the loss of capability.  i doubt anyone is riding these old K's at the limit on a track where those few pounds would make a small difference.  now if your bike is just garage art and it is all about a look, that is something else.

(this coming from a guy who successfully races cars without ABS, am pretty adept at threshold braking, and teach competition driving techniques)

just MHO, yours may vary! :)
Title: Re: My K75 Project
Post by: Dennis de Vries on April 13, 2016, 01:01:40 AM
Lots of pics of an obviously nice clean bike! [emoji106] For what i've read on the interwebs, if and when cutting the frame-loop of, it might be a good idea to ad some kind of brace in the remaning frameparts back there for stability...

And to maybe aid with your speedo, i've come to understand that it can be quite a challenge. You might want to take a look at maru-labs.com for a product that supposedly could make life a lot easier... Or of course reinvent the wheel yourself just for the challenge of it [emoji1]

Verstuurd vanaf mijn GT-I9505 met Tapatalk

Title: Re: My K75 Project
Post by: rbm on April 13, 2016, 07:40:38 AM
Unfortunately, Stuman clipped off the one connector from the harness that would allow his project to work with the BEP from maru-labs.  He's committed to a DIY solution at this point.
Title: Re: My K75 Project
Post by: stuman on April 13, 2016, 07:53:44 AM
Scud - Thanks for the info.  Really useful and I'll be looking out for these points as I go.  I will document the whole build so you'll see the finished article!

mlytle - Yes the ABS removal and the safety issue that goes with that is of course an ongoing debate.  Mine didn't work perfectly but it was always going to go.  This bike is very much for me to chug around on locally.  I won't be touring on it or using high speed rated roads.  I live on the south coast of the UK so I can just cruise at no more than 40mph when the sun is out.  I've ridden non-abs bike before too - careful rider always second guessing and being very aware of dabbing brakes.

Dennis de Vries - Yes I will be bracing towards the back.  Regarding the speedo I've purchased one already but thank you for the recommendation.  I haven't sold my old dials with clip yet so if I need to I can use it with something else so I'll take a look.  My new speedo is fitted now just not wired so I'll post a pic soon.

rbm - hello again - yes you are right but could be reversed.  I'll see...
Title: Re: My K75 Project
Post by: Turbo224 on May 11, 2016, 01:54:22 PM
Cool build, looking forward to seeing how you wire up the gauges. That's the part of my project i'm dreading the most.
Title: Re: My K75 Project
Post by: Wasserwolf on May 21, 2016, 06:27:12 AM
Enjoying the write up! Nothing like being knuckle deep in a project bike! :2thumbup:
Title: Re: My K75 Project
Post by: stuman on May 23, 2016, 01:37:26 PM
Thanks guys - ok today I have been able to do a few more jobs:

Fit new speedo (not wired yet)
Remove ABS system and fit new front brake lines; braded by Hel.
Re-routed the rear brake line that went from the rear master cylinder to the abs module directly to the rear calliper - dead easy!

During the above process I also removed the front wheel and re-sprayed the lower forks, front of engine and left side of engine.

I will now attach quite a few pictures - enjoy.
Thanks
stu
Title: Re: My K75 Project
Post by: stuman on May 23, 2016, 01:39:27 PM
A few more pic's
Title: Re: My K75 Project
Post by: stuman on May 23, 2016, 01:44:07 PM
Speedo now in position and abs removed.  Next I will attacking the rear and cleaning it all up, removing what I don't need of the battery/abs holder.

I will also be cleaning up the rear sections of the frame and welding some new steel in place for a new seat.  The petrol tank is also back from the spray shop in a nice retro cream colour but I won't be re-fitting that until I'm done wedding and painting.

That's it for now - thanks!
Title: Re: My K75 Project
Post by: Turbo224 on May 23, 2016, 03:36:22 PM
Great progress. Where did you mount the ignition?
Title: Re: My K75 Project
Post by: stuman on May 23, 2016, 03:52:54 PM
Thanks, I am currently having an ignition barrel holder fabricated for me by a local company that do bespoke design and 3D printing.  I'll post full details of this and my new position soon.

