Does the Hardy disk need grease?

Restoration forum Bmwbike.com
Allan Atherton

Does the Hardy disk need grease?

Post by Allan Atherton »

Does the Hardy disk need lubrication? When I installed mine, I put some clear di-electric grease in the holes for the drive pegs, and on the pegs, and on the rubber 0-ring spacers that go on each drive peg. I thought that kind of grease would be best for the urethane disk and the rubber spacer rings.

That was 6,000 miles and 5 years ago. Now the Hardy disk is making a dry rubber squeak as it revolves, audible only when I push the bike around in the garage. Is it time to pull the swingarm back to make some clearance, and apply some more grease to the drive pegs that enter Hardy disk?
Gerry Douglas-Sherwood

Re: Does the Hardy disk need grease?

Post by Gerry Douglas-Sherwood »

Hi Allan,

I'm afraid all those Hardy discs always squeak until they get old, hard and worn. Still, that's the nature of soft rubber rubbing against metal.

Yes, I always put a smear of rubber lubricant round the flange pins and in the coupling holes. It will work out eventually but assists assembly and saves wear between the surfaces. Don't use washing up liquid as that promotes rust.

It would be interesting to be able to listen to a brand new R26/ 27 or a pre-55 twin to see if they squeaked. How would the salesman explain that away? Makes you think...


Allan Atherton

Re: Does the Hardy disk need grease?

Post by Allan Atherton »

Thanks for the tip. None of the maintenance manuals mention greasing the Hardy disk.
Someone on the Mono Club Group said they use a grease spray. I have some white lithium grease in a spray can and will use that.
Rolf_B

Re: Does the Hardy disk need grease?

Post by Rolf_B »

I am riding my R27 now for 23 years and always had that squeeking sound (like feeding little pigs - though I am not an expert on pigs). It got very noisy, when it was worn out, and I was amazed to see the crumbs and other remnants, which still allowed me to ride.
I changed the disk and the rubber rings to new ones and am back to the old squeek.
Someone suggested to use silicone spray, but could not find his can, so I did not put anything on.
Allan Atherton

Re: Does the Hardy disk need grease?

Post by Allan Atherton »

Someone on the Mono Club list explained that the manuals do not mention applying grease to the Hardy disk because the original Vulcollan material was rubber (with fibers) and was not compatible with grease.
The present Hardy disks are a tan material, perhaps a urethane or plastic, which is probably compatible with grease.

Ron Long

Re: Does the Hardy disk need grease?

Post by Ron Long »

Hi Allen and Gerry,

Interesting question. I did not use any lubricant on the hardy disk for either my R27 or R51/2 restoration projects. The hardy disk on the R27 squeals, but the hardy disk on the R51/2 does not make any noise at all.
Allan Atherton

Re: Does the Hardy disk need grease?

Post by Allan Atherton »

I used bearing grease when I installed the new disk in 1999, and used a lithium grease spray last week. The wand of the spray can was perfect for inserting the grease to each drive peg.

The disk and its spacers were in good condition, but I think the squeaking indicates friction which must also mean wear and heat, which could not be good for the life of the disk.

So I think lubrication is a good idea. Any excess grease is thrown off to collect on the inside of the guard. I used very little grease in 1999, and most of it ended up inside the guard.
Brian Caro

Re: Does the Hardy disk need grease?

Post by Brian Caro »

I suggest using only silicone grease on the vulcanized rubber disk. Petroleum grease will degrade rubber.
Geoff Curtis

Re: Does the Hardy disk need grease?

Post by Geoff Curtis »

The shop manual for plunger twins says, "Treat rubber coupling of shock absorber with talcum powder to facilitate the entering of flange pegs. No oil or grease must be used". Regards Geoff in OZ.
Allan Atherton

Re: Does the Hardy disk need grease?

Post by Allan Atherton »

I don't thnk the disks are made of rubber anymore. The two I bought recently are tan, and appear to be something more like plastic, nylon or urethane.
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