Misc: Everything Else Prototype of new AVO coilover for Series ‘D’ Vincents

[Bill Thomas]

Sorry Rob/Eddy, I can now see that adjustment would have been too much.
It's a fault of mine, Too Much, Too soon. Cheers Bill.

 

[vibrac]

The new unit looked fine Rob I like it's rear pivot. Thanks for your 'feel' of my damper and I agree that unfortunately there is little you can tell by opening and closing a damper manually

 

[Bill Thomas]

I can't see by the photo, Is the top fitting the full width of the frame opening, I was supplied one a long time ago, That was not, And the bush worked it's way out , Half way. Cheers Bill.

 

[macvette]

When I took my D to bits to rebuild it, there was no wear on either the ufm or rfm caused by the pins. Bike had 120k miles at that stage. On Bill's point, I have the original D damper and the top fitting had about 1/4 ins clearance either side which was taken up by the rubber bushing. The bush was shot so I sourced two rubber bushes from a car, pressed them in from each side and fitted 1/8 ins thick ss washers to clamp the sleeve in the centre of the bushes. Don't remember which car they were supposed to fit.

 

[Bill Thomas]

Went out on the "C" Coilover again, Set the spring to 6,7/8 " and 4 clicks on the damper, Super, I like a firm ride, The Norton forks are Firm, So it rides nice for me.
Didn't think that small adjustment would be enough, Rebound rubber has NOT been squashed.
Many thanks, Bill.

 

[hadronuk]

Thanks for all the feedback. You have highlighted a few things need further checking.

• I'm fairly sure the AVO top rubber bush is bonded so should not "walk". Small spacers either side to centralize. Will check. Spacers could be increased in diameter if required.
• I have not ridden a D, but yesterday I sat on one with an original Armstrong coilover. Very subjective, but it felt very tall and firm to me. (I'm aware that a high spring preload can result in a firm feel when static but still give a good ride quality).
• I also checked D suspension lever ratio, which seems very close to C series and suggests it IS viable to lower the D seat and still have the level of comfort achieved on the C with the AVO coilover.
• Ideal spring stiffness is an utter conundrum as opinions differ so widely. I will write and post an overview elsewhere that I hope will help people make their own choice.
• The good news on springs is that AVO have a wide range available at reasonable prices, and AVO coilover springs are easily changed.

 

[Bill Thomas]

That might be handy for me, Because My "D" will be Comet !.
I did ride it as a "D" Comet, Years ago, For a short time, And with the Twin spring it was a bit stiff, Because of less weight.
Most of us found the standard "D" Spring too soft, But as you say , Maybe the better Damper will change things.
Just been out on the "C", Coilover again, And really getting a feel for it, Maybe too much !, With the Norton Forks, Not worrying as much about potholes, I was getting a bit too excited !.
Cheers Bill.

 

[stumpy lord]

I received this yesterday.


View attachment 22989


This new D unit uses the same basic components as the already well-proven B/C coilover units. So I am hopeful that testing will be straightforward and quite quick.
It should be a straight fit. Damping and preload are fully adjustable and there is a wide choice of springs. Default is likely to be 300 lb/inch with others available to order. The top mounting is a metalastic bush, the lower mounting is a spherical bearing.
There are no plans to fit a dust cover, although should a customer want to fit one they have sourced, this would be very easy as the spring can be changed without the need for a spring compressor. Looking back at my old notes, it seems very possible the dust cover from the original Armstrong unit may fit. I will try to check this.

QUESTION FOR D OWNERS: With the original unit, does rotation of the pins cause wear in the frame & RFM?
The idea is that the low friction spherical bearing will minimise this possibility, as well as overcoming any possible misalignment.

I discussed with AVO the problem some riders have with the high seat height of the D.
If it is specified at the point of order, during manufacture a "droop restrictor" spacer tube could be fitted internally on the damper rod. No other changes would be required as there is a large range of adjustment of the spring preload. If the coilover extension was reduced so that total travel of the units was the same as on the B/C units, D owners could still enjoy an excellent ride quality with a seat height reduced by about 1 3/4 inches. Although this spacer could be fitted/removed retrospectively, AVO are reluctant to do so, as ideally several components should be replaced when rebuilding units.

Stock items should be available about 3 weeks after prototype testing is completed.
Expressions of firm interest (to me) would be greatly appreciated, as AVO need to decide how many to make in the first batch.
Price is expected to be the same as the existing coilovers, so "£200 +VAT. Carriage UK £10 +VAT. Ireland £15 +VAT Rest of world please email for quote."
Extra springs (one for solo, one for two up touring?) are about £40 each, although experience with the B/C coilovers is that the adjustable preload and damping allows the default spring to cope with a very wide range of loads.

I will have this with me tomorrow at the VMCC Founders Day at Stanford Hall, should anyone want a look. Please visit our COVOC stand and ask for Rob.

Hi, being a life time sufferer of chronic ducks disease , one off the new rear spring over dampers for my fully sprung twin , hope fully, will help me reach the ground more easily.
stumpy lord

 

[Gary Gittleson]

My bike is a D Rapide. It had some 31,000 miles on it when I bought it many moons ago. It now has about 48,000 and still no wear in UFM or RFM from the damper pins.

Two years ago, I went through the bike and decided to include an upgrade to the rear suspension. The spring seemed OK to me but the damper was clearly spent. There was very little damping. So I went with Thorntons front and rear.

The springing is now much more controllable but I do think it's a bit stiff in the rear. I was once 5 foot 7 inches but have lost some three inches over the decades. I'm still not sure I need to lower the seat height. There is however, the feeling that the bike is slanted downward front to back, like a "crotch rocket". So maybe a bit of lowering would be pleasant.

Does anyone here have an idea how this new damper would compare to the Thornton? Should I make the switch?

 

[davidd]

Gary,

Before you chuck the Works Performance shock you should check to make sure it was installed and adjusted properly. It has three settings for the springs: soft, medium and firm, assuming it is the same shock I had. Carleton Palmer runs one and he had Works lower the rear shock an inch. I am not exactly sure what they did, but I will ask him.

According to Joe Stimola, who did the shock dyno work for me an Carleton, there is no better damper available anywhere. Joe was well known for his work with Roger Penske, Chip Ganassi, Danny Sullivan and Bobby Rahal, among others. He did not test the AVO because it was not around when we did the work.

This does not guarantee that you would not be happier with an AVO, but I am guessing the AVO is not in the same league. I doubt that good damping is a big issue for most street riders, but excellent damping rarely bothers street riders. It is usually the springing that gets the attention.

David