Author Topic: Steering Head Bearings  (Read 706 times)

Offline oldchuffer

  • Newbie
  • Posts: 26
    • View Profile
Steering Head Bearings
« on: August 17, 2021, 04:21:59 PM »
My CB400F needs new steering head bearings. Should i stick to the "normal" type or go for tapered bearings?
Thanks in advance
Steve

Offline philward

  • SOHC Master
  • Posts: 2193
    • View Profile
Re: Steering Head Bearings
« Reply #1 on: August 17, 2021, 04:30:54 PM »
Have a search for 'taper steering head bearing' using the Search facility in the top menu Steve - loads of info and opinions
Current Bikes:-
Honda CB750K2 (1975)
Honda CB500K2 (12/1972)
Honda CR750 Replica (1972)
Kawasaki ZZR1100D3 (1995)
Kawasaki ZZR250 (1990) Project (Not started)

Offline oldchuffer

  • Newbie
  • Posts: 26
    • View Profile
Re: Steering Head Bearings
« Reply #2 on: August 17, 2021, 04:44:36 PM »
Thanks Phil, i'll try that now.
Glad you enjoyed Anglesey by the way, did you see any planes at Valley?

Offline Macabethiele (Ted)

  • SOHC Master
  • Posts: 1478
  • 07505030740
    • View Profile
Re: Steering Head Bearings
« Reply #3 on: August 17, 2021, 06:09:58 PM »
I settled for taper roller bottom, ball race top - no issues then with the top nut.
Honda CB400F2 under restoration
Land Rover Freelander Series 2
Jeep Grand Cherokee WK
Mercedes R129 SL500

Offline philward

  • SOHC Master
  • Posts: 2193
    • View Profile
Re: Steering Head Bearings
« Reply #4 on: August 17, 2021, 06:29:52 PM »
Thanks Phil, i'll try that now.
Glad you enjoyed Anglesey by the way, did you see any planes at Valley?
Campsite (Shoreside) is right next to end of Valley runway so a really good view daily
Current Bikes:-
Honda CB750K2 (1975)
Honda CB500K2 (12/1972)
Honda CR750 Replica (1972)
Kawasaki ZZR1100D3 (1995)
Kawasaki ZZR250 (1990) Project (Not started)

Offline AndyD

  • SOHC Expert
  • Posts: 277
    • View Profile
Re: Steering Head Bearings
« Reply #5 on: August 18, 2021, 08:14:58 AM »
Steve,
I had problems with tapered head bearings on the 400 and also on the CJ250t (same bearings) where the upper bearing sits higher than the originals.
This was with both All Balls and tapered bearings from Wemoto and it seems to be a common issue.

On the CJ I had the original bearings and side by side could see the difference in height of the upper bearing.
I ended up filing off the ridges in the securing nut to gain a bit of thread but not really happy with it.

Now doing a CJ360T which again has the same bearings and I've ordered some bearings from Wemoto which look to be more like the originals but at a good price. These should arrive over the next few days so I can measure these up against originals and see if this my be a good option - or maybe someone else here has experience of this type?

Cheers,
Andy

Offline Macabethiele (Ted)

  • SOHC Master
  • Posts: 1478
  • 07505030740
    • View Profile
Re: Steering Head Bearings
« Reply #6 on: August 18, 2021, 09:30:21 AM »
When I measured up I found the following:-

Original Ball Bearings Top 26 x 48.5 x 15
original Ball Bearings Bottom 30 x 50 x 18

JMT Tapper Roller  Bearings Top 26 x 48.5 x 15.75
JMT Tapper Roller Bearings Bottom 30 x 50 x 15

At first glance it looks okay as if you add  the two bearing heights together Ball Bearings are a total of 33 mm as against tapers at 30.75 so it appears doable as most will supply you with a spacer in the kits.
Fitting the bottom taper bearing without a spacer gives you clearance issues as the lower fork bracket will contact the bottom of the frame/column - not sure what impact that has on the steering column lock / slot  arrangement.
I used a 3 mm spacer at the bottom so it gave me the original clearances. I did not bother trying to fit the top taper bearing as that leads to a loss of threads at the top so I just used a plain bearing at the top. I am given to understand that at one time top taper bearings were available that were shallower - I could not find any.
I guess with the right machinery it could be possible to reduce the overall height by 0.75 mm.
« Last Edit: August 21, 2021, 11:50:30 AM by Macabethiele (Ted) »
Honda CB400F2 under restoration
Land Rover Freelander Series 2
Jeep Grand Cherokee WK
Mercedes R129 SL500

