Custom fitting a steering damper

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 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.

 

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.

 

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

 

I agree. He can buy a clamp for the fork end from a mail order catalog
and fabricating an anchor point for the frame end is no big deal.

Alternatively, there are *rotary* steering dampers that mount above
the handlebars.

Sometimes I think he's just trolling...

 

Thanks for the replies everyone. Looks like the jury
is thumbs-down unanimous except for one abstention
(ie, the Honorable Member from Montana).

Anyway I crawled around under the bike and had
another look... *maybe* I can install the damper
just above the lower triple clamp. On the left side,
because the radiator filler cap gets in the way
on the right.

However, with the wheel straight ahead the damper
shaft should be at 90 degrees to the steering,
and in this position it wouldn't be. Therefore
the damping force would be somewhat asymmetrical
at the center position, which is where I need
damping the most.

SQ

 

I think this is going to get Very Very Interesting. Or something.

Jesus, you're making a mountain out of a zit. Cables are (to be brutally
honest) the most stupid fucking idea I've ever heard.

Do some research on tank slappers and the forces "enjoyed", then work out
how much work the cables would have to do and then ask yourself this simple
question ... "Why the **** has no-one ever thought to do this before?"

Un-fucking-believeable.

2 minutes in a workshop with a welder and the damper would be on and done.
Think about it.

 

Thanks for your brutal honesty. At the very least I have
the dubious honor of holding some sort of record.

Really, the idea seemed brilliantly original at 2 in the morning.
However, I began to get a glimmer that all was not well when
I got called a troll by Krusty of all people.

SQ

 

What was MUCH worse than that was that the technical part of the
miserable old coot's response was dead on. That should be enough to
make you rethink the whole idea, even if nothing else did!

 

That was so you could weld a mounting tab on the frame.

 

Not a record to be really proud of though, is it? I mean a little thinking
and a touch of research would provide you with enough material to realise
yourself that idea's need to be given consideration before they're offered
up for "confirmation".

Always take a pen and paper to bed, then you can write the idea down and
read it in the morning when your brain has actually switched on. It'd save a
lot of "odd" comments being thrown your way.

It's not like it's the first time though, is it?

 

However perhaps a viable idea did come out of the dialog --
if I can't squeeze the damper into the tiny space near the forks,
I may be able to connect it via an all-mechanical linkage
(ie no cables, wires or pulleys) that would give me more scope
for adjustment. An advantage since I don't know at this point
how much damping I'll need. Details (and pix) later.

SQ

 

I'm familiar with the Honda Magna, and I've had several sidecar rigs
in my day. I can't visualize why this space is so tiny in the case of
your rig.

 

I've seen steering dampeners fastened/bolted to the side of the lower
triple clamp and the upper front sidecar bracket. No cables. Works well.