front end shudder, shimmy

[Deadduck]

So today was the first day I really got the opportunity to take my new to me rt out and run her through the paces.
 Let me backtrack a week or so, purchased the new girl last Friday.  She had a good maintenance record attached to her and I got a really good deal. Over the last seven days I've replaced all the fluids (motor oil twice), spark plugs, new brakes, made sure tires were properly inflated, checked and relubed rear splines (records indicate it had a complete rear lube done 1k miles ago or 3 years ago) rear splines showed that to appear true.  So that's been the last seven days.
 Now onto what I'm not used to or potential problem.  Running up I-75 this afternoon I was in process of getting into my little envelope of space and ran her up to around 90 whilst swinging through a sweeping right hander. I had the feeling of the front end stepping out but didn't feel any tire slide, more like a wobble in the forks, I realise this is an old girl and I've become accustomed to my buell going where I tell her to without any argument.  I guess my question is am I pushing the Beemer too hard or should I start looking for a fork brace and get rid of the rubber? risers my handlebars are mounted to?
 Other than that little weird feeling in the curve she performed flawlessly and seems to run better and better by the mile (thank you Seafoam)

[mystic red]

You might try a fork fluid change....to like 10 weight.....if that doesn't do it an upgrade to after market springs are in order!

[Deadduck]

Did that as part of the fluids change. Running around 8w, mixed 5w and 10w. The ride is good overall, I may go straight 10 next time I change it though. 

[Deadduck]

Looking at the blowup of the controls on bike bandit, is there a rubber bushing that the risers attach to on the triple tree, and could this give me the feeling of a wobble while cornering if worn to bad? If it is rubber, is there a solid mount setup for these or do they all have anti vibration bushings built in?

Agree, springs are probably due for renewal

[turq]

I'm not sure if your " rt" is a k75 or k100.
On my '93 k75s with only 21k miles; on inspection it had loose fluid block damper bolts and the stem nut was loose. To the point of almost falling out (the bolts). Felt like the triple tree 'clacked' back at small cracks in the pavement.

Might check the streering stem nut for tightness, and the dampener bolts.

[johnny]

rear shock...

j o

[mystic red]

rear shock...

j o

The dudes onto sumthin....upgrade that.

[Deadduck]

Didn't even think about the rear shock.....thank you Johnny, it is pretty soft.

Progressive springs seem pretty good for these old bikes for the front and rear? Or are there other options out there?

[Deadduck]

I'm not sure if your " rt" is a k75 or k100.
On my '93 k75s with only 21k miles; on inspection it had loose fluid block damper bolts and the stem nut was loose. To the point of almost falling out (the bolts). Felt like the triple tree 'clacked' back at small cracks in the pavement.

Might check the streering stem nut for tightness, and the dampener bolts.

It's a k100 with 53k on it. The 50k service was documented 3 years ago and so far everything I've looked at and done has proven it to have been true.
Front end overall Is solid, no noticeable play in the stem and bolts are tight.
The sensation I got, or should I say feedback was at a considerable lean and it felt like the forks had a little left right twist, what I couldn't really tell was if it was the forks or if it was from the not so solid mount that the handlebars attach to. Right now I just don't know what it's supposed to feel like I guess, it's not a sport bike and I could probably go broke trying to make it feel like one.

[billday]

This is not a case of "they all do that," your K should feel solid and secure in that situation.

Other people have mentioned the rear shock, front suspension, and steering head.... also give the tires a good look. Even if they have plenty of tread, they may be due for replacement from age.

[Grim]

As old as it is I'd check the head set for notchy spots and wheel bearings on the front wheel. Age is as big of an enemy as miles. To check the head set put something under the sump to get the front wheel off the ground and slowly turn the wheel back and forth by the tire and see if you feel a notch on center. 
One of Chris Harris's Vids http://www.youtube.com/channel/UCRZEzmVmi88hqnVKe7d-wIg talks about the head set was suppose to be adjusted at 600 miles after the bearing have set and MANY were not. Bearing being just a little bit loose causes accelerated wear on center and can cause odd feelings while riding.

[pallum]

As old as it is I'd check the head set for notchy spots

I had the same symptoms while making high speed turns, replaced my steering head bearings and I haven't felt that wobble since. Rear shock is an upgrade still worth doing any way you look at it though.

[BobZ(IL)]

I vote for steering head bearing adjustment as well. Wouldn't hurt to check adjustments on rear shock if you have any. (Sag and damping). Bike should corner solid as a rock.

[racinrich]

Mine does this too at 83,steering head bearings are notchy and the only thing still original at 112k plan on doing them soon. first thought it was wind buffeting but got it to occur with empty smooth road

[Deadduck]

Appears most of the problem was the steering head bearing was out of adjustment.  The bearing feels good just a little loose is all. I haven't had a chance to take her out and run yet but what I found was enough to feel confident that it was most of the problem.  Thank you all for the help.
in the coming month my intentions are to replace the springs both front and rear and at that time I'll go ahead and do a bearing replacement as well.