Offline Andych

  • SOHC Member
  • Posts: 166
    • View Profile
Re: Steering Head Bearings
« Reply #7 on: August 18, 2021, 09:53:21 AM »
If that top bearing dimension is correct at 26 x 48.5 x 15 then you should be able to buy them... this is what came up on Fleabay Australia.
They are based in the UK.. there were also a search as well
https://www.ebay.com.au/itm/270634303381
1975 CB400 - Project
1978 Yamaha SRX250 - Project

Offline Macabethiele (Ted)

  • SOHC Master
  • Posts: 1478
  • 07505030740
    • View Profile
Re: Steering Head Bearings
« Reply #8 on: August 18, 2021, 10:26:14 AM »
If that top bearing dimension is correct at 26 x 48.5 x 15 then you should be able to buy them... this is what came up on Fleabay Australia.
They are based in the UK.. there were also a search as well
https://www.ebay.com.au/itm/270634303381
That was the standard ball bearing kit size I purchased - my old one was "about" the same but was well rusted!
Some sellers give the bearing height they are selling some don't.
The bottom seal design appears to be useless - mine had a large rubber ring that although in good condition obviously did not work looking at the state of the bearings - not sure if this is the standard part. It's a shame Honda did not fit a conventional shaft seal arrangement.

The link you have posted appears to be a firm in Scotland who are selling in Australia so they ought to be available here in the UK - well found Andy!

UK link not bad @ £12.99 each incl P&P
https://www.ebay.co.uk/itm/290781743090?hash=item43b3f147f2:g:dmYAAOSw7n9XFIAG

Too late for me I've fitted plain at the top - worth considering for the future.
« Last Edit: August 18, 2021, 12:57:37 PM by Macabethiele (Ted) »
Honda CB400F2 under restoration
Land Rover Freelander Series 2
Jeep Grand Cherokee WK
Mercedes R129 SL500

Offline Oddjob

  • SOHC Jedi
  • Posts: 4515
    • View Profile
Re: Steering Head Bearings
« Reply #9 on: August 19, 2021, 01:30:04 AM »
I fitted a set of tapers in the early 80s to my 500, just removed one tonight and the top bearing is stamped 26 x 48 x 15. However they don't seem to make that size anymore. When I remove the bottom race I'll post what's stamped on that. There was a 3mm spacer under the bottom taper.
Don't play stupid with me, I'm better at it

Offline Macabethiele (Ted)

  • SOHC Master
  • Posts: 1478
  • 07505030740
    • View Profile
Re: Steering Head Bearings
« Reply #10 on: August 19, 2021, 08:47:43 AM »
I fitted a set of tapers in the early 80s to my 500, just removed one tonight and the top bearing is stamped 26 x 48 x 15. However they don't seem to make that size anymore. When I remove the bottom race I'll post what's stamped on that. There was a 3mm spacer under the bottom taper.

I think you are onto something here Oddjob - I can't check my old original inner race as I have binned it as it was so rusted but I have the outer races. I've checked my old note book and am now having doubts about the O/D being 48.5 even though I have recorded the shaft measurements & bearing sizes several times. The parts manual & DS does not give the bearing dimensions. The original part number was superceded to 53211-268-010 according to DS but thats unlikely to be an explaination.

Please disregard my Top Bearing inside diameter measurements - they are clearly unreliable.

