Front whirring whistling 25-45 mph

Bought the 2008 recently with under 5k miles, up to 6600 now. Added a Givi topcase and HeliBars Tour Performance bar risers.

A few days ago, it was windy out and at about 40 mph, i hear a whistling noise and chalk it up to wind passing under windscreen.

As the days pass by, the sound begins at about 25mph upwards to 45. It has changed a bit to a sort of whirring / whistling sound, and now, i can feel the fast harmonics (a vibration?) in the bars. I pull the clutch in and rev the engine - no it's not an intake vortex sound ... i raise / lower the windscreen and it's still there.

So for the last two days, i discovered two things - (1) if i execute a left turn, the probability the noise happens is more frequent - if i execute a right turn, the sound almost never happens.

If i ride over a Botts dot or abrupt bump in the road, the sound appears instantly (though not always).

I noticed a heavy dose of fork fluid on the left fork, so i sprayed the fork, caliper, and axle/fork area (using low pressure sprayer). I then made my own "seal mate" tool and cleaned out the gunk in the fork seal. The bike hasnt been ridden for over 2 years (prev owner health issues), so understand the fork seal issue.

However, the sound continues. Any thoughts? Bad bearings at 6600 miles?? Calipers / pads?? Front tire?? I plan to check pads tomorrow. My simple bearing test tells me it's not a bearing.

Ooops .... one very odd thing. When the noise appears, i discovered if i "shake" the bars very quickly (very slightly left right left right a few times), the noise goes away.

Me thinks something is loose in the front fairing.
The speed is setting up the harmonic frequency for the vibration.

I'd look for what gets tighter when you make a right turn, something is pressing on something but is loose when the bars are straight.


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Take a look at the tread pattern on your front tire. Does the pattern repeat at a constant length, or is there a slight variation in dimension from one block pattern to the next?

My 2005 ST1300 came with a Dunlop that had a uniform repeat length in the tread pattern. At about 45mph on smooth pavement, the regular frequency of the tread blocks hitting the pavement would excite natural frequency of the front fender and it would literally howl. When I needed a new tire, I got one that had variable length repeat. Problem solved.

When I had no choice later and had to install another OEM Dunlop, the problem recurred. Again, a variable tread repeat tire solved the noise issue.

Thanks to the replies from David and Tom.

For David ... why did this issue not show up until 1500 miles later?

For Tom ... similar request , though i might agree with the analysis, but if it's the front tire, why did it take 1600 miles of me riding it to reveal the issue? Let me go check the tire ... it might be old school by now

Could be that something took that long to work loose.


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First thing I would do would be to loosen the pinch bolts and bounce the forks per Honda's instructions when refitting the front wheel. Check fender for clearance from wheel. Then take it for a ride. No change? Try riding on different surfaces - concrete road, blacktop. This will identify the problem as a tire issue or not. (Check your air pressure). No change? Check clearance between the sensor and ABS disk. Pull the brake pads inspect and check the pistons for crud that might prevent a pad from retracting. Clean the pistons w/ a shoelace and brake fluid. No change? My guess would be wheel bearing going bad. Yes I read you have 6K miles on them. You did not tell us how you checked them.

Oops, of course in the first sentence, I meant tighten everything back up per Honda specs after bouncing the forks.

Although the description makes the noise sound like wind through a loose fairing component, the suggestion that it tends to happen when turning left and can be stopped by shaking the steering might suggest mechanical - although David's point about something tightening is a good one.

For a fairing issue, i would be looking at the left inner cowl for a quick check - it runs very close to the arc of the fork leg and is easy to fit incorrectly if you don't know where the plastic lugs and clips are supposed to go. It is held by 1 screw, 5 large plastic push rivets, and two push pins at the top near the fairing pocket. If not fitted properly, it can rub against the fork leg in a left turn. If the previous owner has added his own electrical stuff, there is very little room for the main harness AND additional cable and can make the inner cowl bulge out and catch the fork leg - this would also make it difficult to fasten the inner cowl correctly - which may be the source of the noises.

But after that quick check, i would want to be certain that the issue isn't anything mechanical. SMSW mentioned bouncing the front forks after loosening the pinch bolts. This is to make sure that the fork legs are settled properly on the axle - but it is important to check that the left end of the axle is flush with the face of the left fork leg AND that the clearance between the brake disc rotor where it passes through the caliper bracket is correct. It should be no less that 0.7mm on both sides. Difficult to see as the fork leg half obscures the line of sight. If this is not correct, then it might be that the whistling is actually the ringing of the disc as it lightly brushes against the caliper bracket, and the whirring could be the noise of the disc bolts catching. Check that the axle spacers are on the correct sides. One is longer than the other. The longest one goes on the right hand side of the wheel ( viewed when sitting on the bike).

Also check that the caliper bolts are not loose, and check that the pads are properly located. Check the pad spring and also the tabbed end of the pad (opposite end to the pad pin) should seat properly in the chromed retaining clip in the calliper bracket. It is possible for a careless insertion to have this drop and rest on the hub of the wheel. It can be seen easily from the opposite side, looking through the 'spokes'.

