Scura handling

[Guest wier]

I have noticed a very disturbing problem with the handling of my scura since I rebuilt it after repainting the engine with the new textured black that Guzzi sent me (thanks to Jim Strefford). I do't know if its me riding a bit harder than usual in my joy at having it back on the road but I have noticed that if I hit a compression mid corner, the bike feels like it wants to highside and won't stay on line. I torqued up all the bolts to the correct settings on the rear end when I put it back together, and I have re-checked everything since. But it feels like there is a hinge in the middle of the frame. Is this just the soft spring problem or have I missed something else. By the way I'm a bit of a porker at 94 kilos.

 

Any idea's

[Alex-Corsa]

From the above details I assume that there is a traction problem with the rear of the bike.Therefore if the tires are new and OK (and the ground you ride has traction) you'll have to check your air tires pressure.Then the suspension(assemply & set-up),. Highside is not a problem of Vmotors and especially on an MG.

[Guzzirider]

I am a similiar weight and found that increasing the rear preload by 2 clicks made things much better for me.

 

May also be worth considering increasing the rebound damping on the rear, which will slow down the release of energy after you have hit a bump.

 

Best to try things a little at a time as the Ohlins suspension seems to be very sensitive to adjustments and 1 click can make a hell of a difference.

 

Guy

[Alex-Corsa]

SUSPENCION settings 101

 

Here's some info from my archive about suspensions in short.

I hope it helps

 

Rebound damping

*Rear suspension

Too much rebound damping can cause:

- The rear "jumps" on the bumps instead of following the surface.

- The rear "jutters" under braking.

- It holds the rear down with the result that the bike will understeer!

- It can cause overheating in the hydraulic system of the shock absorber and make it fade, in other words, it will loose damping when hot.

 

Too little rebound damping can cause:

- The rear "tops out" too fast under braking, causing the rear wheel to jump

- The bike feels unstable.

 

*Front suspension

Too much rebound damping can cause:

- Oversteering!

- It will give poor grip of the front tire.

- It feels like the front wheels will tuck under in corners.

 

Too little rebound damping can cause:

- Understeer!

- The front can feel unstable.

 

Compression damping

Rear suspension

Too much compression damping can cause:

- The rear wheel to slide under acceleration.

-It can give a harsh ride over bumps.

 

Too little compression damping can cause:

- The rear wheel start to bump sideways under acceleration out of the corner.

- The bike will squad too much (rear is too low), that will cause the front to loose grip.

 

Front suspension

Too much compression damping can cause:

- Good result during braking.

- Feels harsh over the bumps.

 

Too little compression damping can cause:

- Strong diving of the front.

 

Adjustment advice:

Compression damping should be adjusted together with front fork oil level.

 

Spring ratio

Rear

Too hard spring ratio:

- Gives easy turning into corners.

- Makes the rear feel harsh.

- Create poor rear wheel traction.

 

Too soft spring ratio:

- Gives good traction in acceleration.

- Creates understeer in entry of corner.

- Makes too much suspension travel, which will make it difficult to "flick" the bike from one side to the other in a chicane.

- Will give a light feeling in the front.

 

Front

Too hard spring ratio:

- Good under braking.

- Creates understeer.

- It feels harsh in the corners.

 

Too soft spring ratio:

- Gives easy turning into corners.

- Creates oversteer.

- Can cause front to tuck under.

- Bad under braking (diving).

[Bruce Reader]

I've had handling problems with my Scura at times. Check the frame to engine and frame to frame bolts. Several of the front bolts at different times have loosened and one even fell out !!! I think they need to be removed and loctite applied as just tightening them results in breaking any previous loctite bond that you may have. On one ocassion a slight grinding feeling could be felt on the bars when travelling downhill through a right hand corner coupled with a tendency to run wide. This noise was the result of the front left frame bolt under the tank being loose leaving a circular abrasion around the contact point. This may be of some use in detecting your problem.

 

Regards

 

Bruce

[Guest friz]

THE SWING ARM NUTS THE ONE's ON THE PORK-CHOPS THAT SET THE SWING ARM LOAD CHECK WHICH PAINT DID YOU USE ON THE CASES THX DFRIZ

[Baldini]

... if I hit a compression mid corner, the bike feels like it wants to highside and won't stay on line...I'm a bit of a porker at 94 kilos...

 

Weir,

 

If this has just started since a rebuild then as suggested you should check all fastenings, s/a pivots, etc...

 

...but...Are you on stock rear spring? Have you set sag for front & rear? I weigh 220lb w/gear for that weight Scura needs stiffer springs. I put in 10Kg f & 100Kg rear (as I remember std are 8.5/85) & am thinking of going stiffer again on the rear. When I got it the bike would sit up & head straight on if it hit a bump mid corner, was awful. Wanted to chuck you out of the seat. Would also drift wide out of corners. Sounds to me like you have same problem. Highsiding refers to when rear loses then regains traction under power & chucks rider over the highside - think there's some confusion over terminology here....I don't think this is what you're describing?

Anyhow as Guzzirider suggested above you could probably get some relief by upping rear preload, & tweaking damping but if this is the problem, the only way to sort it properly is to put in correct springs for your weight (to get correct sag on std springs I had to up fork preload to half turn off max).

 

KB

[Guest markbar]

Hello everyone (first post here),

 

how about check everything over first (bolts etc) and maybe remove the steering damper in case this is the cause (mine is off too for similar reason).

mark