Seeking handling advice for 97 ST1100

Joined
May 7, 2015
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66
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Eastern NC
Bike
1997 ST1100
I bought my 1997 ST1100 about 4 months ago with 49.5k miles on it, I have rode it 3k since and replaced the brakes and tires.
The PO replaced the rear shock with a progressive shock. I do not know if the front springs or steering head bearings have been replaced.

My question is at cruising speed 65-75 mph the front end feels light and very ?flickable? is this normal? Also in very tight turns like the Dragons Tail the front end under steers and I have to work to keep it stable. I am running Dunlop Road Smart II with 40psi front and 42psi rear. (less psi in the front tire causes bad under steering)

Would replacing the front springs or steering head bearings help the handling? How do I check the front springs and steering head bearings to see if thy need replacement?
 
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It has been my experience that just after changing the front tire I notice turn in is a lot easier than it was with the old tire. And I run 42 psi front and rear. It never felt uncontrollable in a turn though.
 
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Fort Worth, Texas
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91 ST1100/06 ST1300
My '91 feels very light and nimble. It steers faster than the GL1000 I sold to make room for it. At the same time, it feels very secure and goes where I point it....haven't noticed any under/over steer. It's all stock set up. If you're really having a problem, find it and fix it before changing anything else out.

Without removing the steering head bearings for inspection, there are really only two extreme conditions you can check for.
Corrosion/dried grease/flat spots....simply sit on the bike, parked on clean cement and rotate the handlebars stop to stop. One of these conditions will cause the bearings to feel catchy or ratchety for lack of a better term.
Extremely worn/loose bearings....prop the bike on the center stand and elevate the front wheel so it has no weight on it (carefully so you don't crack anything....may want to remove the lower cowl). Get off the bike, walk around front and see if there is any obvious movement when you pull and push the front wheel straight forward or back. Badly worn bearings or loose bearings will display a slight bit of give that you can feel.
Over torqued steering head.......You can also pivot the handlebars with weight off the front wheel and get a feel for how tight the bearings are. Overly tight bearings will drag.
Any indications require attention.
That aside, these are tests for extreme conditions. Marginally bad/improperly tightened conditions can only be determined by removing and inspecting the bearings.
 
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USA
New MC tires are rounded to help the bike turn in quicker. A lot of miles especially on the "super slab" puts most of the wear in the center of the tread, making them less rounded and less quick to turn in. Going from flattened off used tires to more rounded new ones will definitely change the cornering and "on center" feel, at least until those get worn, too. As for feeling "light" at speed and unstable, I don't know. Mine never felt that way after new tires, so if it's not just a matter of not being used to the way that style of bike rides and steers, you may have a suspension or weight-and-balance issue. Less than 50k isn't a lot of miles on an ST, so it seems a little early to be having suspension or bearing wear issues.
 

Mark

Gotta make tracks
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Front springs and roller steering head bearings will make an enormous difference with any tires in any condition.

Sonicsprings.com for the front springs, call cbr bearings for the ST1100 roller bearings (they'll know exactly what you need).
 
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Saltydog
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1997 ST1100
Well I am going to start with new springs first, I will update everyone after a few hundred miles as to if it solved the problem.
 

Slydynbye

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Well I am going to start with new springs first, I will update everyone after a few hundred miles as to if it solved the problem.
If you increased the rear spring you probably lifted the rear some which in turn decreases rake in the front which can cause faster steering. You could decrease preload in the rear to see if that helps.

Unless you are 250lbs or more Don't go for the Recommended 1Kg in the forks, they are Too stiff, try something like .85 kg. Stock is .65kg so going to 1kg is quite a "shock"
Also as the spring increases the front rake will increase giving you more stable highway tracking.
 

ST4Sal

Gone Riding!!!
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Williamsville, NY
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4812
saltydog,
When I bought my 02 I felt the front end was very unsettled. Tried new tires and finally bought a race tech gold valve for the forks. MADE ALL the difference in the world.

Hope this helps.
 

wjbertrand

Ventura Highway
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Make sure the correct sized tires are installed. Front should either be a 110/80 x 18 (non-ABS) or a 120/70 x 18 (ABS) for your model year. All ST1100s came fitted with a 160/70 x 17 rear tire. The wrong width or aspect ratio tire can have a big effect on steering, particularly at the front.
 

