High-speed stability off our CB1100

itsme67_imp

Running like a top
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Since a few weeks I'm a happy owner of a black CB 1100 EX
and rode till now the 1500 km.

The CB runs absolutely great and makes a hell of fun. But I noticed that up to about 140km / h, the bike is great on the road, while above 160 km / h I got the impression that the CB becomes a bit unstable. I drive solo and bring with me 185m about 90 kg on the scales. Reasons could be of course the fork & shock absorber settings. But I also suspect the Dunlop D205 as a source of the problem.

How is it with you? Do you have the fork & shock absorbers adjusted differently? And maybe someone has a direct comparison of other tires with regard stability?
 
itsme67_imp said:
Since a few weeks I'm a happy owner of a black CB 1100 EX
and rode till now the 1500 km.

The CB runs absolutely great and makes a hell of fun. But I noticed that up to about 140km / h, the bike is great on the road, while above 160 km / h I got the impression that the CB becomes a bit unstable. I drive solo and bring with me 185m about 90 kg on the scales. Reasons could be of course the fork & shock absorber settings. But I also suspect the Dunlop D205 as a source of the problem.

How is it with you? Do you have the fork & shock absorbers adjusted differently? And maybe someone has a direct comparison of other tires with regard stability?
160 Km = 100MPH

I'm running stock Bridgestone tires. I have my setting front 2 lines showing and rear set on 3. I weight 170. With a bit less dive in the front comes better stability. I've had my bike well over 200Km without any issues. I do run a cut down fairing which also helps stability by adding a bit of down pressure on the front end. If you want to run speeds over 160km you have to be in a tuck or your body is like a parachute taking weight off the front end.
 
Translating from English to English:

Since a few weeks I'm a happy owner of a black CB 1100 EX
and rode till now the 932 mile.

The CB runs absolutely great and makes a hell of fun. But I noticed that up to about 87MPH, the bike is great on the road, while above 99MPH I got the impression that the CB becomes a bit unstable. I drive solo and bring with me 607ft (did you mean 185cm? 6ft tall?) about 198lb on the scales. Reasons could be of course the fork & shock absorber settings. But I also suspect the Dunlop D205 as a source of the problem.

How is it with you? Do you have the fork & shock absorbers adjusted differently? And maybe someone has a direct comparison of other tires with regard stability?
 
Perhaps a screen makes a difference. Have a Puig + and on a trip in March which included about 40 miles of interstate I kept average speed above 80mph with one run up to 92mph to pass. Bike felt steady as a train with not a hint of instability.
 
I hopped on the freeway the other day and accelerated to get in front of some cars and over to the carpool lane. I wasn't going much faster than traffic and realized I was doing over 100MPH. Bike felt fine, no screen. Made me wonder why there's a limiter on it.
 
The Dunlop tyre on mine started to wear abnormally. Honda dealer said they had problems on quite a few bikes running those tyres. I replaced it with a Pirelli sport demon and fitted a small screen. Have had the bike to 190km/h with no probs.
 
Tezza_imp said:
The Dunlop tyre on mine started to wear abnormally. Honda dealer said they had problems on quite a few bikes running those tyres. I replaced it with a Pirelli sport demon and fitted a small screen. Have had the bike to 190km/h with no probs.
Hey Tezza, the Dunlop OE tire on the front of my bike is cupping a bit at only 2,200 miles. Is that the same abnormal wear you were getting?
 
Mine came with the Bridgestones and I had it up to 105mph today on a long stretch of deserted country highway. Probably could have reached 110 if I'd stayed on it a little longer but I was satisfied. :angel: No instability issues here...
 
I really don't know where the stability problems you guys are having is coming from, but mine is solid as a rock. I have no inkling of float or loss of control and any speed. I'm creeping up on 18,000 miles here this week and about to have my second valve check done this Saturday.
 
I have the deluxe with no fairing as of right now got the comet on its way any day now. Had mine to 125mph no shake no wobble rode great wanted to get faster but ran out of road. I weigh about 150 front forks line 4 rear lowest setting. Smooth ride.
 
