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25-30 mph, 2nd gear

It's a cyclic "shutter". Started after rear tire change, and rear brake pads changed together.

Can't feel it at any other speed, or in 1st or 3rd at same speeds.

Checked chain tension, and loosened and moved rear axle fore and aft before adjusting chain tension again.

Motor runs like a top, and all feels swell at all times, but to try to maintain 25-30 mph in 2nd, I feel it through seat and pegs, but very little vibe in mirrors. Feels like it ought to be chain-related, but even running it in gear on the bike lift, I can't see anything suspect.

Any ideas?

Did you make sure the wheel is true with the frame?

Ted

Have a look at your air mix screw setting, that sounds like it occurs right on the transition point between carb circuits.

And check carb balance while you're at it.
Also, you can't go by the marks on the adjusters when
aligning the rear axle.

Good one Charlie! Out of balance carbs and a lean mix screw combined could really exaggerate vibration in a narrow rpm range.

There are so many variables at work.

Carbs just balanced. I noticed this new vibe right after the rear tire change. Even thought for a bit it might be the new rear brake pads, but I have 200-300 miles on since.

Took it to my local independent Jap bike shop (they do my tire work), and had the fork oil and brake fluid changed.

He balanced the carbs & put 2 new spark plugs in. Frankly, she runs great. I'll ride 30 miles across town over 80 mph, and she purrs like a kitten at the red lights. Funny you should mention balancing the carbs, as she sure needed it, but that did not change the vibration.

When I got her back, the screws were backed out to 31/2 turns, and even on the short ride home she was booming badly on roll-off, and I knew she was too rich. I leaned her back out to 2 turns, and she's perfect there.

It would seem that a vibe like this would be constant, even though I can't feel it any other time - like maybe on a 150 mile run maybe I could feel the buzz, but on a 30 mile run, I can't tell. Would never know it except on one long stretch of residential road I have to keep my speed down.

It won't keep me from going anywhere, but definitely has me wondering...

If it doesn't do it at the same speed in other gears I'm left with rpm as the root cause and that points me to a transition circuit in the carbs. Have you tried opening up the mix 1/4 turn?

I will now.

Thank you. I'll let you know.

I think it has to either be that new rear tire, or the tire balance.

Carb screw adjustments ineffective.

I put 65 miles on it Thursday night, all at over 80 mph across Houston and back.

Then Saturday, I rode up to Livingston to see the folks. Took the long way up through the woods, all at speed, and the buzz is pretty bad. I can feel it through the pegs and bars, and at virtually any speed, all gears. ( I did not ever try the 2nd gear / 30 mph on this run, as it was all highway and, going the way I went, took an hour and 45 minutes to get there and again to get home last night.) It's bad, almost unridable. My hands and feet almost hurt by the time I got home, and I have to wonder why anyone would want a V-Twin, if that' inherent. I've never had any vibration or buzziness for 84K miles, unti now,and this started with the tire change.

I will work on getting it rebalanced, but wonder if I might not just order another ME880 in the meantime. For the trouble getting the rear wheel off and back on again, I really don't want to have to pay to have it done twice.

That chain's not over tightened by any chance, is it Keith? If it was uber tight I could see that causing unwanted vibration. Just thinking out loud.

How many miles on that chain? When the links start to get stiff it can cause symptoms like that.

From what you described the tire is suspect; it could be slightly out of round, or have some other rare defect.

You might take it to another shop to check the balance & test the theory on another balancer. It wouldn't hurt to have a run-out test done on the rear wheel, also.

Gotta be something wrong with the tyre in my opinion.

I would take a few pounds of air pressure and see what happens...you should feel a lesser amount if it's the tire. My thinking it could be engine mounts or chain issue with the sprocket. Good luck and keep us in the loop of what the problem is.

Bring it to me at my shop in Conroe. I'll see if I cam help ya sort it out.

I'm looking at the chain and sprockets again in the morning.

At 28 mph, that weird throb is still there, and there is no way that can't be related to what I'm feeling running up through the gears.

With my feet on the rear pegs, at highway speeds, the harder I push on the pegs, the more intense the vibe. I can see it in the mirrors, and feel it through the bars, too.

I rode to work today, just a few miles on the interstate at speed, and she just ain't right. I can't believe it's motor-related, but I will check my airbox and filter just to see what's in there.

