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From: sean_q_ on 30 Jun 2010 22:10
My Magna-sidecar rig needs a damper to stop a bad
steering wobble between 10 and 60 km/hr. I bought
a used damper with a 3" travel but am having
trouble fitting it to the bike. There's no place
anywhere I can find to locate it by direct attachment.

So after futzing around a while and making measurements
I came up with the idea of cables (like clutch cables).

One cable for each side. They would attach to the lower
triple clamp at a radius from the center of steering
rotation such that the stop-to-stop distance is slightly
less than the damper's travel.

The cable jackets would be anchored to the frame,
and the cables would lead to a location convenient
for mounting the damper (such as in front, between
the roll bars). Each cable would only pull, not push.

Actually my 1st idea was bare flexible braided wire
(like they use on sailboats) with pulleys. This could
present less frictional load on the steering than
the cables, but cables seem easier to locate around
obstacles such as the radiator and frame members.

ps. Another bright idea: If the cable mounting points
on the triple clamp result in too much travel,
I could "gear it down" with a pivoting rod
at the damper end. The cables would attach
to the end of the rod, with the damper fixed
to a point on the rod closer to its rotation axis.

Anyone have an opinion on this scheme? Especially
drawbacks: I'd rather find out them out now than
by accident.

TIA, SQ
From: S'mee on 1 Jul 2010 11:28
On Jun 30, 8:10 pm, sean_q_ <nos...(a)no.spam> wrote:

I would suggest you ask Bob, he's smart and knows anything you need to
know about damn near everything and he never sleeps

http://www.resort.com/~banshee/Misc/8ball/index.html


I suggest you invest in a welder.
From: Andrew on 1 Jul 2010 12:37


"sean_q_" <nospam(a)no.spam> wrote in message
news:xOSWn.14410$f_3.14312(a)newsfe17.iad...
> My Magna-sidecar rig needs a damper to stop a bad
> steering wobble between 10 and 60 km/hr. I bought
> a used damper with a 3" travel but am having
> trouble fitting it to the bike. There's no place
> anywhere I can find to locate it by direct attachment.
>
> So after futzing around a while and making measurements
> I came up with the idea of cables (like clutch cables).
>
> One cable for each side. They would attach to the lower
> triple clamp at a radius from the center of steering
> rotation such that the stop-to-stop distance is slightly
> less than the damper's travel.
>
> The cable jackets would be anchored to the frame,
> and the cables would lead to a location convenient
> for mounting the damper (such as in front, between
> the roll bars). Each cable would only pull, not push.
>
> Actually my 1st idea was bare flexible braided wire
> (like they use on sailboats) with pulleys. This could
> present less frictional load on the steering than
> the cables, but cables seem easier to locate around
> obstacles such as the radiator and frame members.
>
> ps. Another bright idea: If the cable mounting points
> on the triple clamp result in too much travel,
> I could "gear it down" with a pivoting rod
> at the damper end. The cables would attach
> to the end of the rod, with the damper fixed
> to a point on the rod closer to its rotation axis.
>
> Anyone have an opinion on this scheme? Especially
> drawbacks: I'd rather find out them out now than
> by accident.
>
> TIA, SQ

I think this is a terrible idea, and you should go about creating an actual
mounting point on the frame.
Why do you want something so simple to turn into something so complex?
You're just asking for trouble.

--
Andrew
00 Speed Triple
00 Daytona
00 Squiddo

From: sean_q_ on 1 Jul 2010 16:02
Datesfat Chicks wrote:

> The mechanical slop
> itself due to the cables may allow the oscillation to continue but with
> reduced amplitude.
> You don't want slop with a damper.

Other considerations aside, there would be no slop
in the system because I would tension the cables
such that they pulled slightly against each other.

SQ
From: Datesfat Chicks on 1 Jul 2010 16:47
"sean_q_" <nospam(a)no.spam> wrote in message
news:vv6Xn.6307$RC5.1924(a)newsfe08.iad...
> Datesfat Chicks wrote:
>
>> The mechanical slop itself due to the cables may allow the oscillation to
>> continue but with reduced amplitude.
>> You don't want slop with a damper.
>
> Other considerations aside, there would be no slop
> in the system because I would tension the cables
> such that they pulled slightly against each other.

Gosh, I wonder if steel cables stretch under load? Let me look that up.
: )

Tensioning the cables will reduce the potential problem but not eliminate
it.

But, tensioning them is better than having slack in them! Let us know how
it goes ...

Datesfat

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