Front Tires and front end decel shake

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New tires:
Z6's, no shake

PR's, no shake

Azaros, no shake

ME880, no shake

BT-021, no shake

I've never found tires new to be a variable in decel shake.
Ok

So far only Renegade and myself have headshake on Avons. Everyone else is saying thay have NO DECEL HEADSHAKE at all reguardless of tire correct?

Iggy, your bike does not exhibit the 40-50 mph headshake everyone says they have? Your statement confuses me and could be interpreted as no headshake at all or I have headshake, but tires don't seem to affect it.

Just to be clear, I am talking about the hands off the bars test
This is crackin' me up!

The only front I've had that DIDN'T do the Decel Boogie is the Avon Storm.

Pilot Road = shake

BT-021 = shake

Metzler = shake

 
'03, solo riding

orig. 020's no decel wobble

P. R. 1's no decel wobble

Conti R.A.s minor decel wobble new..major decel wobble 5,000+ miles

Diablo Strada's perfect!

021's faint, almost imperceptabl decel wobble.

observations (for someone else to analyze)

1) messing with suspension set ups has changed the decel wobble effect a bit (adj. fr. dampening)

2) road surface seems to have a slight affect in my testings (no wobble on hwy. concrete but some on grippy asphalt) The tire that "bites" harder may also have slightly more tendancy to decel wobble.

3) I've talked to track racers who set their bikes up analy and are afraid to let go of the bars for fear of tank slappers. (radical geometries ???)

4) ran with trunk on recent trip (on 021's) and noticed decel wobble that was never there before... ran with trunk off and all was back to normal (virtually no decel wobble)

so... maybe suspension set up, load balancing on bike, aerodynamics, tread design, compound grip of tire all factor in and it's more than just "check your steering head bearings" Some tires do leave the factories out of round (and there doesn't seem to be a middle ground on Avons) some aren't perfectly balanced or properly inflated. Riders of different weight, sitting in different positions on the seat.. many factors.

I do think forces on the front end seem to have a relationship here although some tires seem to pronounce the effect more than others.

...hope that was unscientific enough for the gang ;)

 
Bridgestone OEM 020's: Shake, get worse with wear.

Bridgestone 014: Shake, get worse with wear.

Metz OEM Z6: Shake, get worse with wear.

My old FJ 1100 front end used to shake like this one does.

 
Inlaw1,

Sounds like you may have something else going on rather than tires causing your shakes. Seems you have tires shaking that most don't. Either quit drinking (hahahahaha) or double check who is balancing your tires or check the torque specs on your steering head bearings.

WW

 
Metz Z6 no shake, but not much else going for them either.

Put on the Storms fore and aft, and after @3500 miles got a moderate to severe headshake between 40-60 mph, @50mph the worst. I tried changing tire pressures, but returned to 40front and 42 rear (which had been working well). Then I realized I had firmed up the suspension in front a lot for a camping trip and for some two-up riding, and hadn't adjusted it back for solo riding. Returned the suspension settings to the SPORT magazine recomendations I had used. The wobble lessened, but is still noticeable. I have a pretty good bald spot in the center of the rear as well. No noticeable cupping or defect in the front. I loved these tires until the last 1000 miles.......not sure what to try now, but the wobble was bad enough I'm rethinking the Storms..

 
I now have 10k on my storm front tire, and it shakes like a mofo now....

Shake was about 'average' more like a shimmy when new. Meaning I had very little shake at all (about what you'd expect given the geometry) with the original Z6-s through 0-8500 miles.

Thought he Z6 Front had more miles left in it I put on a 'set' of Storms.

From the get-go the decel shake was worse than the Z-6's however but not by much. It was clearly decel oriented, meaning now shake at a constant 40-50.

The current storm, which has also started wearing really funny, is done. For the last 1200 miles it was a bear to ride with but I was stuck and didn't have a choice.

I think even though mileage wise I can get 2 rears to 1 front on most sets, I don't think I'm going to do that again.

The last 2k miles the front has been bad enough that it's taken away from any 'savings'.

 
Original Bridgestone’s - Visible cupping but no shake

New Metz Z6 rear (still Bridgestone front as Metz was out of stok for a week) - severe shake at 40 (1" of movement at the end of the grips)

New Metz Z6 front added - severe shake at 40 (1" of movement at the end of the) - worse in the rain…was going to take it back to the dealers on Saturday…but…flat back tire last night before I headed home after work...time to call a tow truck back to the dealers...

 
I now have 7,000 miles on my second set of storms. No shaking without the Yamaha top case. Very mild deceleration shaking (30-50 mph) with top case on.

Front storm looks almost "new". very (almost imperceptible) cupping beginning to form. Rear is almost "toast". Past the center wear bar, the next stage will be cord.

Scheduled to put new rubber on this Friday.

LC

 
Last edited by a moderator:
Original Bridgestone’s - Visible cupping but no shakeNew Metz Z6 rear (still Bridgestone front as Metz was out of stok for a week) - severe shake at 40 (1" of movement at the end of the grips)

New Metz Z6 front added - severe shake at 40 (1" of movement at the end of the) - worse in the rain…was going to take it back to the dealers on Saturday…but…flat back tire last night before I headed home after work...time to call a tow truck back to the dealers...
Update...my dealers who fitted the new Z6 found out that Metzler make different versions of the Z6 and specifically on that is designed for the FJR.

The tires they had fitted from stock, although Z6, were not designed for the FJR.

The replaced them both at no charge to me (which was convenient since I'd had the bike towed in with a screw in the rear) with the new tires, the ones designed for the FJR.

I still get head shake, however it's gone from severe (life threatening) to mild (can ride at a constant 40 without holding on to the bars (just testing the headshake), the shake is mild and does not escalate)

I've now put about 2,000 miles on the new tires, the mild headshake is still there, no better and no worse...

 
Original Bridgestone’s - Visible cupping but no shakeNew Metz Z6 rear (still Bridgestone front as Metz was out of stok for a week) - severe shake at 40 (1" of movement at the end of the grips)

New Metz Z6 front added - severe shake at 40 (1" of movement at the end of the) - worse in the rain…was going to take it back to the dealers on Saturday…but…flat back tire last night before I headed home after work...time to call a tow truck back to the dealers...
Update...my dealers who fitted the new Z6 found out that Metzler make different versions of the Z6 and specifically on that is designed for the FJR.

The tires they had fitted from stock, although Z6, were not designed for the FJR.

The replaced them both at no charge to me (which was convenient since I'd had the bike towed in with a screw in the rear) with the new tires, the ones designed for the FJR.

I still get head shake, however it's gone from severe (life threatening) to mild (can ride at a constant 40 without holding on to the bars (just testing the headshake), the shake is mild and does not escalate)

I've now put about 2,000 miles on the new tires, the mild headshake is still there, no better and no worse...
I notice you have a trunk on your bike...Have you noticed any difference when you take it off? My headshake goes away when I take mine off.

LC

 
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