Rolled over 85K Thursday night, and until this started last month, I have never wanted the ride to end, or felt relieved to reach a destination so I could get off - but I do now.

Chad, I would have been there today, Had I not had to work myself. Maybe next Saturday? By the way, I think you and I might have a friend in common un-related to this site...he rides a Harley, and knows your friends over at the Backwoods B & G...I saw his mug on one of the two websites, either yours or theirs...Brian?

The more I think about it, now I have to believe, that when we put the rear wheel back on, I bet we failed to get the bushings and spacers all back in place, or maybe got something out of place...but I bet that's ultimately where he problem lies...now I'm afraid to ride her in the meantime, and hoping I haven't screwed anything up.

Keith, Funny you should think that. When I reinstalled Prudence's rear wheel in Helena, I observed that little spacer that goes between the wheel and carrier hub was on the floor of Geno's garage! (Internal Spacer #20 per the bandit) Dang. First time I forgot that! Of course I couldn't get the freaking wheel lined up again in the dropouts for the life of me after I removed the wheel to install that baby axel. The spacers otherwise are observable whilst the wheel is bolted up to the swingarm drop outs. The flat sided one (looks like a top hot) is on the left while the hollow tube is on the right. Also ensure the rear brake caliper mounting bracket is on it's swingarm slot.

Another thing to consider...Cinnamon Girl. Lou and I changed out her rear tire. Then I noticed a wierd sound. Like a baby chirp at slow speeds. Even when we jacked her up and spun the wheel we heard it. Thought all of the bads things. Then said wth and dropped the wheel. Looked at everything and reinstalled the rear wheel. NO MORE CHIRP. Didn't do a thing except remove and replace. Strange.

Thanks, Jim.

I never got around to looking at it today, but I will. I just got back from Deer Park, and drove instead of riding, missing a good opportunity to ride, even as hot as it is.

I have been hearing a chirp, but not consistent enough to try to chase.

Installing that rear wheel at the tire change, I do remember seeing (and retrieving) one of he spacers. Heck, we were kinda of rushing things now that I think about it - Jeff was trying to leave early, it was Saturday afternoon...after telling me that morning that he could not do the tire change that day, an hour later told me to go get the bike. I was in my truck for some reason, and then had to make a 65 mile trip to Pasadena and back to cash a check....I did that on the scoot though on the way back to the shop. I should have just politely declined, and brought it back and left it there for the week, or just took it back for the tire the following Saturday as I had planned to do in he first place....haste makes waste - we all know that one.

I'm sure that's a factor. Just hope no parts are lost or wasted.

I'll go see Chad next weekend and we'll sort it out. I owe myself a trip to Locopony's shop anyway, just haven't run up that way in a while.

Cheers.

Have you laid a straight edge across the face of the rear spocket above the chain and looked at the run of the links? If a spacer is missing or on the wrong side the run will be at an angle to the face. Frankly, I've been thinking about this ever since your first post and I'm pretty much stumped. No chance the tire is on tread reversed, is there?

I thought: balance, out of round tire (really rare but it happens), bunched up tube, spacers reversed, tread reversed, sprockets out of alignment, possibly the wheel knocked out of true when changing the tire. Then because it was apparent at a certain rpm I thought carbs, balance or mix screw...that could be disproven by revving in neutral, though, so that's probably right out. Any chance the 16 tooth didn't go on straight or isn't tight?

Saw Chad at his Iron Horse Outfitters shop in Conroe, yesterday...nice ride up and back-about an hour round-trip.

Had some audible noise from the rear with the bike on his lift. The rear brake rotor had a spot we could hear rotating the rear wheel, and there was some run-out in that rotor. After taking the caliper off (and discovering the caliper mounting bolts were way over-torqued to the mounting plate), we could hear more audible from the chain at the rear sprocket.

Chad thinks he chain has elongated, and maybe it has, but I can't pull it off the back of the rear sprocket at 9 o'clock, like some would suggest an elongated chain would do.

The chain looks good, and indeed, it has less than 5K miles on it as I just put on a GOOD RK chain in at the New Year. And, I run a Scott Oiler, with the dual injector now hitting the inside and the outside plates of the chain.

