BMW K bikes (Bricks)

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1Back to top Go down   Subframe for mounting sidecar Empty Subframe for mounting sidecar on Tue Apr 23, 2019 5:01 am

OdysseyRider

OdysseyRider
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Chasing used or plans either



Last edited by OdysseyRider on Tue Apr 23, 2019 7:10 pm; edited 1 time in total

    

2Back to top Go down   Subframe for mounting sidecar Empty Re: Subframe for mounting sidecar on Tue Apr 23, 2019 2:57 pm

halflive

halflive
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I presume you have found my subframe?
[url=http://halflive.000webhostapp.com/halflive/K75_EML/K75 sidecar.html]Halflive[/url]

In the meantime i've made a new subframe for another sidecar on (almost) the same K75. I will see if i have made enough pictures to add another chapter.

http://halflive.hostei.com
    

3Back to top Go down   Subframe for mounting sidecar Empty Re: Subframe for mounting sidecar on Tue Apr 23, 2019 3:57 pm

charlie99

charlie99
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not sure if alby still has any bits for the subframe he had built, or plans   but might have to ask him if any of it is left .


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cheezy grin whilst riding, kinda bloke ....oh the joy !!!! ...... ( brick aviator )

'86 K100 RT..#0090401 ..."Gerty" ( Gertrude Von Clickandshift ) --------O%OSubframe for mounting sidecar Au-log10

'86 k100 rs.. #######..  "Fred " (f(rame) red ) ( Fredrick leichtundschnell ) - -
bits and pieces from many kind friends across the k100 world ...with many thanks ..
    

4Back to top Go down   Subframe for mounting sidecar Empty Re: Subframe for mounting sidecar on Tue Apr 23, 2019 7:07 pm

OdysseyRider

OdysseyRider
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Ok thanks


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Steve: 0404485585
    

5Back to top Go down   Subframe for mounting sidecar Empty Re: Subframe for mounting sidecar on Wed Apr 24, 2019 3:07 am

Packo

Packo
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I used this as a "pattern" for my subframe

https://advrider.com/f/threads/another-aussie-outfit-build.554433/page-3

Lots of good info in this build thread


__________________________________________________
______________
 
83 K100 HRD Outfit
77 R100RS
1992 K1100 Outfit
1983 K100
    

6Back to top Go down   Subframe for mounting sidecar Empty Re: Subframe for mounting sidecar on Wed Apr 24, 2019 9:08 pm

Saxon7

Saxon7
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Packo those are good pics.

    

7Back to top Go down   Subframe for mounting sidecar Empty Re: Subframe for mounting sidecar on Wed Apr 24, 2019 10:06 pm

AL-58

AL-58
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That subframe is a good starting point.  Can be improved by taking the front upper mount up to the steering head instead of stopping at the upper engine mount.  Makes a huge difference in handling and removes the risk of front downtubes breaking.

Al


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'87 K100RS/HRD sidecar (1100 motor)  sc25 
'92 K100RS-16v (Paint it Black)

'87 K100RT with Paralever backend

"When I'm too old and too foolish to handle a sidecar I'll buy a Sportsbike"

Subframe for mounting sidecar K-dogs10
    

8Back to top Go down   Subframe for mounting sidecar Empty Re: Subframe for mounting sidecar on Fri Apr 26, 2019 4:39 pm

halflive

halflive
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@AL-58 wrote:That subframe is a good starting point.  Can be improved by taking the front upper mount up to the steering head instead of stopping at the upper engine mount.  Makes a huge difference in handling and removes the risk of front downtubes breaking.

