Unstable rear end

Hi, I have just bought a 1997 vfr 750 with 57,000 on it. I have not had a bike for 15 years and have very limited experience.. Love the bike to bits but I am worried about the handling. On slow tight left hand bends the rear wheel skips out/looses grip very easily, not going too fast and tyre pressures are correct. I fitted Hyperpro lowering triangles when I got the bike and have not ridden it without them fitted (35mm drop)
Have set front and rear preload and rear rebound damping to standard. Tyres are 020`s

 

It sounds like you need go up a couple of clicks on your rear shock. Making it stiffer that, and increase your preload adjustmant with a screwdriver on the said shock.

 

Rear preload and rebound damping were set higher when I got the bike and it was doing it then..I reset to standard settings to try and cure the problem but has made no difference...

 

Hmm I've had great confidence with Bridgestone BT 021's and 022's on my VFR but never tried a 020 so can't really comment. However I found the following on the interweb which might be pertinent - I would draw your attention to the second sentence!!!! Precisely what they mean is far from clear. But it sounds like the previous owners choice of tyre may not be to your liking. I assume you have checked the pressures, tread depth and AGE of those tyres were OK as the 020's have been on sale for over a decade.

"Bridgestone Battlax BT 020 Sport Touring

The Bridgestone Battlax BT 020 was redesigned in 2003 and offers you much higher levels of comfort, exceptional grip and good levels of stability for bikes ridden at high speeds. We recommend these tyres to buy if you enjoy making slides on your bike, as they will manage what some other makes wouldn’t. Bridgestone have given the BT 020s a tread depth that is extra deep to ensure that you can get the best mileage possible from the tyre. The grip of the 020 will be as effective in wet weather as it is in dry weather and the fact that this tyre is also great value for money means we highly recommend it to tyre to buy as it is suitable for an extensive range of bikes"



SkiMad

 

There are two things on VFR's that many have said could stand improvement.

1. The charging system is sometimes less than adequate and they tend to burn out regualtor/rectifiers. Most owners seem to experience this at some point in their ownership.

2. The rear suspension, particularly the rear shock and spring could stand an upgrade. For the most part I have heard it said that the stock shock on the VFR on the 3 through 6th generation is sprung on the soft side.

My last bike (a 97 VFR750) and my current bike both exhibited marked improvement in ride quality after swapping out the rear suspension for something a little stiffer. My 97 VFR's shock was rebuilt and a stiffer spring was added and on my 2000 VFR (current bike) I ordered ann upgraded shock from Jamie D. at Daugherty Motorsports. Jamie is a member of this site and he has a business that does upgrades to the rear shock on VFR's and he is somewhat of an expert in this area to say the least. I think the shock he uses for upgrades on the 4th gen bikes (94-97) is sourced from a CBR600 and he builds the shock to suit you and your particular riding style, and if I can offer my experience, he does an amazing job. Even if you don't buy a shock from him, I'm sure he would be able to offer a lot of information on any question you may have regarding your bikes handling.

Check out his website at Daugherty Motorsports - Motorcycle Suspension Performance and Modification.

Hope you get things all worked out, enjoy the bike and Welcome to the site.

 

Tyre pressures were 30 front and rear when I got the bike..have changed them to 36 front and 42 rear..makes me wonder if the previous owner had the same problem so tried a lower pressure on the rear... Tread is barely worn, like new...will ckeck date on them tomorrow..

 

I have an 020 on the rear of my bike no problems...wonder if you need to set the spring even stiffer then it was originally??? Softening apparently hasn't helped. Just a suggestion.

:unsure:

 

Take a hard look at the bearings & pivot point.

 

New tires new shock she will be as good as new......What is your weight?
The shock can be shot from previous owner riding style

 

Not sure about why it is only doing it in left hand turns...but 57000 miles on a stock shock should be a hint. Your shock is well past it's life expectancy. You won't be able to adequately troubleshoot handling or grip issues until all of the suspension components are up to snuff. Start with a linkage and swingarm pivot inspection, my guess is that the bearings and bushings have never been serviced. If you try to pull the swingarm pivot and it won't pull out easily, you have more than one issue requiring attention.

 

Is there a way to check the swingarm pivot without pulling it apart? Also does anyone know a place that can service the rear shock, or is replacement the only option?
I don't think the previous owner was into maintenance that much as the front sprocket is very worn and so needs replacing. And one of the mounting lugs for the sprocket cover is broken off... Think I will give it a good strip down and change all the bearings etc this winter as I bought the bike for a trip to Spain next year..

 

Just been over and checked my tyres, date is 2008... Wear looks a bit funny to me, bit of a sort of raised flat centre section on rear tyre( centre 2 inches) front tyre also looks more worn on right side with bumpy tread on that side..

 

Get it up on the centerstand and push/pull the rear wheel sideways to check for looseness or play. Grab wheel at top and bottom, pushing and pulling to check for play in hub bearings.

 

Been to the garage today and gave it a good pull and a shake, no movement at all...I am an MOT tester and used to looking for play and wear in vehicles....going to try a new tyre on the back first of all as the one that is on there has quite a pronounced flat section in the middle of the tread pattern....

 

I'm betting the shock linkage bearings may be in serious need of lube or replacement.

 

More than likely it is the tire. But is it possible you are getting chain lube on your tire somehow?

 

MY moneys on the tire, knowing the condition it is in...speaking of which, what kind of shape is the front tire in?

 

How much do you weigh?

 

Front tyre has loads of tread left but the tread pattern on the right side looks a little feathered/bumpy,also slightly flat in the middle...

 

I weigh about 175 kg/ 12 stone