You can't argue with the sizes given by Oddjob marked from a bearing.
« Last Edit: August 19, 2021, 11:23:03 AM by Macabethiele (Ted) »
Honda CB400F2 under restoration
Land Rover Freelander Series 2
Jeep Grand Cherokee WK
Mercedes R129 SL500

Offline Macabethiele (Ted)

  • SOHC Master
  • Posts: 1478
  • 07505030740
    • View Profile
Re: Steering Head Bearings
« Reply #11 on: August 19, 2021, 11:20:26 AM »
After another search this morning I have found my top outer race I have measured it with my calipers as 48.53 mm now I am confused I get a tad over 48.50 with my micrometer?

Clearly a difference between a 400/4 & a 500 by the looks of it.

Hopefully someone else can clarify the top bearing size for a 400/4 F2 as it might be you can get a taper roller for the top that fits without loosing threads.

The taper upper that I did not fit is a JMT Tapper Roller  Bearings Top 26 x 48.5 x 15.75 as I did not want to loose any top threads.
« Last Edit: August 19, 2021, 11:54:33 AM by Macabethiele (Ted) »
Honda CB400F2 under restoration
Land Rover Freelander Series 2
Jeep Grand Cherokee WK
Mercedes R129 SL500

Offline Seabeowner

  • SOHC Pro
  • Posts: 700
    • View Profile
Re: Steering Head Bearings
« Reply #12 on: August 19, 2021, 02:32:56 PM »
Years ago I got a "set" of bearings off Steve with a view to doing my 500 that I've had for 20 years. But the set was missing a bit and to compound it when I took my 500 apart recently it already had tapered bearings installed. I didn't do it, but rebuilt the bike 19 years ago and obviously forgotten! May use bits on a 550.
The bottom bearing is marked H305014. I only have the outer.
https://www.tradebearings.com/h305014-bearing-30-50-14mm-product-84516.html

The top bearing is marked H264815.
https://en.tradebearings.com/N_H264815-170254.html?rel=nobot
Phil
1971  CB500K0  Candy Jade Green
1973  CB500K1  Candy Ruby Red
1975  CB550F1   Shiny Orange
1978  CB550K     Excel Black

Offline AndyD

  • SOHC Expert
  • Posts: 277
    • View Profile
Re: Steering Head Bearings
« Reply #13 on: August 19, 2021, 02:39:44 PM »
Ted,
Interesting - but sad that simply getting replacement bearings is such a pain!

I received the alternative style ones from Wemoto and have had a quick look at these.
The bottom set looks perfect and appears an exact match of the originals, with the exception of the ball bearings being captive.
Top set not so good - the race seems the same but the bearing cage just doesn't fit at all so can't check any further.
Also the top cone is thicker and has a different shape so this may also cause a problem in terms of overall thickness etc. but can't check as the bearings don't fit in.
I've spoken with Wemoto and they are going to look into it - maybe a rogue bearing set but hopefully will find out and update on 'progress'.

Measured up the old bearing and got 48.55 so same as your dimension.
Also measured the overall height of the top assembly and came out at around 14.3mm overall but with only a few BBs fitted - when I get a chance I'll re-check with all bearings in place to see if this is correct or changes much.

Cheers,
Andy

Offline Oddjob

  • SOHC Jedi
  • Posts: 4515
    • View Profile
Re: Steering Head Bearings
« Reply #14 on: August 19, 2021, 05:11:57 PM »
Pic of my top race. Includes the taper roller inside it. The stamping is on the inside so when fitted you can't see it, as soon as I remove the lower one I'll include a pic of that but I'm fairly sure it will be 30x50x15. Make looks to be MCI.

They are in great condition so it's likely I'll refit them when the frames powder coated. Oh and the 400/500/550 and 750 all used the same bearings, at least the same taper rollers anyway. Makes me wonder how something 0.5mm bigger can still fit in the frame. Maybe they got it wrong initially? Oh and my tapers fitted perfectly, no threads lost at all.



Might interest you to know I'm currently looking at converting the original swinging arm to needle bearings instead of the metal sleeves they used back in the 70s. It's about 50% done at the moment with some small machining needed which I'm having to ask a mate to do as I don't have a lathe.
« Last Edit: August 19, 2021, 05:15:55 PM by Oddjob »
Don't play stupid with me, I'm better at it

 

SimplePortal 2.3.5 © 2008-2012, SimplePortal