Steering Stabilizer info needed

[Anonymous]

I'm looking to put a steering stabilizer on my 750EX. The problem is the bike is so old, no one seems to know what size to use. How do I measure (and where from) so I can use them. The bike rides & corners well, but the front shimmies over 100mph. Any help appreciated here.

[earlfor]

Re: Steering Stabilizer info needed

Johnny, I think putting a stabilizer on the bike to stop a shimmy is just covering up a problem. My experience with stabilizers is that they will slow down the steering a little bit and dampen movement, but they will not stop a shimmy. The first thing I would do is to take the steering stem apart and check the stem bearings and races. If they are unscored and the bearings are not flat spotted, just regrease everything, put it back together and torque the steering head to specs. I would be willing to bet that will solve your problem. Also, with the bike on the centerstand, set up a pointer on the front rim and check to be sure the rim tracks in the same plane for 360 deg of rotation. Check your wheel bearings for play/wear. After that, have the tire balanced. Additionally, worn tires can cause a shimmy. This includes both tires. A worn or out of alignment rear can be a contributing factor.

Earl

I'm looking to put a steering stabilizer on my 750EX. The problem is the bike is so old, no one seems to know what size to use. How do I measure (and where from) so I can use them. The bike rides & corners well, but the front shimmies over 100mph. Any help appreciated here.

[saaz]

I agree with earl..check for the cause of the shimmy. Also check the wheel alignment. The type of tyre and wheel balance are the liely causes.

Steering dampers are more for sudden tank slapper type movements...GSs have slower steering than modern bikes with big tyres, so are not prone to this if set up properly.

I have heard some say GS did not handle..well, if set up properly, including replacing rear suspension and serving the forks, and the swing arm bearings, they handle fine and predictably at illegal speeds. Lets see how well an R1 with big miles and no attention to tyres and suspension handles in 20 years time! A generation of riders being hig sided!!

[earlfor]

I forgot to mention that when I first had my 750 on the road, the steering wanted to hunt/wander at 90 mph or more. Replacing the fork oil with 30 weight non detergent oil solved that problem. I suspect unbalanced oil levels in the forks can cause this problem too.

Earl

[SqDancerLynn1]

Earl said it all. My GS would put you in tank slapper if you let the bars go under 50 mph Turned out steering stem just needed adjustment, don't think it would be balance definately could be tire

[Anonymous]

Tires,suspension (front & rear),wheel bearings all new ( within year). Swingarm & steering head bearings all checked & lubed at same time.
Rims were balanced when tires ( Bridgestone Spitfires) put on. Can check the alignment front/rear,maybe cause. The bike handles great below 100mph. Corners better than I thought it would. Just wobble at high speeds a little unnerving on the highway. Won't stop me though!
By the way - Anyone know where to get a digital speedo, the 80mph stock thingee just doesn't cut it.

[argonsagas]

You might also check tire roundness. It doesn't need to be elliptical, just out-of-round a bit, and it will not run true at all speeds.

While not a common problem, an out-of-round tire can lead to your complaint.

Something like this can be caused by a lock-up of the brakes and a long skid, which wears away a good chunk of tread.

You can do a limited check at home, by putting the bike on the centrestand and blocking up the frame to have one tire run free.

You need something to hold a piece of chalk firmly, and the base must be very solid, so it does not move at all. (A heavy jack-stand will work well)

Put a thin piece of paper against the tire, then move the entire unit toward the tire until the chalk barely touches the paper. Remove the paper and rotate the tire.

Do this several times for each tire. starting at different places each time, as it is possible you started at a high spot.

Do the same on the sidewalls.

The chalk should not touch anywhere, but if it does, you will see the result.

If it seems to run without contact, then move the chalk against the tire, again until it barely touches, and rotate the tire again, letting the chalk make a continuous line. If the line breaks, then you found a flat spot.

[Anonymous]

You didn't say anything about your forks. You might want to check them out. I can't remember the exact numbers, but the tolerances are very close to having the same amount of fork oil and air pressure in each side. I would figure that a small difference might not be noticable at lower speeds, yet make a difference at high speeds.

[Anonymous]

Forks just rebuilt by local shop with Progressive Suspension springs & Bel-Ray fork oil ( I forget what weight oil, factory spec). Progressive air pressure regulator on the forks keeps pressure stable. The fork brace greatly improved the cornering, but little help on the wobble. I'll try the chalk trick & see.
By the way, what do European GS speedos read on 80-81 models?

[saaz]

It could be as simple as the tyre combination. Far newer bikes are also sensitive to tyre selection.

[jpaul]

Do you have a fork mounted fairing on the bike? The one on my 1100 causes some front end shimmy when you get up over 120 mph. Only happened on deceleration, but was a little unnerving. Hasn't happened since I got older and slowed down a little.

[Anonymous]

The tires are Bridgestone Spitfires, matching set.Similar to Continental Conti-Blitz. I do have a SlipStreamer SS-28 shield on it, did the same thing with a Maier cafe shield.
I know I'm getting older, but still ain't slowing down. As I've heard it said- " If you aren't scared you haven't gone fast enough!"
Anybody can take a wind-tunnel designed ride to triple digits, it takes balls to redline 20+ year old models.

[earlfor]

Johnny, I had a cafe fairing on my 750 for a while and around 100 mph, it wandered/hunted. It didnt shimmy, but it made it very difficult to hold a steady line. have you tried a speed run without the fairing? It could be the fairing is causing the front end to get too light. Just a guess.

Earl

The tires are Bridgestone Spitfires, matching set.Similar to Continental Conti-Blitz. I do have a SlipStreamer SS-28 shield on it, did the same thing with a Maier cafe shield.
I know I'm getting older, but still ain't slowing down. As I've heard it said- " If you aren't scared you haven't gone fast enough!"
Anybody can take a wind-tunnel designed ride to triple digits, it takes balls to redline 20+ year old models.

[Anonymous]

Have considered it a suspect, along with wheel alignment. Wheels in line with each other, so that's out.Rims good. If the shield is the cause high speeds will suck without it.

[HiSPL]

This is a bicycle computer/speedo that will read triple digit speed. It also allows far greater accuracy by allowing you to input your own wheel circumference. many people with custom built race cars, or go carts, or motorcycles are using this speedo. The other option is a garmin GPS unit that will tell you your speed with great accuracy.
-Tim

http://www.pricepoint.com/product37.html