Author Topic: Front wheel shimmy  (Read 103 times)

Mr. Paul

  • Hero Member
  • *****
  • Posts: 677
    • View Profile
Front wheel shimmy
« on: February 08, 2017, 04:49:34 PM »
When I let go of the bars of my Honda Helix there is a shimmy between 25 and 40 mph. The bars do not shake before 25 and after I hit around 40 to 45 mph it smooths out.  Any ideas? (Other than to not take my hand off the bars!) The rim appears to be true and the wheel bearings roll smooth and do not feel loose to the hand.
2009 Kymco People 150
1993 Honda Helix

ole two wheels

  • ole two wheels
  • Full Member
  • ***
  • Posts: 174
    • View Profile
Re: Front wheel shimmy
« Reply #1 on: February 08, 2017, 05:13:29 PM »
Hey, Mr. Paul, don't know it this is your problem or not, but over the years of riding and working on bikes, I have found that, especially, on older or high mileage machines this fact. A wheel and/or tire even slightly out of balance or out of round can cause the shimmy. You see a spinning wheel will go thru "harmonic" balance and unbalance at certain rpm's. when the unbalance cycle is present the forks tend to flex fore and aft, on both sides, alternating side to side very rapidly. The results is wheel shimmy. If you were to continue to accelerate pass 40 to 45 mph, at some point the shimmy would return and be more pronounced. I hope this makes sense to you. Your thoughts please.


Mac
Mac

MJR

  • Sr. Member
  • ****
  • Posts: 327
    • View Profile
Re: Front wheel shimmy
« Reply #2 on: February 08, 2017, 07:15:59 PM »
Could be either front or rear tire, wear, or road ridden on. I miss my Helix.
'14 MyRoad 700i, '09 White Burgman 650, '06 Gray Burgman 650, another '06 Gray Burgman 650 project/parts bike, '05 Silver Burgman 650 project bike, '03 Blue Burgman 650, and '03 Blue Burgman 650 parts bike

ole two wheels

  • ole two wheels
  • Full Member
  • ***
  • Posts: 174
    • View Profile
Re: Front wheel shimmy
« Reply #3 on: February 08, 2017, 07:53:06 PM »
Scalloped front tire can cause shimmy. If you remember some of the Japanese motorcycles , especially in the 70's and up had fork braces. Some of then went over the fender and some were incorporated as part of the fender. Still used today a lot on sport bikes. They were to dampen fork flex and movement.



Mac
Mac

Mr. Paul

  • Hero Member
  • *****
  • Posts: 677
    • View Profile
Re: Front wheel shimmy
« Reply #4 on: February 09, 2017, 02:39:14 PM »
Hey, Mr. Paul, don't know it this is your problem or not, but over the years of riding and working on bikes, I have found that, especially, on older or high mileage machines this fact. A wheel and/or tire even slightly out of balance or out of round can cause the shimmy. You see a spinning wheel will go thru "harmonic" balance and unbalance at certain rpm's. when the unbalance cycle is present the forks tend to flex fore and aft, on both sides, alternating side to side very rapidly. The results is wheel shimmy. If you were to continue to accelerate pass 40 to 45 mph, at some point the shimmy would return and be more pronounced. I hope this makes sense to you. Your thoughts please.


Thanks Mac. I suspect the tire is slightly out of balance. It is not really noticeable unless I take my hands off the bars. I did this the other day to straighten my glove, definitely not a regular thing I do. I have checked all the bolts and they are all snug. I will continue to watch and if it gets worse I will pull the wheel and have it checked. Thank you sir.

Mac
2009 Kymco People 150
1993 Honda Helix

eamartin

  • Newbie
  • *
  • Posts: 46
    • View Profile
Re: Front wheel shimmy
« Reply #5 on: February 09, 2017, 04:37:10 PM »
Shimmy Shimmy Ko Ko Bop.....

Mr. Paul

  • Hero Member
  • *****
  • Posts: 677
    • View Profile
Re: Front wheel shimmy
« Reply #6 on: February 09, 2017, 04:40:37 PM »
Shimmy Shimmy Ko Ko Bop.....



Shimmy Shimmy Bop. (Couldn't resist!)
2009 Kymco People 150
1993 Honda Helix

eamartin

  • Newbie
  • *
  • Posts: 46
    • View Profile
Re: Front wheel shimmy
« Reply #7 on: February 09, 2017, 07:49:05 PM »
That's what I was waiting for.

NOCO Genius