OK, here's one for ya to ponder....

[slyone]

I just got this bike and started riding 2 weeks...been about 25 yrs. since
when I'm going maybe 30-40mph It feels like the front tire is out of round and the front end is bouncing? The tire appears to be round and the front end tubes were just resealed and gone thru at a dealership within the past year.
any ideas? 79'GS850...the front is a Dunlop Goldseal F11 at 30psi and the rear is some cheng somebody at 35psi.

[tkent02]

How old are these tires?

[sedelen]

How to determine the age of your tires.

http://www.youtube.com/watch?v=JM37mo9p90k

[slyone]

front is 402 and rear is 395. It almost seems like the outer portion of both sides of front tire is chopped? could that be possible?

[azr]

Your bike came stock with air adjustable front forks. Have you checked to see what the pressure is? can't exactly remember what the manual says but it's somewhere between 10-17. If the air pressure is ok it could be that some of your fork oil has leaked out or needs changing. Or..just the simple fact your fork springs are 33 years old and need replacing.

[slyone]

Your bike came stock with air adjustable front forks. Have you checked to see what the pressure is? can't exactly remember what the manual says but it's somewhere between 10-17. If the air pressure is ok it could be that some of your fork oil has leaked out or needs changing. Or..just the simple fact your fork springs are 33 years old and need replacing.

wow that is so funny...I was going to ask that question of air in forks cause I thought I read it somewhere but then thought..naw..impossible!lol.. front end just gone thru so maybe the air pressure is wrong?

[sedelen]

front is 402 and rear is 395. It almost seems like the outer portion of both sides of front tire is chopped? could that be possible?

Looks like the newest it could be would be the 40 week of 2012 for the front, but more likely the 40 week of 2002.
And for the rear, the newest it could be would be the 39th week of 2005.
I think you need new tires, ever have a blow-out? I have at 70mph on the rear of Honda 450 with a passenger on the back. I thought for sure I was a gonner.

[azr]

What exactly was 'gone through' on the front end?

[tkent02]

Those tires were unsafe a decade ago. They were made in 1992 and 1995.

[slyone]

What exactly was 'gone through' on the front end?

They put new seals and those rubber cups, not sure what else? Bill was just over $400.00. Oh great, so now I should get new tires too! I don't see any cracking or dry rot...

[azr]

uummmm....."they"?? Just for your info, a new set of OEM seals are around $15 and the caps are worth about the same. So that's $30, takes maybe an hour to put them in. A brand new pair of Progressive fork springs (which is what the high majority of us GS guys put in) cost about $70. Putting those in would be included in the hour, maybe and hour and a half labor at the most. New fork seals and dust covers with new Progressive fork springs and you have a newly rebuilt front suspension that doesn't require air in the forks (the progressive are stiff enough to eliminate the need for air). If it were me I would want to know 'exactly' what they did for my $400, but that's me. About your tires, there may be no cracks but from the date numbers you put up the front tire was made in the 40 week of the year 1972, 1982 or 1992. The rear tire was made in the 39 week of the year 1975, 1985 or 1995. That makes, at best, those tires are over 17 years old...YIKES.

[slyone]

where's a good place to get tires?

[Crankthat]

For tires I would start with searching tire threads to determine the type of tire you want then mabye ask around on forum who bought that type recent from where at what price.

You will find some posts on price, tire life, handling, and other factors that will help you choose the tire for the type of riding you plan on doing.

You do need new tires no doubt about that, but I would put the bike on the center stand or a bike jack if you have one and rotate and look/feel if that is what is causing your problem.

If the brake is catching you may have a warped disk, Remove from bike and lay on flat glass and check shape.( A large glass mirror works well for this)

While rotating rear tire is there a catch? You will have to determine if coming from break, a kinked chain, misaligned chain,(bounce when hopping on edge of sprocket)

Have seen pictures of bad steering bearings think that might cause problems too, try turning bars with front on the ground and off.

Might also try bouncing front suspension up and down while sitting on bike with front brake pulled in, are there areas in travel that don,t move smooth? Maybe they made a mistake while changing seals.

I hope it is just the tires as they need to be replaced regardless, but here are some more ideas to check to help determine if that is what is causing the jumping. Something more to do while waiting for new rubber.

Don't know what the cost to mount rubber runs near you, or if you will do it yourself?

My local shop charges twice as much if the tires are still attached to bike.

I bought a bike jack and it was within $15. of paying for itself the on the savings for two rubber mounts.

And if you decide to mount them yourself you might save what you paid for jack depending on what your local shops charge.

Well worth looking into.

I bought my jack at sears, they had two models. Wish i had spent the extra $20. and bought the yellow one as it would have been a lot lighter to move around and has a better design for kickstands.

I

[azr]

Motorcycle Superstore has a good reputation and always seems to have decent prices and free shipping. Did you figure out what 'exactly' was done to your front end?

[slyone]

Motorcycle Superstore has a good reputation and always seems to have decent prices and free shipping. Did you figure out what 'exactly' was done to your front end?

no doubt po got ripped...what else is new! I haven't read invoice mtself but new seals, boots, upper tree clamp bolts and some kinda "bushings" but no springs.
Checked front end and tire/wheel runout which seems great. Guess I'll let that one go for now since it is sooo slight. heck, I bet most wouldn't even notice it...