Author Topic: Rebuilt front end is too tight  (Read 3744 times)

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Offline Tugboat

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Rebuilt front end is too tight
« on: February 16, 2012, 08:06:00 AM »
I've been putting my front end back together after installing All Balls bearings in the neck and installing new fork seals and doing some painting. Both the upper and lower races are seated properly, and on the stem I installed small spacer, dust seal & bearing, in that order. The 750F has that weird headlight bracket thing that goes in between the upper and lower trees, so I've got that back together and the forks back in and all the wiring in the headlight done. Without torquing the steering stem nut down, the front end is smooth from stop to stop. But, last night I was looking at the torque value for the steering stem nut - something like ~50 to 80 ft/lbs. When I began tightening the nut the steering became much stiffer, to the point that you can just set it somewhere in the middle and it doesn't just fall to one side like it used to.

My first thought is that I don't have the nut under the upper tree tightened down enough, so that there's not enough at the top for the steering stem nut to grab. But I was under the impression that you weren't supposed to totally crank it down? Just hand-tighten?
If it's worth doing, it's worth doing twice.

nomad

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Re: Rebuilt front end is too tight
« Reply #1 on: February 16, 2012, 08:41:46 AM »
I too have All Balls steering bearings that I bought.  However, ny mechanic told me that All Balls is a Chinese bearing that's just ok at best (I didn't know this).  At this point I'm having second thoughts on installing them.  I may try to find a better set to put on it because once it's rebuilt, they're there to stay.  Anyone else have issues with All Balls steering bearings?  And other brands out there that are worth considering?   

Offline CycleRanger

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Re: Rebuilt front end is too tight
« Reply #2 on: February 16, 2012, 08:48:42 AM »
It will be a bit tight at first, especially compared to the old, worn ball bearings. 
It will loosen up fairly quickly.
You did thoroughly pack the bearings with grease prior to install?

Not sure about the torque values but 50-80 sounds high.

I have All-balls tapered in two of my bikes and not problems at all.
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Offline Really?

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Re: Rebuilt front end is too tight
« Reply #3 on: February 16, 2012, 08:51:17 AM »
I have had to readjust mine a few times but I think I got it now.  It would act a bit tight in corners so I backed it off a tad, then tad back the other way and back again.  Doing that bar drop test at the same time too.
I don't have a motorcycle, sold it ('85 Yamaha Venture Royale).  Haven't had a CB750 for over 40 years.

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Offline madmtnmotors

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Re: Rebuilt front end is too tight
« Reply #4 on: February 16, 2012, 09:15:39 AM »

Not sure about the torque values but 50-80 sounds high.


I believe Tugboat is referring to the top nut, not the spanner nut that preloads the bearings.

Tugboat,
     Like Really says, you might loosen the top nut, back off the spanner nut just a little, retighten the top nut, and keep checking/loosening/tightening/checking until you get it where you want it. As the spanner nut begins to load the bearing slightly, the force on the spanner threads is in the upward direction. When you tighten the top nut down on the spanner nut the force on the spanner nut threads becomes reversed and is now forcing down. This little bit of force shift will snug up your preload on the bearings ever so slightly, so finer adjustment may be necessary. Usually takes me a couple of tries to get it where I want it.  8)

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Offline kerryb

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Re: Rebuilt front end is too tight
« Reply #5 on: February 16, 2012, 09:54:26 AM »
I think another way to describe what madmtn is saying is that the top nut and the spanner nut are locked together (at 50-80 lbs) leaving just enough space for the bearings to turn without any slop.  Thats the way we did it with bicycle headtube bearings
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Offline 754

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Re: Rebuilt front end is too tight
« Reply #6 on: February 16, 2012, 10:13:30 AM »
50 ft lbs seems pretty high..
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Offline MCRider

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Re: Rebuilt front end is too tight
« Reply #7 on: February 16, 2012, 10:16:25 AM »
I too have All Balls steering bearings that I bought.  However, ny mechanic told me that All Balls is a Chinese bearing that's just ok at best (I didn't know this).  At this point I'm having second thoughts on installing them.  I may try to find a better set to put on it because once it's rebuilt, they're there to stay.  Anyone else have issues with All Balls steering bearings?  And other brands out there that are worth considering?
That's an interesting comment. Here's my take. First did he offer an option?

Virtually all bearings are Chinese now. So what. Things are moving so fast in that part of the world, just like when Japan was in ascendency. What was junk last year could be state of the art this year. And compared to what the stock crap? Anythings better than the mini balls and races it came with.

I ran the OEM in my roadracer many years ago. Sure it was abuse, but at the end of a 4 hr endurance race, we loosened up the front end to inspect and the the balls and pieces of races fell out. Smashed to bits.  Never happen with tapers, no matter who made them.

Its not like they really turn fast or do much other than hold the weight. And the worst would do a better job than OEMs.

Put them in you'll wonder why you waited. IMO
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Offline Tugboat

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Re: Rebuilt front end is too tight
« Reply #8 on: February 16, 2012, 10:25:40 AM »
50 ft lbs seems pretty high..

