Jumpy front end

I have just completed a 1981 xj650 I purchased 5 years ago, the front of the bike feels like you are on a bumpy road a lot of the time when on tarmac. I have replaced the fork oil with the correct weight and amount and replaced the front tyre. I have not ridden an old bike for a long time so maybe this is normal for the suspension of the time.

 

did you replace the fork seals?
which weight oil did you use?

check spring length for wear?

 

Fork seals good middle weight oil haven't checked Spring length I thought it would be OK as the bike has only done 16000 miles

 

look close at the tire bead/rim make sure it's seated all the way around

 

Medium weight shock oil of which brand? What weight specifically? The actual viscosity varies from brand to brand.

 

I'm with Polock--check the tire. Also, did you balance the tire when you installed it?

 

Fork oil was Putoline sae10w, the beed of the tyre is perfect right around the rim on both sides and the tyre was balanced. I thought the new metzeler tyre would cure this issue but it is exactly the same symptoms as the old tyre.

 

I'll have to admit that my 85 XJ700 isn't as smooth as my 2004 Honda Aero. They are about the same weight but the Aero has larger tires, especially on the front. I run about the same air pressure in both front tires so I suspect that it is normal for the smaller tire to be a little rougher. Also, when I got my bike the front suspension was pretty soft, even after a shop supposedly changed the seals and oil to stop a leak. When the leak didn't stop I decided to replace the seals myself and found very little and very dirty oil in both forks, even the one that wasn't leaking. After cleaning everything, replacing the seals and installing the proper amount and type of oil the leak went away and the front end is much stiffer. Any chance you put in too much oil?

 

I wish it was that simple it is exact amount to the cc. I thought the new oil might do the trick as the old oil was grim but no.

 

Then unless something is loose in the front end you are probably ok. Like I said, my XJ is not as smooth as my 2004 Honda with the bigger front tire.

 

10W is a bit on the thin side for the weight of the bike and an American rider. Most of us find that 15W is a better choice.

 

you could lift the front wheel and see if it runs true.
are you used to riding a bike with radial tires?

 

The wheel looks true when spun and Kmoe it is carrying a Scottish rider not an American one, pretty sure it will still wobble with an American rider. It looks like everything possible has been suggested, the bike is ok on a smooth road but a bit different on anything that ain't as smooth as a baby's butt. Cheers all for the suggestions

 

there's bushings in the forks that are lined with some sort of plastic. if the plastic were to wear off i could see the forks having extra static friction
sometimes you can flip the bushings to get some extra life from them
contact chacal for availability

 

just looked, yours may not have them, nevermind

 

My 82 maxim 750 had a very similar problem. Turned out to be it was the steering head bolt was a little loose. Just a thought