This new chain cost more than my previous chains have ($160.00), but my last chain, a Regina, only lasted 10K miles, while all previous Regina and D.I.D. Chains lasted 20K or better. This new chain is considerably more robust than the Regina I took off, looking to be of heavier material - it is no doubt a heavier-duty chain. The sprockets look fine, but they do have 20K on them, so I won't replace a chain gain without new sprockets, too.

But I can't believe this chain can be gone so soon. I do not believe it was run too tight, either. There is some side-to-side flex in the chain, between he bottoms of the sprockets, but, I never paid much attention to that before, so I can't say for sure that's a problem, either. Or not.

The T-Bird Sport Cush Drive Rubber was replaced probably 40K miles ago, and when the rear tire was installed last month, it was out, and looked as good as it did new.

So I'm still stumped. I was ready to replace chain, sprockets, and cush drive rubber together coming home yesterday, but when I pulled up my records and see how new that big chain is, I can't believe it's bad.

My previous chains expired when they would no longer hold an adjustment. This chain has not lost it's adjustment yet. The other old chains showed some rust, or sign the red grease had escaped the seals, especially on the inside plates, and that was all before the dual injector was deployed on the oiler. This chain exhibits none of those characteristics. Chad seemed to think it was hitting up on top of the spocket teeth instead of falling into place naturally, causing the audible we heard rolling the chain.

But I keep going back to the fact that this all started immediately with the rear tire and brake pad change.

I ride this thing a lot, and on Thursday nights, it's routine. I take the same route across town, and back. One week it's fine, then I change the tire, and the very next trip over there, and the only time I'm running 28-30 mph in second gear for any distance, and it was very obvious that something was different.

Chad felt it. Whatever it is, has to be felt at higher speeds too, but it is very, very conspicuous at 28 mph in 2nd gear, and I can not pick it up in any other gear, or at any other speed, except for the harsh buzz under all other running conditions at speed.

Stumped.

Okay, concentrating on just swapping the tire I think of the following things: damage to the rotor, Cush drive displaced, wheel bearing damaged, knocked out of true/round/balance, sprocket not seating true. But I still come back to thinking it's a probably a tire defect because you seem to have covered everything else.

+1 on the rear tire showing a defect.

However, I'm still curious as to what the results would be if the (Internal Spacer #20 per the bandit) where to be left out on the carrier hub re-mating.

Keith I'm supposing you don't have the means to remove the rear wheel. If I'm wrong, remove the wheel then insert the axle through the wheel and using two jack stands spin the wheel to discern the balance. And you can remove the carrier hub (you should to anyways when balancing) to observer the Internal Spacer #20.

Its not typical of tire issues. Its not a bump or thump its a buzz for like nearly a second at 28 mph. Its not stretched enough to hit the top of the gear but not landing in the bottom of the chain seats as it should. And its only one section of the chain about 6 or 8 inches long. I think the rotor problem and the way the pipes are mounted are amplifying the problem like a resonant wave at 28 mph.

Are the bike tires balanced with weights or ceramic beads? I use the beads and I get a very brief, but consistent vibration/buzz on two bikes, accelerating from a stop at around 30 MPH. I suspect, it may be the beads conforming into balance. Obviously, I can not prove this, but the vibes did manifest after I switched to the beads. .

We pulled it all apart this morning, and all looks non-suspect. Chain, sprockets, bearings, spacers, bushings, tire....

Trying to hone in on this thing, and at 28 mph, 2nd gear, nothing we've done affects it, but, if I pull the clutch in, or shift to neutral, it stops.

It is hard to maintain that 25-30 mph speed for very long that way, but, just like trying to replicate it at other speeds or in another gear, you only really notice it in 2nd, at a out 28 mph, under load/trying to maintain speed.

What might that indicate? Transmission? Clutch?

(My 83K oil report did not indicate anything suspicious...)

We pulled it all apart this morning, and all looks non-suspect. Chain, sprockets, bearings, spacers, bushings, tire....

Trying to hone in on this thing, and at 28 mph, 2nd gear, nothing we've done affects it, but, if I pull the clutch in, or shift to neutral, it stops.

It is hard to maintain that 25-30 mph speed for very long that way, but, just like trying to replicate it at other speeds or in another gear, you only really notice it in 2nd, at a out 28 mph, under load/trying to maintain speed.

What might that indicate? Transmission? Clutch?

