Slow Corning < Fast Cornering

[ajacstern]

Hi All,

When I first got my FJ1200 a year ago, the first thing I noticed (after getting over the insane engine and torque) was its heavy pig handling. In slow speeds its great, falls right into corners and is very maneuverable (so long as you don't have to try and walk it backwards up an incline). But by the time I get to 60, even to do a lane change I am putting all my weight onto the end of the bars and barely getting the bike to turn. A bit of an exaggeration, but still once you get any speed above 30 it barely turns in, I don't expect it to be as twitchy as dirt / sport bikes but it is almost dangerously slow turn in. New tires, head bearings, forks rebuilt, proper tire pressures, the handling is much improved from when I got it but it is still much to slow turning in for my tastes.

I am on the 16" front wheel and looking to move to the 17", but has anyone found good solutions for faster turn in with the stock FJ forks? I can't raise them up any higher without the seals hitting the triple trees on bottom out. Trying to decide whether I want to go with 88+ front forks or a GSXR/YZF/R1 front end swap. The latter is very expensive, (more than these bikes are worth unfortunately) but if the 88+ FJ forks still have very slow turn in then I am not so interested in that front end swap.

Cheers! 

[Sparky84]

Have a read of this

http://www.fjowners.com/index.php?topic=12381.0

[Pat Conlon]

The oem 16" front rim with the dual faced vented rotors, and the 120/80 bias ply tire is a heavy combination. By contrast, the '88+ 3 spoke 17" rim, single faced rotors and 120/70 radial tire is lighter. Several pounds lighter. I noticed a distinct ease on turn in when i converted my '84 over to the lighter 17" rim/tire combo.
The gyroscopic effect of a heavy rim/rotor/tire is real.

The oem FJ shock was weak when it left the factory, now even more so 35 years later.
Replace your shock with a new height adjustable shock. (Hagon, Penske, etc)  Raise the back end up.
Get more weight on the front tire. You will be happy with the results.

[Millietant]

I know all things are relative but I've never found (nor to I know) anyone who has described their FJ steering as badly as you do.

The 16" front wheel FJ's if anything are a little more twitchy and quicker to turn in initially than the later 17" front wheel models, but I did find it felt a little "heavier" on the front than my later 17" wheel model. A touch of counter-steering should be all you need to get a FJ to initiate a turn at any speed.

My first port of call to resolve the poor steering would be to do the things you've already done (tyres and pressures and maybe (just maybe as you say it's ok at lower speeds) steering head bearings....etc). So I'm at a bit of a loss as to what could be causing such a reluctance - although you don't say if it's the same problem specifically on only left turns, right turns or both. Have you had the wheel alignment checked? And just maybe, are the the frame and forks straight?

What tyre brand and sizes are you using, this might possbly have an effect also ??

As Sparky has pointed out, rather than pushing the forks through the yokes (which gives less cornering clearance) to quicken the steering, I'd go the way of slightly shorter dog bones to raise the rear ride height and steepen the steering head angle slightly.

Quite a few FJ's have been successfully raced so I'm sure there's nothing inherently wrong with the steering, but at the extreme I know one multi-championship winning FJ had its steering head cut out and repositioned at a slghtly steeper angle - but this was done after a host of other tweaks and an a one putting out +160bhp at the back wheel, and it was done just as an experiment rather than out of necessity (just to see how it worked and if it did indeed give any real gains in lap times.

I've done the FZR 1000 USD front end and 3.5" front and 5" rear wheel conversions and with modern radial tyre's, the steering feels miles better than standard, but only because it's more linear/predictable when turning in, not because it's particularly any quicker or lighter steering.

Personally, I think the cost of my front end conversion (around $500) was worth every penny, but I've had my bike for almost 32 years and absolutely love it, so am happy spending a bit on it to bring it bit more into the modern world.

[krusty]

My immediate thought from what you described is the tyres. I sounded exactly the same problem as a fellow VJMC member was having with his 1200. On a club ride we swapped bikes (I was also on a 1200) and my experience was as you described, particularly when going through roundabouts. We stopped after a few miles and when I checked the tyre pressures they were way down. Inflating them to correct pressure solved the proble. Another thing could be the age of the front tyre.
I ride both an 1100 and a 1200 with no steering problems at all, very lttle difference between them except the 1100 is a little more nimble than the 1200. Neither have heavy steering. My 1100 has '88, 1200 forks but retains the 16" wheel. There should be no need for raising the forks into the triple tree at all.  Regardless of the amount of tread your tyres have check their age!

