xs bottoming out after tire change

[dschmitta]

hello, have '80g with fairing and rear bag assembly. changed rear tire and bike has been bottoming out on even small bumps and dips. this is with just passenger on, do not even have rear fairing assembly on bike(repairing a few cracks). always rode with passenger, bag assembly(full of tools, safety items, etc.). much more weight than on shocks now and never botttomed out. dealership told me tire was softer than one previous, just can;t believe that would cause this to happen. Running bridgestone battle ax bt45 now. Any ideas? Thanks, Dave

[WMarshy]

You might want to double check your preload on the rear shocks. The dealer might have put them on the lowest setting in order to compress the rear swing arm/shocks to get the axle bolt out..? Are you sure it is actually bottoming out or do the bumps just feel more defined? Tire pressure might be high and make it feel like the bumps hit harder..?

[jetmechmarty]

Tire pressure? 35 year old shocks? If you're running the original shocks, they may be junk by now. The rear wheel assy weighs quite a bit. You may be feeling the wheel on the return, or no damping of any kind. The springs may have seen better days, too. Am I close?

[James England]

They wouldn't suddenly become junk shocks just because had his tire changed, would they?

[jetmechmarty]

They wouldn't suddenly become junk shocks just because had his tire changed, would they?

More info is needed. Who changed the wheel? Are the shocks OEM? Properly installed? Was the old tire at 12 psi and the new one at 45 psi?

[SFerinTEXAS]

OE Shocks. Butt busters.

[dschmitta]

bottoming out

they are original oem shocks. haven't checked or adjusted air pressure since change. figured they would do correct pressure when changed. changed shock and damper to what was set at prior to change. what can i try??? Thanks for help.
p.s. someone had mentioned to check frame for possible crack, etc?

[CaptonZap]

Are the shocks 12 5/8ths inch center to center on the eyes?
What and where does it rub when it bottoms out?

CZ

[CaptonZap]

Are the shocks 12 5/8ths inch center to center on the eyes?
2 1/2 inch OD with about 5/16 in dia springs?
What and where does it rub when it bottoms out?
Is the damper dial at the top of the shock set on 4?
CZ

[James England]

Ignorance on my part here. I didn't realise they are air shocks.........

[WMarshy]

they are original oem shocks. haven't checked or adjusted air pressure since change. figured they would do correct pressure when changed. changed shock and damper to what was set at prior to change. what can i try??? Thanks for help.
p.s. someone had mentioned to check frame for possible crack, etc?

Check the frame where the center stand and side stand are welded. I've heard of them cracking there...

Its jsut hard to believe they acted fine before the tire change and now its acting estrange.

[mjpxs11sh]

*

my tire pressures have never been right after a tire change, always over pressured. they have no idea what the pressure s/b, they just put general pressure in. thats why i dont let anybody work on my bike or cars but me unless i dbl ck their work b4 picking it up n paying for it, other than tires where i have no choice lol. theres no way a new tire with the same oem size il make u bottom out. what size rear tire does ur passanger have lol. just my .02cents

[jetmechmarty]

Ignorance on my part here. I didn't realise they are air shocks.........

James,
You're still on track. They are not air shocks if they are OEM.

dschmitta
Get somebody to straddle the bike and hold it up for you. Bounce the rear of the bike. Is there any damping, or does it feel like you're bouncing just a spring?

[dschmitta]

Are the shocks 12 5/8ths inch center to center on the eyes?
2 1/2 inch OD with about 5/16 in dia springs?
What and where does it rub when it bottoms out?
Is the damper dial at the top of the shock set on 4?
CZ

I'll have to do some measuring. damper is set at 4. having trouble sensing where action is, didn;t see anything as to tire rub when i checked, plenty of distance from fender to tire, didn't notice any marks or anything on main stand, will have to check welds. not sure what else to try? tried changing shock settings and damper settings, but seems to still happen?

[CaptonZap]

When you say "bottoming out" what are you referring to? If the tire isn't bottoming out, (rubbing on top), then the only other thing is that the shocks are compressing to the point that the rubber snubbers at the top of the shock, (inside the cover) are hitting the body of the shock. If that is the case, then the springs are broken or weak, or not the right spring. Did the mechanic swap shocks with some 650 that was in the shop at the same time?
Measure the eye to eye distance on both shocks and the size of the spring wire and let us know.
Sumpthun ain't right.
CZ