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Discussion Starter #1
In the last 2 days I've noticed a weird noise coming out of the front of my motorcycle. It's like a chirping/scraping type noise - sometimes it's just for a moment - when it is, it seems timed with coming up after hitting a bump, but I can't reproduce it at will just by trying to hit rough patches of road. Tonight it got really disconcerting - at one point I reached about 45mph, the noise started with a chirp, then was like a semi-constant scraping noise that lasted until I slowed down to < 20mph.

I've pulled over a few times to investigate, haven't found anything. No sign of anything obvious like a speedo/brake cable rubbing a tire or anything like that. I can't tell specifically where it's coming from at speed, since for one the noise is weird from inside my helmet and also since it happens mostly at speeds between 40 and 60mph - it's not like I can put my head down low to listen for the specific source.

Here are all the variables I can think of that have changed lately (unfortunately, there are a LOT) - in order from most recent to oldest:
  • dropped bike a week ago, light drop, only scraped a mirror and foot peg - or so i thought
  • replaced a speedo light bulb that burned out about 2 weeks ago, then had a weird episode where i hadn't tightened the speedo cable back in all the way and got a horrible screeching noise that started on the highway and didn't stop until i pulled over and tightened the cable back up
  • installed highlander bars, replaced brake, throttle, and clutch cables
Could my speedometer have been damaged by the 2nd item I listed above, and just now be subject to making weird noises that start from some kind of vibration? Could something about the front brake caliper be a little screwed up in a way that would only occasionally make noise against the disc?

Any other ideas? How would you approach diagnosing this? It's not like I can put my bike on the lift and get the front wheel up to the rotational speed it'd be going at above 40mph, or especially compress/uncompress my forks while doing so...

Help appreciated,
Jeff
 

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Pieman is right, the cable will whine when cold. re-route the cable outside the lower loop to reduce the bend angle and grease the cable good. You could also remove the cable and take a test drive, if the noise is gone you know it is in the cable or the speedo head.
 

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Discussion Starter #4
Have the last two days been quite cold when you've been riding, if so it's more than likely the speedo/speedo cable.
Actually, it's been unseasonably warm (82F yesterday). I know the cold speedo cable noise you're talking about, and this isn't quite the same. Still, good idea to try disconnecting it to rule it out. Thanks!

Jeff
 

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I think you didn't change your brake fluid and the pistons are sluggish...I'm sure you kept accurate records to verify recommended service was faithfully preformed with a good humor?

I'd also look at the front brake pads...sounds like they're worn to the limit and dropping boulders...then they clear until the next one breaks loose...don't ask me how I know...

new fluid, retract the pistons and make sure they're free, and new pads...scuff the rotor in an X pattern if you want to break the glaze and get some off the ridges...and let the new ones seat in for 100 miles (some even say 250 miles of city traffic).
 

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Discussion Starter #6
I think you didn't change your brake fluid and the pistons are sluggish...I'm sure you kept accurate records to verify recommended service was faithfully preformed with a good humor?

I'd also look at the front brake pads...sounds like they're worn to the limit and dropping boulders...then they clear until the next one breaks loose...don't ask me how I know...

new fluid, retract the pistons and make sure they're free, and new pads...scuff the rotor in an X pattern if you want to break the glaze and get some off the ridges...and let the new ones seat in for 100 miles (some even say 250 miles of city traffic).
I did change the brake fluid last month when I installed my new bars - I had to install a new brake line, so obviously a fluid change was necessary.

Pad wear is a possibility - is 7K miles a reasonable duration for the stock pads to wear out? I thought they looked like they had about the 2mm showing past the ridges that I think the Haynes manual indicated, but were getting pretty close. So you're saying when they're at the end of their life, pieces will start to break off, and the noise I'm hearing could be the latest chunk that came off rubbing between the pad & the disc until it breaks free? Sounds reasonable.

What's a good source for replacement brake pads? I see the Carbone Lorraine pads on New Bonneville. I'm assuming I won't be able to find suitable replacement pads at a local auto parts store?

Jeff
 

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is 7K miles a reasonable duration for the stock pads to wear out?

no...it sucks. but they are what they are, and you need them. mine went by surprise about the same...I was expecting more and got too lazy to stay on top of it. check the rears too.

> I see the Carbone Lorraine pads on New Bonneville.

quick and easy.

> I'm assuming I won't be able to find suitable replacement pads at a local auto parts store?

nary a one...but the brakes are used on Kawasaki too and maybe more, so they're not "prissy" special.
 

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Used on Hondas as well I believe - I forget which ones.


Buy a set of front and rear brake pads from British Customs, Triumph Performance USA, or whoever your vednor of choice is, and keep them in stock.
 

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Discussion Starter #10
replaced brake pads, still get noise

So I got replacement brake pads (hadn't even thought about just getting them from my local dealer - duh). I put them on earlier today - the original pads were pretty worn, to the point where the grooves were mostly gone, and the edges looked like they'd been chunking off.

On a test ride, the longer scratching kind of noises I'd been hearing where gone - so modre's theory on the pad material chunking off and getting stuck explains that one away.

But I'm still getting this really aggravating chirp/screech noise - now I have it isolated as something that only happens when I'm going > 35mph on roads that aren't perfectly smooth. Roads with some dips, ruts, manhole covers, whatever - seems like it's related to bouncing, and also seems more like it's timed with the forks decompressing than with compressing (i.e. i'll hear the noise if the front tire falls into a depression in the road, not if i hit something above the plane of the road's surface).

I also removed and re-lubricated the speedo cable, so I don't think it has anything to do with that. Though I may still do the test of riding with it disconnected to completely rule it out.

Is there any way dirt could be lodged in my forks somewhere? Is there anything else anybody can think of that might cause noise like i'm describing over slightly rough roads?

Thanks,
Jeff
 

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That sounds VERY much like a problem I had. In my case the bike was still under warrante. Scrapping is very descriptive of what I would hear. The dealer replaced some of the speedo drive components in the front hub and that cured it. Since I did not do the work myself I am not sure exactly what was replaced.

I have been through the speedo noise problems as well but clearly a different sound. And there was no doubt it was coming from the speedo. The needle would sweep wildly when the noise occurred. At that time a lot of people suggested the cable lube and routing. I lubed it and rerouted it but no good. I sent it to Bob's Speedometer in Michigan and they lubed it. That pretty will took care of it although some times at around 35 degrees F it has done it again.

Good luck, Paul
 

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Discussion Starter #12
yep. speedo cable.

So it really was the speedo cable after all. I did a test ride with the cable completely removed - the noise was gone.

Then I wondered, well gee, how can I validate whether it's the cable or the speedo itself? Then my eyes wandered over to my wife's T100 and I had my answer - I installed the cable from her bike, did another test ride - no noise. I also noticed that her cable seemed to fit better (kind of sunk up in there are screwed further up) than mine had.

So then I reinstalled my original cable - and also noticed that this time it seemed to screw farther up this time than any time previous that I'd had it off/on. And another test ride - and...no noise.

So I either found and fixed the issue (STILL hadn't been screwing the speedo cable in far enough), or whatever it is has gone away to taunt me another day.

At least I have refreshed front brakes. :D

Jeff
 
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