Flex

[Steve97]

Can someone enlighten me to this "Tuned flex frame " thing that we apparently have on our Storms,
I keep on reading about it on various "review" sites, the latest being visordown.

or is this just a technical phrase for, the swingarm is nailed on to the back of the engine mate

[tony.mon]

Not quite...
A rigid frmae, with no flex, would be almost unridable- see Ducati's first attempts at a carbon frame in racing.
Lots of flex leads to low frequency weaves and wobbles. Just right is good, and the Storm's frmae isn't bad as standard.
If racing, or the engine's been tuned to over 130BHP, then frame bracing at the lower rear edge is a good idea (called frame ears, usually) to give additional support to the swingarm pivot and stop the possibility of stress fractures at the rear crankcase where the swingarm pivots off the engine.

[Steve97]

Cheers tony
Also read somewhere that you can feel it working when the bike is ridden hard into bends, in that it "gives"a little, cant say as I've noticed anything myself

[tony.mon]

Cheers tony
Also read somewhere that you can feel it working when the bike is ridden hard into bends, in that it "gives"a little, cant say as I've noticed anything myself

Just brace the swinging arm, that helps.
And strip, replace bearings in SA and shock linkages, and new slider bushes in the front forks.

[8541Hawk]

Another way to look at it is chassis flex is your suspension while leaned over.

To much flex and the bike wobbles around. Not enough flex and you get chatter.

So it is all about finding the proper amout of flex for the riding situation or conditions.

The 'Hawk, 'Storm or whatever you want to call it does have a bit too much flex if ridden hard but like was stated brace the swingarm, hang a good front end on one and it is a different bike.

If you really ride it hard you can add a bit of bracing to the frame also, or if you build a monster engine you need the "ears" to control the swingarm without destroying ebgine cases.

[popkat]

They go on most about chassis flex in motogp it's a big issue to get right due to the lean angles they achieve (which the tyres are designed to do) when that far over the shocks don't work the same and the chassis effectively becomes the shocks.. Thats a simplified answer but gives the general idea.

I've never found the need to brace anything on a storm, if you feel there's flex then check the suspensions working as it should be and all bearings and bushes are in good nick. before considering bracing i'd say a change of shock and fork springs should be in order and makes a big difference as the standard stuff is poor to start with.

[8541Hawk]

They go on most about chassis flex in motogp it's a big issue to get right due to the lean angles they achieve (which the tyres are designed to do) when that far over the shocks don't work the same and the chassis effectively becomes the shocks.. Thats a simplified answer but gives the general idea.

I've never found the need to brace anything on a storm, if you feel there's flex then check the suspensions working as it should be and all bearings and bushes are in good nick. before considering bracing i'd say a change of shock and fork springs should be in order and makes a big difference as the standard stuff is poor to start with.

Well I have a Ohlins shock and a Sp2 front end with Ohlins internals so I think I have the suspension stuff covered..... The swingarm is rather a wet noodle when riden hard without a brace.... Even now I get a little twisting around the middle when pushing hard.

So I guess I have a bit differnt opinion on how much flex the bike actually has.....

Though in the end it does also come down to how you ride and how hard you push the bike.

[Steve97]

I dont have any problems with flex,
and am quite happy the way it handles.
Was just wandering what the term "Tuned flex frame " actually meant.