Author Topic: Making a Silk Purse out of a Sow's Ear...  (Read 34039 times)

Offline Kai Ju

  • Motobrick Curious
  • Posts: 34
Making a Silk Purse out of a Sow's Ear...
« on: January 30, 2017, 12:18:52 AM »
or the rescue of another disastrous Cafe Racer attempt.
Starting with somebody else's failure is in some regards more satisfying than starting with a perfectly good motorcycle.
Mind you, I'd like to think that even if I had done gone that route I still would have ended up with this bike, it just would have cost more to start with.
My goal was to build a bike that I can ride anywhere, albeit solo and without luggage, and that I can take to any BMW dealer for service.
Having said all that, here is what I did start with:











Here is what it looks like today:





















If you're curious about the steps in between, you can find a "built" thread here:  http://advrider.com/index.php?threads/so-i-bought-this-k100.1198140/


I realize this is a cheeky way to do this but I don't really want to duplicate what I've done on ADVrider already.
If there are specific questions about any of the steps, let me know and I'll do my best to answer those.
Thanks for looking.
  • SoCal
  • '85 K100

Offline billday

  • ^ Quintessential Motobricker
  • Posts: 1341
Re: Making a Silk Purse out of a Sow's Ear...
« Reply #1 on: January 30, 2017, 06:01:48 AM »
Thanks. Nice project! Your exhaust came out great.
  • New York State, USA 10977
  • 1985 K100

Offline Markus77

  • ^ Motobrick Curious
  • Posts: 94
Re: Making a Silk Purse out of a Sow's Ear...
« Reply #2 on: January 30, 2017, 06:58:32 AM »
Great bike Kai Ju! I had a look at your build at adv rider. Really great work on the seat/cowl - it has to be one of the toughest aspects to get right and yours like great. Enjoy it! Also like the rear fender for wet weather - very practical!
  • Toronto
  • '94 K75RT

Offline Chaos

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  • Mars needs women!
Re: Making a Silk Purse out of a Sow's Ear...
« Reply #3 on: January 30, 2017, 08:01:36 AM »
nice save of some elses mess!  Only complaint is the logo treatment looks a little like a vaccination scar  :mbird
  • sw ohio
1987 K75S    VIN 0231
Original owner, Original litter
200,000 miles (plus or minus) and 5 paint jobs
sold 6/23
2023 Ural 2WD sidecar (BMW's bastard step child)

Offline jakgieger

  • itinerant farmer
  • ^ SuperNatural Motobricker
  • Posts: 618
Re: Making a Silk Purse out of a Sow's Ear...
« Reply #4 on: January 30, 2017, 08:02:20 AM »
A tasteful set of mods :bmwsmile
  • Kansas USA
  • 1989 K100rs se
"What we've got here is failure, to communicate.  Some men, you just cain't reach.  So you get what we had here last week.  Which is the way he wants it...Well, he gets it.  I don't like it any more than you men do."

Offline Laitch

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Re: Making a Silk Purse out of a Sow's Ear...
« Reply #5 on: January 30, 2017, 08:14:29 AM »
Only complaint is the logo treatment looks a little like a vaccination scar  :mbird
It was a vaccination for caféplague.  :2thumbup:
  • Along the Ridley in Vermont.
  • 1995 K75 89,000 miles

Offline Kai Ju

  • Motobrick Curious
  • Posts: 34
Re: Making a Silk Purse out of a Sow's Ear...
« Reply #6 on: January 30, 2017, 10:56:30 AM »
Thanks for the kind words everyone, except the Vaccination Scar comment by Chaos. That one stung just a bit since I designed and made the Roundels myself.  :neener:
Luckily the sting was then taken out by Laitch, thanks.
I didn't just want to buy something off the shelf so I decided to make my own.
Just like the rear sets, the exhaust, etc.
  • SoCal
  • '85 K100

Offline Laitch

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Re: Making a Silk Purse out of a Sow's Ear...
« Reply #7 on: January 30, 2017, 11:05:35 AM »
. . . I designed and made the Roundels myself. 
Would you please tell us the material, its thickness and the adhesive you used for the roundels, Kai Ju?
  • Along the Ridley in Vermont.
  • 1995 K75 89,000 miles

Offline Kai Ju

  • Motobrick Curious
  • Posts: 34
Re: Making a Silk Purse out of a Sow's Ear...
« Reply #8 on: January 30, 2017, 11:18:29 AM »
The roundels are made out of 3000 series aluminum, 0.060" thick, which is the same material the tail cowl is made of. Speaking of, I need to make one more for the tail.
They are attached with outdoor rated 3M doublestick tape.


  • SoCal
  • '85 K100

Offline Martin

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Re: Making a Silk Purse out of a Sow's Ear...
« Reply #9 on: January 30, 2017, 04:39:34 PM »

Most comfortable seat I have seen on a café actually looks rideable, and could possibly rack up a decent mileage on it.  :2thumbup:
Regards Martin
  • North Lakes Queensland Australia
  • 1992 K75s Hybrid, Lefaux, Vespa V twin.

