BMW K bikes (Bricks)

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1Back to top Go down   Rose Joint question Empty Rose Joint question Sun Mar 08, 2020 10:11 pm

Packo

Packo
Silver member
Silver member
I have been using Rose joints as the pivot for a sidecar swingarm, see photo

Rose Joint question Img_0123

They are 16mm in size

One joint has snapped  through the threaded part and both of the spherical bearings have got some movement due to wear. Not sure whether the break was due to movement in the spherical bearing because of wear or whether it was not big/strong enough or a combination of both.

Initially I thought I would increase the size and quality of the joints but this is not possible unless I rebuild the whole system. These joints have been on the bike for about 10 years
I think in future I will check for wear annually and maybe swap them out regularly.
Now here is the question:
If I was to get the same size but better quality rose joints, say racing or aviation spec would it give me a stronger and more durable product ???


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83 K100 HRD Outfit
77 R100RS
1992 K1100 Outfit
1983 K100
    

2Back to top Go down   Rose Joint question Empty Re: Rose Joint question Mon Mar 09, 2020 5:45 am

Dai

Dai
Life time member
Life time member
It depends if your originals were made of Chinese cheese. If they weren't, I'd settle for an annual check as surviving ten years under the stress of a heavy sidecar is good going.

As for 'aviation spec'... my favourite story there concerns the Lockheed C-130 (Hercules). For a 20mm hydraulic copper washer bolted to the undercarriage, Lockheed-Martin certified it as 'aviation spec' and charged the  US govt. U$198 per washer. Someone did some materials testing and found that said U$198 washer could be had for 0.80 cents at the nearest autoshop.


__________________________________________________
1983 K100 upgraded to K100RS spec, 1987 K100RT
Others...
1978 Moto Guzzi 850-T3, 1979 Moto Guzzi 850-T3 California,1993 Moto Guzzi 1100ie California
2020 Royal Enfield Bullet 500
    

3Back to top Go down   Rose Joint question Empty Re: Rose Joint question Mon Mar 09, 2020 10:02 am

duck

duck
Life time member
Life time member
@Dai wrote:It depends if your originals were made of Chinese cheese. If they weren't, I'd settle for an annual check as surviving ten years under the stress of a heavy sidecar is good going.

As for 'aviation spec'... my favourite story there concerns the Lockheed C-130 (Hercules). For a 20mm hydraulic copper washer bolted to the undercarriage, Lockheed-Martin certified it as 'aviation spec' and charged the  US govt. U$198 per washer. Someone did some materials testing and found that said U$198 washer could be had for 0.80 cents at the nearest autoshop.

Would you fly in an airplane that was assembled with hardware from a local hardware store?

There are valid reasons why said washer would cost $198.


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Current stable:
86 Custom K100 (standard fairing, K75 Belly pan, Ceramic chromed engine covers, paralever)
K75 Frankenbrick (Paralever, K11 front end, hybrid ABS, K1100RS fairing, radial tires)
86 K75C Turbo w/ paralever
94 K1100RS
93 K1100LT (x2)
91 K1
93 K75S (K11 front end)
91 K75S (K1 front end)
14 Yamaha WR250R
98 Taxi Cab K1200RS
14 K1600GT
http://www.ClassicKBikes.com
    

4Back to top Go down   Rose Joint question Empty Re: Rose Joint question Mon Mar 09, 2020 11:56 am

Dai

Dai
Life time member
Life time member
In that particular case, Lockheed-Martin admitted they were taking the piss gilding the lily. The price of the washer dropped to (IIRC) somewhere around $1.00 a unit.


__________________________________________________
1983 K100 upgraded to K100RS spec, 1987 K100RT
Others...
1978 Moto Guzzi 850-T3, 1979 Moto Guzzi 850-T3 California,1993 Moto Guzzi 1100ie California
2020 Royal Enfield Bullet 500
    

5Back to top Go down   Rose Joint question Empty Re: Rose Joint question Mon Mar 09, 2020 9:09 pm

TacKler

TacKler
Life time member
Life time member
And when you get into "aviation spec" there are different standards for different applications.  

Some examples are NAS, AN, MS which are American standards.  Different tensile strengths, alloys, etc.  A lot of components are "lifed" or replaced on condition depending on the application.  Is the item subject to extreme temperatures (hot/cold) or just holding something in place which may also be subject to violent movement such as military aircraft hydraulic powered flight controls?  Some items are made for one specific job and nothing else.  What is the torque on the item?  

As for your rose joints it depends on the application.  Like all bearings, are you carrying axial or rotary loads or a combination of both?  Looks like there a grease nipple fitted, so do you give them a squirt occasionally?  

The aviation industry has always been expensive and I would expect the racing industry to be the same.  The bottom line is if something fails on your vehicle then generally you will come to a stop and walk away.  In aviation if something fails then there is a good chance you will die.  

Perhaps the engineers on this site would like to put us to sleep with their knowledge.


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Red 1991 K75S
    

6Back to top Go down   Rose Joint question Empty Re: Rose Joint question Mon Mar 09, 2020 9:34 pm

RicK G

RicK G
admin
admin


__________________________________________________
"Man sacrifices his health in order to make money.
Then he sacrifices money to recuperate his health.
And then he is so anxious about the future that he does not enjoy the present; the result being that he does not live in the present or the future; he lives as if he is never going to die, and then dies having never really lived."   Dalai Lama


Bikes 1998 K1100 LT, 1993 K75 RT, 1996 K75RT, 1986 K75 GS, 1979 Z1300 Kawasaki
    

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