Help me with a vibration issue...

[gggGary]

Yeah, you should have someone drive alongside you and look at the chain, you might be surprised at what you see. A long stretch of chain can get get some rather wild harmonics going. And being tight might make it worse. We probably should all check our sprockets for true to center also. How good of chain did you buy? Just covering more bases.

 

[manofsteele]

Um the chain is an o-ring roller chain, kinda on the cheaper side. I need to replace the rear tire anyways so I'll continue with that.

 

[XSLeo]

How old are the tires? If they are more than a few years old, that can make the bike shimmy and shake.
The 81 I have with the tires it had on it would headshake bad enough to scare me. I swapped wheels around from my 75 and the 82 parts bike and got it to be ok, not good but ok.
I got a new set of tires on it and it's great now.
To tell how old a tire is read the DOT number, at the end are some numbers in an oval. If the number is 3 digits it is older than 2000, In 2000 they started using 4 digits. The first two digits are the week of manufacture, the second two are the year of manufature.
The bad tires off the 81 were marked 275, as in 27th week of 1995, the other 405, 40th week, 1995. Good tread, no cracking, but no good.
The new ones are 1310 and 1610, 13th and 16th week off 2010.
The tire manufacturers reccomend not running tires over 6 years old. As the tire ages the layer can delaminate, the tread can come off in chunks or as one piece. Bolwouts are common.
A few years back they had a big deal on brand new old tires blowing out on SUV's and causing crashes, a few people got killed.
Companys would buy a wharehose full of tires and take years to sell them. On tv the did some checking at tire stores and found tires dated as old as 15 years being sold.

 

[jamesgs4]

Not 100% on the wheel bearings, but what's the chance both sets are bad? How do you check the wheel bearings for play? Ill try tightening up the steering head some more, I currently have it torqued to factory specs 40 ftlbs. What do you recommend I torque it to?

650skull, when I drove it without the front brake I never got it passed 45mph. I also rechecked and retorqued the whole front end including the brakes.

Tighten here

 

[manofsteele]

Yeah they are some cheap kendas, they look good but I think the rear is out of round and it does have some cracking on the sidewalls. So those are next to go. Any thoughts on cheaper tires, kenda or shinkos?

Jamesgs4, yeah that's where I tightened it up after I rechecked everything. I tightened it to a point where there was a little resistance in the triple trees. I don't want to tighten it too much and damage the bearings.

 

[XSLeo]

I ran some Kenda Challengers a few years back. An inexpensive tire, yes a cheap tire not so much. They handle very well, wet or dry, the tar snakes and rain grovves didn't bother much. They are a somewhat soft compound tire so the rear wore out in about 5000 miles, the front lasted about 7000.
I have Bridgestone Spitfife II's on the 75, Pirelli Route MT66's on the 81. I think the Pirelli's handle tar snakes just a shade better. I can't say how long they will last. The Bridgestones went on early last season, maybe 2-3000 miles, the Pirelli's just a few days ago.
I've heard good things about the Shinko's.
On your head bearings, they can loosen up some as all the parts get settled in.
Leo

 

[manofsteele]

Yeah I just tightened up everything on the front end and still no change. Gonna order tires next week.

I need to order another set for my 82 Gl500, it still has the original dunlops on it, but it only has 2,000 miles on it, lol.