Offline Laitch

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Re: Making a Silk Purse out of a Sow's Ear...
« Reply #10 on: January 30, 2017, 04:43:23 PM »
The roundels are made out of 3000 series aluminum . . .
Thanks for the info!
  • Along the Ridley in Vermont.
  • 1995 K75 89,000 miles

Offline The Mighty Gryphon

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Re: Making a Silk Purse out of a Sow's Ear...
« Reply #11 on: January 30, 2017, 05:52:26 PM »
Kudos on a nice job!  :clap:

That seat jumped out at me as soon as I looked at it.  I think there are only one or two other cafe bikes I've seen here that had seats I would want to sit on for more than 15 minutes.  Yours looks like I could go for at least a couple hours.  The lines of the cowl also work quite well on this bike.  The sculpting of the cowl is so well done that it looks like it came from the factory. 

All in all a very well done bike where reliable functionality hasn't been sacrificed on the altar of styling or something.
  • In my garage in Marilla, NY
  • '91K100RS White/Blue
Current:
'91 K100RS16V "Moby Brick Too"

Past:
'94 K75RT "Ilsa, She Wolf of the SS"
'92 K100RS16V "Moby Brick" (RIP, deceased in a vehicular assault)
'94 K75S Special Edition Dakar Yellow "Cheetos"
'89 K100RS Special Edition "Special Ed"

Offline The Dude

  • ^ SuperNatural Motobricker
  • Posts: 509
Re: Making a Silk Purse out of a Sow's Ear...
« Reply #12 on: January 30, 2017, 07:21:03 PM »
S
Kudos on a nice job!  :clap:

All in all a very well done bike where reliable functionality hasn't been sacrificed on the altar of styling or something.
+1
  • Auckland, New Zealand
  • K75s
Current.
TR6R 1973 from new.
Moto guzzi 850 III .1983 from,almost, new.
K75S 1986 from new.vin-0103141
On my second millionth km.give or take a hundred k Kay's.
"The Dude abides. I don't know about you but I take comfort in that. It's good knowin' he's out there."
All the best!

Offline Kai Ju

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  • Posts: 34
Re: Making a Silk Purse out of a Sow's Ear...
« Reply #13 on: January 30, 2017, 09:29:45 PM »
Thanks everyone. Appreciate the kind words.
My goal was to build a "Custom" that worked like a motorcycle. Not a showpiece.

Thanks for the compliments on the seat and seat cowl.

When I researched custom K-Bikes, that's the one thing that jumped out more than anything else. Lots of planks with foam and vinyl. Very few people seemed to consider the lines of the seat in relation to the fuel tank or the subframe.
My goal was to mimic the stock shape of the cowl and side covers in a one piece unit.










There are four inches of proper motorcycle seat foam under that cover. I've spent a day in the canyons and the seat never even came to mind.
It still has a center stand for a reason, such as oil level and tire pressure checks. Not to mention working on the bike while I was building it.
  • SoCal
  • '85 K100

Offline trek97

  • ^ Proficient Motobricker
  • Posts: 200
  • The Anti-Cafe racer
Re: Making a Silk Purse out of a Sow's Ear...
« Reply #14 on: January 30, 2017, 09:35:18 PM »
That Sir, is the finest example of making a cafe styled seat actually work w the funky frame/tank angles.
Good show.
Also, Loving the roundels!

  • Illinois
  • 87 K75C

Offline Kai Ju

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  • Posts: 34
Re: Making a Silk Purse out of a Sow's Ear...
« Reply #15 on: January 30, 2017, 11:41:29 PM »
That Sir, is the finest example of making a cafe styled seat actually work w the funky frame/tank angles.
Good show.
Also, Loving the roundels!


Then you'll get a chuckle out of this:





Seems that Chaos is in a minority of one regarding the Roundels.... :hide:



  • SoCal
  • '85 K100

Offline The Mighty Gryphon

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Re: Making a Silk Purse out of a Sow's Ear...
« Reply #16 on: January 31, 2017, 12:23:05 AM »
Where did you get your double sided adhesive for the roundels.  I have been looking for double sided sheet that I could cut to shape, but all I can find is tape.
  • In my garage in Marilla, NY
  • '91K100RS White/Blue
Current:
'91 K100RS16V "Moby Brick Too"

Past:
'94 K75RT "Ilsa, She Wolf of the SS"
'92 K100RS16V "Moby Brick" (RIP, deceased in a vehicular assault)
'94 K75S Special Edition Dakar Yellow "Cheetos"
'89 K100RS Special Edition "Special Ed"

Offline Kai Ju

  • Motobrick Curious
  • Posts: 34
Re: Making a Silk Purse out of a Sow's Ear...
« Reply #17 on: January 31, 2017, 12:30:37 AM »
Tape is what I used since the center of the roundel doesn't touch the tank anyway. I just applied it in strips around the perimeter and then trimmed the excess, in gray below, with scissors.





