[Windmill John]

Well I think that says it
1979 Standard CX500
Let's get all the standard stuff out of the way:
New head bearings. Plus just re-adjusted after initial fitting and rides.
New tyres.
Front bearings feel good.
Yokes correctly tightened; not triple potato chops or whatever my friends across the pond call them
New fork oil with now equal quantities in both forks; certainly wasn't prior to my ownership.

Taken rear suspension preload up a notch.
Definitely worse with top box fitted. So I am beginning to think this might be standard for the model. Transalps certainly shake\tank slapped if you let go with anything more than a rear rack fitted.

Before I put it down to that's the way it is, any other suggestions? More pronounced around 30MPH but detectable at most speeds.

Thanks

 

[Randall-in-Mpls]

I think it's a load balance issue. Shift you weight forward and it should stabilize.

 

[Windmill John]

I tried, on my ride home from work, leaning very far forward and resting my chest on the front of the tank. The shake was still there. Possibly reduced a little, but…
I might try whacking my rear preload to the firmest setting and seeing.

 

[Gerard]

Front axle tight? Side to side wheel/ tire runout.

 

[bahn88]

I know u had new tyres fitted.. was the front balanced?
Did the wobble happen after you adjusted the new s/stem bearings or there even in initial fit?

 

[Thumper]

On centerstand, somebody pushing down on rear, front wheel in the air, are you sure the stem bearings aren't loose ?
If not, does sound like a tire issue.

 

[Windmill John]

Thanks all.
Tyres were 17 and 20 years old. Fitted new, thought about balance. Balanced it myself. As a double check i took the front wheel to a bike mechanic. He said it was a tad out and rebalanced anyway; no change.

All fasteners correct.

It was there on the initial ride, hence checking head bearings which were bone dry.
Had front wheel off ground and head bearings fine once new ones were fitted and as above I’ve tweaked them since fitting and riding.

Running Avon Roadriders at 25 and 30 as per Avon suggestion. I could whack these up to often often suggested 36/42….

 

[Gerard]

Does the rear tire run straight?

 

[Windmill John]

Leave it with me, I’ll check the back end again.

I haven’t got a long enough bit of wood to test front/rear wheel alignment. But, the rear wheel has no runout. It is spot on. So is the front.

Didn’t realise the Hagons only have two adjustment positions, having just trapped my hand when it jumped back to the lowest setting!

 

[Gerard]

Only other thing that comes to mind how are the rear swingarm bearings? Loose bearing might cause it.

 

[brinkcx]

Running Avon Roadriders at 25 and 30 as per Avon suggestion

My 1978 CX would be unhappy using that, too low, Have you tried running higher pressures ?

 

[bahn88]

My 1978 CX would be unhappy using that, too low, Have you tried running higher pressures ?

I run 34 to 36 on the front.... and 38 on the rear....
But im probably 85kg geared up...
Thats for pirelli sports demons, a stiffened front and ikons on the back ...
At 30psi or so id find the front would squirrel...meaning it would feel like a krispy creme donut was on the front not a tyre..

 

[Windmill John]

Hi All,
I loosened the swinging arm bearings and greased when I had the bike in the shed.
I'm starting to think it might be wheel bearings. They feel okay etc, but I might first, as per your comments, whack up the tyre pressure and try another ride.

 

[Windmill John]

Well, I could stay quiet….. but worked on bikes enough to admit I made a mistake…
Pressures up to around 33/36
The wobble I had at 30-35mph, now at 40-45mph and much les…. Ooh tyres I thought….

Now the idiot kicks in…. I thought I’d check the head bearings again. Turns out when I thought I’d nipped them up, no more movement, my C spanner was touching the kink on the top yoke!…. Ooh embarrassing as I could actually take them comfortably another quarter turn 🙄

All adjusted and bike covered, as I am now confident the lunatic in the room has been removed!

Thanks for all your input, I’m sorry I wasted your time.

 

[Randall-in-Mpls]

Good that it was something simple, even if a little embarrassing. Thanks for having the humility to help the rest of us avoid the same slip.

 

[Thumper]

Lucky for me I've never made a mistake so I can laugh.