noise from rear end

[1998valk]

1998 tourer with 21,000 miles. put my bike on motorcycle lift with back tire off ground and run it thru gears and I hear a noise from rear end in hi gears. Also I notice my tire has a flat spot from sitting from PO will this cause a noise from rear end? Thanks for any help.

[Bighead]

I would remove the rear tire and check the grease situation.

[Chrisj CMA]

1998 tourer with 21,000 miles. put my bike on motorcycle lift with back tire off ground and run it thru gears and I hear a noise from rear end in hi gears. Also I notice my tire has a flat spot from sitting from PO will this cause a noise from rear end? Thanks for any help.

Stop running it on the lift.  You are sure to hear stuff thats unusual.....running it on the lift is unusual.

The advise to remove the wheel and check all the grease is a good thing and check the U-joint as well.

[1998valk]

The u-joint seems two be ok. Just had the rear greased and all seals replaced. I know tire is bad with flat spot but would this cause a noise? It's probably a bad bearing.

[olddog1946]

Unless you have run some straps to compress the shocks and have the swing arm level, you are putting undue stress on the ujoint. Don't do it.

[Chrisj CMA]

With the wheel off the ground (on the lift) you can test for a bad wheel bearing by grabbing the bottom of the wheel and trying to move it side to side.  If it moves (would sound/feel like a "tic tic") then its a bad bearing.  If its totally solid when you try the side to side, then The bearings cant be that bad, and if you dont hear anything while RIDING, then ride it!

[Michvalk]

Do NOT run the bike on the lift! The wheel hangs down and throws the drive out of alignment, and will make noise, and can cause damage. Check wheel bearings, pull the rear and driveshaft and check the splines on the pinion cup and driveshaft.

[Paxton]

SHUT OFF THE COMPUTER, GO BUY A NEW TIRE.   Come back and tell us what you bought.

RIDE SAFE

[Bighead]

How do you think a new tire will cure his problem?
As others have stated pull the rear wheel check all the splines and grease. And don't run with the swing arm hanging.

[Paxton]

Bighead;
I should have been clearer. I was not addressing the noise problem.
My comment is specific to his tire. Would anyone want to ride on a tire with a flat spot? ???

[Chrisj CMA]

Bighead;
I should have been clearer. I was not addressing the noise problem.
My comment is specific to his tire. Would anyone want to ride on a tire with a flat spot? ???

Most tires will "develop" a flat spot if it sits too long.  This flat spot usually goes away once you put the air up to 40 something and ride it a bit.  BUT, no flat spot caused the noise he was talking about.  I think running the bike on the lift caused the noise and most likely there is no problem with the bike.

[Paxton]

Chrisj CMA;
I agree with you 100%. However a flat spot on a who knows how old the tire is, invites disaster. just sayin...'

[Valkpilot]

Do NOT run the bike on the lift! The wheel hangs down and throws the drive out of alignment, and will make noise, and can cause damage.

Only if the shocks are also removed.

[Chrisj CMA]

Do NOT run the bike on the lift! The wheel hangs down and throws the drive out of alignment, and will make noise, and can cause damage.

Only if the shocks are also removed.

I thought that initially also (about the shocks being on or off)  Even with them on they will be at full extension, not partially compressed as when on the ground.  Also with no resistance on the drive train, any "slop" in the mating parts will be more noticeable and maybe even make noise.

I think running through the gears with the bike on the stand is a bad idea.

[Valkpilot]

Do NOT run the bike on the lift! The wheel hangs down and throws the drive out of alignment, and will make noise, and can cause damage.

Only if the shocks are also removed.

I thought that initially also (about the shocks being on or off)  Even with them on they will be at full extension, not partially compressed as when on the ground.  Also with no resistance on the drive train, any "slop" in the mating parts will be more noticeable and maybe even make noise.

I think running through the gears with the bike on the stand is a bad idea.

The shocks will be at full extension, but the swing arm will not be at its full-drop, most-extreme deflection angle, where the u-joint gets in a bind.

[Jess from VA]

I polished my rear wheel with the bike on the jack, running at 2k in gear on the throttle lock.  

Risky for your fingers, hands, but did hours of work in 15 minutes per side.

No drive train issue.  But you could (more) easily damage the drive train this way if you are not careful.  (shocks on obviously)

I probably won't do this again, after seeing Jeff's experience with the cement mixer.  Or if I do it again, I have to design a polish pad on a stick, and not reach my hand up in there. (no ring, watch, sleeve, glove; nothing to catch)

[pancho]

I don't care how many precautions you take Jess,,,,  that is just risky behavior...  pretty quick and efficient,,,,, but risky!

[Jess from VA]

There's very little risk down on bead and the flat rim, but moving up to the slots you stove your fingers if you go against the spin... you must work behind the spin, and up in the brake caliper cutout is downright scary.   

I certainly don't' recommend it to anyone.  Besides getting a hand/finger caught, there's always the possibility of the bike falling on you, pushing the rear end sideways laying under in it back.  And the exhaust gets hot and you cannot work behind it (choke).

Obviously, the time to polish the rear wheel on a bagger is when it is off the bike.  But it gets pretty cruddy before that happens.  Once you decide you can live with clean light grey wheels (in back) it does not need to be repeated.

[Ricky-D]

Chris is correct in his feeling that running the bike, in gear, while elevated is a bad idea.

The reason being there is only a single universal joint in the drive line.

Honda tries to compensate for this shortcoming by having the pinion cup assembly

which can alleviate some of the problems associated with employing the single universal joint.

However, the drive line is designed to function with the bike on it's wheels and a nominal

load on the seat. It is this configuration which is most accommodating to the drive line and

to which the bike was designed.

With the bike elevated, and running in gear, there are abrupt forces of acceleration and deceleration

being transmitted to the running gear that can cause harm and unnecessary wear to all

the components in the drive train.

***

[Valkpilot]

...the drive line is designed to function with the bike on it's wheels and a nominal

load on the seat...

I agree except for the above statement.  It's ludicrous to believe that Honda designed the driveline to only perform when the suspension is loaded since it is quite possible in some riding situations to completely unload the suspension.

I stand by my statements that with the shocks fully extended, you are not going to bind the drive line. Without the shocks is another story entirely.

Regardless, it is still risky to operate the bike elevated on a jack.

[Jess from VA]

The issue is not binding the ujoint  (with shocks on and driveline straight).

The issue is hitting and releasing the throttle off the ground.  With no load from wheel on ground, there is nothing to dampen the powerful twisting forces on the entire driveline from tranny output to all pumpkin gears/splines (including the ujoint), from gas on/gas off.   When I did it, I slowly raised RPM to 2K, locked it there, then slowly reduced throttle to idle.  It's bad enough banging and dropping the throttle in first on the ground (like if you are trying to discover how much slop you have or if you are checking to see if you have a failing Ujoint), let alone up on the lift.  

[Valkpilot]

The issue is hitting and releasing the throttle off the ground.  With no load from wheel on ground, there is nothing to dampen the powerful twisting forces on the entire driveline from tranny output to all pumpkin gears/splines (including the ujoint), from gas on/gas off.   When I did it, I slowly raised RPM to 2K, locked it there, then slowly reduced throttle to idle.  It's bad enough banging and dropping the throttle in first on the ground (like if you are trying to discover how much slop you have or if you are checking to see if you have a failing Ujoint), let alone up on the lift.  

Agree.