Author Topic: A need help! Crazy steering on a '76 CB750F*SOLVED*  (Read 1349 times)

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Offline shinyribs

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A need help! Crazy steering on a '76 CB750F*SOLVED*
« on: May 05, 2012, 10:27:49 PM »
I put my All Balls tapered steering bearings in last night. It cured the low speed ,front end rump-rump-rump I had but now the bike handles reeeeeally stupid. It does not want to go straight AT ALL below 45 MPH.Above 45MPH it is tolerable,but it is still a chore to drive. It feels like you are riding on a tight rope having to balance it constantly. If you give the handlebars the slightest bit of an accidental bump it wants to go into a pretty bad wobble. A front wheel side-to-side wobble. I hate to think what would have happened if I did not have a stabilizer on the bike because on time it tried to wobble it took a good amount of strength to hold it tight. Slight turns at moderate speeds it feels perfectly normal,but if you try to lay it over any real amount at all it feels as if the bike tries to jump back up straight! It actually feels like the bike has ZERO rake whatsoever.Turning 90 degrees from from a side street on to the main street it feels like the front tire is trying to fold up under the bike in what ever direction you are turning.

I have not pulled it all the way back down to the point of getting the steering stem back off,but I did pop the upper triple clamp off to see if I forgot to tighten the top spanner nut.

When I put the bearings in last night I kept turning and turning and turning the spanner nut and finally the bearing seemed to seat. It took a bit more pressure than I thought it should,but the handle bars felt nice and free with just a touch of resistance,which seemed correct. After riding and feeling what it is doing now I thought I may have over-tightened the spanner nut. I popped the upper triple clamp off to check that and the spanner nut was barely finger tight! I thought"OK,maybe I didn't have the bearing fully seated so I snugged it up a little bit and now it is even worse!!! Plus the bars are pretty tight now.Not extremely tight,looser than what the stabilizer creates at full tension which is where I keep it all the time.

My bike used to feel rock solid,now it is un-rideable. Turns on the 55MPH highway near my house I used to be able totake at 90-100 MPH+ I feel uncomfortable at 55-60 MPH.

I'm gonna strip it down tomorrow,but for now I am completely lost and totally fed up.  HELP!!!!
« Last Edit: May 06, 2012, 08:59:24 PM by shinyribs »
The darn fool didn't know it couldn't be done...so he went ahead and did it anyway.

My Hackjob build- http://forums.sohc4.net/index.php?topic=106103.0

Offline phil71

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Re: A need help! Crazy steering on a '76 CB750F
« Reply #1 on: May 05, 2012, 11:43:33 PM »
are you sure you got the spacers set up right? Stem nice and snug in the inner race?

Offline Retro Rocket

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Re: A need help! Crazy steering on a '76 CB750F
« Reply #2 on: May 06, 2012, 12:08:22 AM »
It sounds like you have something too tight, with a steering damper on its highest position {most resistance} it will make the bike weave at slow speeds, this is normal, if the steering head bearings are tight and you have the damper full on then it will weave at slower speeds as you are experiencing. Have you ever had an adjustable damper on another bike before.?  If your bearings were originally stuffed then the over stiff damper may have just made it feel ridable, now you have good bearings, try backing the damper back to the 2nd or 3rd position.....
750 K2 1000cc
750 F1 970cc
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If You can't fix it with a hammer, You've got an electrical problem.

Offline shinyribs

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Re: A need help! Crazy steering on a '76 CB750F
« Reply #3 on: May 06, 2012, 01:05:24 AM »
I have had the damper for about about 4-500 miles now. With the bike acting like it is now the damper is the only thing making is even remotely safe to ride. It is an absolute mess right now.

You may be right that I have it too tight. When i retightened it it seemed a little worse,which makes sense,but a tighter setting on the damper helps right now,which doesn't make sense. I will try loosening it,though.

Thanks for the ideas guys. I will look into all of them. Keep 'em coming please!
« Last Edit: May 06, 2012, 01:07:52 AM by shinyribs »
The darn fool didn't know it couldn't be done...so he went ahead and did it anyway.

My Hackjob build- http://forums.sohc4.net/index.php?topic=106103.0

Offline dave500

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Re: A need help! Crazy steering on a '76 CB750F
« Reply #4 on: May 06, 2012, 01:08:26 AM »
maybe one of  the cones you tap in hadnt seated fully,,and its now seating with use and loosened up the tension?

Offline Retro Rocket

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Re: A need help! Crazy steering on a '76 CB750F
« Reply #5 on: May 06, 2012, 01:09:16 AM »
I have had the damper for about about 4-500 miles now. With the bike acting like it is now the damper is the onlt thing making is even remotely safe to ride. It is an absolute mess right now.

Thanks for the ideas guys. I will look into all of them. Keep 'em coming please!

That was one of my points ribs, if the front was "loose" with dodgy bearings, the damper may have made up for that, now that you have new bearings the damper should be backed off , also if the bearings are poorly seated it will steer like crap....
750 K2 1000cc
750 F1 970cc
750 Bitsa 900cc
If You can't fix it with a hammer, You've got an electrical problem.

Offline shinyribs

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Re: A need help! Crazy steering on a '76 CB750F
« Reply #6 on: May 06, 2012, 01:36:18 AM »
I understand Retro.The damper really did help with my old bearings. Just seems backwards that if my new bearings are too tight that the extra tightness of the damper would help. I guess it's just a different kind of tight.

Thanks for your help.I'll see what I find in the am
The darn fool didn't know it couldn't be done...so he went ahead and did it anyway.

My Hackjob build- http://forums.sohc4.net/index.php?topic=106103.0

72500john

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Re: A need help! Crazy steering on a '76 CB750F
« Reply #7 on: May 06, 2012, 03:57:14 PM »
i have been searching for something in the faqs about these..could have sworn i saw something there..about i million threads on this.
almost sounds like you may have not put the correct spacer under the lower bearing or one of you races is not seated all the way.
good luck and hope to see you on the road again soon.

Offline shinyribs

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Re: A need help! Crazy steering on a '76 CB750F *SOLVED*
« Reply #8 on: May 06, 2012, 08:58:30 PM »
You are exactly right. I put the spacer between the register and the lower bearing race.Dooooh!!!! Got everything swapped around and it is good to go now. I cant believe I did something so dumb and I really hate to tell on myself...but ya gotta come clean sometime :-[

btw-that pic by the stream you asked about is in Roanoke,VA. Tinker Creel Dam.
The darn fool didn't know it couldn't be done...so he went ahead and did it anyway.

My Hackjob build- http://forums.sohc4.net/index.php?topic=106103.0

Offline Retro Rocket

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Re: A need help! Crazy steering on a '76 CB750F*SOLVED*
« Reply #9 on: May 06, 2012, 09:28:54 PM »
At least you got it sorted, thats the main thing... ;)
750 K2 1000cc
750 F1 970cc
750 Bitsa 900cc
If You can't fix it with a hammer, You've got an electrical problem.