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Front Wheel Shakes

GaryN.

GaryN.

Training Wheels
I am wondering what is the likely reason for my front wheel shaking kind of violently when I let go of the handlebars. It does it at certain speeds worse than other speeds. The shop I take it to told me until I replace the front tire with a sport tire I will have that problem. Does that make sense. I had them check the steering head to see if there was in play there and they said there is no play. Now if I had asked them to check the wheel bearings for play that would have been good but I forgot to ask that. My only other suspicion may be that the forks need servicing like 15 weight oil and possibly new better springs. Can anyone tell me what worked for you.
 
do you have any idea how they checked the steering head for tightness?  in my experience, steering head problems cause a wobble at around 45 mph.  above or below it doesn't seem to have the problem.  tightening the head solved it.  I can let go of my handlebars at about 55 and coast down to about 30 with no wobble at all.  rather than asking them to check one thing at a time, you might ask them to check the entire front end to determine where the problem is.  However, it sounds like they aren't going to help you unless you replace the  tire.  any idea how many miles on the tire or how old it is?
 
To completely eliminate head shake you must:
1. Have a good front tire, preferably new,
properly mounted and balanced.
2. Have good wheel bearing. Replace if loose
or rough.
3. Have a properly tightened stem nut.
Easier said than done. Actually requires a little
finesse and following the correct sequence.
4. Last, but not least, properly torqued engine
mounting bolts.
Do all of the above, in order, and you should see
a marked improvement.

FWIW, my bike exhibits no head shake at all,
so while it may seem elusive, it is possible.
 
To Sport Rider and Works for Me- The tire has 5500 miles on it and is a Avon AV55. The tire was mounted backwards for 5500 miles and I just noticed it last Sunday 7-17 and went in and they mounted it in the correct direction. The motor mounts have been torqued, fronts 40 lbs. and rear two I never had the specs for the rear so I went 45 lbs. My forks do also not shake until they hit a certain speed probably right around 45mph. I dont know what they did to check the steering head tightness but I think they just while on a stand they pushed the fork from front to back. I also read to my surprise one member said taking the fork brace off was a part of his wobble being resolved. I was surprised by that.
 
Front wheel oscillation, head shake, wobble, call it what you will, can have many causes. Tony Foale's engineering work has shown that problems at the back of the bike such as low tire pressure, bad swingarm bearings, etc., can result in head shake. Add to that all bikes are subject to headshake by the inherent design of a bike, the C10 more so than most it seems.

You need to do two things:

Replace both tires with new. The front you have is old and has been run backwards for what could be half or more of its life. Plus you haven't said what the rear tire is. Get new tires so you have a baseline to work from.

Second - do some reading on the subject. The first link was in a thread in the accessories section asking about fork braces. While I don't know who the author is or agree with his conclusion, he hits all the important points in language anyone can understand.

The second link is to Tony Foale's work on the subject. A lot more in depth engineering discussion, but understandable by most. Start with the "Camber thrust and how tires work" and "Experiments with steering geometry" and then maybe "Feel - funny stuff."

Once you have a baseline and a better understanding of the dynamics, you can spend time wisely working the problem and not just chasing suggestions.

http://web.ncf.ca/ag136/frontWheelWobble.htm

http://www.tonyfoale.com/Articles/index.htm
 
I might add that for balancing I had the shop put in the beads instead of a wheel weight. It did shake thought with the wheel weight as well. I dont know if the beads are better than a wheel weight but my thinking was that it made sense that it might be more dynamic and continuously balancing with the beads.
 
JPavlis_CA said:
. . . . The first link was in a thread in the accessories section asking about fork braces. While I don't know who the author is or agree with his conclusion, he hits all the important points in language anyone can understand. . . .
Click to expand...
I hereby own up to being the author of the first link and admire your independent thinking about my conclusion.
 
Garrett said:
To Sport Rider and Works for Me- The tire has 5500 miles on it and is a Avon AV55. The tire was mounted backwards for 5500 miles and I just noticed it last Sunday 7-17 and went in and they mounted it in the correct direction. The motor mounts have been torqued, fronts 40 lbs. and rear two I never had the specs for the rear so I went 45 lbs. My forks do also not shake until they hit a certain speed probably right around 45mph. I dont know what they did to check the steering head tightness but I think they just while on a stand they pushed the fork from front to back. I also read to my surprise one member said taking the fork brace off was a part of his wobble being resolved. I was surprised by that.
Click to expand...

Unless the service techs examined, disassembled, lubed, and correctly reassembled the stem bearings and stem, and shortcutted like most folks do by just tightening it, you will never know if those bearings are good, or bad....
Here's what they end up like when shortcuts are taken.... not pretty, and this bike didn't shake all that bad.... but when it began, I fixed it....

Mmm
Bottom bearings..


Top race...
 
ajsfirehawk said:
Good Gawd almighty MOB, that is THE worst steering bearing I've ever seen.
Click to expand...

Surprisingly, I've seen WORSE.... :rotflmao:
That is the direct result of an owner never disassembling and inspecting it, and lubeing it, along with power washing the bike... and when they had the speed wobble, they just "tightened" ita bit... this was found on my 86 about a monh after I bought it, well used, and it started to have shake issues...
Luckily the bike came with a bunch of new spares, and I didn't complain, but was shocked when I saw it...
Like I say, you don't know what's in there till you check... and if I was on an extended cross country ride, this would have been a real tough fix on the road..

I outlined the replacement procedure in the Concourier artical "shake, rattle, n roll", along with the correct tools and part numbers...
 
Here's a thought. If you tighten the steering head bearing enough to prevent wobble, the grease gets pushed out and the dry bearing is more prone to rusting.
 
GeorgeRYoung said:
Here's a thought. If you tighten the steering head bearing enough to prevent wobble, the grease gets pushed out and the dry bearing is more prone to rusting.
Click to expand...

Doesn't quite work that way. There isn't enough deflection to "squeeze" out the grease causing a dry bearing situation. Only pressure washing, heat, or lack of maintenance will cause dry bearings.
 
GeorgeRYoung said:
Here's a thought. If you tighten the steering head bearing enough to prevent wobble, the grease gets pushed out and the dry bearing is more prone to rusting.
Click to expand...

:rotflmao: :rotflmao: :-[

This is why some people should not own mechanical objects.

Ride safe.
 
My Nomad looked much the same when I bought it (used with 42k miles).  I just replaced my C10 with 70k and it looked no where near as bad.
 
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