Handling problems...

[gearhead13]

My bike (in sig) has fairly old spitfires on it. I know they need changing, trying to gather up the cash for new rubber. When i try to take a corner at high speed the bike doesnt want to lean into the turn. It will lean so far then nothing and I have to hit the brakes to stay on the road Otherwise it just drifts to the outside. Is there any suspension tuning that could help this, like stiffen the front end or rear end? I am at a lost for tuning the handling of bikes, and this has scared me a few times. I think new rubber is going to help, but I can't see it being just the tires. They are not visually worn out, but manufactured about 6 years ago.
Any help/ideas greatly appreciated

 

[BassCliff]

Hi Mr. gearhead13,

Suspension upgrades/replacements can help a lot; Progressive springs in the front and new shocks in the back. How are your fork bearings and swingarm bearings? Do you counter-steer? Do you lean your upper body into the turn? Check out this thread... CLICK HERE.


Thank you for your indulgence,

BassCliff

 

[gearhead13]

I think I lean into curves properly, nobody has ever commented on my body position. I think I am leaning the right way, I even stick my leg out into the turn. My bike kinda hits a 'wall' where it just wont lean over any more. Nothing ever drags on the ground. Could the profiles of my tires be doing this? I can feel a little play in my steering head bearings that I should fix. What do you mean by fork bearings? I have tried to move my rear wheel side to side while on the center stand and I cant feel any play.
BTW by high speed I mean 150 km/h in an 80 km/h zone close to double speed limit.

 

[nisom512]

I think I lean into curves properly, nobody has ever commented on my body position. I think I am leaning the right way, I even stick my leg out into the turn. My bike kinda hits a 'wall' where it just wont lean over any more. Nothing ever drags on the ground. Could the profiles of my tires be doing this? I can feel a little play in my steering head bearings that I should fix. What do you mean by fork bearings? I have tried to move my rear wheel side to side while on the center stand and I cant feel any play.
BTW by high speed I mean 150 km/h in an 80 km/h zone close to double speed limit.

I would be careful going that fast. but you didnt tell bass if you counter steer cause that is a make or break move right there.

 

[Guest]

Not sure how you can defy gravity.
Check the air in the forks for even air pressure. Could be bent forks or even bad swing arm bearings.
How flat are the center of the treads? Lots of highway miles?

 

[yaddy]

most likely to be a soft front end imo, GS's are known to be a bit soft upfront as standard and 30 years (ish) can take it's toll on standard suspension if not serviced correctly. A set of soft forks when cornering would cause the bike to push down on the front which in turn, tries to stand the bike upright, making you run wide.
There are many other possibilities that could cause this too, not least of all, your own riding style. Braking while trying to lean makes the bike reluctant to peel into the corner, quickly releasing the brakes will make the forks bounce up suddenly, again making the bike want to sit up. Under-inflated tyres would make the bike reluctant to turn also.

Sounds like your bikes setup wants a good coat of looking at, just beware that you won't ever get a decent setup if your tyres are on the way out. Trying to compensate for bad tyres with suspension changes is not the best way to do things, especially at higher speeds. Read the many threads on suspension setups and tuning for more detailed info, i'll bet that all though, assume you have a decent baseline setting, ie: a bike with decent tyres, serviced suspension and adequate brakes.

 

[gearhead13]

As I said there is little visible wear, even on the rear, in the middle, I really dont know how, with all the extra snort this thing has. These spitfires are fairly hard tires from what i hear
Countersteering? as in putting pressure on the bars the opposite way than if you were going slow? For sure, I am trying to teach my wife that right now. Maybe its technique or bike setup or tires? Or some of all three
I dont have a digital pressure gauge or hand pump for the forks, they are on my list.

 

[BassCliff]

What do you mean by fork bearings?

Sorry, wrong terminology. Yes, I meant the steering bearings. Pardon me while I pull my foot out of my mouth.


Thank you for your indulgence,

BassCliff

 

[gearhead13]

Sorry, wrong terminology. Yes, I meant the steering bearings. Pardon me while I pull my foot out of my mouth.


Thank you for your indulgence,

BassCliff

Yes i guess I need to tighten them. Can it be done without 'special' tools?
what air pressure should the front forks have?

