The BSA A7-A10 Forum

Technical => Frame => Topic started by: KiwiGF on 19.05. 2011 10:27

Title: Ariel Rear hub spacer missing? and silent blocs DONE (with pics)
Post by: KiwiGF on 19.05. 2011 10:27
Hello,

The left hand bearing is loose on the rear wheel axle on my 56 A10, the shaft is worn, I think the reason might be a spacer is missing so the centre part of the bearing is not clamped as it should be, but maybe it is not supposed to be clamped by the left nut and relies on being tight on the shaft, can anyone confirm if I have all the parts?

The bearing is 5/8 wide and the shoulder it fits on about a 1/16 wider than that. Hopefully the pic shows the possible problem.

Secondly, those silent blocs are 1.262 OD but the swing arm 1.25 ID which gives a large interference fit over 010, I am sending them back anyway as the rubber is not properly filling the gap (i can poke a wire down between the tubes in places!) but I thought I'd ask the supplier for smaller ones if these are too big as I've heard they can be on this forum, it occurred  to me these might be "metric" equivalents to the OEM ones as they are almost exactly 32mm OD.

So are these silent blocs over size?
Title: Re: Ariel Rear hub spacer missing? and silent blocs again
Post by: muskrat on 19.05. 2011 20:15
G'day KiwiGF,
                  looks like your also missing the grease retainer pt # 42-6105. That side cops a beating with 50 years of wheel removal, mine was worn in the sprocket. You do need the spacer pt # 42-6085 to stop over clamping the hub.
Can't help with the silent blocks, I made bronze bushes 20 years ago.
Cheers
Title: Re: Ariel Rear hub spacer missing? and silent blocs again
Post by: KiwiGF on 20.05. 2011 07:52
Thanks muscrat can you describe the design of the bronze bushes please? Did you modify the swing arm? as although there are conflicting reports on how long they last I think that might be my best option. I guess the secret is in providing a bearing that prevents side movement?

Ref the rear axle I have one grease retainer but its stuck in the hub and also is stopping the right hand side longer spacer you referred to coming out if the hub

I guess the other grease retainer is missing as the bearing is sealed on the lhs side, the outer side, so maybe the PO did not fit it but as the 2 spacers have the same part no. I thought they were not intended to clamp the inner part of the bearing

My parts book does not show any spacers on the lhs but the more I think about it the more I reckon the inner part of the bearing should be clamped when the lhs nut is done up as occurs when the rhs bolt is done up

As the outer part of the rhs bearing is locked into place by a threaded ring that bearing provides all the sideways movement prevention- I think!
Title: Re: Ariel Rear hub spacer missing? and silent blocs again
Post by: muskrat on 20.05. 2011 20:18
G'day KiwiGF,
                  I made top hat type bushes to take care of sideways movement, sorry can't find the drawing I made 20 years ago. I fitted a grease nipple and fill till it just appears out the sides.
2 spacers with the same part # ?? Are we looking at the same drawing?
Cheers
Title: Re: Ariel Rear hub spacer missing? and silent blocs again
Post by: KiwiGF on 20.05. 2011 22:43
Not surprising the drawing is gone!
Yep we have the same drawing  - part 8 there are 2 off but I have only one fitted and that is stuck in the hub but I can leave it there as there is not much need to remove it

But I think I have worked out what was wrong assuming the bearing inner should be clamped so it can't spin on the lhs axle shaft

I think the shoulder on on the rhs of the lhs  axle had been worn away by the bearing inner and so that part of the shaft diameter was wider than 5/8 which is the bearing width so I built up the shaft last night with mig weld and machined it ( im no machinest so this was about my limit of capability) to be a tight fit in the bearing and also slightly shorter than 5/8 so part 4 the washer with internal flats now clamps the bearing inner when part 1 is done up

It seems to all look ok like that but I'll see if the lhs axle part is available overseas (it's not in NZ)

Thanks for yr help with this!
Title: Re: Ariel Rear hub spacer missing? and silent blocs again
Post by: KiwiGF on 10.07. 2011 06:42
Well I've got different silent blocs this time from c and d auto in the UK and they are only slightly smaller in diameter than the ones I bought and returned

