Wheel alignment?

[PDoz]

Ok, so I've finally got my suspension working well enough to no longer be a distraction and now I'm noticing a really subtle tendency to veer right over bumps. Is thIs just a normal v11 thing that I should ignore, or should I get out the stringlines and perhaps start playing with those big bolts at the front of the swingarm?

 

I'm talking about a VERY subtle tweak, for example if I ride over a series of decent bumps with a light grip on the bars at 100 ish she needs the slightest pressure to correct direction. I've got the steering damper right off, no issue with sweeping bends at silly speeds, in fact she's just about perfectly behaved except this . NB I'm writing this from australia, we ride on the left so she's drifting up the road camber and potentially towards oncoming traffic. Not that there is any traffic on the roads I ride along. As I'm writing this , I'm thinking I might go ride along the opposite side of the road and see if she drifts left ( wide back tyre /narrow front moving out of sequence?????)

 

Newish pirellis, awesome wilburs shock in the back, and those evil 43 mm marzzochis finally have decent wilburs springs and fresh oil etc

[docc]

Certainly worth checking the swingarm alignment. Strings, glass light tubes, laser - what have you.

 

I suppose, also, the triple clamps could be twisted. (Not sure how to check that).

[PDoz]

Tripple clamps are less likely, I put the forks in myself , did the bouncy thing etc before tightening everything up . They look straight but if all else fails I'll recheck them.

 

I guess the real question is how normal is this with the v11 ? Lets face it, the bike isn't exactly symetrical and there are some weird forces at play..... I'm talking about something that I never would have even noticed on my older guzzi ( v50) , that thing felt like there was a hinge in the frame.

[docc]

True, the whole donk and drive line is, what, 12mm to the right? maybe they all hop right over bumps.

 

You could check the swingarm pin depth from the lock nuts with a dial caliper:

[stewgnu]

I've noticed similar with mine: With hands off the bars, say tracking downhill on closed throttle, I can feel forces working in the bike to favour the right side.

I kinda assumed it was the crank spinning.    However, it's subtle and doesn't bother me when riding 'normally'.

I like how I can do this on my W650 (chain drive) and she tracks nice and straight.

 

Stew

[czakky]

I've noticed similar with mine: With hands off the bars, say tracking downhill on closed throttle, I can feel forces working in the bike to favour the right side.

Noticed the same on mine, the other day I was re-attaching my x-over and noticed the lower frame  rail bolt was backed out about 1/4" or more. Tightened it down and it sure feels like it tracks more straight. Check those frame bolts!

[PDoz]

Thanks guys, it turns out 1.2 mm at the pins equates to about 1 cm at the front wheel. All the frame bolts were tight, I'll see if this fixes things when the roads dry a little.

[docc]

Were your swingarm pins equal? When we measured pins at the South'n Spine Raid a few years back, they were all over the place, but mostly shifted the swingarm right.

 

How did you come up with that formula ?

[PDoz]

My pins were out by 1.2 mm , and the front wheel was offset by 1 cm. When I adjusted the pins to be equal, the wheel was central. I was surprised it made such a difference , in fact I had thought the pins would move the wheel sideways rather than twist it???? So after much head scratching I've decided it's just some mystical guzzi thing.