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Re: [SCT] Re: Sidecar on a SWB /5? Robert Fleischer dba Fleischers Service Tue Jan 27 13:01:21 2009

----- Original Message ----- 
From: "Morg" <[EMAIL PROTECTED]>
To: <[EMAIL PROTECTED]>
Sent: Tuesday, January 27, 2009 8:36 AM
Subject: [SCT] Re: Sidecar on a SWB /5?


> --- In [EMAIL PROTECTED], "Robert Fleischer dba Fleischers Service"
> <[EMAIL PROTECTED]> wrote:
>> No.
>> Be sure your driveshaft bolts are the later shorter ones, use NO
>> lockwashers, install with Loctite BLUE.
>> You will need, of course, a proper subframe....and a cross-bar above
> the
>> battery (bolt-in is OK, if you have the tabs there that are unused).
>> Some subframe ideas for an Airhead are on my website.
>> 'bum
>>
>
> Not trying to get into a spitting match but I ran 60K with no subframe
> or cross bar.
>
> Suggested? - Yes
> Required? - No
>
> Hackless in TN
>
>


I want to discourage that idea, here &  now,....as best I can.  Not using a 
good and proper subframe on a BMW....and many other bikes....is a VERY bad 
idea, as you probably know...or should know.  The BMW frames after 12/1969 
are not designed to handle sidecar loads.  They are much lighter gauge 
tubing, and there is little between-the-framerails support, if any.   The 
UPPER of the rear frame (the rear frame is a separate item on most BMW's) 
is held to the front with two small bolts, and is flimsy for any load 
except up and down, and there is some question about THAT.  Side support is 
nil.   There is little support, left to right, on the main frame, for 
sideloads. Same at the steering head on early models.  All is easily 
fixable....and not very expensively.   It is partly due to the design, done 
for various reasons on purpose by BMW, that gives the 2-wheeler its famous 
Rubber Cow description.

It is particularly onerous to mount a sidecar on the early models, such as 
the /5, without a truly proper subframe.   BMW made incremental 
improvements many times to the frames...but NONE OF THESE FRAMES should be 
used without a subframe.  You will put massive loads into the frame, which 
might actually BREAK....very dangerously.  If used without a subframe, only 
a very light...and I mean LIGHT...sidecar should be used, even then not 
very safely on these early models.  Further, if a frame does crack, it is 
not easy to properly fix, a simple welding job is NOT adequate....often the 
frame is simply ruined beyond economical repair.

 I VERY MUCH suggest that NO ONE use a BMW airhead frame without a 
subframe.    I would even go so far as to advise folks to not purchase such 
a rig, or a bike that has had a sidecar so attached.
I have actually seen broken BMW airhead frames (and have been sent photos 
of some others), from normal sidecar road use....not from off-roading or 
other abuse.
With a proper subframe, such as the one Lowell Neff, and some others make, 
the Airhead is quite capable of even some moderate off-road use, and the 
main and rear frame will hold up to enormous mileages.
snowbum