If all of that is ok and you say your bearings are fine ( how do you know ?), then i would go back to air / vibration noise through the fairing.

My St1100 used to have a plastic radiator grill, which at a certain speed would make a noise exactly like the sound that a tyre makes when travelling over wet tar. Such noises are difficult to track, and the 1300 is much less prone to such spurious sounds, but eliminating the safety critical possibilities i reckon should take priority.

+1 Heathy, I think this is disc noise, might just be the caliper pistons are a bit sticky with lack of use and the steering jiggle just released them back a thou or two.
Upt'North.

tire noise

Interesting tidbit. As I'm riding from the loaner house to our Hurricane Harvey ravaged house, i only hear the noise for two brief moments.

Whats different? The ambient temp now is 45 degrees F. It's been much warmer, 75+. Granted, i did hear it twice for about 2-3 seconds and once it was in a gentle right sweep (contradicting my left turn theory).

Throughout the day, i will toggle working on the house and working on the bike, based on everyone's great input !!

I don't hear the noise anymore - hopefully, never again.

So, everyone ready? I did three things

a) the right side panel - there is a mating tab that should be behind the front [nose] fairing, just under the right edge of the headlight. It wasnt mated, so that created an open gap between the right side panel and its inner panel.

b) i removed the front calipers, cleaned the pistons, then slowly pushed them in - now when i pull on the brake lever, the brakes grip RIGHT NOW.

c) the next step was to remove the front wheel to check the bearings. WHAT THE PHUCK ??? There's no friggin front axle nut !!!!! So i scavenged the nut off my 2003 ST.
.

caldercay said:

I don't hear the noise anymore - hopefully, never again.

So, everyone ready? I did three things

a) the right side panel - there is a mating tab that should be behind the front [nose] fairing, just under the right edge of the headlight. It wasnt mated, so that created an open gap between the right side panel and its inner panel.

b) i removed the front calipers, cleaned the pistons, then slowly pushed them in - now when i pull on the brake lever, the brakes grip RIGHT NOW.

c) the next step was to remove the front wheel to check the bearings. WHAT THE PHUCK ??? There's no friggin front axle nut !!!!! So i scavenged the nut off my 2003 ST.
.

Click to expand...

Holy crap, good catch!
Glad it was a noise that prompted the thorough examination and not a near disaster.


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I went back to the original photos posted for the ad - i zoomed in on the right side, and sure enough, the nut is missing!!

caldercay said:

c) the next step was to remove the front wheel to check the bearings. WHAT THE PHUCK ??? There's no friggin front axle nut !!!!! So i scavenged the nut off my 2003 ST.

Click to expand...

So the lesson to be learned is, as long as you don't mind a whistling noise at 25-45 MPH, the front axle nut isn't really needed.

caldercay said:

There's no friggin front axle nut !!!!!

Click to expand...

Yes, that would do it !

This is pure supposition on my part, but it is definitely possible for the axle bolt to drop off even though the bolt was torqued to the correct value.

If the previous owner spotted that the axle was turning when he tightened the bolt, he might have stopped this from happening by clamping it with the pinch bolts on the right hand side fork leg.
So when the bolt was torqued, it was unable to pull the axle across - which effectively clamps the entire bearing and spacer assembly against the right fork leg. Instead, the axle would stay in its previous position, as the axle would be clamped by the pinch bolts.

Then he realises (maybe just after or maybe a little later) that he needs to bounce the forks, and slackens the pinch bolt. The axle is no longer clamped and because it was never drawn across fully to the right fork leg, it is able to move laterally. Result, the axle bolt is now slack, and is free to work its way loose and drop off un-noticed some time in the future.

After bouncing the forks, both pinch bolts were tightened, but the bearings are not fixed on the axle - not being clamped against the right fork leg. The result is that the wheel is free to move between the forks, the bearings sliding back and forth on the axle. Probably only a bit, but enough.


Whether or not this analysis is correct, it is worth noting that to tighten the front axle nut, the axle needs to be held firm. I use a large allen wrench in the hex socket of the left hand end of the axle, but pushing the axle home by hand and clamping with the LEFT hand pinch bolts will suffice (and this is suggested in the later Honda Manuals, apparently) - until the axle bolt is torqued. Don't use the Right hand pinch bolts to do this , for reasons above. Also best to have the front wheel off the ground to allow it to move. It is Ok to tighten the right pinch bolts AFTER the axle bolt has been secured. (This is me reasoning - follow the prescribed procedure)

Then slacken the left pinch bolts, bounce the forks and then torque up the pinch bolts on both sides.

Have a visual check on things that could catch the wheel as it was spinning - in particular, parts of the calliper and the heads of the disc rotor mounting bolts and pulsar ring bolts. They may have just slight scuff marks, but they may have been ground down and need to be replaced.

Glad that you found the problem !