ST1100Y

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+1 on tire dimensions...
Also unclear if the installed after-market shock has the proper dimensions (like being too long?)
Head bearings?
Wheel bearings?
Condition of forks? (like worn down slider bushings...)
 
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Dahlonega, GA
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2018 NC750X
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7666
Having a properly set up suspension can make all the difference in the world! During one of my tech events, I had the opportunity to ride a couple other 1100. One gentleman had "upgraded" his suspension and I could not believe the difference in the handling. Started to ask lots of questions. I'm fairly mechanical... little above average, but not a mechanical genius by any means. I can replace parts, but when it comes down to understanding all the dynamics of how the front and rear suspension play together on a well tuned bike... that's a little too much science for my head. In short, I had the suspension rebuilt and set up by Traxxion dynamics and OMG what a difference. I had 90K on the bike then so the springs were a little soft and the fluid was mineral based and pretty much useless after that amount of mileage. She rides like a dream and others notice the difference right away when they ride mine.
If you are having handling issues, might want to get someone familiar with suspension issues to help sort out the proper cure. There is a lot of time dismantling and playing with parts, oil, settings and etc to achieve the best for your weight and riding style if your just guessing.
YMMV... hope this helps.
 
Joined
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Fort Worth, Texas
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91 ST1100/06 ST1300
Perceptions............Wearing mechanical things pick up bad habits slowly. Replacing worn out components with specialty equipment will show an improvement. But....is it a significantly better 'improvement' than simply replacing the worn out parts with factory new parts? The only effective comparison is side by side with both suspension systems in the same condition of wear.
 
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Perceptions............Wearing mechanical things pick up bad habits slowly. Replacing worn out components with specialty equipment will show an improvement. But....is it a significantly better 'improvement' than simply replacing the worn out parts with factory new parts? The only effective comparison is side by side with both suspension systems in the same condition of wear.
It is that much better... I have my own experiences with other's ST's and I have some friends, two of which have owned more than 4 ST-1100 apiece. That's pretty powerful testimony!
 
Joined
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Netherlands
Hai,

I have the hyperpro springs and the shoch absorber with the hyperpro spring.

The springs only make a lot of difference.
I changed the oil in forks. I used less thicker oil.

I have the same tyres as you have.

What you dont know if the oil has been changed in the forks.
Find out if this is done.

(sorry for my english)

Regards


De dwazen zijn die mensen die denken dat een spiegel er alleen is om hun uiterlijk een cijfer te geven.
 

ST1100Y

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Replacing worn out components with specialty equipment will show an improvement. But....is it a significantly better 'improvement' than simply replacing the worn out parts with factory new parts?
Well... an almost "religious" question... ;-)

Methinks it depends on how much you push the envelope... or get forced to once by having to perform some heavy evasive manoeuvres...

The OEM equipment "is not that bad"... it provides a good compromise, more then sufficient for the average user... I used them for a decade in my first, '92 ST, and they served me well while I rode the crap out of that thing...

However will an improved suspension add a lot on cornering and braking stability... it will feel like a different motorcycle, and significantly more the larger the payload, and the faster, harder one goes...

My refurbed '94 with OEM suspension "feels" comfy/mushy like a fast Ottoman, whilst my '00 with Wilbers shock and Hyperpro forks appears firm, agile and precise... thus more alive...
(OTOH is the '94 engine smoother, more precise, begging for revs, whilst the '00 engine with half the mileage always had a slight buzz, won't breath as easy...)
 
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Saltydog
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May 7, 2015
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Eastern NC
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1997 ST1100
I got a friend to help and we checked the rear shock to see what the PO had set up the replacement shock for Sag, it had 10mm of Sag, so I reset it for 30mm.

Then we checked the front and found 57mm of Sag, it looks like I will be replacing the front springs.
 
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Saltydog
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May 7, 2015
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Location
Eastern NC
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1997 ST1100
OK when I checked the sag it was 10mm in the rear and 57mm in the front.
I reset the rear progressive shock to 30mm of sag and added 25mm spacers to the old stock front springs and changed to oil to 15wt now the sag is 30mm in the front and rear.
I took it back to the mountains and rode hard twisters for 4 days; it handled much better and no more under-steering.

Cost
1 resetting rear shock-$0
2 adding 25mm PVC spacers-$1
3 new shock oil - $15-$20
= much better handling- good deal :biker:
 
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