I'm pretty sure these will be the correct spec so wish me luck as I'll get the 16mm studding out and give fitting them a go later this week......
Title: Re: Ariel Rear hub spacer missing? and silent blocs again
Post by: bsa-bill on 10.07. 2011 08:27
The silent block bushes I bought for my first Flash from Bri-Tie were to big, I reordered from C&D and they sent ones which were spot on.
They told me when I ordered them they had got them made up by the original suppliers from original drawings
Instantly recognisable by the rounded shoulder on leading edge of outer case which helps a lot.
C&D -   one of the good guys in my book
Title: Re: Ariel Rear hub spacer missing? and silent DONE (with pics)
Post by: KiwiGF on 23.08. 2011 10:37
Here a few pics of the silent blocs installation - I was REALLY surprised how easy this job was after hearing horror stories of huge presses required to install the blocs. The only slight issue was that the width over the blocs once they were installed was 1/16 too wide to fit in the frame (even thought the blocs are touching inside the swing arm) but I'll fix that by grinding a little off the blocs. If I did the job again I would measure up everything first and mod the blocs before fitting them.

I found the outer tube of the blocs fits slightly inside of the swing arm so I had to modify one of the 2 steel bushes I had made up to press on the ends of the outer tube of the blocs (without touching the inner tube)  so that it fitted fit inside the swing arm and could press the bloc in that extra 1/32.

Getting the old blocs out is much harder then fitting the new ones!

I bought the blocs from C+D Auto in the UK, the blocs are almost 010 larger OD than the swing arm ID (of 1.25") and look like they will never fit - but they do.

I polished the blocs with a rotary wire brush before fitting them, this also removed the protective coating they seemed to have, I also oiled the inside of the swing arm to reduce the force needed to press them in.  



  
Title: Re: Ariel Rear hub spacer missing? and silent blocs DONE (with pics)
Post by: RichardL on 28.10. 2014 01:49
Using a rig just like Kiwi's, pressing in my oversize blocs was one of the most grueling physical tasks I can remember in my life. Even with a cheater bar on a long pipe wrench I was pouring sweat for, it seemed like, hours. I have to think that turning the outer sleeve down to a more conventional interferance fit, or even a small bit more, would be appropriate. By the time they were in, they weren't quite lined up at the center and I couldn't get the spindle through. I bought an expandable reamer to solve that problem.

At the time I did mine, I had no idea of the theory. I thought the idea was for the swing-arm to pivot on the spindle. I have since accepted the idea of the rubber acting as a torsion bar, as Bill has said? On the other hand, I am guessing that many or most end up rotating around the spindle. There just seems to be a fundamental flaw in the concept of expecting the inner sleeves to stay put when pressure from the outer plates against the small surface area of the inner sleeves is applied by tightening the spindle. Having said that, there are propably twenty people here, who I fully respect, that will tell me their inner sleeves never slip. Dying to here it and, thankfully, running out of battery in this here portable device.

Richard L.
Title: Re: Ariel Rear hub spacer missing? and silent blocs DONE (with pics)
Post by: muskrat on 28.10. 2014 10:09
Good one Richard.
What I can't understand is why would anyone push the same new ones in *????*
When I got the A7SS I had to cut the frame plate to get the spindle and s/arm out together  *eek*. Frozen solid.
Harden the spindle and turn up some phosphor bronze bushes and fit grease nipples. One of the first jobs I did to a BSA 35 years ago. But then if your only putting around (legal road speeds) most wouldn't notice any difference. *whistle*
Now ducking for cover. *smile*
Cheers
 
Title: Re: Ariel Rear hub spacer missing? and silent blocs DONE (with pics)
Post by: bsa-bill on 28.10. 2014 11:19
Quote
I am guessing that many or most end up rotating around the spindle.
probably does happen Richard but both mine had spindles well and truly seized in, the first one I managed to get out but was US after it did, the second was so seized in I had to cut it between the frame and the S/A at both ends (with just a smidgen of damage to the
frame ) *red*