Suspension problem? with ST1100

Bought a '99 ST1100 with only 32,000 miles. Gradually going through and doing maintenance repairs etc. that previous owner overlooked.

I didn't notice this until new tires went own so maybe that's the issue but,

At about 35 mph I get significant "bouncing" of the front end. The problem may be happening at lower and / or higher speeds but it's most noticable at about 35. It seems like a suspension issue but I don't know enough to be sure.

How can I determine what the problem is for sure and what do I do about it?

Need to realign the front wheel. Loosen up the axle a little and the lower fork bolts ride or push the bike around and grab the front brake hard a few times. Tighten one side of the forks to spec. Push brake again. tighten up the other fork leg push brake. Then tighten the axle to spec.......Everyone has their own way but that works for me.

Also check the rear axle. If you set the pinch bolt before the axle nut it could cause a bobble too. Loosen the axle pinch bolt check the torque on the rear axle then the pinch bolt.

Good luck with your new ride!!!

Do a run out test on the front tire. I have had bad tires that were out of round and made the bike jump as you describe.

barto said:

Bought a '99 ST1100 with only 32,000 miles. Gradually going through and doing maintenance repairs etc. that previous owner overlooked.

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This may or may not be relevant to the problem you describe, but since its a '99 and the P.O. apparently 'overlooked' some maintenance is there any way to find out if the fork oil has ever been changed?

Also, any oil residue on either of the forks? I blew a fork seal and had the same symptoms you describe although the symptoms were present at just about any speed.

I have no idea if the fork oil has ever been changed - but I doubt it. Still, there are sure no obvious leaking seals.

Geoff, what do you mean by a "run out test on the front tire"?

So here's the latest - took the bike to the Honda dealer today for evaluation. After a test ride by the tech confirmed the bouncing, he checked out the front tire (essentially brand new) and says there's a flat spot on the tire causing the "bouncing" of the front end around 35 mph.

However, 1) this is "perfectly normal" and 2) "it should work itself off after some unspecified amount of miles." "of course, everytime you park the bike you get a flat spot on the tire if it sits too long (like a week or two) so this may always be an issue.

SERIOUSLY? That's the answer????

Well after much back and forth the dealer - with Bridgestone's support has agreed to replace the tire- of course the dealer doesn't expect much improvement if any AND "It could even be worse"

SERIOUSLY?

We are talking about a pronounced amount of bounce and I'm not convinced the tire is to blame at all - and furthermore, if it actually is the tire that this is "perfectly normal" in any way.

Has anybody else seen this sort of issue caused by a tire? And if so, is it really normal???


PS: The bike hasn't sat for two DAYS since I got it much less two weeks. I'm on it absolutely every chance I get...oPoST1:

You didn't say if you took it for a ride after the new tire was put on, the old tire may have bounced because of a lost weight OR maybe it was never balanced at all, if the PO put Slime in or a product of that kind the long set would have caused it to settle and create a heavy spot, after it sets for a while it will get thick and not want to move/spread out.

The bounce showed up when the new tire was installed a couple of weeks ago, I never noticed it at all with the old tire.

The new tire they're putting on was just ordered today - I'll have it installed next week when it comes in...

So here's the latest - took the bike to the Honda dealer today for evaluation. After a test ride by the tech confirmed the bouncing, he checked out the front tire (essentially brand new) and says there's a flat spot on the tire causing the "bouncing" of the front end around 35 mph.

However, 1) this is "perfectly normal" and 2) "it should work itself off after some unspecified amount of miles." "of course, everytime you park the bike you get a flat spot on the tire if it sits too long (like a week or two) so this may always be an issue.

SERIOUSLY? That's the answer????

Well after much back and forth the dealer - with Bridgestone's support has agreed to replace the tire- of course the dealer doesn't expect much improvement if any AND "It could even be worse"

SERIOUSLY?



Barto: It is possible to get a tire with a defect! I would take the Tech's word that there's a flat spot. This is also evidenced by Bridgestone willing to replace it. I would let that dealer's Tech install and balance the replacement. THEN, I would never set foot in that dealer's place again.
I run Bridgestones and frequently my scoot has sat for two or three weeks without moving, and I've NEVER had a tire develop a flat spot. Just doesn't happen! Keep 42 psi in them and you should never feel anthing but smoothness!

Jim

Don't put 42 psi in it. The correct pressure for the 1100's front is 36 psi.

: Oops! Guess I should put my glasses on when I read these threads! Somehow, I missed that in the title of the thrread.
Hound is correct.

