Howling sound only when turning left?

Discussion in 'Touring Models' started by Delmar, Apr 2, 2010.

  1. Delmar

    Delmar Active Member

    Here is an odd one for you…I discovered a howling sound coming from the lower-rear area of the bike, maybe the belt area. The odd part is I only hear it at speed and only when turning left. The noise is mid- to high- pitched.

    The noise first became obvious when I was going through a left sweeper. I attempted to duplicate the noise by weaving within my lane at 60MPH. Only heard the noise when weaving to the left, and not the right or straight.

    Upon arriving home I jacked-up the Copking to visually inspect. I spun the rear tire and nothing looked amiss with the tread. I crawled underneath and looked up at the drive belt and was surprised to see the belt guard did not enclose the belt, it only covered the outside edge. Additionally there was this rubberish flap thingy on the inside of the belt. (Is this the standard setup for a bagger?) I also noticed some intermittent rub marks in the tire sidewall.

    I took a pic of the belt and suspicious rub marks. Please excuse the filth because I got caught in the rain today. Note also I am still running the stock Police bead-retention tire if that makes a difference. Any ideas of what to look for next?

  2. biscuit

    biscuit Junior Member

    Has the bike ever done this before?

    It looks like that "rubberish flap thingy" is maybe bending back and rubbing against the sidewall of your tyre.How flexible is it?It dosen't look all that rigid in your picture.

    Mayhap it takes a decent airflow to get under it and force it back;at about 60 mph.
    Put the bike back on the jack and spin the wheel with the flap rubbing;and then without.
    Shouldn't take long to track down.

    NEWHD74FAN Experienced Member Retired Moderators

    Just a rough "guess" but between the tire flexing a bit at speed (remember that tire is unweighted on the lift and suspension not "hunkered down", so could easily take up that 1/8" or so clearance you have AND making a high speed turn; I would think that enough tire flex to contact splash guard fairly easily. Does it look like the flap may have moved out of position in the mounting that is out of view? You might be able to loosen the fasteners and move it away from the tire a bit, but not too much...otherwise it may contact the belt which would be much worse than "just a noise"...
  4. ironmark

    ironmark Junior Member

    You may want to check the rear wheel bearing .
  5. Delmar

    Delmar Active Member

    I rocked the wheel itself and it felt very solid. I then attempted to move the wheel sideways and the wheel did not move relative to the swingarm, but I managed to get the slightest amount of movement in the swingarm relative to the frame. I believe the swingarm mounts rigidly to the motor which is then rubber mounted to the frame. This minor sideways movement I assume should then be normal.

    I removed the belt guard to inspect the inside. The flexible inner flap is made from rubber, and saw what I expected for a tire contact problem.

    With the belt guard removed the wife and I took a weave down the highway, and we noticed the noise was faint but pretty much gone. On the return trip the wife innocently asks…”did you check the tire pressure?” Yeah right, what do women know.

    I let the bike cool and reinstalled the belt guard. I then checked the rear tire pressure…uuhh oohhh…30 PSI. I pumped up the tire to 40 PSI and we went for another weave. The noise was slightly louder than without the guard, but definitely quieter than yesterday. Makes prefect sense that an underinflated tire will flex more under cornering, however also I believe is not the total problem.

    My next suspect area to check will be rear wheel alignment. I have never needed to adjust the belt tension so this looks like a good time to learn. I may even temporarily tweak the wheel a smidge to the right to gain belt clearance, and will listen to hear if the belt tracks any quieter on the pulley when spinning by hand.
  6. Jack Klarich

    Jack Klarich Expert Member

    Well done
  7. SunnyVale

    SunnyVale New Member

    So, did you ask the dealer what the purpose of that rubber flap is for?...i.e. prevent rocks or mud from kickup up in between the bell on pully or what...interesting to hear their answer.
  8. maine-e-axe

    maine-e-axe Junior Member

    Look up inside the fender, tail light wires maybe rubbing the tire as well.
  9. kemo

    kemo R.I.P

    Often when checking a bearing you won't feel in side play in the bearing. You have to remove the wheel and rotate the bearing with your finger to feel for any roughness in the bearing
  10. jim1102

    jim1102 Member

    leave the guard off,unless you travel a lot of gravel roads.makes it alot easier to check belt on your pre-ride inspection.I have a bike with over 60000 miles on it that i took the lower belt guard off of when it was new,never had a problem.