Stu
Title: Re: My K75 Project
Post by: stuman on May 24, 2016, 01:55:59 PM
ABS units removed!
Title: Re: My K75 Project
Post by: stuman on June 01, 2016, 11:17:15 AM
Here is my new ignition barrel holder.  From CAD to produced part.  I'll be fitting at the weekend I hope but I need to find the right kind of connection method.  More pictures soon.
Title: Re: My K75 Project
Post by: stuman on June 01, 2016, 11:22:43 AM
CAD pdf's
Title: Re: My K75 Project
Post by: stuman on June 01, 2016, 11:23:36 AM
2
Title: Re: My K75 Project
Post by: stuman on June 05, 2016, 12:51:14 PM
Cleaning up the rear end!  Drive shaft and rear derive splines checked and re-lubed with white lithium.
Title: Re: My K75 Project
Post by: stuman on June 05, 2016, 12:55:57 PM
Rear Drive and Battery.
Title: Re: My K75 Project
Post by: stuman on June 05, 2016, 12:57:23 PM
Last few for today.
Title: Re: My K75 Project
Post by: kryder on June 05, 2016, 01:49:38 PM
Cleaning up the rear end!  Drive shaft and rear derive splines checked and re-lubed with white lithium.

White lithium will not last. You need Guard Dog or Honda Moly 60 ( The Honda brand is now being sold under a different name. ) White lithium? You may as well lube with tooth paste.
Title: Re: My K75 Project
Post by: Laitch on June 05, 2016, 02:33:01 PM
White lithium will not last. . . . White lithium? You may as well lube with tooth paste.
:2thumbup:
Title: Re: My K75 Project
Post by: The Mighty Gryphon on June 05, 2016, 02:52:11 PM
Yikes, are those splines at the rear end of the drive shaft as bad as they look? 
Title: Re: My K75 Project
Post by: Laitch on June 05, 2016, 03:11:22 PM
Yikes, are those splines at the rear end of the drive shaft as bad as they look?
The rear of the driveshaft looks sawtoothed and ready to loose its points but the front looks almost unused. A head-on perspective of the final drive splines could be informative, too.
Title: Re: My K75 Project
Post by: Elipten on June 05, 2016, 03:31:20 PM
Them splines are looking bad! 


Sent from my iPhone using Tapatalk
Title: Re: My K75 Project
Post by: stuman on June 05, 2016, 03:44:50 PM
Yes you are all correct. On seeing this I'm now thinking of a new or rebuilt drive shaft in the not too distant future. I'll be lubing it properly then.

Sent from my D6603 using Tapatalk

Title: Re: My K75 Project
Post by: jjs1234 on June 05, 2016, 06:49:38 PM
I would get an ebay driveshaft off a k75 or k100. Those wont last 2000mi
Title: Re: My K75 Project
Post by: stuman on August 18, 2016, 08:01:42 AM
I haven't been on for a bit so I thought I'd post some pictures of where I'm at.  Below you'll see some paint work on the wheels and tank and various engine parts.

The next stage is fit the seat area and then I can paint it ready for the arrival of my seat.  Finally it'll require some electrics work - indicators and speedo!

Then I'm nearly there!
Title: Re: My K75 Project
Post by: stuman on August 23, 2016, 01:42:56 PM
Ignition in place.  I wanted it on the headset rather than down low somewhere but I may change my mind.  It doesn't stop me going full lock to the right thankfully but only just.  It kisses the tank so I may look to move it but there seems to be plenty on lead to go down to the right side.
Title: Re: My K75 Project
Post by: jjs1234 on August 23, 2016, 02:14:41 PM
I really like the modern and clean look you have made. Its like a modern-twist on the scrambler!
Title: Re: My K75 Project
Post by: stuman on August 23, 2016, 02:23:49 PM
Thanks, yes simple lines and as naked as possible was always my aim!