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knock from front end.

Discussion in 'Technical and Troubleshooting Torque' started by dedmn80, Jul 28, 2015.

  1. Hi all just a quick question i have a knock from the front wheel of my mc19. I tested the wheel by running it on my spada and still have a knock when i hit front brakes or go over a bump. It is only that wheel. Some assistance on what may be causing it would help out heaps. Thanks in advance.

  2. Check to ensure that the axle is properley contained in the wheel, and that the bearings are complete and correctly located.
    • Agree Agree x 2
  3. Put the bike on a front stand and slowly turn it by hand to see if any clearance issues around the rotor, rotor bolts, speedo cables (if hooked up to front rim), rim weight, screw/nail stuck in the tyre hitting the guard etc.
    • Agree Agree x 2
  4. I have a sneaky sensation that it is the wheel bearings but just want to make sure with other opinions first. Would it be possible at all for the wheel centre to expand over time so it leaves the bearings with a little bit of play or the axles does not fit properly.
  5. Are you sure it's the wheel and not the steering head? They will make a distinct knocking sound when the steering head bearings are loose, as will worn out fork bushes (inside the forks).
  6. Positive as the bike was not knocking at all until i swapped the wheel across as has a new tyre on and wanted to replace that wheels bearings due to a whine which indicates worn bearings
  7. As the bearings wear they will lose size and shape, so you get more movement. It can be helped by tightening the hub a little, but if you already have noise at speed just get them done.
    Also, the axle can wear faster if the bearings are going. If it were an old bike and the bearings had dried out and not been well lubricated then it would just magnify the effects.
    • Like Like x 2
  8. Cheers for that. I will have to look at it this weekend and hopefully it is only bearings
  9. is it related to the speed of the wheel or just the occasional knock?

    Wheel bearings will squeal rather than knock. So I'm thinking it's either steerign head bearings or a disc that has become too loose on the carrier. Or even a warped disc.
  10. hard to diagnose with a description.. Ticking sound could be disc carriers, knock with a new wheel from a different model may be hitting something it shouldnt, check the wheel clearances with forks calipers and guard, Even tho the wheels look the same, no guarantee's they are exact. knock from the wheel sounds like spokes hitting brake caliper. knock when you use brakes or go over a bump is usually steering bearings or fork bushing wear.. edit - re-read your post so the wheel is on the original bike?
  11. I'd change the wheel bearings to start with. you can pick them up cheap from any bearing shop.

    (Trick: to fitting the new bearings is place the bearing in a zip-lock back, then into the freezer for 10 mins before you need them, while this is happening, gently apply heat to the wheel hub, where bearing is to go, a heat gun or hair dryer will do the job. the new bearing (with a smear of grease around the recess) can almost be pushed in by hand, if it needs gentle persuasion, use a socket head that fits neatly into the recess where the bearing sits, don't hammer on the bearing 'balls')
    • Like Like x 1
    • Agree Agree x 1
  12. The knocking sound could be one or two of the actual ball bearings have broken.
    I had this on the back of my bike on the way back from a trip through France.
    The knock was quite loud and I could feel it coming through the bike. Then all of a sudden it disappeared.
    Rode another 250 miles home without a sound.
    A few weeks later it started again so I took the back wheel out and found I had 4 bearings missing from one side of the bearing case, but the bearing felt smooth to turn by hand.

    Bearings are not expensive, I'd just change them anyway.
    • Funny Funny x 1
  13. Seems be doing that on my spare front so getting the bearing numbers this week and going to definately change them on one set of wheels then the other set will be done the following week. i just jave to get them out which is the hard part and have a 12 ton press here to get the new ones in
  14. When you knock the old bearings out, I would remove the brake rotors first, they can easily be damaged and get in the way.
    Between the two sets of bearings there is normally a guide tube for the axle.
    If you get a large flat blade screwdriver thats capable of taking a hammering, you can poke it through at an angle and get to the inside of the bearing. Start tapping the driver but move it around the bearing each time you hit it.

    When you put the new bearings in, don't forget the guide tube, like I did once.:facepalm:
    • Like Like x 1
  15. another way to knock out a bearing, if you do not have a bearing puller, is to buy 'Dyna bolt' that fits snug inside the bearing, then tighten the nut so it expands against the buggered bearing inner. Now you have a flat surface to pound on from the other side of the wheel. A bit of heat applied to the outside of the hub, will make things a bit easier.
    • Informative Informative x 1