Front end alignment technique?

Noblehops · 07-09-2011, 12:07 PM

Men - happy Saturday. I just got back from 60 or so miles on the S, and we're getting acquainted.

I'm shaking down my bike now, and it has what feels like a twist in the front end. It's happy to carve to the right but takes considerably more bar pressure to turn to the left. I'm thinking the fork tubes got a skosh twisted or tweaked in the lowside before I bought it. I did search and found a few threads, but I'm still a little misty on the best way to do it.

I recall reading about alignment methods that included loosening up the lower fork clamp, fender bolts, axle pinch bolts, and then bouncing the front a few times to let everything come to it's natural alignment. Reading the threads I found searching describe loosening the upper and lower clamps and eyeballing it. Presumably the shock keeps the bike from going *clank* when you do this, but I'm still a bit dubious about loosening the uppers, or the accuracy of this method in general.

Who's got the tried-and-true method of getting the front end aligned?

Thanks in advance,

N.

jaytee · 07-09-2011, 12:27 PM

Not sure if you have had boxer engined motorcycles before but the engine does generate torque in the chassis to the right. Are you sure this is not what you are feeling?

I remember when I got my first boxer I damn near dropped it in the garage when I first revved it in neutral and the whole bike lurched to the right.

JT

Meeni · Meeni's Garage

Follow the procedure in the Clymer manual for remounting the front wheel:

Untighten the two front allen clamp bolts
with the front wheel off the ground1, make the front wheel rotate and apply light brake to reset/center pads and rotors
put the bike back on the floor, apply serious front brake and pump the front up and down like 10 times
tighten the clamp bolts (22Nm) on both sides

put back front wheel off the ground and check (visually) that the wheel has no axial/radial play, and that the rotors turn freely in the calipers. Apply brakes and check that it brakes evenly.

If you tighten the clamp bolts without pumping the front, the wheel is not set and the bike has horrible handling.

While you are removing the wheel, you might check that the axle is not grooved, the bearings are not shot, and sufficient grease is still in.

jduke · 07-09-2011, 01:22 PM

There's also a shim that goes between the rear wheel and the FD. If that's missing it might have some effect. Bobby Wooldridge, son of the owner of BMW Atlanta and a sometime poster here, once said, not sure 100%, but something like his bike took two shims to corner right.

Noblehops · 07-09-2011, 02:05 PM

Quote:

Originally Posted by jaytee

Not sure if you have had boxer engined motorcycles before but the engine does generate torque in the chassis to the right. Are you sure this is not what you are feeling?

I remember when I got my first boxer I damn near dropped it in the garage when I first revved it in neutral and the whole bike lurched to the right.

JT

No, thanks though JT, I have a GS and so torque roll was not what I was feeling. Meeni had it right. Thanks though.

N.

Meeni · Meeni's Garage

Don't have that. I think shim is only for early on ABS models. If the shim was missing, the rear brake would drag anyway, that's unexpected.

Noblehops · 07-09-2011, 02:08 PM

Quote:

Originally Posted by Meeni

Follow the procedure in the Clymer manual for remounting the front wheel:

...

If you tighten the clamp bolts without pumping the front, the wheel is not set and the bike has horrible handling.

Man do you have this right. That was it, and I thought I had done it correctly, but apparently not. I redid this pinch-bolt-brake-pump-retorque thing and the difference in the handling was night and day.

Thanks Meeni, if our paths should cross I'm buying you a beer.

N.

Noblehops · 07-09-2011, 02:12 PM

Quote:

Originally Posted by jduke

There's also a shim that goes between the rear wheel and the FD. If that's missing it might have some effect. Bobby Wooldridge, son of the owner of BMW Atlanta and a sometime poster here, once said, not sure 100%, but something like his bike took two shims to corner right.

Thanks Jerry. I think I read here that the 5.5 inch wheels (which I have) align correctly, and the 5 inchers need 1/4" shims to get the wheels perfectly in line with each other. I will check that at some point for fun, but Meeni had this issue nailed. I just got back from a test ride, and I am good to go. Now I know what these things actually steer like* :-).

N.

*and I LIKE it!

jduke · 07-09-2011, 02:12 PM

Meeni, mine had the shim and sometime or another I lost it. No difference that I could tell.

Paulaner · 07-10-2011, 07:16 AM

Quote:

Originally Posted by Meeni

Don't have that. I think shim is only for early on ABS models. If the shim was missing, the rear brake would drag anyway, that's unexpected.

Hey, thanks for this!

Mine has the 5.5" wheel, and no shim.
Since I live on a dusty road, every night when I get home I seee that the dust "stripe" is offset towards the left dide of the wheel centerline (by a very small ammount).

I was assuming that I am missing a shim (for the 5.5") that, once installed betweeen the rim and FD, would bring the wheel back to center.

Also, my rear brake disc is grooved so bad it's scary! Possibly this is from the offset?

PP Forum rocks, no way could I figure this bike out without you guys!

edit: bike rides fine, wheelies at will, pulls right with no hands on the bars...

R111S · R111S's Garage

Um, the Repair Manual does not specify perfect alignment between front and rear wheel. There's actually 4.5mm offset.

twodear · twodear's Garage

Quote:

Originally Posted by Paulaner

Hey, thanks for this!

Mine has the 5.5" wheel, and no shim.
Since I live on a dusty road, every night when I get home I seee that the dust "stripe" is offset towards the left dide of the wheel centerline (by a very small ammount).

The obvious answer is that road surfaces are not flat, they have a slight crown to aid water runoff. As you probably tend to stay on the right hand side, the stripe will be offset to the left due to the crown.

For me, tyre wear is offset to the right. The crown also makes me more cautious on right hand bends as I will tend to run out of ground clearance to the pegs by a few degrees.

Paulaner · 07-10-2011, 01:51 PM

Quote:

Originally Posted by R111S

Um, the Repair Manual does not specify perfect alignment between front and rear wheel. There's actually 4.5mm offset.

Thank You so much, I will worry about it even less now!

Paulaner · 07-10-2011, 01:53 PM

Quote:

Originally Posted by twodear

The obvious answer is that road surfaces are not flat, they have a slight crown to aid water runoff. As you probably tend to stay on the right hand side, the stripe will be offset to the left due to the crown.

For me, tyre wear is offset to the right. The crown also makes me more cautious on right hand bends as I will tend to run out of ground clearance to the pegs by a few degrees.

LOL, there is no 'crown' on my road, just dirt and gravel, potholes and dead squirrels... but your point is well taken!