Al
In my opinion the headstock connection with double downtubes and headstock bearing is no added value. The engine, drivetrain of the K-series is solid and stable, it is bearing all the forces. That is the reason i refrained from the complex, heavy forward downtubes. I'm running my second K75 sidecar now and there is no lack of stability.
The stability comes from the rugged suspension, low car tires and the stable Earles fork.

http://halflive.hostei.com
    

9Back to top Go down   Subframe for mounting sidecar Empty Re: Subframe for mounting sidecar on Fri Apr 26, 2019 6:38 pm

OdysseyRider

OdysseyRider
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@halflive wrote:I presume you have found my subframe?
[url=http://halflive.000webhostapp.com/halflive/K75_EML/K75 sidecar.html]Halflive[/url]

In the meantime i've made a new subframe for another sidecar on (almost) the same K75. I will see if i have made enough pictures to add another chapter.
would you have a few measurements to go with the pics to speed things up a little, the length of the sub frame tubes and the dimenssions of the rear plate would be great if you have them thanks

    

10Back to top Go down   Subframe for mounting sidecar Empty Re: Subframe for mounting sidecar on Sat Apr 27, 2019 1:56 am

AL-58

AL-58
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Life time member
@halflive wrote:
@AL-58 wrote:That subframe is a good starting point.  Can be improved by taking the front upper mount up to the steering head instead of stopping at the upper engine mount.  Makes a huge difference in handling and removes the risk of front downtubes breaking.

Al
In my opinion the headstock connection with double downtubes and headstock bearing is no added value. The engine, drivetrain of the K-series is solid and stable, it is bearing all the forces. That is the reason i refrained from the complex, heavy forward downtubes. I'm running my second K75 sidecar now and there is no lack of stability.
The stability comes from the rugged suspension, low car tires and the stable Earles fork.
You are completely welcome to your opinion. I've  actually had both types of subframe and know from experience that it does make a world of difference to the overall handling when the top front mount goes closer to the steering head. 
I have also previously snapped a K frame downtube where the subframe stopped at the top engine mount due to stress. I'm not alone in this either, I know at least three others. Its the downtube away from the sidecar that can snap. 1100 frames might also be better, thicker wall tubing I think.
Maybe if I stuck to sealed roads and highways it may not have happened, but thats never going to happen.


__________________________________________________
'87 K100RS/HRD sidecar (1100 motor)  sc25 
'92 K100RS-16v (Paint it Black)

'87 K100RT with Paralever backend

"When I'm too old and too foolish to handle a sidecar I'll buy a Sportsbike"

Subframe for mounting sidecar K-dogs10
    

11Back to top Go down   Subframe for mounting sidecar Empty Re: Subframe for mounting sidecar on Sat Apr 27, 2019 12:24 pm

halflive

halflive
Silver member
Silver member
I have never seen a K-series with broken tubes. But on the other hand, i've never ridden unpaved roads. The nearest my sidecar has seen are British roads full of potholes and repairs. My sidecars have seen a lot of fluctuating forces, mountain roads full of hairpins, roundabouts on speed, all loaded with two man and camping gear. I think the high frequent vibration of the dirt roads is killing your frames, something hard to find in Europe for more than a kilometer.
Anyway, i'm happy with my construction and it does not have any flexibility..

http://halflive.hostei.com
    

12Back to top Go down   Subframe for mounting sidecar Empty Re: Subframe for mounting sidecar on Sat Apr 27, 2019 12:42 pm

halflive

halflive
Silver member
Silver member
@OdysseyRider wrote:
@halflive wrote:I presume you have found my subframe?
[url=http://halflive.000webhostapp.com/halflive/K75_EML/K75 sidecar.html]Halflive[/url]

In the meantime i've made a new subframe for another sidecar on (almost) the same K75. I will see if i have made enough pictures to add another chapter.
would you have a few measurements to go with the pics to speed things up a little, the length of the sub frame tubes and the dimenssions of the rear plate would be great if you have them thanks

Sorry, i do not have taken measurements. I've build the subframes on the bike and working along. I have started with the horizontal tube running along the engine. I have used a piece of steel scaffolding. The forward lower connection of the sidecar comes just in front of the engine. Then you have to make the tube long enough to fetch both the fwd and aft connection of the chair. If you drill two holes for the M8 (crashbar) holes in the engine you can hang the tube to the bike and take measurements from there.
The gearbox plate can be about 6mm thick but you have to support it from flexing along the weld to the main tube. A few reinforcement angles can be enough.

http://halflive.hostei.com
    

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