Well now, what do we have here.....

[AussiXS11G]

Regarding frame stiffening, fork braces and the like.
It is probably obvious that in a perfect world our machines frames would all be straight and true.
The front wheel directly in line with the rear and both wheels vertical.
This being the case when travelling in a straight line, at any speed, the machine should not wobble etc.
The forces imposed on the (apparently flimsy c/f to modern machinery) frame when cornering will make the forks, swingarm and frame change shape.
All this I learned from Mr Pitman when I posed the question to him back in 2002 when I was re-jigging my XS. Below is my enquiry and his response.


I took my frame with the engine fitted to Mr Dave Kellett at Springwood to have it straightened. I learned from him that basically ALL bikes are not created perfectly ex factory and that any bike that is to be raced has the frame checked as part of the preparation.

[Eveready1100]

not tarred to track standards.

I like that quote, mate.

[Fred]

Fitting the fork brace should definitely not create a front end wobble.

Are you sure that the brace is not pinching one of the downtubes as I found I had done ever so slightly when fitting mine. That would certainly create this symptom, especially at speed .

Since realigning the brace I have absolutely no head shakes even at high speeds as was yet again confirmed on this weekends Club Run when I hit  230kph  : on one of our local country roads which is definitely not tarred to track standards.

[SCARFEY]

My first XS wobbled about like that. It was the rear shocks that did it. Try a set of another bike to see if it fixes it.

Had a major tank slapper at 160 once, but apart from that it used to shake it's head each morning like an impatient pony.

A big handful of throttle made it sit down though. Used to frighen the shite out anyone new to the bike.  Bunch of sooks.

[tripodtiger]

Those pics beg the question.  Does it work?

Looks like a simple sort of mod, provided the heat doesn't distort the swing arm.  And I've got a spare swing arm, or two, too.

The reason being, since I put the fork brace on my XS, the thing shakes in the front end like a Norton engine in an isolastic frame.

The fork brace was supposed to work, help things.  Unrideable above 130kph. Maybe it's my front end.  Not a huge issue since the XS doesn't get out much, but it's on the increasingly large list of stuff to check out.

[SCARFEY]

Drawings were great but every picture tells a story. Thanks Brian

  :-*

[AussiXS11G]

Mine is 20mm hollow square......

[Aussiexs11]

Is there any economy in doing another at the same time? I have a spare swing arm and I like this idea.
regards Grant

[SCARFEY]

 
That's pretty fancy the way you've drawn it. I was going to get some fencing wire and a bit of wood to do mine. I'll use proper packing case wood not ya cheap stuff.


But seriously thanks for the email I can do that I think. Might look at using square hollow section if I can bend it successfully.

[AussiXS11G]

stiffen the swingarm - absobloodylutely......
some sketches I prepared earlier - as a general guide

[SCARFEY]

Brian

Rego runs out on the XS in July (they can be registered for 3 months at a time in the ACT) so I've bought some fancy stuff for the conversion, [LED lights, dynajet kit, pod filters etc] cut some old plugs and sockets out of a stuffed loom and connected the Acewell to them so I can simply plug it in and found an old seat base to modify.  Also found an old black rear guard. It should cut down nicely.

If it ever bloody warms up up here and I get over the Flu I'll make a start on it. Want to make it so it can be converted back if I have to without any fuss.

Are you convinced your rear swing arm conversion/strengthening was worth it. I have a spare one an d may have a go at it if you reckon its worth the effort

[AussiXS11G]

I must admit that Dave and I had just got directions from 2 young thangs .........

[excess.11]

Bryan........would nt do that!!!
He d probably do this though.......



"http://www.youtube.com/v/_SDFt5B0dJE?version=3&feature=player_detailpage"

[melbxs]

Glad you are OK Brian.

Admit it though, you were busy looking at some little tart in a miniskirt when you lost it.

[AussiXS11G]

thats too true Scarfy...
looks like I have secured another XS11G...
that will give me a seat base among other things