Author Topic: Aero 600 Oilite clutch bearing modification issue  (Read 802 times)

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Offline Aero

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Aero 600 Oilite clutch bearing modification issue
« on: 13 Sep 2019 at 10:06 »
The bearing surfaces on my clutch actuating cam finally wore through last month, so after no luck obtaining a replacement I set about a repair.
I managed to affix a hard steel axial bearing washer to the actuating cam face, using industrial glue, and that is holding well.
At the same time I did the bronze Oilite washer modification instead of the ring of ball bearings.
The clutch now works again, but I have an odd side effect.
When the clutch is in use it is creating a huge drag on the primary drive, which feels like a brake is being applied to the gearbox.
With the engine stopped and gearbox in neutral, if I hold the clutch lever in & try & turn the primary chain by hand I can hardly move it.
Is this what I should expect with the bronze washer mod or can anyone shed light on what may be occurring please?
« Last Edit: 12 Oct 2019 at 15:53 by Aero »

Offline Aero

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Re: Aero 600 Oilite clutch bearing modification issue
« Reply #1 on: 18 Sep 2019 at 17:47 »
To answer my own question the Oilite washer isn't such a good idea on an Aero, as the clutch actuation is a different design to earlier models.
The actuating cam on early models bears through the replacement oilite washer onto the central sleeve whereas on the Aero it bears straight onto the side of the primary sprocket so when you replace the ball bearings with an oilite washer it creates considerable drag there.
Still looking for a good clutch actuating cam & now also a flywheel, as the bearing surface that the central sleeve runs on is in poor condition
« Last Edit: 18 Sep 2019 at 19:36 by Aero »

Offline Doug

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Re: Aero 600 Oilite clutch bearing modification issue
« Reply #2 on: 19 Sep 2019 at 01:31 »
I have skimmed the flywheel hub (slightly) and pressed a thin wall bronze sleeve over it. Then that gives you the opportunity of having an oversized diameter and honing the carrier sleeve (or clutch center) to suit.

-Doug

Offline Daren W Australia

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Re: Aero 600 Oilite clutch bearing modification issue
« Reply #3 on: 19 Sep 2019 at 01:41 »
This is on Ebay www.ebay.com.au/itm/Douglas-Fly-Wheel/223542311086?hash=item340c28f8ae:g:-gsAAOSwFpVcqVP9 if the seller wont ship to UK send it to me and I will forward it on to you. Daren
too many dougli not enough time!

Offline Aero

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Re: Aero 600 Oilite clutch bearing modification issue
« Reply #4 on: 19 Sep 2019 at 19:35 »
Doug, can you give me details of the thin wall sleeve you used please, as this sounds a good solution.
Daren if all else fails I might take you up on your kind offer, thanks.

Offline Doug

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Re: Aero 600 Oilite clutch bearing modification issue
« Reply #5 on: 20 Sep 2019 at 03:43 »
The nominal hub diameter is two inch. I turned it down to 1-7/8 for a length of about 1-7/8 and pressed on a bronze sleeve. Then I turned the o.d. down to something a little over two inch to make up for what I honed out of the clutch center. Don't turn a square shoulder at the end of the hub, rather run the cut out at a large radius to minimize the stress riser. Cut a big internal chamfer on the sleeve to span the majority of the radius. That is the gap that you see at the end of the sleeve, towards the flywheel.



-Doug

Offline eddie

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Re: Aero 600 Oilite clutch bearing modification issue
« Reply #6 on: 20 Sep 2019 at 10:34 »
Check out Simply Bearings website - they list 'Needle thrust bearings' that may be suitable for adaptation - there is one 60mm bore x 85mm O.D. x 5mm @ just under 12 + vat. With an adaptor ring turned up to fit it to the clutch release, and adjust the height, this may be the easiest solution.

  Regards,
                  Eddie.

Offline Aero

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Re: Aero 600 Oilite clutch bearing modification issue
« Reply #7 on: 20 Sep 2019 at 14:39 »
Thats not a bad idea Eddie.
Only problem I foresee is the 85mm OD, as it needs to clear the inside of the chain thats wrapped around the crank sprocket.
The OD would have to be 75mm max to clear this.
The 60mm ID & 5mm width are ideal.
Not sure if theres enough width available to squeeze a stepped spacer between the sprocket & bearing as I've temporarily reassembled the clutch with the old ball bearings so I can ride it to a local bike show at Forden this Sunday.
I'll get that clutch back off soon & see if its possible though.



Offline Aero

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Aero 600 flywheel/clutch hub oversize 3/16 x 3/16" rollers
« Reply #8 on: 12 Oct 2019 at 15:10 »
Dougs bronze bush mod was a success, thanks Doug.
The case hardening near the end of the hub caused me a few headaches!
I could now do with addressing play in the rollers, so does anyone know where I can obtain oversize 3/16 x 3/16 ones?
« Last Edit: 12 Oct 2019 at 15:53 by Aero »