Pauley_imp said:
Tezza_imp said:
The Dunlop tyre on mine started to wear abnormally. Honda dealer said they had problems on quite a few bikes running those tyres. I replaced it with a Pirelli sport demon and fitted a small screen. Have had the bike to 190km/h with no probs.
Hey Tezza, the Dunlop OE tire on the front of my bike is cupping a bit at only 2,200 miles. Is that the same abnormal wear you were getting?
Hey Tezza, the Dunlop OE tire on the front of my bike is cupping a bit at only 2,200 miles. Is that the same abnormal wear you were getting?
try pumping the front tire pressure by a couple of pounds using the air gauge you normally use, say to 38 pounds and see if that doesn,t straighten it out.
 
I seem to recall one fellow dissatisfied with his CB and was going to trade it in until he tweaked the suspension a bit and completely changed the bike.

From the other responses (I don't ride mine that fast and it has been stable at all the speeds I've darned try) it appears the bike is capable of good manners so I'm thinking something is out of balance with your sample and you need to check it out. But it does sound like you can fix it cheaply.
 
I've bounced off the speed limiter a few times and the bike felt solid as a rock. Fairing on and fairing off.
 
The ferret_imp said:
Pauley_imp said:
Tezza_imp said:
The Dunlop tyre on mine started to wear abnormally. Honda dealer said they had problems on quite a few bikes running those tyres. I replaced it with a Pirelli sport demon and fitted a small screen. Have had the bike to 190km/h with no probs.
Hey Tezza, the Dunlop OE tire on the front of my bike is cupping a bit at only 2,200 miles. Is that the same abnormal wear you were getting?
Hey Tezza, the Dunlop OE tire on the front of my bike is cupping a bit at only 2,200 miles. Is that the same abnormal wear you were getting?
try pumping the front tire pressure by a couple of pounds using the air gauge you normally use, say to 38 pounds and see if that doesn,t straighten it out.
Hey Tezza, the Dunlop OE tire on the front of my bike is cupping a bit at only 2,200 miles. Is that the same abnormal wear you were getting?
try pumping the front tire pressure by a couple of pounds using the air gauge you normally use, say to 38 pounds and see if that doesn,t straighten it out.
Hi Ferret, missed this reply earlier, do you mean run 38 psi permanently? Have you experienced something like this before?
 
Pauley_imp said:
Tezza_imp said:
The Dunlop tyre on mine started to wear abnormally. Honda dealer said they had problems on quite a few bikes running those tyres. I replaced it with a Pirelli sport demon and fitted a small screen. Have had the bike to 190km/h with no probs.
Hey Tezza, the Dunlop OE tire on the front of my bike is cupping a bit at only 2,200 miles. Is that the same abnormal wear you were getting?
Hey Tezza, the Dunlop OE tire on the front of my bike is cupping a bit at only 2,200 miles. Is that the same abnormal wear you were getting?
Pauley,

I have 3800mi on my Bridgestones and there cupped. I bit more on the left then the right. Most roads are banked left to right causing the tire to wear more on the left. I started noticing it around 2500 mi. This is normal since are tires are rounded not flat. Proper inflation and change the front out at 5000mi. ( I always change both at the same time )whether there worn or not. New set of tires will get rid of road vibration too.
 
Pauley on my ST my front Michelin was starting to cup prematurely. I bumped the front tire pressure up 2 pounds to 44 (calls for 42) and within 1000 miles the cupping went away. My theory is no matter what the tire gauge said (and who knows which one is accurate? I have 3 that all read differently ..one's a pencil type, another digital, and an analog gauge) the tire was showing signs of being under inflated. So, I used the analog gauge which I normally use, and bumped it 2 pounds to 44.

Yours is already showing cupping, it's only going to get worse at current inflation poundage, try something new. What have you got to lose.

I normally get around 12-13,000 miles out of a front tire and maybe 9-11,000 miles out of a rear tire. At that point they will have about 2 /32 tread remaining. I also get 5 or 6 years out of my motorcycle batteries.

I know guys that change batteries out on their motorcycles every 2 years... just because. I don't replace until they (tires and batteries) need replacing.
 