 

[duaneage]

Get the tire off the front and the forks in the air. If you feel any catching when you slowly turn the bars then the bearings in the head are bad. This can cause pits to form that could hinder movement. This is not safe obviously and should be repaired.

Make sure the wires and cables are not binding or being trapped in the triple tree when it goes side to side.

is the triple tree damaged or bent? This can cause handling to favor one direction over the other.Check the steering stem as well for true as a bent steering stem can cause the bearings to bind.

To replace the set search this forum for methods used, there are few threads for it. I use Park bicycle grease in the head bearings since it has good properties. The adjustment is made by using a tool for adjusting headsets on bicycles, it has a hook to catch the nut with. Adjust for no play with smooth operation. For roller bearings they should have a slight amount of drag.

Convert to roller bearings for longer life and better operation. This requires pressing the new bearing onto the lower triple tree at a shop but it is worth it.

 

[Steve]

My bike has fairly old spitfires on it. ... When i try to take a corner at high speed the bike doesnt want to lean into the turn. ... it just drifts to the outside. Is there any suspension tuning that could help this, ... this has scared me a few times. Any help/ideas greatly appreciated

I think I lean into curves properly, nobody has ever commented on my body position. I think I am leaning the right way, I even stick my leg out into the turn. ... Could the profiles of my tires be doing this? I can feel a little play in my steering head bearings that I should fix. ... BTW by high speed I mean 150 km/h in an 80 km/h zone close to double speed limit.

I would be careful going that fast. but you didnt tell bass if you counter steer cause that is a make or break move right there.

Countersteering? as in putting pressure on the bars the opposite way than if you were going slow? For sure, I am trying to teach my wife that right now. Maybe its technique ...

WOW.

Hard, old tires.
Loose steering bearings.
Not sure whether you are counter-steering, yet teaching it to your wife.
Yet willingly running up to 150 kph (about 95 mph).

Not gonna preach here, but I think the only adjustment necessary would be to the nut that holds the handlebars.

Bikes don't lean into curves. You don't lean into a curve. Because the two wheels act as pretty good gyroscopes, your bike really wants to go straight. You have to turn it into a curve. Above about 5 mph, you will use counter-steering. Just remember PUSH LEFT, GO LEFT. When you push on the left handgrip (it makes the whole handlebar/fork/wheel assembly turn to the right), you will move the bike's point of support to the right, making it lean to the left. If you are not turning hard enough for your curve, push harder on the handgrip. Practice this in an empty parking lot at about 20 mph, get comfortable with the concept. Move on out to a lesser-traveled highway, keep practicing until you get really comfortable. Eventually, it will become second nature.

By the way, EVERYBODY who has successfully negotiated a curve in the road has used counter-steering. They might not recognize it by those terms, but they do it.

And thanks for the warning about your preferred travelling speed. If I ever make it out to BC, I'll keep a good look in the mirror so I don't get in your way. ray:

.

 

[gearhead13]

ok, ok ya I guess I had that coming. LOL
I wasnt sure of the terminology, but I do countersteer (of course) and I understand how it works. I conciously practice it in corners. I just dont do high speed corners all the time to practice it. The two or three times I did, it scared the crap out of me and I want to get better at it.
I guess I am kind of a nut, I can admit. But I am a nut that doesnt want to end up as pavement pizza.
I was riding one time and the handling problem was worse, so I pulled over for a while and softened the damping and preload in the rear and it helped greatly. So I am thinking that I may need to firm up the front end to help. Along with other things Like steering head bearings, tires, front fork air pressure etc.
Too much time on the engine making it faster and not enough on other stuff

 

[Guest]

ok, ok ya I guess I had that coming. LOL
I wasnt sure of the terminology, but I do countersteer (of course) and I understand how it works. I conciously practice it in corners. I just dont do high speed corners all the time to practice it. The two or three times I did, it scared the crap out of me and I want to get better at it.
I guess I am kind of a nut, I can admit. But I am a nut that doesnt want to end up as pavement pizza.
I was riding one time and the handling problem was worse, so I pulled over for a while and softened the damping and preload in the rear and it helped greatly. So I am thinking that I may need to firm up the front end to help. Along with other things Like steering head bearings, tires, front fork air pressure etc.
Too much time on the engine making it faster and not enough on other stuff

I'm rolling around on an L model pushing 150HP so you're not crazy. I can throw that thing through the corners though.

