Front Wheel Bounce with new E4's

tamathumper · Aug 2, 2018

New-to-me '03 GL1800A.

Forks rebuilt two weeks ago to fix blown seal on left side.

ADV nickeled last night due to being frozen.

Drove for 50 miles this morning on very old E3's. Everything was great, forks worked fine, bike was settled.

Shop put on new E4's at noon. Commented on nickel but replaced it as instructed. Installed new straight screw-on valve stems for future TPMS.

Drove for 50 miles home, and noticed at low speeds a "bounce" to the front end, like a bouncing ball. WTH?

rayjoe · Aug 3, 2018

nickel

Take out the nickel and see if that makes a difference? Did they line up the yellow circle on the tire correctly? Not balanced it correctly?

Rayjoe

techdude2000 · Aug 3, 2018

tamathumper said:
New-to-me '03 GL1800A.

Forks rebuilt two weeks ago to fix blown seal on left side.

ADV nickeled last night due to being frozen.

Drove for 50 miles this morning on very old E3's. Everything was great, forks worked fine, bike was settled.

Shop put on new E4's at noon. Commented on nickel but replaced it as instructed. Installed new straight screw-on valve stems for future TPMS.

Drove for 50 miles home, and noticed at low speeds a "bounce" to the front end, like a bouncing ball. WTH?

Jack up the front end and spin the wheel while you watch the sidewalls, maybe they didn’t get the bead seated properly.

Robert H · Aug 3, 2018

While you have the tire rotating, check the center of the tread to make sure the tire is actually round. Not all tires turn out round like they should, and an out of round tire will make the front end "bounce" even if it's balanced.

Big_Bear · Aug 3, 2018

Check your air pressure. With too much air every pebble feels like running over a boulder.

PastoT · Aug 3, 2018

My 2d E-4 perfectly mounted and with beads did that at about 27mph. No freaking idea why. It's not the first time I've heard it. My tire was early on in production after they changed max cold psi value. I'm on my 3d front E-4 and it's fine. Seriously think they had a flawed batch , perhaps the balance point was wrong, causing misaligned installation. Won't notice on anything but smooth black top, or at different speeds . It's only about a 2 to 3 mph difference from what I noticed. O tab the tire for 17k, no issue.

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PastoT · Aug 3, 2018

Also running max pressure helped reduce, so I used that observance as a low pressure warning. I noticed a difference between 41 and 39 psi just as my FoBo starts to alert me.

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GLblinded · Aug 3, 2018

Fork bind from just slapping it back together? Bead seat/tire trueness/imbalance/inflation pressurel have been addressed. Oh, did they bend the rim?

UNCLEJOHN · Aug 3, 2018

Try some beads if nothing else works should balance it if thats the problem

tamathumper · Aug 3, 2018

Great advice, thank you all!

OK, so from easiest to hardest I'll do the following:

1. Confirm the yellow dot is aligned with the valve stem.
2. Check that the bead is seated all the way around.
3. Check that the tire is round circumferentially and laterally.
4. Check that the rim is not bent.
5. Inflate to the full 41 lbs. (it looks a pound or two low because my 40# red-green-yellow tire stem is a little yellow).
6. Put in this bottle of Run-On? [nomex=on]

Bullet Bob · Aug 3, 2018

Seems to me, that after you've reinstalled the tire axle you'll want to lower the bike down and bounce the front tire a few times before you torque the pinch bolts.

tamathumper · Aug 3, 2018

Would that be to "seat" an off-axis axle?

Bullet Bob · Aug 3, 2018

tamathumper said:
Would that be to "seat" an off-axis axle?

Aww, you've got to ask someone much smarter than I. I just know the book says to do it...:grin2:

tamathumper · Aug 3, 2018

Update:

1. The yellow dot is aligned with the valve stem.
2. The bead is uniformly seated all the way around on both sides.
3. The tire is true circumferentially and laterally.
4. The rim is true on both sides all the way around.
5. The tire was very low - 30 pounds! I inflated it to 40 pounds. Test on Sunday, weather permitting.
6. I ordered two more bottles of Run-On.

Thanks for all the advice!

GLblinded · Aug 3, 2018

tamathumper said:
Would that be to "seat" an off-axis axle?

I believe it allows the forks to move ever so slightly to neutralize the effects of reassembly. Fork bind.

Richard Clem2 · Aug 4, 2018

Did you replace the springs while you were working on it. The bounce you are describing is common with Race Tech and Progressive tubes set too stiff for the rider using them.

Richard

tamathumper · Aug 4, 2018

Thanks for the response.

The bike rode great for 50 miles, just before the tires were replaced, so I am thinking it is/was something related to the new rubber, or something introduced during the process of changing the tires out.

PastoT · Aug 4, 2018

I really surmise Dunlop had a batch with a hard spot on the tire. Just for GPs post the manufature date code. I still have my previous set as they still have about 5k left on them, I only changed to take an extended trip that wasn't going to be interrupted by a tire change out.

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tamathumper · Aug 4, 2018

Great question.

I'll have to check later today, I recall the tech saying one of the tires was made in March of this year, and the other in November of last year, so both were relatively new.

tamathumper · Aug 4, 2018

Date codes are 4317 in front, 1118 in back.

Pretty new by tire standards.

Front Wheel Bounce with new E4's

tamathumper

rayjoe

techdude2000

Robert H

Big_Bear

PastoT

PastoT

GLblinded

UNCLEJOHN

tamathumper

Bullet Bob

tamathumper

Bullet Bob

tamathumper

GLblinded

Richard Clem2

tamathumper

PastoT

tamathumper

tamathumper

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