I know, right?!? Got that value here:
http://www.salocal.com/sohc/tech/torquetable.htm
If it's worth doing, it's worth doing twice.

nomad

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Rebuilt front end is too tight
« Reply #9 on: February 16, 2012, 10:59:16 AM »
Its not like they really turn fast or do much other than hold the weight. And the worst would do a better job than OEMs.

Good point.  I guess being used on a bike that'll never see any serious hard riding, any taper bearing will be more than adequate.  Thanks.

Offline MCRider

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Re: Rebuilt front end is too tight
« Reply #10 on: February 16, 2012, 12:11:12 PM »
50 ft lbs seems pretty high..

I know, right?!? Got that value here:
http://www.salocal.com/sohc/tech/torquetable.htm
I think 50lbs on the stem nut,which is the top one, is fine. AS others mentioned it is clamping down on the adjusting nut to hold it from moving.

Now what the adjusting nut should be is a matter of feel and experience. Snug and release a tad. Then clamp down with the stem nut.

Ride it and then retighten after everything seats in.
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Offline Tugboat

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Re: Rebuilt front end is too tight
« Reply #11 on: February 16, 2012, 12:18:42 PM »
Thanks guys - I really appreciate all the input!
If it's worth doing, it's worth doing twice.

Offline Bankerdanny

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Re: Rebuilt front end is too tight
« Reply #12 on: February 16, 2012, 12:39:03 PM »
The tool for measuring the correct force on the slotted nut that seats the bearings is more like a luggage scale that measures the drag on the bars.  Most of us won't have one,  so it's more of a feel thing.  You want the bars to swing easy from side to side with the idea on the center stand.  If you can't move the bars with one finger the nut is too tight.
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Offline Really?

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Re: Rebuilt front end is too tight
« Reply #13 on: February 16, 2012, 12:42:16 PM »
What Danny said.
I don't have a motorcycle, sold it ('85 Yamaha Venture Royale).  Haven't had a CB750 for over 40 years.

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Offline Tews19

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Re: Rebuilt front end is too tight
« Reply #14 on: February 16, 2012, 12:48:30 PM »
I think my ALL Balls work great.
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Offline seanbarney41

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Re: Rebuilt front end is too tight
« Reply #15 on: February 16, 2012, 01:25:46 PM »
not really trying to start a huge controversy here...(heh heh)...but I have noticed no improvement of any sort after swapping in tapered bearings...I'm not saying tapered shouldn't be stronger and stay adjusted longer, but, honestly, I was expecting the bike to feel more solid...and haven't felt anything different.   When I first got the bike, I adjusted the stock ball bearings...that made a BIG difference...
If it works good, it looks good...

Offline Rookster

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Re: Rebuilt front end is too tight
« Reply #16 on: February 16, 2012, 01:38:47 PM »
Quote
not really trying to start a huge controversy here...(heh heh)...but I have noticed no improvement of any sort after swapping in tapered bearings

This is going to sound wierd but what difference would you expect to feel?  Properly adjusted balls and races would feel the same as properly adjusted tapered bearings.  The issue is longevity and availablilty.  Now if your oem races were indented then you would feel a difference.  Have you changed the swingarm bushes yet?  Decent rear shocks and new swingarm bushes will make it feel much better in the corners.  Add a steering damper and your confidence in the handling will improve as well.

Scott

Offline seanbarney41

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Re: Rebuilt front end is too tight
« Reply #17 on: February 16, 2012, 01:44:20 PM »
Quote
not really trying to start a huge controversy here...(heh heh)...but I have noticed no improvement of any sort after swapping in tapered bearings

This is going to sound wierd but what difference would you expect to feel?  Properly adjusted balls and races would feel the same as properly adjusted tapered bearings.  The issue is longevity and availablilty.  Now if your oem races were indented then you would feel a difference.  Have you changed the swingarm bushes yet?  Decent rear shocks and new swingarm bushes will make it feel much better in the corners.  Add a steering damper and your confidence in the handling will improve as well.

Scott
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If it works good, it looks good...

bollingball

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Re: Rebuilt front end is too tight
« Reply #18 on: February 16, 2012, 02:05:26 PM »
Even the factory setting is 58 to 87 ft/lbs I set my to 50 to 55 and the spanner nut to feel. My balls are stock and have been working fine for 62 years ;D


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Offline Tews19

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Re: Rebuilt front end is too tight
« Reply #19 on: February 16, 2012, 02:09:44 PM »
Even the factory setting is 58 to 87 ft/lbs I set my to 50 to 55 and the spanner nut to feel. My balls are stock and have been working fine for 62 years ;D


                                           Ken

LOL BEEN WAITING FOR SOMEONE TO COMMENT LIKE THAT!!!!
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bollingball

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Re: Rebuilt front end is too tight
« Reply #20 on: February 16, 2012, 02:16:23 PM »
The devil made me do it :)
« Last Edit: February 16, 2012, 02:34:57 PM by bollingball »