  • SoCal
  • '85 K100

Offline The Dude

  • ^ SuperNatural Motobricker
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Re: Making a Silk Purse out of a Sow's Ear...
« Reply #18 on: January 31, 2017, 01:16:49 AM »
A great example of what it takes to do a proper job.

Then you'll get a chuckle out of this:
Fair enough,Were you tempted to mimic the bottom of the tank "angles"where the seat cowling returns (upper green and yellow lines) to the frame rail under seat /tank?
Risky but "if you can't beat it then join it"and could be a solution to this significant styling anomally.
  • Auckland, New Zealand
  • K75s
Current.
TR6R 1973 from new.
Moto guzzi 850 III .1983 from,almost, new.
K75S 1986 from new.vin-0103141
On my second millionth km.give or take a hundred k Kay's.
"The Dude abides. I don't know about you but I take comfort in that. It's good knowin' he's out there."
All the best!

Offline Kai Ju

  • Motobrick Curious
  • Posts: 34
Re: Making a Silk Purse out of a Sow's Ear...
« Reply #19 on: January 31, 2017, 01:46:24 AM »
If you are talking about that short section of tubing that is visible above the fuse box and below the tank, then no.
The only change made to the frame is the 5" section that was cut out of seat frame between the rearmost cross brace and the original seat mounts which are not being used. Except the right one. It's holding the mounting bracket for the turn signal resistors.
The rear loop is still stock.





The cross brace now supports the seat in the middle while the old rear bag mounts are now the rear mounts for the seat cowl.
I wanted to modify the frame as little as possible. 
  • SoCal
  • '85 K100

Offline The Dude

  • ^ SuperNatural Motobricker
  • Posts: 509
Re: Making a Silk Purse out of a Sow's Ear...
« Reply #20 on: January 31, 2017, 01:59:57 AM »
Just the shape of the aluminium seat cowl mimicing the tank bottom lines.
  • Auckland, New Zealand
  • K75s
Current.
TR6R 1973 from new.
Moto guzzi 850 III .1983 from,almost, new.
K75S 1986 from new.vin-0103141
On my second millionth km.give or take a hundred k Kay's.
"The Dude abides. I don't know about you but I take comfort in that. It's good knowin' he's out there."
All the best!

Offline Kai Ju

  • Motobrick Curious
  • Posts: 34
Re: Making a Silk Purse out of a Sow's Ear...
« Reply #21 on: January 31, 2017, 02:11:49 AM »
It's late, or I'm really dense right now, but I don't understand your question.
My original goal was to have the bottom edge of the seat cowl parallel the bottom edge of the fuel tank, as seen by the yellow lines.
And that the rear of the tank meet with the front of the seat and cowl, as seen by the green lines. It just so happened that they also parallel the frame tube and the front 'knee dent' line on the tank.
Everything else that lined up I give credit to my minds eye, after years of designing and making jewelry. (slight pat on the back there)
  • SoCal
  • '85 K100

Offline TrueAce

  • ^ SuperNatural Motobricker
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Re: Making a Silk Purse out of a Sow's Ear...
« Reply #22 on: January 31, 2017, 04:43:11 AM »
Really nice job.......very clean, good workmanship! :2thumbup:
  • Florida
  • '85 K100GS, '85 K100RSSC,', '94 K1100RS,'10 S1000rr,'14 Ural Sidecar, '15 R Nine T

Offline The Mighty Gryphon

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Re: Making a Silk Purse out of a Sow's Ear...
« Reply #23 on: January 31, 2017, 08:40:54 AM »
Everything else that lined up I give credit to my minds eye, after years of designing and making jewelry.

I guess that explains the level of craftsmanship displayed in this bike.
  • In my garage in Marilla, NY
  • '91K100RS White/Blue
Current:
'91 K100RS16V "Moby Brick Too"

Past:
'94 K75RT "Ilsa, She Wolf of the SS"
'92 K100RS16V "Moby Brick" (RIP, deceased in a vehicular assault)
'94 K75S Special Edition Dakar Yellow "Cheetos"
'89 K100RS Special Edition "Special Ed"

Offline The Dude

  • ^ SuperNatural Motobricker
  • Posts: 509
Re: Making a Silk Purse out of a Sow's Ear...
« Reply #24 on: January 31, 2017, 01:16:15 PM »
Kai Ju,I'm just a mind's eye guy too.Your creation is fantastic.
This sketch could get my mind's eye across to you.I can see this as being a way to use this aesthetic problem as a feature.
The thing is all these modified bricks rarely deal with this quirk at the bottom of the tank which is normally covered up by some radiator cowling.Duplicating it would be neat and imply intelligence...that's all.
  • Auckland, New Zealand
  • K75s
Current.
TR6R 1973 from new.
Moto guzzi 850 III .1983 from,almost, new.
K75S 1986 from new.vin-0103141
On my second millionth km.give or take a hundred k Kay's.
"The Dude abides. I don't know about you but I take comfort in that. It's good knowin' he's out there."
All the best!

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