(My 83K oil report did not indicate anything suspicious...)

Post Extras:      

The last finding makes me suspect the clutch or the 2nd gear cogs. If it goes away when you disengage the clutch and you're still rolling that lets the rolling gear, chain thru wheel, off the hook. Doesn't necessarily eliminate the tranny because it isn't loaded, just spinning. Might just have a worn bushing or shim that needs replacing, or, the clutch springs could be out of adjustment causing a tiny wobble...that would be my first look-see.

Tuesday, I went by and looked at the clutch plates and basket.

In a word, immaculate. Considering the 85K miles, all of these parts looked virtually brand new. I have no point of reference, but, coming from someone who's been around motorcycles his whole life, Ken, the shop owner was impressed, and said nothing in there warrants suspicion, and nothing needs to be replaced.

So back together it went, and he rode it for the first time (the other two techs had been riding it before), and he confirmed everything I had been saying, but he never rode it very long at highway speeds - just concentrating on this 28-29 mph thing in 2nd gear....

Ken says it might be some worn parts on the 2nd gear cog, but, he thinks we should order another Metzler tire. If that fixes it, we know it's the Michelin tire. If it doesn't, well, I'll have a slightly used Michelin tire to put back on it next Summer after I wear out the new Metzler. I'm good with that.

He said he would ride it longer at highway speeds before and after changing the tire to see what I'm talking about at the higher speeds, too.

Progress? At least we are ruling out some things.

But I am anxious for a ride already, and it's only been a week!

So it's back to the tire, eh? You've covered everything else. I am totally clueless now, all of the usual suspects have been addressed.

New Metzler on, new steering head bearings in, somewhere between 200-300 miles on since...

Vibe still there at 28 mph, so tire made little difference.

It is what it is. When I wear out this chain, and put new chain & sprockets on together, we'll see what happens.

Definitely rideable. My mind is more at ease now knowing what's NOT wrong, and that most everything IS okay.

I hate not getting to ride for a couple of weeks.....



But it's all better now that she's back in my garage and ready when I am.

Quote:

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This new chain cost more than my previous chains have ($160.00), but my last chain, a Regina, only lasted 10K miles, while all previous Regina and D.I.D. Chains lasted 20K or better. This new chain is considerably more robust than the Regina I took off, looking to be of heavier material - it is no doubt a heavier-duty chain. The sprockets look fine, but they do have 20K on them, so I won't replace a chain gain without new sprockets, too.

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Keith, It may be okay to reuse the rear sprocket, but the front? It seems you put a new chain on with the front sprocket having 15K on it. Okay let's talk about what came first, Chicken or egg? However, take a look at any of the front sprockets removed from my bikes during chain kit installs and they are waved out. Those sprockets can be waved out only slightly and still be waved out enough to eat up a new chain. The cost of a front sprocket is 25 bucks. The cost of the oem rear sprockets runs anywhere from $63.22 (purchased Aug 15th) to $85.00 (purchased July 20). Those might be worth reusing (might flip them over too) due to their high cost. But reusing a front sprocket? At the risk of destroying prematurely a $115.39 DID 525VM2 chain? Not preaching here, just scratching my head. I still don't know what came first, but I guarantee that a chain kit gets installed all at once anymore.

You got that right, Jim!

I might let a rear sprocket go if it looks all right, but since I've gone back to the 16t front, I think a new front sprocket is in order every chain change from here on, for sure.

This RK chain is so much heavier than the Regina I had before....I have to believe that, with that little tight spot Loco found, is very likely the culprit.

Still doesn't explain only getting 10k out of that last Regina chain that we put on with new front & rer sprockets, though.

I'm just gonna run her on out and see what happens....we get so "tuned in" to these things if we right as much as we do, and then any little thing gets our attention when we notice something different.

That's a lot better than riding with an unknown problem and then having something happen.

I put some new Tork speakers in last week too, so now I have tunes on the go. Bought a Sena SMH10, too, but I don't know if I'm ready for that yet.

Bought a small Fiio amp, works well with the IPod, but still feels like a hassle gearing up with all the wires every time. Almost makes me want another helmet. (no!)

jeez. And I was enjoying my breakfast...operative word: was.

Hope it wasn't EGGS!

Duck eggs are the best!

Yummy! Balut