[yamaha fj rider]

The oem FJ shock was weak when it left the factory, now even more so 35 years later.
Replace your shock with a new height adjustable shock. (Hagon, Penske, etc)  Raise the back end up.
Get more weight on the front tire. You will be happy with the results.

Plus 1
Raising the back of my 93 made a huge difference.

Best wishes

Kurt

[ribbert]

The oem FJ shock was weak when it left the factory, now even more so 35 years later.
Replace your shock with a new height adjustable shock. (Hagon, Penske, etc)  Raise the back end up.
Get more weight on the front tire. You will be happy with the results.

Plus 1
Raising the back of my 93 made a huge difference.

Best wishes

Kurt

Yes it does, I've told of my experience with this many times here over the years. My FJ handles better and is easier to ride in the twisties than my BMW and that's saying something. Nimbleness is the one quality the BMW's are renowned for having over FJR's, GTR's and all the other big sports tourers.

Noel

[andyoutandabout]

Somethings up for sure with your bike.
Unless you're having a technique issue.
I'd swap Fjs with someone and race them round the block.
Every Fj I've had a go on, pretty much felt like an Fj. Sure when you get going, those who have new suspension or upgraded brakes start to make themselves noticed.
Anyway, do that and you won't even have to lift a spanner.

[gumby302ho]

 I would go over everythng and re-check steering stem play. Should be smooth from lock to lock. Never heard an FJ described in this way. Plus 2 on raising the rear and it will be even easier to put up on the center stand!!

[Pat Conlon]

Several years ago I noticed a strange quirk on my FJ. My bike would tip in very easy into left hand corners and track very stable thru the corner,  yet on right hand corners, i seemed to struggle getting the bike over and once over had trouble holding a line.  I thought to myself...Shit, I really need some practice, I'm getting rusty.

Turns out, my back tire was crooked in the swing arm. I had miscounted the index marks when I was setting the chain tension. I was off 1 whole index mark with the back tire pointing to the left. Stupid mistake.
No wonder right hand turns were harder....

[ajacstern]

Thanks for all the replies!

Some information I should have included, I am running Avon Roadrider's, 38/42. They have about 2000 miles on them, the rear is a bit worn in the middle but not the point cornering should be effected significantly. Front has perfect tire wear. I do not have enough traction to get the rear wheel in the air under braking no matter what I do. Loud tire screech with enough time to save it is all I get under maximum braking. Not as much traction as I was hoping for but they seem to be wearing quite well.

I moved the front tire pressure up to 40 and that did seem to have a marginal improvement. I can turn in at 50 now, 60 and up is still slow and very heavy but that might be the way a touring-ish bike is supposed to be. Sadly I do not know anyone else with an FJ nor have I ever seen another one on the road in my state so no way to test out a different one. One FJR though, guy was coming to a stop by grinding his loafers against the ground so I didn't stop and chat with him haha.

Headbearings are in excellent condition with fresh grease, I was really surprised that the bearings and races were completely perfect. No notchiness in the steering or anything. Tension is correct to factory manual and play feels right. Chain is aligned correctly (I use an alignment tool, the marks on the swingarm are typically off).

I like all of the suggestions of raising the rear, sounds like a good option for quicker turn in and it would improve the look of the bike (especially with a fender eliminator). I have a 1987 and I think I remember reading somewhere we have a different dog bone setup than the later bikes. Is the best option to modify the existing dog bone (and replace the shock with stock height) or replace the shock with something slightly taller? I don't have access to machine shop tools so I would be paying someone to modify the dogbones.

With the suspension overall, I could probably put a new shock + 88+ front end on or I could do a USD conversion and stick with the stock shock. I would like to go FZR upgrade route for USD but haven't been able to find one yet. 07/08 GSXR USD is my next favorite, but I would lose the speedo or have to figure out a GPS route. I want to keep the stock gauge faces. Not sure which way I want to go yet.

Alternatively forget the suspension and make 200hp...Will finally be able to power wheelie.

Cheers!

[Old Rider]

Have you measured the sag ?  what are your preload settings front and rear? My experience is that with a well balanced suspension setup the fj turns into corners just by looking thru the corner.
Maybe you have to much preload in front  running high

[krusty]

There is something wrong with the way your bike is handling that will not be cured by raising the rear. The front needs to be sorted before you go down that path.
How old are the tyres?

[Old Rider]

Just posting some pics if you not familiar with measuring the sag and adjusting the fork settings.

[Motofun]

I set dynamic sag on my race bikes at 27mm.  Street bikes at 35mm.  Dynamic sag is from fully extended (ie wheel off the ground) to bike + rider + gear + full tank of fuel.  Just a starting point but if you have a fully adjustable suspension then compression and rebound can be tweeked as needed.