Author Topic: CB 750 steering heavy  (Read 6094 times)

Offline Patric

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CB 750 steering heavy
« on: July 23, 2008, 11:39:55 AM »
Hi guys,
 Just finishing my 12 year restoration of my '77 750 K6. On test rides have found the steering very heavy, almost like i have a flat tyre! I have new metzlers, new spokes and new cone type steering head bearings. forks have been re built. Jacked up the steering feels light and the bearings are just tight enough to stop wobble. tyre pressures are correct.
any ideas why it would feel so heavy? do new bearings need to wear in to feel light when under weight? Or (having not ridden the bike for so long) is this handing normal for a CB 750?
many thanks
Patric

Offline douglas

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Re: CB 750 steering heavy
« Reply #1 on: July 23, 2008, 07:06:17 PM »
You've just forgotten after all these years!!

Offline Searchguru

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Re: CB 750 steering heavy
« Reply #2 on: July 24, 2008, 02:00:20 AM »
Hi Patric,
Your new Metzelers, are they identical size/cross section etc to your old tyres? Tyre technology has come on leaps and bounds in 12 years and how old were your tyres before the re-build? If the steering is fine with no load then I would suggest experimenting with different tyre pressures, though you have done a number of things which muddies the water. Don't adjust your pressures too much either way but try and find something you're happy with. You may have put a bit of weight on in 12 years and like me you are now more like the old you plus a pillion! As you haven't ridden it for a while you have nothing but an old memory to go by.  I know straight away if my bikes' tyres need air but that's because I use them regularly. It could just be that Metzelers don't suit your bike.

Offline twolitre

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Re: CB 750 steering heavy
« Reply #3 on: July 25, 2008, 04:34:38 AM »
Have you used the original forks on this bike?  If by some means to have increased the 'trail' (called 'caster angle' in olden days) the bike will have a greater tendency to want to run straight.  Also the 'trail' actually means you are raising the front of the bike against gravity when you steer.
  'Trail' is the distance that  the axis of the fork legs intersect the ground in front of the tyre contact point.  It was (is?) called caster in car terms because it makes the wheel behave like a furniture caster, wanting to run in the direction of motion.  It is responsible for the 'self-centreing' action of car steering - too much makes the steering heavy.
   Some 'trail' is essential or it would be impossible to let go of handle bars or steering wheel without losing control, but too much is not good.  The 'heaviness' increases with speed and tighter radius of turning.
« Last Edit: July 27, 2008, 07:13:31 AM by twolitre »
Jim Walker.

Offline thunderbird

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Re: CB 750 steering heavy
« Reply #4 on: July 27, 2008, 05:53:22 PM »
hi patric congratulations on finishing your rebuild,you haven't been spoiled by more modern machines whilst rebuilding the honda?. I had a 750 four  of about the same vintage from what i can remember it was great in a straight line but i had a few hairy moments going into corners to fast there a heavy old machine, i do remember fitting more modern rubber to it and it did improve its handeling,sounds like you checked everything well when re fitting the forks,just a thought did you change the grade of springs/oil  in the forks i wonder if this may have some effect. best of luck Regards Steve

Offline sticks

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Re: CB 750 steering heavy
« Reply #5 on: February 15, 2009, 11:29:30 AM »
Hi patric
i bought a 750 k6 last year,it also had metzelars fitted,it also felt very heavy on the steering compared to my mates K2, i changed the tyres to avon roadriders,and it changed the feel completly,and was much lighter on the steering,hope this helps.
Dave.