Violent wobble in front end (updated)

[kudzufarmer]

I have had an issue come up that i have not yet been able to diagnoise and need some help......while riding I let the bike coast while still in gear to snap my jacket sleeve....when decelerating i got a very violent side to side wobble. that went away as the bike slowed down further. I do not feel any vibrations in the front end at highway speed so I don't think its balance.....I am running dyna-beads in the tires and have been for a while w/o any problems. I put the bike on a jack and checked all bolts, etc and everything was tight......did not see any issues with the tire or treads........any ideas????


I am suspecting that it is brake pads grabbing, but would it be possible low fluid might cause this issue?/// Just speculating....on a whim I recreated the situation and when I got the wobble I applied the front brakes and it seemed to straighten it out.

i also felt a slight wobble when putting the brakes on lightly in a slow speed turn when riding over the weekend.


thanks for any feed back.....oh the tires are Avon Cobras....

[bobzinger]

Mine only does that when the tires are pretty worn

[kudzufarmer]

Originally Posted by bobzinger

Mine only does that when the tires are pretty worn

No I still have pretty good tread left.....thanks though...Oh and Bob your bike is a carbon copy of mine.....2005 1600 black and silver

[dabull]

i had/have the same issue....do a forum search for "Wobble"....i found that checking my air pressure helps but still at about 35-40 mph get the wobble...is very disturbing.

[kudzufarmer]

Originally Posted by DaBull

i had/have the same issue....do a forum search for "Wobble"....i found that checking my air pressure helps but still at about 35-40 mph get the wobble...is very disturbing.

I think i am going to take the brake calipers off and wire them in place for testing......just take it slow and easy and just use the rear brake and see if it goes away without the front pads rubbing the rotors....will advise

[phenrichs]

many have reported this deceleration wobble. Tire pressure fixed it for some. Tire cupping was an issue for others. Many have found that the steering head bearings are not properly greased or torqued which left room for the front end to do its own thing. I have not heard of anyone wiring back the calipers for a test. Might be a good new idea although if that takes care of it the problem is more likely the rotor than the caliper.

[kudzufarmer]

Originally Posted by OP

many have reported this deceleration wobble. Tire pressure fixed it for some. Tire cupping was an issue for others. Many have found that the steering head bearings are not properly greased or torqued which left room for the front end to do its own thing. I have not heard of anyone wiring back the calipers for a test. Might be a good new idea although if that takes care of it the problem is more likely the rotor than the caliper.

how big of a job is it to check the bearing torque?

[cactusjack]

My 2007 had this problem since new. It would come and go with new tires, but I could pretty much count on the "death shake from hell" to happen anytime I took my hands off the bars. Alas, it's now a thing of the past since I serviced my steering head bearings and tightened them a little.

I can now lift my hands from the bars at virtually any speed and it tracks straight and smooth. Not that I do that very often, just every now and then to test it, or when performing a two-handed task, like fixing a sleeve or glove.

It isn't that hard to do, although a second pair of hands is useful when getting the fork back into position. It's worth the couple of hours it takes to do the service. Note that most of the time is spent removing and replacing the front end chrome sheet metal.

[spirello]

+1 STEERING HEAD TORQUE AND GREASE BEARINS IT WORKED FOR ME.

[kudzufarmer]

Hey scott;

if you just take off the steering stem cap, can you check the steering stem nut w/o removing all of the accesory trim and pieces?

[ringadingh]

It seems to a common problem with a lot of Nomads. Mine does it especially with Metzeler ME880's. I checked the bearings and It didn't help, I'll check them again in the spring. When I replace the front tire with a Dunlop earlier this summer it went away for a while but is now back again. It seems to have a lot to do with tire wear, at least on my bike.

[cactusjack]

Originally Posted by kudzufarmer

Hey scott;

if you just take off the steering stem cap, can you check the steering stem nut w/o removing all of the accesory trim and pieces?

No, the steering stem nut is hidden beneath the top clamp cover. That must come off to check it, which necessitates removing the front end sheet metal, to some degree. It isn't a regular hex nut. It has 4 notches in it like a front <s>hub</s> spindle nut on a 4WD axle. This is why I adjusted mine by "feel" rather than with a torque wrench.

[macmac]

Head bearings tend to be too loose. If you have the book for 1600's it says WRONGLY 64 inch pounds.. The spec should be more like 25 foot pounds.. If course there is NO dammned grease...

So you will need to add some grease. Then, instead of torquing straight up to 25 foot pounds, go a little past it, so the forks get stiff, then back off, as you would on a NON front wheel drive wheel bearing.

Then tighten to 25 ft pnds if you wish and test the ft end again.

When the ft end is right, it will not slap from straight to one side if slightly bumped.

Really there can be no spec for tightening here, but books make funny specs.

'IF' the rotors are warped, that too, could be a part or another problem. I haven't heard of any warped, cracked or bent rotors on Nomads, but in general it is common.

With the bearings 'right' the bike will feel more stable, which is a +.

[VulcanE]

I had this exact same thing with mine. I installed new bearings (my old lower one was shot, little or no grease from the factory) and torqued to the factory spec of 43 in-lb after seating the new races at 90 ft-lbs. Still had the wobble, and like Mac, CJ and others have said, re-torquing the stem bearings worked for me, I re-torqued to around 25-28 ft-lbs. Mine is a 2005 also. While your at it, I would strongly suggest that you go ahead and change your fork oil, since you're already over 1/2 way there doing the steering stem. It's not a hard job, but it is a little time consuming.

[kudzufarmer]

Updated...just finished re-tourquing the stem bearings.....when I started the steering was loose and the fender, etc would flop over to the downhill side w/o any restriction (bike was on jack front wheel in air)....regreased bearing and tourqued nut so that fender would stay in place when turned and then just a little push to go downhill. basically the steering would hold in any postion...only a lite pressure to move......I did this based on Macs comment about the steering not "slapping" to the side when slightly bumped.......It is raining now but will go for a ride when it quits and update this post.

Vulcan E question on your advice on changing fork oil......it looks to me like you could take the caps off each of the fork legs and change out the oil......i guess the problem would be how to get the oil out of the forks.......Oh well never mind I think I answered my own question.