My '01 ST1100 has 116,000+ miles and the front tire hasn't had one revolution with less than 42 lbs.

Jim

From the advice of the ST1100 Sages, I've always run 40 to 42 in the front tire on my 11's. At 36 it feels more like it plows than turns. BTDT. YPMV... (your pressure may vary)

Did you try the alignment procedure???? How is your sag set??? If it is wrong wobbles occur.

If your running the bt021 get rid of it they are crap.....

btw 40 in the front 42 in baxk for me...kind of tubby

Well a month after the problem showed up (right after the new tire went on) and after the STealer replaced the tire with the identical model (Bridgestone Exedra) which did nothing to alleviate the problem I think I've finally got an answer.

Despite the tech's assertion that the problem was normal and nothing to worry about I took the bike to another dealer. After a test ride the new dealer - My new dealer - said there is definitely a problem and No it is definitely NOT normal.

Dealer put the tire on the spin balancer and showed me the tire is definitely out of round. Also said that the previous dealer had very carefully balanced the tire out to "zero" which indicated that he may have known there was a problem - apparently techs usually get within about 5 grams a true balance and call it good.

Long story short - I know, too late - the new dealer has ordered a Pirelli tire to replace the Bridgestone and it will be going on this Saturday. If this solves the problem both Bridgestone - TWO bad tires in a row - and the STealership - Bald face LIES - have lost me as a customer for good.

I'll update this post once the tire's been replaced and I know the problems resolved.

Whilst Hound is quite correct regarding recommended front tyre pressure being 36lbs/psi, I have found that my bike runs better at 38..... I tried 40-42 but found that far too hard making handling 'interesting'.......

The slightly higher pressure reduced a tendency to heel toe wear on the tread blocks, commonly known as cupping. It also improved tyre life, although I can't absolutely claim that as the first tyre was a Bridgestone BT020F and the second was an Avon Storm ST55.

Some may say that 2lbs/psi doesn't sound much but it is nearly 5% high.
42 lbs/psi would be nearly 15% high and really not recommended as it will give bad squaring off of the front tyre as well as rattling your dental work.... leave that pressure to the 1300 boys.

Firstpeke said:

Whilst Hound is quite correct regarding recommended front tyre pressure being 36lbs/psi, I have found that my bike runs better at 38..... I tried 40-42 but found that far too hard making handling 'interesting'.......

The slightly higher pressure reduced a tendency to heel toe wear on the tread blocks, commonly known as cupping. It also improved tyre life, although I can't absolutely claim that as the first tyre was a Bridgestone BT020F and the second was an Avon Storm ST55.

Some may say that 2lbs/psi doesn't sound much but it is nearly 5% high.
42 lbs/psi would be nearly 15% high and really not recommended as it will give bad squaring off of the front tyre as well as rattling your dental work.... leave that pressure to the 1300 boys.

Click to expand...

Boy I wish there were hard and fast rules. I have been running 42 in my front PR2 and it has been wearing fine. I do have 100% nitrogen in it and I doubt I will bother again. I am a big guy, 6'6" and 250 ish so maybe that is why the higher pressure seams to work for me

Barto,

Re-reading this post has caught my interest again as I am currently dealing with a VERY similar set of issues on a Bridgestone Exedra front. Almost the same speed, with the same symptoms. In my case, we pulled the front wheel and rechecked the balance - good. My tech went ahead and rebalanced to make sure, but no love - problem is still evident. The major difference for me is my symptoms did not show up until a bit over 3,000 miles and it seems to be gradually growing more pronounced.

I bounced my situation off one of our resident gurus and his opinion was it sounded kinda like a belt slipping. I have contacted Two Bros and they concur with the description that a belt is a plausible cause.

I hope your Pirelli fixes the issue. In my case I will look at another Exedra as many have run these with excellent results over the years. I have run Exedra's before and had no issues, so I will probably take a chance one more time. But only once...

TNST - I'm gettin' the new tire mounted on Saturday, I'm hopeful this resolves the issue. Either way, I'll let you know.

PS: If they'll let you in the shop area you may be able to see the tire on the spin balancer. When we did that it was obvious the tire was out of round.

Well after two months and three different tires it looks like this issue is finally resolved.

Had a new Pirelli "Speed Demon" mounted on Saturday and the bounce is Gone!

I've put way more money into this bike than I thought I was going to have to - but it looks like for a while at least I'll be able to ride it someplace other than the shop. YEA!!!

Thanks to everyone who replied to this thread to try to help out. This is a Great Site and I look forward to being a part of it in the future!

Now about those farkles....