 

[Steve]

Too much time on the engine making it faster and not enough on other stuff

That was a problem with lots of old-time hot-rodders, too. Too much GO, not enough WHOA.

You don't necessarily have to practice on high speed corners all the time, either. Just practice on the corners you encounter every day. Get better at them, then move on to the next set of corners.

There's just something that scares me reading about someone who isn't comfortable taking corners at high speed, but trying to do it anyway. ANY curve on a public highway that is taken at almost 100 mph can be scary. Best to reserve those kinds of speeds for the race track. Besides, on a track, you get to practice that same corner lap after lap after lap until you get good at it. Consider looking up a track in your area to see if they have "track days".

.

 

[gearhead13]

That was a problem with lots of old-time hot-rodders, too. Too much GO, not enough WHOA.

You don't necessarily have to practice on high speed corners all the time, either. Just practice on the corners you encounter every day. Get better at them, then move on to the next set of corners.

There's just something that scares me reading about someone who isn't comfortable taking corners at high speed, but trying to do it anyway. ANY curve on a public highway that is taken at almost 100 mph can be scary. Best to reserve those kinds of speeds for the race track. Besides, on a track, you get to practice that same corner lap after lap after lap until you get good at it. Consider looking up a track in your area to see if they have "track days".

.

Ya, no road courses here. Just a roundyround, and an 1/8th mile. I am really looking forward to taking it to the drag strip.
I just realized I have no idea of what tire pressures are on the bike. This is the biggest bike I have ever had. My old Yamaha 400 didnt have enough power to get me into trouble.

 

[Guest]

I run Spitfires and love 'em.Have you checked your pressures? I run 34 psi front and 38 in the rear (add a couple of psi if you regularly carry a pillion) and have only noticed any abnormal handling if I get a bit slack about checking pressures.As has been said-checking ,adjusting or replacing bearings should become a regular part of keeping these magnificent old beasties on the road and keeping them reliable.Cheers,Simon.

 

[terbang]

We all countersteer, whether we know it or not. I had a beat up old trail bike and (just for a laugh) mounted a set of handle bars directly onto the frame above the existing ones (welded them there). Five mins on that machine rapidly showed people that it is all countersteer as you just could barely get the thing to turn when hanging onto the upper (fixed) bars. Converted even the stauncest of coutersteer naysayers...
Lean angle limits generally are (1) Bike ground clearance (2) tyre limits (you loose it) (3) Whats between your ears. Item three being very common as Ive seen guys go off the edge, on good tyres, with no ground clearance issues. It was all between their ears.
If your bike is still understeering with all the tyres and steering sorted then you need to have a look at your springing as a lowering of the rear end will slow your turn in down, or paerhaps you are too pumped up in the front. Raising the back or lowering the front will decrease trail and the bike will turn in much quicker. Do a static sag check on the bike and get that springing sorted first...

 

[82Shafty]

I think I lean into curves properly, nobody has ever commented on my body position. I think I am leaning the right way, I even stick my leg out into the turn. My bike kinda hits a 'wall' where it just wont lean over any more. Nothing ever drags on the ground. Could the profiles of my tires be doing this? I can feel a little play in my steering head bearings that I should fix. What do you mean by fork bearings? I have tried to move my rear wheel side to side while on the center stand and I cant feel any play.
BTW by high speed I mean 150 km/h in an 80 km/h zone close to double speed limit.

http://www.thegsresources.com/_forum/showthread.php?t=139774

Look at the pictures. You may discover your problem.

 

[reddirtrider]

There is nothing that will keep a bike upright in a corner, just the rider. It sounds as if you are mentally avoiding going deeper into the turn. Sticking your leg out and putting on the brakes are classic symptoms. Use countersteering and LOOK thru the corner, not at the side of the road. You'll go where you look. If you're avoiding a turn, you won't make it.

Now, having said that, get new tires and check the other mechanical issues these good folks have laid out for you. They're not your problem, but they're necessary for safety.

 

[curseboy]

If your forks are way up or way down on the triple trees, the same symptoms you described could happen, don't ask me how I know
Sounds like you have more issues, maybe you should have someone sort out your bike for you, someone who knows.