A little Wobble

[Sexagenarian]

I was reflecting back on my first riding season this past year. As I have said many a time, I wish I would have done this years ago. My wife has a 1200 sportster and I have the 97 RSTD. I wouldn't trade my bike for all the Harley's in China (if there are any?)... However, there is one small concern that I have. When turning at intersections with the RSTD, there is sometimes a little slip or wobble about half way into the turn. It happens much more frequently on a left turn than it ever does on a right turn. I would say my speed going into the turn is typically around 20-30 mph. If I was stopped prior to the turn due to a red light or a stop sign then my speed is so slow in the turn that I never get that sensation!! It feels like I just passed over one of those oily black snacks on a hot tar road. But many times, there is just no black snake on that tar road. I cannot say if this has ever happenned on a cement road as there just are not any of them around this area.

If I "borrow" the wife's bike and take that same turn at the same speed then I do not get that sensation at all. Thus my concern.

Being so new to this, I am at a total loss of experience on just what this may be. My tread depth gauge on the front tire reads almost 5mm. Would it have something to do with the front fork? Or something to do with front bearings? I typically notice this moreso on a left turn but it has happenned occassionally on a right turn. I have never noticed it at highway speeds but then again my highway speeds seldom reach 65mph. As usual, any and all thoughts from anyone are most welcome on this subject. If I need to give you more info for your troubleshooting thought process, please just ask and I will try to give you as much info as I can remember...Cheers all !! - Wayne

[SummerBreeze]

My first thought would be to do a close inspection of the tires then I would check/replace the rear control arm support bushings. How many miles on the bike and do you know if the bushings have ever been changed? Happy hunting.

[BratmanXj]

I had/have the same problem with my '99 RSV. So far I've replaced a worn out rear tire and it got slightly better. Then pulled the swing arm and greased and torqued the bearings, again slightly better. Next step is new stearing head bearings as I bought the bike with 50k miles and they were loose. I did tighten the steering head but still have some "notchy" spots.

[CaptainJoe]

Probably a dumb question but when is the lat time you checked the pressure in your tire(s)?

 

 

Last month, mine started to do same thing, I was about 20 lbs. low on the front..

[Sylvester]

I had this problem years ago on my 02 and it was a broken belt on the front tire. Last time I put Metzlers on my bike.

 

[Mike G in SC]

Likely the front tire. But I've replaced rear tires too and got rid of some wobble in turns.

[billmac]

I check the air often in my tires an always needed some air after a few checks, my buddy said it was from checking so often and I lost a little air each time. get a Harley no leak pump for checking the pressure and the low air problem went away.

[GeorgeS]

All the above, especially tire pressure, and maby Worn Front tire. If you need tire, I suggest a set of Dunlop E-3's ( I know everybody does not agree with that )

 

OK, have you done the Head Shake Driveing test ???

 

On straight flat road, ( that you are familiar with ) ride bike at increasing speeds, from about 30 MPH up to about 70 mph.

Remove hands from both bars ( slightly !!! ) and check for " Head Shake " !! Do this every 10MPH up to about 70.

 

If bars start shakeing, grab them FAST, as this situation can get very dangerous, Very Fast !!!!!!!!!

 

If you have head shake, the Torque Setting, of the Fork Steering Bearings, needs to be increased, OR, you need to Replace the steering head bearings, or just Greese them and RE - Set the Torque setting.

 

Bottom line here is this is NOT, a fun job. As you have to pull off lots of stuff to get to the NUT, !!!

 

Usually, a Very Small amount of increased torque will to the job.

 

Its always best to start with a NEW Set of Tires, and Service the rear suspension first before tearing into the Front Steering.

 

Point here is, if you are Fairly New to rideing--- HEAD SHAKE IS DANGEROUS, AND --- WILL CAUSE YOU TO CRASH !!!!!!!!!! -----

 

Any motorcycle will do this !! its just a matter of what Speed, does the condition rear its ugly head !!! 1st Gen Ventures, have been notorious for this condition, 2nd gen not so much, ( My 89 did this, and adjusting the Nut on steering head cured the problem ) But, I still had the head shake start at about 110 mph. However I don't normally ride at that speed, so not a problem.

 

Frame stability and bike geometry effect head shake. Think of it this way, A Suziki Hyuabusa, is designed to go about 200 MPH. Head shake is not a problem on these bikes untill you hit about 210 MPH on a race track !!

 

I have had my Busa up to about 135 mph, and Absolutly NO Head Shake !! But the FRAME construction on this bike is " Massive " compared to any Cruizer, Harley, or Venture.

 

My Father in Law, crashed on a Honda 450, on the Ventura Freeway in Los Angeles, back in 1972 due to " Head Shake "

[Sexagenarian]

Thank you everybody for your replies.. Noticing the date of GeorgeS's reply means that I got an extra Xmas gift this year... thank you, George!! Will try out the "Head Shake" driving test once all this white stuff melts and a good thunderstorm cleans all the salt off the roads.. The way this winter is going, that will hopefully be before the end of April this year .... thanks again for the ideas on what to check.. cheers!!

[Sexagenarian]

Probably a dumb question but when is the lat time you checked the pressure in your tire(s)?

 

 

Last month, mine started to do same thing, I was about 20 lbs. low on the front..

Problem solved... 10 psi low in front and 10 psi low in the rear... Haven't noticed the wobble anymore so far.. keeping fingers crossed...