The ferret_imp said:
Pauley_imp said:
Tezza_imp said:
The Dunlop tyre on mine started to wear abnormally. Honda dealer said they had problems on quite a few bikes running those tyres. I replaced it with a Pirelli sport demon and fitted a small screen. Have had the bike to 190km/h with no probs.
Hey Tezza, the Dunlop OE tire on the front of my bike is cupping a bit at only 2,200 miles. Is that the same abnormal wear you were getting?
Hey Tezza, the Dunlop OE tire on the front of my bike is cupping a bit at only 2,200 miles. Is that the same abnormal wear you were getting?
try pumping the front tire pressure by a couple of pounds using the air gauge you normally use, say to 38 pounds and see if that doesn,t straighten it out.
No, don't do that. Tires are designed to work properly within a certain temperature and pressure range. 36 psi is the maximum pressure for our motorcycle.

Increasing the pressure will decrease the size of the contact patch and decrease the running temperature of the tire.

Traction is dependent on the size of the contact patch and the temperature of the rubber compound. So, you will reduce available traction by increasing the pressure beyond the recommended amount.

For example, when we take a motorcycle to the racetrack for a track day or school, we always decrease the tire pressure to allow for the increased pressure buildup in the tire due to the high speeds creating more heat than we would get on the street. See this link:

Frequently Asked Questions (FAQs) | Dunlop Motorcycle Race Tires

The same is true for automobile tires. I had an educational experience with this last week; I increased the tire pressures in my high-performance sedan to get a bit better mileage. When I hot-footed it around a traffic circle I'd gone around many times before without issue, the rear tires broke loose, and this is with a front-wheel drive car where you'd normally get understeer. I was running 40 psi instead of the recommended 35. Mistake.

Fortunately I was driving a car and not riding a motorcycle where the loss of control would have likely been a lot worse than just getting sideways.

36 psi is at the top of the normal safe range for the CB1100; we can actually go a bit lower if the load on the bike is less than maximum. I run my front tire at 34 and the rear at 36 for mixed conditions of freeway and backroads. I run my sportbikes at 32 front/34.5 rear on the street, whereas at the track, especially if it's cold, I might bring them down to 29 front/28 rear.

If your bike is truly unstable you'd be better off finding out the real cause rather than trying home-brewed solutions that can create problems rather than solve them. If you just add a couple of psi to the front tire and then go out and test it again by running it up to 160 kph, if you've made things worse or have to suddenly turn or stop the bike, you might not have a stability problem, you just may have a problem with your medical insurance.

Any good technician will recommend that you:

- check the tire balance on a machine
- check the steering head bearings
- check the suspension settings
- check weight and loading
- check for a defective tire/wheel/wheel bearings
- checkup from the neck up because why are you going 160 kph?

OK, that last was a joke but seriously, get your bike looked over; I've run mine up to 110 mph and didn't experience anything that I wouldn't have expected given it's not a racebike. Maybe there's an issue with yours that needs to be corrected.
CIP57_imp said:
Pauley_imp said:
Tezza_imp said:
The Dunlop tyre on mine started to wear abnormally. Honda dealer said they had problems on quite a few bikes running those tyres. I replaced it with a Pirelli sport demon and fitted a small screen. Have had the bike to 190km/h with no probs.
Hey Tezza, the Dunlop OE tire on the front of my bike is cupping a bit at only 2,200 miles. Is that the same abnormal wear you were getting?
Hey Tezza, the Dunlop OE tire on the front of my bike is cupping a bit at only 2,200 miles. Is that the same abnormal wear you were getting?
Pauley,

I have 3800mi on my Bridgestones and there cupped. I bit more on the left then the right. Most roads are banked left to right causing the tire to wear more on the left. I started noticing it around 2500 mi. This is normal since are tires are rounded not flat. Proper inflation and change the front out at 5000mi. ( I always change both at the same time )whether there worn or not. New set of tires will get rid of road vibration too.
Good advice. I had cupping on my Dunlops. Some tire/bike combinations just do this. Normally it can be corrected by going to a different brand/type of tire. Exceeding recommended pressure is verboten. As I mentioned a while back, I went to the bias-ply Bridgestones, running the 150/70 rear. Absolutely no issues, no cupping, no problems. 34F/36R for standard weight (160 pound) rider.

Also, it should go without saying that you want to confirm the accuracy of your pressure gage. Digital gages are not any more accurate than analog gages, since digital gage uses an analog transducer anyway and the output is simply converted to a digital display. But find a good reference gage that is known to be correct and use that for checking your accuracy.
 
Red Mist just very eloquently and in much more detail said what I was about to say.

Don't 'home brew' solutions, just get it sorted by a pro.
 
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