WTB Luftmeister vibration damper donuts

[Barry]

Anyone find thes coupling rubbers in the UK ?

I've tried without success.

[clonmore1]

Barry,

It would seem they are David Brown items, I live a couple of miles from the David Brown factory and have a mate who works there, I'll try and find out, sounds like a worthwhile upgrade.

[quixotic]

So, do the donuts somehow fit in where the 5mm spacer washers are currently?  I'm totally mystified.

[Barry]

Barry,

It would seem they are David Brown items, I live a couple of miles from the David Brown factory and have a mate who works there, I'll try and find out, sounds like a worthwhile upgrade.  

Thanks Chris.

I know what a cone ring coupling looks like. Pic shows one half of a coupling with the rubbers.


 I am unclear though if it's a David Brown Tractor spare or a David Brown Transmission spare.  According to a Farmer friend David Brown Tractors are not the most common in the UK and he said the spares web site is rubbish. David Brown Transmissions on the other hand is so big I doubt they are much interested in old tech couplings.

So, do the donuts somehow fit in where the 5mm spacer washers are currently?I'm totally mystified.

They replace the spacers on the front engine mounts only. The nuts are then very lightly torqued up so as not to distort the frame and then thread locked or double nutted. I've never seen exact dimensions but I imagine they would have to be the same bore and length as the exiting spacers. Diameter I guess could be bigger.

It's hard to see from the pic but thinking about how a pin and bush coupling works they may convoluted rather than just plain rubber bushes.  

Anybody confirm that ?

[clonmore1]

I may have found a UK supplier who were part of David Brown.

I have sent an enquiry through, they are local to me, so collection should be easy if they can source the product!

[Tony Smith]

Barry,

It would seem they are David Brown items, I live a couple of miles from the David Brown factory and have a mate who works there, I'll try and find out, sounds like a worthwhile upgrade.  

Ok, here is a (poor) scan of the two "rubber" and two "urethane" couplers I purchased on Monday.
 
I should have also scanned the "BMW" ones that were still on my rebuild project - allowing for the fact that the originals are nearly 30 years old, I reckon the David Brown ones look identical.
 
Anyway, if people are genuinely unable to source them near to home PM me and I will buy a few more and dispatch them at cost.

[Semper Gumby]

Hi

I 've had a Lufty set of dampners on my R65 for years.  Makes a world of difference.  No cracks yet.

I found mine on eBay.  Good luck.  

Ps - I almost forgot about the 4-5000 rpm buzz.  Haven't felt it n years.  But no worries - I have BSAs now to remind me of VIbRaTiOn.

(yesh yesh)  

[clonmore1]

I have been contacted by the company that makes these.

If you want to let me know if these are what you are looking for, I can now source them.

Cheers

Chris

[georgesgiralt]

Hi Lads,
Can someone explain what these are used for and where they fit ?
Many thanks in advance

[Luca]

They were an aftermarket product sold by Luftmeister to reduce the midrange buzz.  They replace the metal washers that go between the frame and the engine on the front engine mount with a rubber bushing.  The engine mount is then lightly torqued, and the mounting stud double-nutted (or in other words, a jam nut is attached) on both sides to keep everything in place.

This reduces tension on the frame a bit and also lets the engine move around a little more (but it is damped by the rubber).  This is why some people say the rubber donuts will negatively impact handling (less frame rigidity) and can lead to frame cracking issues.  As always, YMMV

[georgesgiralt]

Thanks for the explanation !

[bruce_launceston]

I can confirm that the ring coupler rubbers are not David Brown Tractor parts, they ARE David Brown Transmission parts, its a different company.

The idea is to remove only the front 5mm spacers (ONE at a time) and replace them with a rubber sandwiched in between 2 steel washers, 1 assembly on each side. The nuts on this engine mount are torqued up to only 12 lb/ft torque, use loktite!

The rear mounts are torqued to the factory specs, of the top of my head 48 to 52 lb/ft.

[quixotic]

Well, I e-mailed Blackwoods a few days ago to ask if they'd ship to North America or if there is a dealership here, but no answer.  I'd like to try out the 0860 1906 washers.  So that looks like a dead end.

Aegis, I'm a bit puzzled on the cone rings that you show on the Series X sheet.  The "N" dimension of 7.6mm looks like it might be squeezed into the space where the current spacer is.  Is a person supposed to cut the rubber unit into 3 bits and then use just 2 of them?  (I'm still a bit mystified).

[clonmore1]

quixotic,

I'm not sure how they work, one of the members on here (Barry) asked if anyone could source these in the UK, I found a (the?) supplier very close to where I live in Yorkshire.

They sent me this spec sheet, so the product is available if required.

We need some of the resident experts to shed light on this...

[R65Singh]

Thanks for starting this thread.  I just finished making a home made version of the idea and installed in my bike.  I have to admit these things work and the vibration is about 70% gone.  No vibration in the handlebars or foot pegs. At 60 Km it is super smooth.
I sandwiched about an inch dia hard rubber bushing between two cup washers that I had lying around and the whole job took me less than half an hour to finish.  It is worth it. Try this if you are looking for that super smooth ride.