New AVO coil-over for B and C series, plus damper update.

[macvette]

Morning Mac, Any chance you could give me how long the straight tubes are on your "D" seat frame, I mised buying one on Ebay the other day, So will have to make one myself, I have a seat, So that will give me how wide it is, Many thanks, Bill.

Hi Bill,
All measurements to centre lines so you will need to allow for fittings at ufm and RFM pivot. The tube from the RFM pivot is all one piece from RFM to RFM . The horizontal tube from the ufm centre line of bolt to centre line of RFM tube is 21 1/2" where it is welded. The length of the straight from the RFM pivot to centre line of the horizontal tube is 25 ins. The horizontal tube is welded to the inside of the curve where the RFM tube bends to the vertical to form the seat hoop.
The distance at the rear between the seat support tube is 12" and 6 1/2" a the front .
Regards Mac

 

[Bill Thomas]

It is, It is !!, All that work and it's still a Bloody "D" !. Just a bit of Fun, Bill.

 

[macvette]

It is, It is !!, All that work and it's still a Bloody "D" !. Just a bit of Fun, Bill.View attachment 14729

I always suspected there was something not quite right with my D. It has the wrong forks, brakes, carbs, wheels and seat just to mention a few

 

[greg brillus]

Bill........... I've heard of "Dangling a carrot in front of a horse"..........But not a "Dipswitch in front of your head"..........What's going on...........?............

 

[greg brillus]

Bill is that one of those Kawasaki steering dampers on there.....? Looks the same as the one I've just bought for my road Rapide, which I'm coupling up to one of Norman's modified stems. All coming together pretty quickly now........Cheers, Greg.

 

[Bill Thomas]

Hello Greg, It's a Lash Up !!, I have the attension span of a Gold Fish !, Just trying to gee myself up to finish it off.
I was not sure the seat would look right with the Small Tank, When it was a"D" it had a big tank, Ron made me, Oil and Petrol, + 2 1/2" taller.
Now it's a"C" with Rob's Coilover, I think it will look OK ??.
Well I like it !!.
Always like to be a bit Different !.
Cheers Bill.

 

[Bill Thomas]

Yes Greg it's a Cheapie Kawa copy, But it's been on there since 1975 !, You just need a penny washer under the rubber pivot, They say it could work it's way OFF !!, Good Luck, Bill.

 

[hadronuk]

Just got the "C" Special on the floor, The Coilover feels very Modern!, Not like a Standard Vin'.
Wound the spring to 7", Wound the Damper to 8 clicks, Feels good, I thought I would need the heavy spring, But maybe not.
Seems to miss the Big Alternator by a good bit.
The "D" stand is very close to what it was, With a "D" frame !.
Will still be some weeks before it's on the road, Cheers Bill.

Hi Bill, very interesting bike, thanks for the picture.
As Eddy says, for solo use you will probably find you can use less spring preload without bottoming out problems.
But you may want the rear raised to get more weight in the front forks?
On the subject of telescopic fork stiction, my very low mileage T160 was terrible when I first bought it. Turned out that the yolks had not been slotted sufficiently and the stanchions were still gripped very tightly even with the clamp bolts loosened. This made it almost impossible to set the stanchions perfectly parallel. Much smoother action after a lot of fettling.
A point about the settings for the damping. My general recommendation is that for initial testing the damping should be set to the softest setting, ie adjuster turned fully anti-clockwise. Even at this setting, I think most people would agree that the ride is still well controlled. Another reason to start soft is that I think that the dampers are slightly stiff for the first couple of hundred miles, though AVO disagree with me. Even with my now well used rear damper and heavy luggage, I do not use more than 6 clicks or so. But it's also a matter of taste of course. I am keen that on the first ride the AVO units create a good first impression for comfort!

 

[Bill Thomas]

Thanks Rob, After riding my Standard Comet with standard seat fittings it will be like a Roll's !!.
I am not trying to stop bottoming, Just to keep the rear frame away from the Alternator, And the rear mudguard wacked under the Rickman seat at some time in the past when it was a "D".
The Motor Cycle press, Back in 1970, Talked of the Sticksion with Standard Commando's, Also they topped out, ie, Went Clonk when you gave it some stick !!.
Mine has not done that for many years, But I have made them a bit longer than standard to miss the Engine.
Can't wait to get it on the road, Just spent 2 days trying to fit a hand made Alloy Petrol Tank, It's all I have left, So it must be made to Fit !.
Just had to take a hammer to my nice new tank, It's too tight where the Oil Filler comes out !.
I don't think I will build another Special, Too much Trouble !. Cheers Bill.

 

[hadronuk]

Below is a copy of the fitting instructions I have asked AVO to put out with every unit.
I would appreciate feedback on anything that is unclear or omitted.
(PC1511 is the part number for the standard length coilover. PC1507 is the part number for the shorter version that allows a slightly lower seat height. AVO have decided they will continue to offer both versions.)


Fitting AVO Vincent Dampers and Coilovers.

When fitting all units be careful that it is not strained sideways.

Do initial road testing with the damping adjustment turned fully anti-clockwise. (Softest)

Front Damper TA1447.

Check that the mounting points on the bike are accurately aligned, particularly the lower eyebolts. AFTER FITTING THE NEW DAMPER, CHECK THAT WITH THE FORKS FULLY EXTENDED THERE IS ADEQUATE CLEARANCE BETWEEN THE MUDGUARD AND THE EXHAUST PIPE ETC. This is particularly important if long eyebolts are fitted.

Rear Dampers TA1445 & TA1446

THESE REAR DAMPERS MUST ALWAYS BE FITTED WITH THE 0.4 INCH LONG STEEL BUSH FITTED IN THE TOP EYE.

It is important this is used to ensure that the damper top mounting is free to rotate independently of the spring eyebolts.

Rear Coilovers PC1507 and PC1511

Check both spring bolts are straight and are a sliding fit in the coil-over before it is fitted to the bike.

Tighten the spring pre-load ring enough to ensure it will clear the RFM.

Fit the top mounting first. Fit the front (top) spring bolt and the spacers supplied and tighten it firmly as this stiffens the top mounting point in the UFM. The top eye is fitted with a steel bush specifically to allow this. Check the damper and spring bolt assembly can still rotate freely in the frame.

Take care fitting the rear (lower) spring bolt, as it can be a little difficult to get the RFM and coilover accurately aligned. An assistant lifting the rear wheel is helpful.

The rear (lower) spring bolt should be tightened just enough to ensure it does not come loose. Overtightening may crush the spacers onto the spring bolt, making them difficult to remove.

Coilover adjustment in use.

Note that excessive spring preload may allow the spring to become coil-bound on full bump. (If a heavy load is causing bottoming-out, the damping can also be increased a little.)

With the suspension fully extended, the spring length should not be less than the following:

Unit and Spring.....................................Min Spring Length

PC1507 with 275lb/inch spring.............................6 1/2 inches

PC1507 with 350lb/inch spring.............................6 3/4 inches

PC1511 with 275lb/inch spring..............................6 3/4 inches

PC1511 with 350lb/inch spring..............................6 7/8 inches

RAS 10/08/16